Download Infections in Pregnancy and the Newborn 2009 Annual Scientific Meeting

OFFICIAL JOURNAL OF THE AUSTRALIAN SOCIETY FOR MICROBIOLOGY INC.
Volume 29 Number 4 November 2008
2009 Annual Scientific Meeting
ASM’s Golden Jubilee Year!
Perth Convention Centre
6-10 July 2009
Infections in
Pregnancy and
the Newborn
OFFICIAL JOURNAL OF THE AUSTRALIAN SOCIETY FOR MICROBIOLOGY INC.
Vertical Transmission
170
First Words
172
From the Editors
173
In Focus and Under the
Microscope articles
174
Page 179
Serology testing for syphilis in pregnancy:
is it still relevant?
174
Congenital and perinatal cytomegalovirus (CMV):
has diagnosis improved in 30 years?
176
What happens when a baby dies:
stillbirth investigations for infection and other aetiologies 179
When a baby dies: stillbirth from the community
perspective and what parents want to know
184
Longer-term outcomes of infections in pregnancy:
pathogenesis of diabetes and other chronic infections
186
Toxoplasmosis in pregnancy:
often suspected, rarely convicted
188
Page 188
Diagnosis and treatment of herpes simplex virus (HSV)
infection in the newborn
194
Respiratory infections in the newborn
197
Pathogenesis of cytomegalovirus (CMV) infection
in pregnancy
200
Pathogenesis of malaria in pregnancy
204
Goal setting and reality:
maternal, perinatal and childhood malaria
208
Infection and preterm birth
212
Mother-to-child transmission of HIV: positive impacts
215
Intrauterine infection: preterm birth and
pulmonary impact
Page 212
217
ASM Affairs
220
What’s On
223
Who’s Who
224
M I CROB I O L O G Y A U S T RALIA • NOVE MB E R 2 0 0 8 November 2008
Volume 29 Number 4
169
Vertical Transmission
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Dr Ruth Foxwell
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Prof Hatch Stokes
Dr Paul Young
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170
Hatch Stokes
President ASM
Planning for the national meeting in Perth is now very much in full swing. As mentioned
previously, we hope to make this meeting extra special as the Society will be turning 50
in 2009. We will have the usual impressive array of international speakers that will include
Bonnie Bassler as the Rubbo Orator. In addition, the American Society for Microbiology has
very generously agreed to sponsor an additional speaker to this meeting to help us celebrate
our 50th anniversary. Following an approach from the Perth LOC, I am pleased to be able to
announce that Rita Colwell has accepted an invitation to attend the conference and speak. As
many of you know, Rita has a number of links to Australia and has attended past meetings.
Another important positive outcome for us in 2009 is that Australia Post has agreed to produce
a commemorative edition pre-paid envelope, the release of which we hope to time with the
National conference. These envelopes prove very popular and ours will be available through
post offices nationwide. The Editorial Board of Microbiology Australia will be working with
Australia Post on a suitable distinctive design so this is definitely something to look out for.
The ASM has also commissioned a history consulting company to write a short history of
the Society to be completed by the Perth meeting. This will be a ‘living history’, drawing on
information from prominent members who helped shape the earlier years of the Society.
The interviews of these people have now been completed and we will have the final draft
document in a couple of months. At that time we will decide in what form this history will be
made available to members and the general public.
Now is a good time to remind everyone that planning is also underway for the National
meeting to held in Sydney in 2010. If you have suggestions for the scientific programme,
either for international speakers or symposium themes, I would encourage you to contact
the relevant members of the National Scientific Advisory Committee. These are Andy Holmes
(the Scientific LOC Chair for Sydney) or Jon Iredell, Peter White, Linda Blackall and Ruiting
Lan (the Division 1, 2, 3 and 4 Chairs respectively for Sydney). On a related theme, we are
also keen to get suggestions from members for the Visiting Speakers’ Program. Suggestions
can be forthcoming at any time so, for example, if you have an international visitor to your
lab, let Carol Ginns at the National Office know and we may be able to support them visiting
other parts of the country to speak.
I was recently in Istanbul representing the Society at the International Union of Microbiological
Societies (IUMS) Congress. This congress is held every 3 years and, as well as myself, TuckWeng
Kok and David Ellis also attended on your behalf. Our attendance is supported to a large
extent by the Australian Academy of Science to whom we are grateful. This is a useful exercise
as it is an opportunity to network and discuss matters important to us all. The feedback
from our British and American colleagues in regards the new postgraduate travel awards
established between us and their respective societies was overwhelmingly positive. I am
therefore optimistic that these will become long-term initiatives. One other positive outcome
of the Congress for us was that TuckWeng was elected to the Scientific Advisory Board of the
International Congress of Virology for a 3 year term; congratulations TuckWeng.
Finally, I draw your attention to the fact that we have recently revamped the rules for the
awarding of Distinguished Service Awards. The details can be found on the ASM website.
The closing date for nominations is 30 November. Please consider nominating someone you
would consider appropriate for one of these important awards.
MICROBIOLOG Y A U STRA LIA • N OV EM BER 2008
MRSA
SeRiouS infection
SeRiouS ReSultS
1
MRSA = Methicillin-resistant Staphylococcus aureus.
PBS Information: this is not listed on the PBS.
Please review Product Information before prescribing. Full Product Information is available on request from Pfizer.
ZYVOX® (linezolid). Indications: Infections due to resistant organisms, including MRSA and VRE. No clinical activity against Gram-negative pathogens. Contraindications: Hypersensitivity.
Precautions: Monitor blood in certain populations. Antibiotic-associated pseudomembranous colitis. Reports of serotonin syndrome when co-administered with serotonergic agents.
Symptoms of visual impairment; monitor visual function. Convulsions (rare). Safety and effectiveness following 28 days not established. Gram-negative pathogens. Pregnancy:
Category B3. Lactation: discontinue. Adverse Effects: Headache; candidiasis; taste perversion; GI disturbances; peripheral and optic neuropathy; lactic acidosis; angioedema; rash;
myelosuppression; bullous skin disorders; serotonin syndrome (very rare); abnormal haematology and liver function tests. Interactions: Tyramine; serotonergic agents; vasopressive/
dopaminergic agents. Dosage and Administration: IV (30−120 min infusion) or oral bid (with or without food). Adults: CAP/nosocomial pneumonia: 600 mg IV or orally for 10 to 14 days;
SSTI: 400 mg to 600 mg orally or 600 mg IV for 10 to 14 days; enterococcal infections: 600 mg IV or orally for 14 to 28 consecutive days. Children and adolescents: nosocomial pneumonia
and SSTI: 10 mg/kg IV or orally qid for 10 to 14 days; enterococcal infections: 10 mg/kg IV or orally qid for 14 to 28 days. Neonates: refer to full PI. Based on Full Product Information, TGA
approved 15 November 2005. Date of most recent amendment: 4 April 2008. Minimum Product Information prepared 29 January 2007. 1. ZYVOX Approved Product Information.
Pfizer Australia Pty Limited, ABN 50 008 422 348, 38-42 Wharf Road, West Ryde NSW 2114. Medical Information: 1800 675 229. www.pfizer.com.au H&T PZR0054/MA.
First Words
Infections in pregnancy and the newborn
William Rawlinson
Senior Medical Virologist SEH &
UNSW
Head, Virology Division, SEALS
Microbiology
Prince of Wales Hospital
Randwick NSW 2031
Tel (02) 9382 9113
Fax (02) 9398 4275
Email [email protected]
... about in 1951 I met in Oxford a very well known scientist
and I said to him that I was a friend of Eccles. And he said
Eccles [recipient of the Nobel prize for physiology 1963], [was
a] very good man but you know the man must be a bit
crazy. He refutes his own theories.
Sir Karl Popper
There are many important issues relating to the investigation
of infections during pregnancy and immediately after birth.
They relate to the scientific areas of the need for diagnosis, for
definition of markers of infection, and for the use of surrogate
markers of severity, as well as clinical areas relating to diagnostic
and therapeutic interventions. Ideally, at the same time, the
integrity of any scientific research done to understand the
pathogenesis of damage to the fetus and neonate must not be
compromised.
Further, the important area of parental involvement in decision
making, often at a time of intense emotion, must be carefully
integrated into this process. With parental consent, studies of
infections of pregnancy, neonates, and adverse outcomes of
pregnancy can be made more effective with a multi-disciplinary
approach.
Many of the authors of the articles in this issue of Microbiology
Australia have been involved in such approaches to research,
diagnosis and therapy of congenital and perinatal infections. In
this edition we have papers discussing pathogenetic studies of
the role of prenatal infections in later clinical outcomes such
as the role of infection in precipitating spontaneous preterm
birth, the possible role of enteroviral infection in type 1 diabetes
mellitus, and the pathogenesis of damage from cytomegalovirus
in pregnancy. In the clinical setting, there are important papers
summarising our understanding of infections with malaria,
cytomegalovirus, toxoplasmosis and HIV during pregnancy, as
well as herpes simplex and respiratory viruses in the newborn.
We also have an article specifically on the personal and social
consequences of stillbirth – a problem which results in almost as
many deaths in Australia each year as from breast cancer.
with various adverse outcomes of pregnancy, we must avoid
simplistically linking association with causation. Infections
need to be seen in the context of the maternal-placentalfetal interaction that develops during pregnancy, the changes
in the immune system as the fetus is born, and neonatal
immunological development. We should consider the results of
diagnostic testing as a whole, including all possible information
from serological, molecular, microbiological and histopathologic
sources. These need to be related to the clinical setting, as testing
may be adjunctive, rather than definitive, in the diagnosis of fetal
or neonatal damage. We need to be aware of the utility, as well as
the limitations, of our current knowledge.
What is important about many of these studies is that the list of
potential aetiologies of many conditions is being expanded by
the use of nucleic acid and other molecular techniques to define
the organisms present more clearly.
It is useful to examine these studies using criteria suggested by
Karl Popper – we utilise observation, but such observation is
selective and driven by theory. Indeed, as he stated succinctly
“Our knowledge can only be finite, while our ignorance must
necessarily be infinite.” It is our ability to use the scientific
observations relating infection to adverse outcomes of pregnancy
and infection in the neonate to inform our current practice that
is important for the patients who seek our assistance currently. It
is equally important to be able to discard these scientific findings
if new findings prove our hypothesis incorrect.
The importance of continuing research in this area cannot be
underestimated. Establishing what organisms are important in
different adverse pregnancy outcomes, the nature of placental,
fetal and neonatal infection with these organisms and the
associated host response is vital. The determination of causality
(or not) needs to follow soon, if we are to introduce therapeutic
and preventive strategies.
Fortunately, there are microbiologists, clinicians and members
of the community who are interested in the scientific, clinical,
social and personal consequences of infections in pregnancy
and early infancy. These are people who continue to propose
theories, study and research in this area. They remain prepared,
like Sir John Eccles, to use the scientific method to discard
incorrect theories, and propose new testable hypotheses. Some
of them are represented in the papers presented in this edition
of Microbiology Australia, and I hope you find their insights
useful.
Professor William D Rawlinson (MBBS, PhD, FRACP, FRCPA) is the head of
the Virology Division at SEALS, Conjoint Professor at UNSW and infectious
diseases physician at Prince of Wales Hospital, Sydney Children’s Hospital
and Royal Hospital for Women. His research position involves supervision of
several groups who undertake basic research into the pathogenesis of viral
illnesses, with integration of these basic studies into clinical outcomes.
In reviewing the findings from studies associating infections
172
MICROBIOLOG Y A U STRA LIA • N OV EM BER 2008
From the Editors
Microbiology Australia:
have your say
How
is
Microbiology
Australia meeting your
interests? We would love to
know.
We have worked with the
Editorial Board for 3 years
now trying to present you
with issues that are of
relevance, even though they
may sometimes fall outside
your area of immediate
interest. In this way, ASM’s
microbiologists can be kept up to date with the breadth of
microbiological developments. Some of these issues are relevant
beyond our society and so the issues are now also made available
to journalists and science writers. In some cases, journalists have
worked with our contributors and built major feature articles.
We are often asked how themes for issues are decided upon. The
Editorial Board makes these decisions about a year in advance
in response to what we think the ASM membership wants to
hear. Your input is highly valued! Another key factor is whether
there will be Guest Editors and sufficient contributors to provide
material for an issue. Guest Editors are key people in their field
and have strong connections or knowledge with their field. They
are able to pull together a cross section of contributions that
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daunting task and sometimes there are difficulties about what
can be said on more contentious issues. Issues coming up soon
include water, climate change and indigenous health.
We would like to take this opportunity to thank everyone who
contributes to MA. The list includes the Editorial Board, Guest
Editors, contributing authors, reviewers, the National Office,
advertisers, and our publishers Cambridge Media who always do
a great job in working with us to meet all our requests. In the last
issue, an excellent issue on Staphylococcus aureus, we were able
to move deadlines forward and complete the print run of 3400
to get copies to Cairns so all registrants at the 13th International
Symposium on Staphylococci and Staphylococcal Infections
meeting received a copy. In the issue before, on biosecurity
and biosafety for microbiology, new rules for microbiology were
enunciated. These have a significant impact on many in the ASM.
We took a special personal interest in the current issue because
we were blessed with two new grandchildren in the past few
months and one contracted respiratory syncytial virus (RSV) at
just 4 weeks of age. This required hospitalisation to control the
symptoms and was obviously of concern. We are certainly glad of
the modern techniques to enable the diagnosis and to provide
care but obviously there are needs for research into therapeutics
to prevent or control diseases such as RSV and other children’s
diseases.
Finally, as this is our last issue for the year, we want to wish you
well for the forthcoming holiday season and New Year.
Ian and Johann Macreadie
M I CROB I O L O G Y A U S T RALIA • NOVE MB E R 2 0 0 8
In Focus
Serology testing for syphilis in pregnancy:
is it still relevant?
Peter W Robertson
SEALS Area Serology Laboratory
Prince of Wales Hospital
Barker Street, Randwick NSW 2031
Tel (02) 9382 9153
Fax (02) 9382 9151
Email Peter.Robertson@sesiahs.
health.nsw.gov.au
Until the emergence of HIV and other more spectacular
viral diseases, syphilis has probably been referred to
more than any other infectious disease throughout
history – in theatre, literature and politics. During the
19th century, aside from being a notorious disease
transmitted sexually, it was the diverse clinical and
pathological forms of syphilis which led to much of this
mystique and fear.
The main consequences of syphilis are the long-term effects of
dementia or damage to the cardiovascular and central nervous
systems or transmission to the fetus during pregnancy . Prior to
1
the introduction of the Wassermann complement fixation test
in 1906, there was no laboratory confirmation for the diagnosis
of syphilis and the manifestations of many other diseases – for
example most inflammatory diseases of the eye, a number of
psychiatric conditions and congenital malformations – were
incorrectly attributed to syphilis.
After the 1940s, a variety of penicillin-based clinical treatments
in pregnancy were shown to effectively prevent neonatal
transmission of syphilis. Consequently, this disease began to
decline. The success of penicillin also reflected a decline in the
number of cases of syphilis in the general community.
Antenatal testing
One of the most tragic consequences of syphilis is congenital
syphilis. Congenital syphilis is the result of transplacental passage
of Treponema pallidum from an infected mother. This occurs
when a mother is infected or becomes infected during pregnancy.
As with other intrauterine infections, there is a widespread
spectrum of disease ranging from intrauterine death to mild
effects. Because of this wide spectrum, it has been estimated
that many infections go unnoticed 2. However, some specific
pathological and radiological signs are unique to this infection.
174
Serological screening for syphilis during pregnancy is advocated
because the effective prevention of congenital syphilis depends
on the diagnosis and treatment of the disease in a pregnant
woman. Unlike other causes of intrauterine infection such
as rubella and cytomegalovirus, syphilis does not have to be
acquired during the pregnancy. Serology should be carried out as
part of antenatal screening, preferably at the first prenatal visit.
Maternal treatment in preventing congenital syphilis has an
overall success rate of >98% 3. Most failures of maternal treatment
in preventing congenital syphilis occur if the mother is in the
secondary stage, the most infectious stage of the disease. Success
rates of maternal treatment also vary with the gestational age at
which treatment is initiated. Most successful outcomes occur
when the disease is diagnosed and treated early in the course of
the disease, as the success rate in preventing congenital infection
may be as low as 90% after 26 weeks 3. This emphasises the need
to test at the first antenatal visit.
Apart from management of the pregnant woman with syphilis,
information regarding the disease status of partners must also
be obtained. Contact tracing and testing of the partners of
women diagnosed with syphilis in pregnancy is important in
order to prevent re-infection during the pregnancy. The CDC
recommends that these women should also be tested for HIV 4.
Recently, the testing strategies for syphilis screening in pregnancy
have changed largely due to the development of automated
enzyme immunoassays using recombinant antigens of
T. pallidum. Prenatal screening using Reagin serological tests is
still feasible and affordable in most undeveloped countries. One
issue, however, is that some of these non-treponemal Reagin
tests are prone to giving false-positive results in pregnancy.
Consequently, all positive results must be confirmed with
treponemal-specific tests. Conversely, if treponemal-specific tests
are used for screening, a Reagin test (usually RPR) is required
to determine the stage of the disease and as a base line for
monitoring treatment. Once the mother has been treated during
pregnancy, sequential titres using RPR or other Reagin assays
should be performed to monitor the response to treatment.
Although not common in Australia, serological testing and
interpretation of results is complicated in women who have been
infected with HIV. This may be further complicated in intravenous
drug-users whose serum can give false-positive Reagin tests.
Testing of the newborn
Congenital syphilis is largely a preventable disease. However,
it continues to be an important public health problem both in
developed and developing countries. Even with treatment during
pregnancy, CDC recommendations are that all infants born to
women who have positive serological tests during pregnancy
should be examined thoroughly for evidence of infection,
including microscopic examination of placenta or umbilical cord
using a specific fluorescent staining 4.
MICROBIOLOG Y A U STRA LIA • N OV EM BER 2008
In Focus
Serological evidence of congenital infection in the past could
only be established by following the decline of maternal antibody
or persistence of antibody in the neonate during the first 6
months of life. This has a number of disadvantages, in that the
actual decline in the Reagin will depend on the gestational age of
the baby and the titre of Reagin in the mother’s serum at delivery.
The development of specific IgM assays, including the IgM FTA,
has made the serological diagnosis of syphilis more convenient
and practical. Overall, decisions on treatment will result after
examination of clinical, laboratory and radiographic evidence of
congenital syphilis.
Table 1. Infectious syphilis in south-eastern Sydney 2001-2007 6.
Year
Patients with infectious syphilis:
2001
0.46% (61.4% male)
2002
0.68 (73.6% male)
2003
1.44 (73.2% male)
2004
1.60 (81.7% male)
The argument for continued screening
2005
1.39 (83.7% male)
During the 1990s, some experts were suggesting that syphilis
would soon be eradicated from Western society. In the USA,
syphilis testing was mandatory before marriage licences could be
obtained in several States, but over the years this requirement
lost support and, as of 2008, Mississippi was the only State in
USA still requiring couples to take a blood test for syphilis before
marriage. Following these decades of decline, in 2000 overall
rates of syphilis began rising throughout the developed world,
especially in sexually active homosexual men. An increase in
the rates of infectious syphilis in south-eastern Sydney between
2000-2004 was reported 5 and continues to the present time
(Table 1) 6.
2006
1.95 (84.8% male)
2007
1.95 (86.1% male)
Various factors have been blamed on the resurgence of syphilis
in this century, including ‘safe sex fatigue’ and the evidence that
decline in safe sex behaviour has occurred since antiretrovirals
were introduced in 1990s. In some cases, journalists have blamed
the internet for the increase in the sexually transmitted disease
due to the rise in the number of net-based networks of infected
men seeking partners for unprotected sex.
The Australian national notifications of congenital syphilis rose in
2001 (Table 2) 7, possibly reflecting a spill into heterosexuals and
bisexual males. This figure does not, however, reflect the number
of infections diagnosed and treated in pregnancy. In Australia,
syphilis screening during pregnancy is reimbursed by Medicare
in a series of items. In 2006/07 the cost of reimbursement of
these antenatal screening items was more than $9.6m. Antenatal
syphilis screening is not itemised separately but is grouped with
various combinations of other screening tests, including hepatitis
C, hepatitis B and rubella. Thus it is not possible to determine
how many syphilis tests were carried out during pregnancy in
Australia to estimate a cost benefit analysis.
The resurgence of syphilis infections and the knowledge that
congenital syphilis, a devastating disease, can be prevented by
antenatal treatment leaves no doubt that testing for syphilis in
pregnancy is still relevant. One risk is that, in many people’s minds,
the disease does not tend to be associated with patients in higher
socioeconomic groups and, to avoid offending these patients,
syphilis testing is not included in the request for an antenatal
serological screen. There are a number of well documented
instances where this has had disastrous consequences. This
mindset is also reflected in the changes that were made to the
Medicare item for antenatal serological screening – previously
M I CROB I O L O G Y A U S T RALIA • NOVE MB E R 2 0 0 8 as a % of population and broken down into gender
Table 2. Notifications of congenital syphilis 7.
Year and no. notifications
1998
4
2003
13
1999
4
2004
13
2000
5
2005
15
2001
21
2006
13
2002
18
2007
8
it was mandatory to include syphilis testing, but the item was
changed so that now syphilis screening in pregnancy has become
optional.
References
1.
2.
3.
4.
5.
6.
7.
Silverstein, A.M. and Ruggere, C. (2006) Dr Arthur Conan-Doyle and the case
of congenital syphilis. Perspect. Biol. Med. 49, 209-219.
McFarland, B.L. et al. (1994) Epidemic syphilis – maternal factors associated
with congenital infections. Am. J. Obstetrics Gynaecol. 170, 535-540.
Alexander, J.M. et al. (1999) Efficacy of treatment for syphilis in pregnancy.
Obstetrics Gynaecol. 93, 5-10.
Center for Disease Control and Prevention (2006). Sexually Transmitted
Diseases Guidelines. US Department of Health and Human Services.
Botham, S.J. et al. (2006) Epidemic infectious syphilis in inner-city Sydney:
strengthening enhanced surveillance. Aust. NZ. J. Public Health 6, 529-533.
Robertson, P. et al. (2007) An epidemic increase in infectious syphilis (IS in
south-eastern Sydney 2001-2007). National Serology Reference Laboratory
Workshop 2007.
National Notifiable Diseases Surveilance System. Australian Govt. Dept of
Health and Ageing ( 2008).
Peter Robertson supervises the SESIAHS Area Serology Laboratory, which is
also a State reference laboratory for HIV diagnosis, as well as having an active
role in teaching and research. Recently, his main research interest has been in
the development and evaluation of an antibody assay for diagnosis of invasive
Meningococcal disease (IMD) and for evaluating responses to N. meningitidis
serogroup C vaccine. He has twice been invited to deliver lectures on
serological diagnosis at the National Institute of Health in Maryland USA and
has been author of more than 50 publications in refereed journals. One of his
most important achievements was using IgA antibody to identify Bordetella
pertussis as a major cause of chronic cough in adults, a study he published in
1987. This study prompted developed countries to alter vaccination strategies
in an attempt to eliminate this debilitating disease in adults.
175
In Focus
Congenital and perinatal cytomegalovirus
(CMV): has diagnosis improved in 30 years?
Jonathan Howard, Beverley Hall
and William Rawlinson
Virology Division,
Dept of Microbiology,
South Eastern Area Laboratory Services
Prince of Wales Hospital,
Randwick NSW 2031
School of Medical Sciences and
Biotechnology and Biomolecular Sciences,
University of New South Wales
Sydney NSW 2052
Tel (02) 9382 9113
Fax (02) 9398 4275
The implication of a diagnosis of cytomegalovirus (CMV)
during pregnancy or in the neonatal period remains
uncertain despite our increased understanding of the
pathophysiology of the disease. Current tests for CMV
include serological tests (usually EIA IgG, IgM, avidity)
and nucleic acid testing (NAT). When used together, these
tests offer improved reliability in diagnosis of CMV in
pregnant women and infants.
Diagnosis in pregnant women
Congenital CMV infections may be the result of either a primary
or recurrent infection. Less than 5% of pregnant women with
primary CMV infection are reported to be symptomatic 1 and
most CMV infections are asymptomatic during the acute stage 2.
There are many diagnostic procedures for the detection of
CMV 3, 4; however, there is no adequate single test. The primary
concern to most pregnant women and their medical advisors is
a diagnostic test that predictively defines the clinical outcome
for the baby.
Virological and serological testing of the mother is necessary to
establish a diagnosis. Documented seroconversion of the mother
from IgG seronegative to IgG seropositive is the definitive method
of determining a primary CMV infection. CMV IgM positivity is
used extensively as a marker of active or recent infection, but
IgM positivity does not always correlate with primary infection.
Indeed, older studies suggest IgM antibody may not be detected
until 6-9 months after the acute phase of a primary infection in a
small number of women 5. IgM detected using modern sensitive
enzyme immunoassay (EIA) methods may persist for years postprimary infection in a proportion (5-10%) of infected women 6, 7.
During reactivations or reinfections, pregnant women may also
test IgM positive and excrete CMV in their urine 6.
176
Improvements in serological testing include the CMV IgG avidity
test. Avidity results (a numerical value) are informative despite lack
of standardisation between the various manufacturers of the tests
[eg. VIDAS, BioMerieux]. Low, intermediate and high values offer
broadly useful information in defining recent (<3 months, low
avidity) or past infection (>3 months, high avidity) 6, 8. However,
not all past infections show high IgG avidity and not all recent
infections show low avidity. Careful interpretation of avidity
testing in conjunction with IgM and NAT testing of peripheral
blood may identify primary CMV infection and offer a guide to
timing of the infection (Table 1).
The advent of NAT has certainly improved the detection of clinical
infectious pathogens and is now increasingly being adopted by
diagnostic laboratories. Polymerase chain reaction (PCR) is more
sensitive, specific, cost-effective, less laborious and provides
accurate and rapid diagnosis compared to conventional culture
methods. Some laboratories can now screen clinical samples for
CMV in blood, urine, amniotic fluid, newborn screening cards
(NBSC) and autopsy materials. In addition, PCR can be adapted
to test for various causative agents in one PCR reaction (multiplex
PCR) 9.
Prenatal diagnosis
Routine antenatal screening for CMV during pregnancy is not
performed in Australia but is performed as a matter of clinical
judgment. Fetal abnormalities, if detected on ultrasound, may
lead to maternal investigation with subsequent diagnosis of
CMV. However, ultrasound is an insensitive method for detecting
congenital CMV 10 and this technique has poor sensitivity. It has
been claimed that ultrasound detects less than 5% of infected
babies 11 and does not detect the subset of infected neonates with
sensorineural hearing loss and other subtle late complications
of congenital CMV. Nonetheless, ultrasound has the advantages
of being non-invasive and can show structural and/or growth
abnormalities.
MICROBIOLOG Y A U STRA LIA • N OV EM BER 2008
In Focus
After diagnosis of maternal infection, some pregnant women
may desire fetal diagnosis (Table 2). Invasive techniques for
diagnosing CMV include cordocentesis and amniocentesis.
Cordocentesis is used in some centres for detection of CMV
IgM antibody status, CMV PCR, liver enzymes, hematocrit and
platelet count; however, analysis of amniotic fluid is probably
the most appropriate for prenatal diagnosis 12, 13. Sampling of
amniotic fluid for CMV testing is usually done between 21-22
weeks’ gestation 14, 15. This gestation has been selected as it may
take 9 weeks for CMV to be excreted from the fetal kidneys and
be detectable in the amniotic fluid.
A positive CMV PCR of the amniotic fluid indicates fetal infection,
although the association between infection and disease remains
an area of uncertainty. Qualitative analysis of CMV in amniotic
fluid is sensitive (92-98%) and specific (90-98%) 16. Some authors
correlate worse outcomes with higher viral load in the amniotic
fluid 17. A negative PCR result, generally an indicator of absence
of CMV, may also be a false-negative result if the procedure is
performed less than 6-9 weeks after maternal infection and/or
before 21 weeks’ gestation.
Diagnosis in the newborn
The reference standard for diagnosing congenital CMV infection
remains isolation of the virus from urine, saliva or plasma in
the first 3 weeks of life. IgM positivity is indicative of congenital
infection, but IgM antibodies are present in about 70% of infected
babies 18. Beyond 3 weeks of life, tests can no longer differentiate
congenital from perinatal infection.
Infants suspected of CMV beyond the early neonatal period
(especially for infants presenting with deafness) may have blood
tested for CMV if blood has been routinely collected at birth and
dried on a NBSC as part of a newborn screening programme.
Retrospective diagnosis of congenital infection in infants
presenting with later clinical illness and not to genetic causes is
routinely performed by some laboratories 19, 20. Detection of CMV
in blood at birth has been claimed to be as sensitive and specific
as detection in urine 21, 22.
NAT is used to detect the presence of CMV in maternal and
infant urine, plasma and serum, along with fresh placenta,
fresh umbilical cord and paraffin-embedded tissue, using CMV
PCR. In addition, using in situ PCR, placenta and fetal tissue
from CMV PCR positive liveborn and stillborn babies may be
Table 1. Determining time of CMV infection.
CMV IgM
CMV IgG avidity
• May remain positive for >2 years
• If low infection, usually <3 months previous
• Different assays with different sensitivities
• May be high in recent infection (uncommon)
• Some laboratories utilise two assays
• If low in trimester 1 infection, may be pre-pregnancy
• May inverse in recurrent infection
• Retesting in 2-3 weeks may indicate kinetics of antibodies
Table 2. Diagnosis of congenital CMV during pregnancy (fetal infection) and in infants.
Fetal infection
Neonate and older infection
Serology
CMV IgG pre-pregnancy + pregnancy scan if possible
CMV IgG
IgM
IgM
IgG avidity
IgG avidity
Amniocentesis
Amniocentesis of >21 weeks’ gestational age (CMV viral load in
amniotic fluid (high value suggests increased risk fetal infection)
Molecular
Maternal peripheral blood (NAT)
Peripheral blood and urine (NAT)
Placenta at birth (NAT)
>21 days old, request testing of NBSC (NAT)
M I CROB I O L O G Y A U S T RALIA • NOVE MB E R 2 0 0 8 177
In Focus
examined. This allows the determination of several factors:
References
the anatomical localisation of CMV in the placenta, addressing
1.
Pass, R.F. et al. (2006) Congenital cytomegalovirus infection following first
trimester maternal infection: symptoms at birth and outcome. J. Clin. Virol. 35,
216-220.
2.
Munro, S.C. et al. (2005) Diagnosis of and screening for cytomegalovirus
infection in pregnant women. J. Clin.Microbiol. 43, 4713-4718.
3.
Rawlinson, W.D. (1999) Diagnosis of human cytomegalovirus infection and
disease. Pathology 31, 109-115.
specialised method that is not available to most pathology labs;
4.
however, it is a sensitive method of addressing these issues
Trincado, D.E. and Rawlinson, W.D. (2001) Congenital and perinatal infections
with cytomegalovirus. J. Paediatr. Child Health 37, 187-192.
5.
Stagno, S. et al. (1986) Primary cytomegalovirus infection in pregnancy. J. Am.
Med. Assoc. 256, 1904-1908.
6.
Lazzarotto, T. et al. (1997) Search for cytomegalovirus-specific immunoglobulin
M: comparison between a new western blot, conventional western blot, and
nine commercially available assays. Clin. Diag. Lab. Immunol. 4, 483-486.
improving the prognosis of congenitally ill babies.
7.
Ultimately, further tests and research are required to develop the
Lazzarotto, T. et al. (2004) Congenital cytomegalovirus infection: recent
advances in the diagnosis of maternal infection. Human Immunol. 65, 410415.
8.
Munro, S.C. et al. (2005) Symptomatic infant characteristics of congenital
cytomegalovirus disease in Australia. J. Paediatr. Child Health 41, 449-452.
9.
McIver, C.J. et al. (2005) Development of multiplex PCRs for detection of
common viral pathogens and agents of congenital infections. J. Clin. Microbiol.
43, 5102-5110.
cellular tropism in vivo; the co-localisation of virus and tissue
inflammation, informing if tissue damage is from viral mediated
or immune mediated (possibly cytokines); and the sensitivity
of histopathology for detecting viral infection. In situ PCR is a
whilst providing details about viral transcription 23. These data
are significant for further understanding the pathophysiology
of CMV, providing correct diagnosis, directing therapies, and
diagnostic test that predictively defines the outcome of a CMV
infection during a woman’s pregnancy. In the meantime, use of
multiple tests, with careful consideration of the results, allows us
to provide useful information to mothers with infection during
pregnancy and to parents of infected children.
10. Liesnard, C. et al. (2000) Prenatal diagnosis of congenital cytomegalovirus
infection: prospective study of 237 pregnancies at risk. Obstet. Gynecol. 95,
881-888.
11. Ville, Y. (1998) The megalovirus. Ultrasound Obstet. Gynecol. 12, 151-153.
12. Lazzarotto, T. et al. (2000) Prenatal indicators of congenital cytomegalovirus
infection. J. Pediatr. 137, 90-95.
13. Revello, M.G. et al. (1999) Quantification of human cytomegalovirus DNA in
amniotic fluid of mothers of congenitally infected fetuses. J. Clin. Microbiol.
37, 3350-3352.
14. Azam, A.Z. et al. (2001) Prenatal diagnosis of congenital cytomegalovirus
infection. Obstet. Gynecol. 97, 443-448.
Preliminary Announcement
Parasitology & Tropical Medicine MasterClass 2009
Clinical School – University of Tasmania, Hobart
6 – 7 March 2009
www.parasitologymasterclass.org
A joint meeting of
• ASM Parasitology and Tropical Medicine SIG; and
•Australian College of Tropical Medicine (ATCM) Standing
Committee on Medical Parasitology and Zoonoses
The MasterClass will cover Introductory & Advanced Parasitology
as well as topics related to tropical Medicine and will be suitable
for Specialists & Trainees and Laboratory Scientists/Technicians in
Infectious Diseases/Clinical Microbiology, Parasitology and Tropical
Medicine and Haematology.
The day and half program will include:
• Expert Faculty
•Practical Laboratory Workshops for Introductory &
Advanced Parasitology
•Half day Malaria Workshop incorporating seminars and
hands-on laboratory sessions
Chair: Richard Bradbury, University of Tasmania
Co-Convenors: Dr Andrew Butcher – Microbiology and Infectious
Diseases, SA Pathology
Dr Harsha Sheorey – Microbiology, St Vincent’s Hospital, Melbourne
Registration to open soon!
Conference Organisers – Australian Society for Microbiology
178
15. Gouarin, S., et al. (2001) CMV gB genotypes and outcome of vertical
transmission: study on dried blood spots of congenitally infected babies. J.
Clin. Virol. 21, 75-79.
16. Enders, G. et al. (2001) Prenatal diagnosis of congenital cytomegalovirus
infection in 189 pregnancies with known outcome. Prenat. Diagn. 21, 362377
17. Lanari, M. et al. (2006) Neonatal cytomegalovirus blood load and risk of
sequelae in symptomatic and asymptomatic congenitally infected newborns.
Pediatr. 117, e76-e83.
18. Revello, M.G. et al. (1999) Diagnostic and prognostic value of human
cytomegalovirus load and IgM antibody in blood of congenitally infected
newborns. J. Clin. Virol. 14, 57-66.
19. Barbi, M. et al. (2006) Neonatal screening for congenital cytomegalovirus
infection and hearing loss. J. Clin. Virol. 35, 206-209.
20. Barbi, M. et al. (2000) Cytomegalovirus DNA detection in Guthrie cards: a
powerful tool for diagnosing congenital infection. J. Clin. Virol. 17, 159-165.
21. Revello, M.G. and Gerna, G. (2002) Diagnosis and management of human
cytomegalovirus infection in the mother, fetus and newborn infant. Clin.
Microbiol. Rev. 15, 680-715.
22. Ross, S.A. and Boppana, S.B. (2005) Congenital cytomegalovirus infection:
outcome and diagnosis. Sem. Pediatr. Infect. Dis. 16, 44-49.
23. Trincado, D.E. et al. (2005) Highly sensitive detection and localization of
maternally acquired human cytomegalovirus in placental tissue by in situ
polymerase chain reaction. J. Infect. Dis. 192, 650-657.
Dr Jonathan Howard is a postdoctoral research officer at the Virology
Division at SEALS and a conjoint lecturer at UNSW. He has worked on stillbirth
and congenital infections for over 2 years. His interests are in the detection of
pathogens associated with stillbirth and congenital infections.
Beverley Hall is a registered nurse and midwife and works as a research
nurse for the congenital infection study at the Virology Division at SEALS. Her
interests are maternal, infant and fetal health.
Professor William D Rawlinson – See Bio on page 172.
MICROBIOLOG Y A U STRA LIA • N OV EM BER 2008
Under the Microscope
What happens when a baby dies:
stillbirth investigations for infection and
other aetiologies
S Chaudry and TY Khong
SA Pathology, Women’s and Children’s Hospital
North Adelaide SA 5006
Email [email protected]
AK Charles and AD Keil
PathWest Laboratory Medicine, King Edward Memorial and
Princess Margaret Hospitals, Subiaco WA 6008
Infections in stillbirths are common, often clinically silent
and need to be screened. The microbiology laboratory
needs to have the appropriate culture techniques
and expertise. The results of the clinical features, the
pathology findings of the fetus and the placenta and
the microbiological and serological features need to be
interpreted together; individual results should not be
considered in isolation.
intrauterine infections. There is an association with older
women, obesity and infertility treatment that are factors likely
to be increasing the rate of stillbirths. Other common factors
associated with stillbirth include placental disorders (e.g.
placental abruption and vascular under-perfusion), complications
of multiple gestation, and umbilical cord abnormalities or
accidents. Several factors may coexist in individual cases. In
approximately 15-25% of stillbirths no cause is identified.
Stillbirth is defined in Australia as the loss of a fetus who shows
no signs of life at birth and is at least 400 grams in birth weight
or at least 20 weeks’ gestation. In Australia in 2005, there were
1,979 reported fetal deaths, at a rate of 7.3 per 1,000 births, about
19% of which are at term, making stillbirth a far more common
condition than SIDS 1.
Infection, which may involve mother, fetus or placenta, is
associated with 10-25% of stillbirths in developed countries; it
is a more frequent cause of stillbirth in developing countries 2.
Infection may cause stillbirth by a number of mechanisms
including direct infection, placental damage, and indirect
mechanisms without identifying infection of the fetus or placenta
or severe maternal illness. Assigning a specific infection as a
cause of death may not be straightforward. Firstly, stillbirths
may have multiple causes and infection may be one of them.
Secondly, in an already compromised fetus due to maternal or
fetal cause, infection may accentuate or precipitate the demise.
Thirdly, despite finding a specific organism on culture or
serological evidence of recent infection, these agents may not be
the actual cause of death. The earlier (in gestation) the stillbirth,
the more likely it will be associated with infection. It is not clear
why ascending infection is so common in midtrimester.
Stillbirth has been a hidden medical issue but has an immense
effect on the woman as well as family members, physicians and
nurses. It may be a potential marker of maternal or inherited
disease but, despite this, it is an area that is under investigated.
This paper sets out the investigations that may explain the cause
of death and which may be valuable in counselling parents about
recurrence risk in subsequent pregnancies, with an emphasis on
information regarding the infectious aetiology of stillbirth.
Currently, the principal risk factors and causes of stillbirth in
developed countries are congenital anomalies, preeclampsiarelated complications, intrauterine growth restriction and
M I CROB I O L O G Y A U S T RALIA • NOVE MB E R 2 0 0 8 The important clinical point is that fetal and placental infection
is often clinically silent, and therefore each stillbirth needs to be
179
Under the Microscope
investigated with infection in mind, especially the non-macerated
cases. Around 70% of all acute chorioamnionitis is clinically
silent. Chorioamnionitis can also present with bleeding and
abdominal pain like abruption or be associated with premature
prelabour rupture of membranes and so, even if symptomatic,
may not be recognised. Most of the patients with histological
chorioamnionitis have no maternal symptoms such as fever,
uterine tenderness or maternal leukocytic response.
There are two major microorganism-related mechanisms
associated with significant perinatal mortality and morbidity.
First, ascending genital tract infection, almost always bacterial,
which ranges from localised choriodecidual inflammation to
frank chorioamnionitis with fetal sepsis; this is a major cause of
mid trimester miscarriage and severe preterm delivery (Figure 1).
Second, haematogenous spread of maternal systemic infection,
be it bacterial, viral or parasitic 3.
Organisms mostly associated with ascending infection are the
genital mycoplasma species Ureaplasma urealyticum and
Mycoplasma hominis, but a large variety of bacteria can colonise
the female genital tract without causing any symptoms in
pregnant woman. Listeria infects by the haematogenous route
and is readily identified culturally and by special stains; it leads
to abscess formation in the placenta and is one of the definitive
causes of stillbirth 4. In case of parasitic infection, as in malaria,
it is not uncommon to find parasitaemia in intervillous spaces
of the placenta of infected mothers with uninfected fetal blood.
Toxoplasmosis is a worldwide zoonosis. Fetal infections result
from parasitic disease of placenta that can destroy the fetus
or lead to varying degrees of fetal/congenital infection. The
organism can be detected by placental tissue or body fluid
culture and specific polymerase chain reaction (PCR) testing of
these samples. However, the overall contribution of toxoplasma
to fetal death is relatively small. Stillbirths or neonatal deaths
occur in 5% of pregnancies with first trimester toxoplasmosis, in
2% with second trimester infection and in 0% in third trimester
infection 5.
Although it is clear that viruses can cause stillbirth, the overall
nature of this relationship is unclear. Serological or PCR evidence
of an infection does not prove causation. Parvovirus B19
(Figure 2) appears to have strongest association with stillbirth as
it can either infect fetal erythropoietic tissue – leading to severe
fetal anaemia and/or hydrops, both potential mechanisms for
fetal death – or infect myocytes – leading to myocarditis and in
utero heart failure. The risk of stillbirth is greater for parvovirus
infection occurring prior to 20 weeks’ gestation 6.
Enteroviruses, including Coxsackie A and B, echoviruses and
other enteroviruses are also associated with stillbirth. Coxsackie
viruses can cross the placenta and cause villous necrosis,
inflammatory cell infiltration, calcific pancarditis and hydrops.
Cytomegalovirus (CMV) is one of the common congenital
infections and placental involvement is well documented. The
virus can be detected through serology and culture/PCR but
the exact mechanism of how CMV causes stillbirth is not clear.
Rubella virus can cause endothelial damage and thrombosis
in placental and fetal vessels, leading to stillbirth. The risk
to the fetus is greater at early gestation and decreases with
increased gestational age. However, with the development of
rubella vaccine and its widespread adoption, this virus has little
contribution in stillbirths in developed countries.
Syphilis is one of the major causes of adverse pregnancy
outcomes in developing countries and high rates are reported
in parts of rural Australia. With primary and secondary syphilis,
stillbirth, neonatal death or prematurity occurred in 50% of cases,
whereas with early latent or late syphilis, stillbirths occurred in
only 10% 5.
Figure 1a. Acute chorioamnionitis.
180
Figure 1b. Funisitis, with margination and infiltration of
neutrophils through the venous wall of the umbilical cord
into the stroma.
MICROBIOLOG Y A U STRA LIA • N OV EM BER 2008
Under the Microscope
Outside the context of infectious aetiologies of stillbirth, the
autopsy could reveal other causes of death. Careful external
examination and measurements could reveal growth restriction
as an associated finding of stillbirth. Other causes obvious
on external examination are hydrops fetalis (which may have
an infectious aetiology), congenital malformations, such as
skeletal dysplasias, or karyotypic anomalies, such as trisomy
18 or triploidy. Internal examination could reveal numerous
congenital malformations or corroborative evidence of growth
restriction. Uteroplacental vascular insufficiency, often associated
with maternal hypertensive disorders of pregnancy, and placental
abruption could be confirmed by placental examination.
Figure 2. Parvovirus inclusion in an early pregnancy placental
villus.
Protocols for investigation of stillbirth
It is important to have a set of rules or protocols to investigate
stillbirths. Almost all protocols follow the same set of
investigations. It is important that the microbiology laboratory
is set up for the investigation of stillbirths and is able to
culture both for the unusual and more fastidious organisms
such as genital mycoplasma and Haemophilus species. The
fetus is often delivered through the vagina and exposed to
A microbiological examination must be taken – swabs from
lung, stomach and liver for microbiological cultures. Group
B Streptococcus (GBS), Escherichia coli and Ureaplasma
urealyticum are the organisms commonly associated with
chorioamnionitis and fetal infection. Stillborn infant blood (cord
blood or, if this is not possible, infant cardiac blood) is collected
for microbial cultures of GBS, Haemophilus species, Listeria and/
or coliforms. Maternal serology testing of syphilis, parvovirus,
toxoplasmosis, rubella, herpes simplex virus (HSV) and CMV,
as well as specific PCR testing of fetal tissues can be done.
Mycobacterium testing is of interest if TB is suspected or the
cause of death is not obvious. In ambiguous situations, elevated
fetal serum b2 microglobulins can be used as a reliable marker
for intrauterine infection due to CMV or toxoplasmosis 9.
the vaginal flora, and it is easy for fluid to be moved as the
If consent not given
fetal chest and abdomen are compressed, and for bacterial
If consent is not given, a limited fetal evaluation should be
discussed with parents who are resistant to a complete autopsy.
However, there is no adequate substitute for a full fetal autopsy.
Some less invasive alternatives that are acceptable by parents are
MRI, needle biopsy of tissue and the non-invasive component
of the standard autopsy such as external fetal examination and
placental examination (see below).
contamination to occur. Bacterial overgrowth is particularly
common after a prolonged delay from delivery until post
mortem. The interpretation of the microbiology results is ideally
a communication between the clinician, the perinatal pathologist
and the clinical microbiologist.
Full autopsy
The most important part of the workup of a fetal demise is the
autopsy of the fetus. The decision to proceed with an autopsy
must be made by the parents and informed consent is necessary.
The healthcare providers should strongly emphasise that the
Placental examination
Culture
Subamniotic swabs for at least aerobic and, ideally, anaerobic
cultures including for bacterial vaginosis-associated organisms
result of the autopsy may be useful to the patient and her family
in planning future pregnancies. However, despite the autopsy,
cause of death may remain undetermined in 12-50% of cases 7.
If consent given
The standard fetal autopsy includes a comprehensive external
examination, photography and radiography of the fetus and gross
and histological and supplementary laboratory investigations
such as microbiological, cytogenetic and metabolic studies 8.
Examination of the internal organs (weights, detailed macroscopic
and histological examination) should also be carried out. There
should also be examination of the placenta and umbilical cord
(Figure 3) with cultures if unable to be taken from the fetus.
M I CROB I O L O G Y A U S T RALIA • NOVE MB E R 2 0 0 8 Figure 3. Candida colonies on surface of umbilical cord on
careful inspection.
181
Under the Microscope
if resources are available, are recommended for all cases.
Fresh placental tissue is collected for tissue culture if infection
is suspected (GBS, Listeria, Haemophilus, coliforms and
viruses). If TB is suspected, a separate sample is collected for
mycobacteria.
Cytogenetics
Atay et al. showed that histopathological chorioamnionitis
and placental culture positivity rates in control and study
group were 64.7% vs 0%. Bacteria were recovered from
90.9% of placentas and 36.4% of fetal lungs of the cases with
histopathological chorioamnionitis 10. Pankuch et al. showed that
bacteria were recovered from 72% of placentas with histological
chorioamnionitis and from 82% of clinical chorioamnionitis, all
of which had histological chorioamnionitis. Nearly 50% bacteria
recovered from placentas were anaerobes 11. Viral cultures
and serology are often not available or are of relatively low
sensitivity. The microorganisms most commonly recovered from
the chorioamnion include Ureaplasma urealyticum, facultative
and anaerobic Gram-positive cocci, Gardnerella vaginalis and
Bacteroides species. Haemophilus influenzae (usually nontypable), Neisseria gonorrhoeae and Chlamydia trachomatis
are rarely recovered from placentas 12.
Clinical history
Histopathological examination
Histological acute chorioamnionitis (Figure 1) is defined as a
maternal neutrophilic response to bacterial infection with or
without an accompanying fetal neutrophilic response. Acute
chorioamnionitis is usually the result of infection in the female
genital tract. Other less common routes are haematogenous
seeding of placenta and contiguous spread of organisms from
adjacent pelvic viscera. Fetal inflammatory response does not
necessarily mean fetal infection; it is an indication of activation
of fetal immune system. Immune activation in turn leads to
increased levels of cytokines in fetal blood that are associated
with increased risk of brain injury and chronic lung disease.
Histopathological examination of placenta contributes to
a better understanding of the cause of intrauterine fetal
death. Rayburn et al. showed that significant histological
aberrations were found in placentas of 98% cases. The most
frequent abnormalities were those of vascular insufficiency,
haemorrhagic endovasculitis, retroplacental haematoma, acute
chorioamnionitis with fetal involvement, and erythroblastosis/
hydrops 13. Mayo et al. showed that histological chorioamnionitis
occurred in 2.6 times more often in women with stillbirths than
in women with live births 14.
Chorioamnionitis with acute villitis is seen with fetal bacterial
sepsis especially by streptococci and Gram-negative bacilli. The
presence of mixed lympho-histiocytic infiltrate in the terminal
villous stroma is the feature of chronic villitis (Figure 4). Chronic
villitis is usually associated with placental infection with CMV,
syphilis or toxoplasma. Less common agents like HSV and
coxsackie viruses are occasionally associated with chronic
villitis. Less virulent organisms such as the genital mycoplasma
species cause asymptomatic maternal infection; however, they
are associated with histological chorioamnionitis and adverse
pregnancy outcome.
182
Where relevant, if karyotyping has not been done, then placental
tissue can be used for cytogenetics studies.
Maternal investigations
When stillbirth and neonatal death occurs, the obstetric history,
including exposure (e.g. medications and viral infections), history
of amniocentesis, intrauterine contraceptive device and family
history with three generation pedigree, if possible, should be
reviewed. Maternal history of fever, abdominal pain or other
evidence of lower genital tract infection such as offensive vaginal
discharge should also be recorded. Consideration of performing
an antenatal ultrasound scan prior to stillborn delivery is
recommended by most protocols (whenever possible, following
confirmation of stillbirth) for the identification of unknown
abnormalities. The ultrasound findings may be helpful when the
family does not consent to a full autopsy 15.
Gram-staining and fibronectin test should be carried out on
vaginal or cervical secretions. A positive test is strongly associated
with chorioamnionitis and neonatal sepsis 16. Also, at the time
of stillbirth confirmation and prior to delivery, collection of
amniotic fluid by amniocentesis is recommended. This results
in good microbiological specimens and material for cytogenetic
analysis. It may be screened for leukocyte count, Gram-stain, pH,
glucose concentration, endotoxin, lactoferrin, cytokine levels
(e.g. interleukin-6). The cytokines commonly quantified in either
the amniotic fluid or the blood include interleukin-6, TNF alpha,
interleukin-8.
Further, PCR testing can be used to identify agents such as
human immunodeficiency virus, CMV, HSV, parvovirus B19,
toxoplasmosis and bacterial DNA in amniotic fluid. Screening
for GBS carriage should be done by combined vaginal/rectal
swabs and a white blood cell (WBC) count done in maternal
blood. Serology tests for parvovirus B19, toxoplasmosis, CMV,
syphilis, rubella, HSV and HIV are recommended as core
investigations. Maternal blood cultures should be taken if the
Figure 4. Chronic villitis: chronic inflammatory cells in the
stroma of a terminal villus.
MICROBIOLOG Y A U STRA LIA • N OV EM BER 2008
Under the Microscope
clinical findings suggest active chorioamnionitis, with additional
cultures being performed when indicated (e.g. faeces for Listeria
and campylobacter infection).
Conclusion
High vaginal/low vaginal swabs (HVS/LVS) should also be taken.
There is an association between bacterial vaginosis and premature
labour but antenatal management of bacterial vaginosis as a
means of preventing premature labour remains controversial.
Possible further research would include serum concentrations of
interleukin-6, interleukin-8 and tumour necrosis factor, and noncytokine markers of infection, including serum C-reactive protein
and serum ferritin.
with close collaboration of all involved specialists in the
Interpretation
Acute chorioamnionitis is considered to have virtually always an
infective aetiology, even though bacteria are only cultured in some
of the cases. This discrepancy may be due to maternal antibiotic
administration, failure to culture for implicated organisms such as
the genital mycoplasma species or bacterial vaginosis-associated
organisms, or the reporting of potentially pathogenic organisms
as ‘normal’ flora with no further specification.
A fresh stillbirth with no evidence of chorioamnionitis does not
exclude an infectious aetiology. Organisms such as GBS can cause
fetal infection with intact membranes. The infection may be
overwhelming, with insufficient time to initiate an inflammatory
reaction. Furthermore, there may be no inflammatory response
at autopsy as the cellular immune system in an extremely
premature fetus may be immature. In a fresh stillbirth with
evidence of chorioamnionitis, the possibility of isolation of
organism from fetal tissue or placenta is always high (with the
caveats mentioned earlier) and an infectious cause must be
considered.
Caution is advised in the interpretation of organisms cultured
in these scenarios as being either ‘vaginal contaminants’ or
normal flora, since they may, in fact, be very significant. In
cases of macerated stillbirths, the presence of chorioamnionitis
does not necessarily mean infection unless a fetal reaction is
identified. In a macerated stillbirth where there is no evidence
of chorioamnionitis and no organism isolated, other causes of
stillbirth should be considered. Most macerated stillbirths appear
to have a low yield of identification of a causative bacterial agent,
although syphilis and viral causes may be found.
In practice, every non-macerated, and not obviously dysmorphic
fetus should have bacterial cultures taken and assessed in
the light of histology. Viral infections should be considered in
growth restriction and in stillbirths with rashes, localised areas
of necrosis (e.g. liver) and hydrops in both macerated and nonmacerated stillbirths.
Infections remain a frequent factor in stillbirths and are often
clinically silent. Stillbirths require active screening for infections
interpretation of results.
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Fretts, R.C. (2005) Etiology and prevention of stillbirth. Am. J. Obstet. Gynecol.
193, 1923-1935.
ACOG Committee Opinion No. 383 (2007) Evaluation of stillbirths and
neonatal deaths. Obstet. Gynecol. 110, 963-966.
Dreux, S. et al. (2006) Fetal beta2-microglobulin as a marker for fetal infectious
diseases. Prenat. Diagn. 26, 471-474.
Atay, G. et al. (2004) The possible role of intrauterine infections in unexplained
second trimester abortions and macerated stillbirths: a study from a single
center. J. Perinatol. 24, 679-685.
Pankuch, G.A. et al. (1984) Placental microbiology and histology and the
pathogenesis of chorioamninitis. Obstet. Gynecol. 64, 802-806.
Hillier, S.L. et al. (1991) Microbiological causes and neonatal outcomes
associated with chorioamnion infection. Am. J. Obstet. Gynecol. 165, 955-961.
Rayburn, W. et al. (1985) The stillborn fetus: placental histological examination
in determining a cause. Obstet. Gynecol. 65, 637-641.
Moyo, S.R. et al. (1996) Stillbirths and intrauterine infection, histologic
chorioamnionitis and microbiological findings. Int. J. Gynecol. Obstet. 54, 115123.
Protocol for Stillbirth Investigation. Alberta Heritage Foundation for Medical
Research. October 2005.
Goldenberg, R.L. et al. (2000) Intrauterine infection and preterm delivery. N.
Engl. J. Med. 18, 1500-1507.
Sadia Chaudry is a paediatrician, having received her fellowship training from
the College of Physicians and Surgeons Pakistan (CPSP). She is currently a
registrar in paediatrics at the Women’s and Children Hospital. Her research
interests range from investigating infective causes of stillbirths to diseases of
the neonates.
Adrian Charles is a paediatric and perinatal pathologist who trained in the
UK and has been in Perth since 1999. His research interests are in placental
development, intrauterine infection/inflammation and paediatric tumours.
Tony Keil is a medical microbiologist and head of the Department of
Microbiology at Princess Margaret Hospital for Children and King Edward
Memorial Hospital for Women. He and his scientific staff work in close
collaboration with perinatal pathology colleagues in elucidating infective
causes of stillbirths.
Yee Khong is a perinatal and obstetric pathologist who trained in the UK and
has been in Adelaide since 1991. His research interests are in placental and
obstetric pathology.
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M I CROB I O L O G Y A U S T RALIA • NOVE MB E R 2 0 0 8 183
Under the Microscope
When a baby dies:
stillbirth from the community perspective
and what parents want to know
Emma Kirkwood
Ros Richardson
Stillbirth Foundation Australia
Level 18, 55 Market Street
Sydney NSW 2000
Tel 0419 995 464
Email emma@stillbirthfoundation.
org.au
SIDS and Kids NSW
PO Box 431
Camperdown NSW 1450
Tel (02) 8585 8702
Fax (02) 9818 4555
Email [email protected]
The death of a child at any time is a devastating experience
for parents, with lifelong physical, psychological and
spiritual sequelae. The death of a baby before birth
presents its own particular challenges. This article
is written by mothers whose babies have died. Our
daughters, Olivia and Annie Rose, were stillborn at 36
weeks after uneventful pregnancies 15 years apart. In
this article we describe the reality of stillbirth expressed
by parents in sadness over their lost hopes and dreams
and in the loss of a social identity that would validate the
individuality and significance of those little lives. Over
the last 10 years, we applaud the improvement in and the
more humanised approach to the care of stillborn babies
and their parents; however, concern now exists around
the levels of awareness about stillbirth in the community,
before, during and after any pregnancy.
“I’m sorry but your baby has died” are the hardest words
for any parent to hear. With stillbirth, these words introduce
parents to a death and grief that is not well understood and
is poorly accepted by the community. Stillbirth is emotionally
complex, with long lasting symptoms of grief and significant
struggles to find meaning 1. Stillbirth is an event that happens
often completely unexpectedly to a happy couple, who then
commence a journey travelled without consistency of care that is
typically far removed from any previous life experience. In such
circumstances, much information and support is needed from
the medical community, family and friends.
In Australia, one in every 140 babies is stillborn; in the scheme
of things, stillbirth is a relatively common form of death
(Table 1) 2,3. In an age of enormous medical and technical
advances, it is surprising that the number of stillborn babies
has not reduced over the last decade. We live in an age of great
technology and information; however, stillbirth remains an event
cloaked in mystery. In most cases, the first time a family hears of
stillbirth is when it happens to them.
184
A plethora of extreme emotions is felt at the time a baby dies
– incomprehension, disbelief, intense sadness, crying, anger,
anxiety, guilt, loneliness, fear, grief, love, joy and pride. The
emotional and physical shock and trauma associated with stillbirth
requires personal sensitive care. It is a confusing time; not only
does one mourn the death of their baby and ask why did their
baby die, but parents will also wonder and marvel at the child
they have created. Parents need privacy and information. There
are many considerations, including what they will experience
during the birth, pain, blood loss, lactation, along with guidance
and information about seeing their baby, registering the birth,
planning the funeral, as well as life beyond this time.
The first time parents meet their baby, he or she is dead; this
may be the first time they see a dead person. Parents may feel
frightened about how their baby will look 4 and may find it
challenging to accept that their baby has really died. They may
need assistance in both facing and separating from their baby 5.
Although the value of parents seeing their stillborn baby is still
debated, the choice is for the family to make.
Table 1. Deaths in Australia 2005 2,3.
Number
Cause of death in Australia
2946
Men died from prostate cancer
2736
Adults died from breast cancer
1979
Babies were stillborn
1273
People died from skin melanoma
884
Women died from ovarian cancer
87
Babies died from SIDS
MICROBIOLOG Y A U STRA LIA • N OV EM BER 2008
Under the Microscope
Stillborn babies are born into a void of silence and into the
love and desperate longing of their parents. Parents love their
stillborn baby as they do their other children. Yet a stillborn baby,
and to an extent its family, is defined by the word stillbirth which
in itself can bring a conversation to an abrupt halt.
Parents must learn to live with their loss in a society that defines
the value of a person through life. Many bereaved families, and in
particular mothers, struggle with this for many years. Despite the
fact that stillborn babies do not breathe, their existence is very
real to their parents, who are left with unfulfilled plans, hopes
and dreams for their future lives. For many parents, creating an
identity around their child and gathering mementos of their brief
time together is enormously important.
Whilst there have been great advances in the care of stillborn
babies and their families over the last 20 years, consistency of
care remains an issue today. The care received by families whose
baby is stillborn varies greatly between hospitals and staff, and is
dependent on the skill, experience and empathy of the caregivers.
Caregivers need to support parents in moments of chaos and at
other difficult times 5, while knowing that their every action and
piece of advice will be remembered in clear and accurate detail
by the parents. Caring for families who have experienced the
stillbirth of their baby is challenging and demanding for the
medical 6, nursing and allied staff.
Once trust is established, parents value the guidance of caregivers.
Many parents speak fondly of the facilitated care and support
they received during the precious time spent with their stillborn
baby and will forever treasure this memory. There is no fear, just
love and a desperate longing to cherish and get to know this
beautiful person. The short period of time spent with their baby
must give opportunity and allow for every detail to be etched in
each parent’s heart and mind. To have the opportunity to collect
mementoes, such as locks of hair, footprints and handprints,
take photographs and to bathe, dress, wrap, kiss, and introduce
him or her to family and friends is important for many bereaved
families.
Loneliness and isolation are two very great emotions that parents
of stillborn babies experience, along with intense pain and
sadness. These are felt at the time of the birth and thereafter,
with some parents forever reporting a sense of isolation. Whilst
there is no evidence from randomised controlled trials that
there is or is not a benefit from providing specific psychological
support or counselling after perinatal death 7, meeting with
others is anecdotally beneficial for many families.
Death is not accepted well or wholly in today’s western society,
and the death of a baby is even more challenging for family and
friends, particularly if that death is unexplained. Condolences
and suggestions that it is “God’s will” or “not the right time” are
not supportive for the grieving family. Parents need to be able to
normalise and comprehend their grief and loss, and the task of
educating friends and colleagues about stillbirth is an additional
and unfair stress. The best way to describe stillbirth and to make
it real has not yet been elucidated or promoted. Perhaps the
use of the more accurate term, “deadbirth”, coined by an 8 year
old boy when describing his little sister to his friends, is more
informative and honest.
M I CROB I O L O G Y A U S T RALIA • NOVE MB E R 2 0 0 8 At the time of their baby’s birth, families wish to know why
their baby died and most will desire to save others from living
the same tragedy. For many families, the cause of their stillborn
baby’s death will never be determined, despite a full post
mortem investigation. Consenting to an investigation of their
baby’s body is unthinkable for many parents and the guidance
and expertise of senior, knowledgeable carers is required. Any
decision made at the time of a baby’s death is challenging;
even normal everyday decisions are not easy such as when to
take a shower, have a drink or eat! Therefore, the monumental
decision to allow investigations on their baby can only be made
with the provision of accurate, honest information about every
aspect of post mortem. All examinations of a baby’s body must
be conducted with dignity and respect of both the baby and
the parent’s values. Results must be provided in a timely and
sensitive manner to parents.
Today, the collective community does not know, yet should,
what families learn at the time of their baby’s death. The facts
about stillbirth, including the incidence and what is being
done to reduce it, as well as risk factors and support services
available, are important public health messages. The death of
a baby is a massive life changing event and parents, along with
health professionals, must work together to reduce the stigma
of stillbirth. It is not a scary word. For us, stillbirth describes
two very real, beautiful and beloved little girls who have entirely
shaped our lives and those of many others.
References
1.
Cacciatore, J. and Bushfield, S. (2007) Stillbirth: the mother’s experience and
implications for improving care. J. Soc. Work End Life Palliat. Care 3, 59-79.
2.
Australian Bureau of Statistics – Causes of Death (2005).
3.
AIHW National Perinatal Statistics Report (2005).
4.
Saflund, K. and Wredling, R. (2006) Differences within couples’ experience of
their hospital care and well-being three months after experiencing a stillbirth.
Acta Obstet. Gynecol. Scand. 85, 1193-1199.
5.
Saflund, K. et al. (2004) The role of caregivers after a stillbirth: views and
experiences of parents. Birth 31, 132-137.
6.
Gold, K.J. et al. (2008) How physicians cope with stillbirth or neonatal death:
a national survey of obstetricians. Obstet. Gynecol. 112, 29-34.
7.
UK National Health Service’s Palliative and Supportive Care website (http://
www.library.nhs.uk/palliative/ViewResource.aspx?resID=126800).
Guidelines for Clinicians: Perinatal Mortality Audit Guideline incorporating
Psychological and Social Aspects of Perinatal Bereavement can be found at
http://www.psanzpnmsig.org/guideline.html
Emma Kirkwood’s second child, her first daughter, Olivia, died unexpectedly
in utero and was born on 31 July 2002. At the time, Emma was amazed and
disturbed to discover that little funds were being spent on stillbirth research
and therefore resigned from employment within the pharmaceutical industry
to establish the Stillbirth Foundation in 2005. Today, on an entirely voluntary
basis, Emma runs the Stillbirth Foundation which operates to reduce the
incidence of stillbirth in Australia through funding in addition to encouraging
research into stillbirth and increasing public awareness about stillbirth.
Ros Richardson is the General Manager of SIDS and Kids NSW. Ros is a
bereaved parent and has a background in nursing and public health. Her
service provides support for families who experience the death of their baby
or child during pregnancy, birth and infancy. Ros has particular interest in
access to care and support for bereaved families, and in increasing awareness
and preventative public health campaigns in perinatal and infant death.
185
Under the Microscope
Longer-term outcomes of infections in
pregnancy: pathogenesis of diabetes and
other chronic infections
Maria E Craig
Virology Research, POWH and
UNSW Research Laboratories,
South Eastern Area Laboratory
Services, Prince of Wales Hospital,
Randwick NSW
Kin-Chuen Leung
Virology Research, POWH and
UNSW Research Laboratories,
South Eastern Area Laboratory
Services, Prince of Wales Hospital,
Randwick NSW
School of Women’s and
Children’s Health, University of
New South Wales, NSW
Institute of Endocrinology and
Diabetes, The Children’s Hospital
at Westmead, NSW
Faculty of Medicine, University of
New South Wales, NSW
Discipline of Paediatrics and Child
Health, University of Sydney, NSW
Department of Paediatrics, St George Hospital,
Gray St Kogarah NSW 2217
Tel 02 9113 3637 Fax 02 9113 3810 Email [email protected]
Rubella and cytomegalovirus (CMV) are recognised
causes of congenital diabetes. The role of in utero
infection with other viruses, such as enteroviruses
(EV), in the development of childhood diabetes is
less clear. Epidemiological studies have demonstrated
an association between maternal EV infection and
subsequent development of type 1 diabetes in their
offspring, suggesting that the disease process begins in
utero.
Congenital infection with viruses such as Rubella and CMV may
result in severe long-term sequelae, including developmental
delay, hearing loss, cerebral palsy, epilepsy and diabetes 1. CMV
is the most common cause of viral-induced congenital
malformation – primary CMV infections occur in up to 2% of
pregnant women, with 30-40% of mothers vertically transmitting
the virus to the fetus. The virus may be transmitted in utero during
primary maternal infection, or by reactivation or reinfection of
seropositive mothers. While most (85-90%) of congenital CMV
cases are asymptomatic at birth, 10-15% will develop symptoms
in later life, the most common being sensorineural hearing loss.
Infection with rubella virus during the first 12 weeks of pregnancy
results in congenital infection and/or miscarriage in 80-90%
of cases. The congenital rubella syndrome involves multiple
organ systems, with a long period of active infection and virus
shedding in the postnatal period. The syndrome includes a range
of malformations, including sensorineural deafness, cataracts,
cardiac anomalies and mental retardation, with late complications
including diabetes, thyroid disease, growth hormone deficiency,
and progressive panencephalitis.
Congenital forms of virus induced diabetes result from direct
infection of the pancreatic ß-cells which may be chronic. Certain
viruses are known to be pancreotropic, including mumps 2,
rubella 3 and picornaviruses 4. In the case of congenital rubella
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MICROBIOLOG Y A U STRA LIA • N OV EM BER 2008
Under the Microscope
syndrome, overt disease can develop after more than 20 years
following in utero infection 3. Congenital CMV infection is also
thought to result in late development of diabetes 5. In these
relatively uncommon cases, the process is probably due to
gradual ß-cell destruction rather than an autoimmune process.
However, an association was found between CMV infection
and islet cell antibodies in patients with newly diagnosed
diabetes 6, suggesting that persistent CMV infection (but not
necessarily congenital) can lead to autoimmune diabetes.
The majority of children who develop diabetes have type 1 (insulin
dependent) diabetes, a condition that affects approximately 1 in
700 children aged <15 years. This is an autoimmune disease
caused by destruction of the insulin producing ß-cells in the
pancreas, which is probably mediated by autoreactive T-cells. The
risk of developing type 1 diabetes is to some extent genetically
determined, but environmental factors also appear to be involved
in the autoimmune process. Indeed, the rapid increase in the
incidence of type 1 diabetes during recent years, particularly in
Australia 7, 8, is highly supportive of a major role for environmental
factors in the disease process.
EVs, in particular Coxsackie virus B4 (CVB4), are the most widely
studied and likely environmental triggers of ß-cell autoimmunity
and type 1 diabetes. Higher rates of enterovirus infection have
been demonstrated in children at onset of type 1 diabetes, in
particular amongst those who do not have diabetes associated risk
genes 9. An increased number of enterovirus infections have been
found in pre-diabetic children in several prospective studies using
serological tests and enterovirus RNA detection 10. Enterovirus
infections during pregnancy have also been associated with an
increased risk of developing type 1 diabetes in the offspring 11,
suggesting that the autoimmune process may begin in utero.
Whilst most studies imply a causal association of enterovirus
infection and type 1 diabetes, there are also several studies
demonstrating direct infection of ß-cells in humans with type 1
diabetes 4, 12.
2.
Helmke, K. et al. (1986) Islet cell antibodies and the development of diabetes
mellitus in relation to mumps infection and mumps vaccination. Diabetologia
29, 30-33.
3. Forrest, J.M. et al. (1971) High frequency of diabetes mellitus in young adults
with congenital rubella. Lancet 2, 332-334.
4. Yoon, J.W. et al. (1979) Isolation of a virus from the pancreas of a child with
diabetic ketoacidosis. NEJM 300, 1173-1179.
5. Ward, K.P. et al. (1979) Congenital cytomegalovirus infection and diabetes.
Lancet 1, 497.
6. Pak, C.Y. et al. (1988) Association of cytomegalovirus infection with
autoimmune type 1 diabetes. Lancet 2, 1-4.
7. Taplin, C.E. et al. (2005) The rising incidence of childhood type 1 diabetes in
New South Wales, 1990-2002. Med. J. Aust. 183, 243-246.
8. Chong, J.W. et al. (2007) Marked increase in type 1 diabetes mellitus incidence
in children aged 0-14 yr in Victoria, Australia, from 1999 to 2002. Pediatr.
Diabetes 8, 67-73.
9. Craig, M.E. et al. (2003) Reduced frequency of HLA DRB1*03-DQB1*02 in
children with type 1 diabetes associated with enterovirus RNA. J. Infect. Dis.
187, 1562-1570.
10. Lonnrot, M. et al. (2000) Enterovirus RNA in serum is a risk factor for beta-cell
autoimmunity and clinical type 1 diabetes: a prospective study. J. Med. Virol.
61, 214-220.
11. Dahlquist, G.G. et al. (1995) Maternal enteroviral infection during pregnancy
as a risk factor for childhood IDDM. A population-based case-control study.
Diabetes 44, 408-413.
12. Dotta, F. et al. (2007) Coxsackie B4 virus infection of beta cells and natural
killer cell insulitis in recent-onset type 1 diabetic patients. Proc. Natl. Acad. Sci.
USA 104, 5115-5120.
Dr Maria Craig is a senior lecturer in the School of Women’s and Children’s
Health, University of New South Wales and conjoint senior lecturer, Discipline
of Paediatrics and Child Health, University of Sydney. Her research interests
include epidemiology of childhood diabetes and the role of enterovirus
infections in diabetes pathogenesis.
Dr Kin-Chuen Leung is a senior hospital scientist in the Virology Research
Laboratory, POWH and conjunct senior lecturer in the Faculty of Medicine,
University of New South Wales. His research interests include pathogenesis of
autoimmune diabetes and cellular models of enterovirus infection.
Several mechanisms for the induction of ß-cell destruction by
viruses have been suggested. Viruses may also cause a direct
cytolysis of infected ß-cells or induce bystander activation of
autoreactive T-cells due to the inflammatory mediators released
in infected islets, or alternatively the process may be due to
molecular mimicry, whereby viral antigens cross react with ß-cell
antigens and induce autoreactivity.
Whilst there is currently limited evidence that enterovirus
infection in utero is an important cause of childhood onset
diabetes, prospective studies of infants at genetic risk of type
1 diabetes, such as the international studies TRIGR, DAISY and
TEDDY, and the VIGR study in NSW, may help to address the role
of virus infections early in life.
References
1.
Munro, S.C. et al. (2005) Symptomatic infant characteristics of congenital
cytomegalovirus disease in Australia. J. Paediatr. Child Health 41, 449-452.
M I CROB I O L O G Y A U S T RALIA • NOVE MB E R 2 0 0 8 187
Under the Microscope
Toxoplasmosis in pregnancy:
often suspected, rarely convicted
Clinical manifestations and presentation
Toxoplasmosis is usually asymptomatic or causes non-specific,
self-limiting illness with malaise, mild fever and lymphadenopathy
Lyn Gilbert
(commonly cervical). Severe, multi-system disease can occur in
Centre for Infectious Diseases and
Microbiology
Institute of Clinical Pathology and
Medical Research
Westmead Hospital
Westmead NSW 2145
Tel 61 2 9845 6252
Fax 61 2 9893 8659
Email [email protected]
severely immunodeficient individuals. If toxoplasmosis occurs
during pregnancy, the immunologically immature fetus is at risk.
Maternal toxoplasmosis is often suspected because of symptoms
or a positive toxoplasma IgM which often persists for months or
years after acute infection.
At least 80% of intrauterine infections are asymptomatic and
often unrecognised. Gross clinical features of fetal/congenital
toxoplasmosis – hepatosplenomegaly, hydrocephalus liver and/
Toxoplasmosis during pregnancy is uncommon and
usually asymptomatic but can cause catastrophic fetal
disease. It is often suspected because of non-specific
symptoms or positive serological tests. However,
false-positive toxoplasma IgM tests are common and
confirmatory tests not always reliable. The risk of fetal
infection increases as pregnancy progresses; it should be
diagnosed or excluded by amniotic fluid PCR, especially
early in pregnancy when the risk of severe damage is high.
Prompt antibiotic therapy of maternal infection probably
reduces fetal infection and disease, but its efficacy has
not been confirmed by randomised controlled trials.
or brain calcification (Figure 2) – are rare. The most common
sign – Toxoplasma chorioretinitis (Figure 3) – is often missed
Figure 1. Life cycle of T. gondii.
The culprit – Toxoplasma gondii
Sexual reproduction of T. gondii (Figure 1) occurs in the intestines
of felines. Infected cats excrete oocysts in faeces which are
infective, after several days, if ingested by warm-blooded animals
including food-producing livestock and humans. Toxoplasmas
spread throughout the body until halted by the host immune
response. A few organisms remain dormant but viable, in tissue
cysts in muscle, eyes or brain, where they can reactivate if local
or systemic immunity is compromised.
Epidemiology and risk factors
Faecal oocysts mature rapidly in warm, moist conditions; the
geographic prevalence of toxoplasmosis is, roughly, inversely
proportional to distance from the equator. Humans are infected
by eating undercooked meat or by coming into contact with
soil contaminated by cat faeces (e.g. on hands or unwashed
vegetables) 1. A case control study showed that consumption of
undercooked or cured meat products (30-63% of cases), contact
with soil (6-17%) and travel outside Europe and North America
were the most common risk factors; contact with cats was not 2.
188
MICROBIOLOG Y A U STRA LIA • N OV EM BER 2008
Under the Microscope
at birth but can progress and first present as sight-threatening
reactivation during childhood or early adult life. Progressive
encephalitis can cause developmental and intellectual delay.
Vertical transmission
The risk of fetal infection increases from <15% when maternal
infection occurs in the first trimester, to 44% in the second and
72% in the third trimester of pregnancy 3, 4. Fetal infection in
the first trimester causes symptomatic disease in about 75% of
cases, compared with about 15% in the second and none in the
third 5, 6.
Antenatal screening and diagnosis
Routine prenatal screening has been practised routinely in some
European countries for many years, but is not recommended
in Australia – maternal infection is uncommon and fetal disease
rare, the sensitivity and specificity of screening tests are poor and
the efficacy of treatment is doubtful.
Toxoplasma IgG can be measured by a variety of methods (some
of which are historical). Enzyme-linked immunoassays (EIA) are
now most commonly used. Seroconversion is the best serological
Figure 2. Severe fetal toxoplasmosis. Routine fetal ultrasound
examination at about 16 weeks’ gestation showed gross
hydrocephalus and ascites and pregnancy was terminated.
Toxoplasmosis was confirmed by histological examination of
fetal tissues.
evidence of recent infection, whereas toxoplasma IgM EIA has
poor specificity 7. If IgG and IgM are positive and unchanged
when repeated with different kits or on another specimen,
further tests are needed to improve specificity, for example:
• A quantitative antibody test – e.g. differential agglutination
may show a rising titre in paired sera, as toxoplasma IgG titre
continues to rise for about 3 months after acute infection.
• A double sandwich IgM EIA and IgM immunosorbent
agglutination assay (ISAGA) are more specific than commercial
IgM EIAs – levels rise and fall rapidly after infection, albeit at
variable rates.
• IgG avidity is now the standard ‘confirmatory’ test.
Following acute infection, the affinity of IgG for specific antigen
increases progressively, making disruption of serum antigen/
antibody complexes, e.g. by treatment with 8M urea, increasingly
difficult. The avidity index is the ratio of IgG levels (measured by
EIA optical density values) in aliquots of treated and untreated
serum, tested in parallel. In general, high avidity indicates past
and low avidity recent infection.
IgG avidity tests are not standardised. A recent review of 11
published studies, involving six in-house and eight commercial
IgG avidity tests, showed considerable variation in definitions
of low avidity index (from <15% to <50%) and high avidity
index (from >20% to >58%) and the maturation period, which
defines recent infection (from 3-6 months). Generally, delayed
IgG maturation was found in fewer than 5% of subjects but
two methods showed poor sensitivity. Occasionally, low avidity
persisted for years. In one study, the same method demonstrated
Figure 3. T. chorioretinitis.
M I CROB I O L O G Y A U S T RALIA • NOVE MB E R 2 0 0 8 189
Under the Microscope
diagnosis or exclusion of recent toxoplasmosis.
amniocentesis and treatment, on the accuracy of PCR for
diagnosis of congenital toxoplasmosis. The positive predictive
values (PPVs) increased, from 0.75 to 0.94 and the NPVs fell, from
0.98 to 0.56 between the first and third trimesters. There was
considerable variation in specificity centres 10.
If recent toxoplasmosis is likely or cannot be excluded during
Treatment
delayed maturation in 9.5% of pregnant women compared with
0.9% of non-pregnant subjects. High avidity indices within the
maturation period were reported with five methods 8. Despite
these limitations, properly validated IgG avidity tests can assist in
pregnancy, intrauterine diagnosis is recommended, especially
in the first half of pregnancy, because of the high risk of fetal
damage. Amniotic fluid PCR, at 18 weeks’ gestation or later,
is highly specific and much more sensitive (97%) than mouse
inoculation (64%), fetal blood IgM or non-specific inflammatory
markers (30-40%) 9.
A study in nine European centres examined the effects of
gestational age at maternal seroconversion, timing of
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T. gondii is susceptible to several types of antimicrobial. Workers
in some European countries, where routine antenatal screening
has been compulsory for years, recommend treatment with
spiramycin (a macrolide, which can be used safely in early
pregnancy), as soon as possible after the diagnosis. Termination
is often recommended for fetal infection in the first trimester
because of the high risk of severe disease. Later in pregnancy,
spiramycin may be continued or replaced by combined
sulphadiazine and pyrimethamine (with folinic acid, to reduce
side-effects) 7.
There have been no randomised controlled trials of treatment.
Despite extensive experience and circumstantial evidence of
efficacy 5, 6, a recent systematic review of published cohort
studies 4 and a large case review 11, only weak evidence that
treatment reduced placental transmission was found and none
that it reduced clinical manifestations; there were, however,
significant biases in selection of treated cases and controls. It is
therefore likely that benefits are greatest in or limited to cases
in which treatment is started within 3-4 weeks of maternal
infection 4, 11.
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References
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Montoya, J. G. and Leisenfeld, O. (2004) Toxoplasmosis. Lancet, 363, 19651976.
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Cook, A.J. et al. (2000) Sources of toxoplasma infection in pregnant women:
European multicentre case-control study. European Research Network on
Congenital Toxoplasmosis. BMJ 321, 142-127.
3.
Dunn, D. et al (1999) Mother-to-child transmission of toxoplasmosis: risk
estimates for clinical counseling. Lancet 353, 1829-1833.
4.
Submitting an article
The SYROCOT (Systematic Review on Congenital Toxoplasmosis) study group.
(2007) Effectiveness of prenatal treatment for congenital toxoplasmosis: a
meta-analysis of individual patients’ data. Lancet 369, 115-122.
5.
• Step 1 – Type the title, type of paper and abstract. Select
publication – Microbiology Australia.
Hohlfeld, P. et al. (1989) Fetal toxoplasmosis: outcome of pregnancy and infant
follow-up after in utero treatment. J. Pediatr. 115, 765-769.
6.
Couvreur, J. et al. (1993). In utero treatment of toxoplasmic fetopathy with the
combination pyrimethamine-sulfadiazine. Fetal Diagn. Ther. 8, 45-50.
7.
Petersen E. (2007). Toxoplasmosis. Semin. Fetal Neonat. Med. 12, 214-223.
8.
Lefevre-Pettazzoni, M. (2006) Delayed maturation of immunoglobulin G
avidity: implication for the diagnosis of toxoplasmosis in pregnant women. Eur.
J. Clin. Microbiol. Infect. Dis. 25, 687-693.
9.
Hohlfeld, P. et al. (1994) Prenatal diagnosis of congenital toxoplasmosis with
a polymerase-chain-reaction test on amniotic fluid. N. Engl. J. Med. 331, 695699.
• Confirm your details.
• Step 2 – Confirm author. Add co-author details (all
fields) if applicable.
• Step 3 – Upload files. Only Word documents are
accepted. Please ensure your document contains the
required information and is formatted according to the
author guidelines.
• Step 4 – Add any comments for the editor.
• Step 5 – Review your information then click submit.
Once submitted, the manuscript is reviewed by the editor
and, if acceptable, sent for peer review.
Peer review
Peer reviewers will be asked to review the manuscripts
through the electronic process.
190
10. Thalib, L. et al (2005) Prediction of congenital toxoplasmosis by polymerase
chain reaction analysis of amniotic fluid. BJOG 112, 567-574.
11. Gilbert, R. et al (2001) Effect of prenatal treatment on mother to child
transmission of Toxoplasma gondii: retrospective cohort study of 554 motherchild pairs in Lyon, France. Int. J. Epidemiol. 30, 1303-1308.
Professor Lyn Gilbert is an infectious disease physician and clinical
microbiologist, director of the Centre for Infectious Diseases and
Microbiology, ICPMR, Westmead, NSW and clinical professor in medicine at
the University of Sydney. She has longstanding clinical and research interests
in infections in pregnancy and the newborn, in vaccine preventable diseases
and in bacterial infections of public health importance.
MICROBIOLOG Y A U STRA LIA • N OV EM BER 2008
TriState 2008 Alice Springs
12 – 13 September 2008
Post-Event Report
www.tristate2008.org
The ASM TriState meeting was initiated by members of the SA, WA and NT branches several years ago to
provide for a regional meeting specifically to focus on local issues and themes; to be held every three years
in the Northern Territory. Once again supported by the ASM, this year’s TriState meeting was held in Alice
Springs from 12 – 13 September at the Crowne Plaza Hotel.
Professor Henri Verbrugh, University Medical
Centre – The Netherlands at TriState 2008.
It has always been the intention of TriState for the meeting to be held in a relaxed and informal atmosphere
conducive to discussion of local issues and to provide an environment for networking – this year was no
exception with the program providing several such opportunities.
With an all inclusive registration fee making things easier for delegates, the meeting kicked-off on Friday with a networking luncheon
providing everyone with their first opportunity to catch up with old acquaintances and a chance to make new ones. The afternoon sessions
then focussed on the big (parasitology) and small (virology) ends of microbiology. Dr Andrew Butcher gave an excellent update on the
diagnosis of Entamoeba histolytica which was followed by a number of quite stunning case presentations by Dr Harsha Sheorey. Dr David
Smith spoke with his usual expertise on the topics of Arboviruses of the Top End and issues related to the application & point of care testing
in virological diagnoses, and Dr Geoff Higgins presented a first class review of viral gastroenteritis.
The afternoon sessions were capped with a Welcome Mixer of fine NT tastes which then extended into the evening for some enjoying a warm
night by the pool!
Saturday morning commenced with a selection of some of the best talks from the International Symposium on Staphylococcal Infections
(ISSI) which was held in Cairns just a few days prior. Overseas special guest speaker, Professor Henri Verbrugh, spoke on aspects of Staph.
aureus infection, Geoff Coombs on the molecular diagnosis of MRSA and Dr Graeme Nimmo on community MRSA. Later that morning, Dr
Michael Watson and Associate Professor Amanda Leach presented pneumococcal surveillance data and non-vaccine serotype replacement
problems respectively, with the session rounded out by Dr Duncan McLellan speaking on clinical aspects and genotyping of group A
streptococci.
After lunch, Professor Tom Riley presented an excellent overview on the epidemiology of Clostridium difficile and Paul Southwell spoke of his
experience with the establishment of the new PC3 facility at Royal Darwin. Sincere thanks is extended to both Tom and Paul for assisting
with some last minute program changes.
The final session was an update on sexually transmitted infections with Professor Sue Garland presenting very recent data on the WHINURS
project in which Alice Springs played a key role. Dr David Whiley gave an excellent review on the molecular diagnosis of STIs with the
meeting completed by Professor Verbrugh discussing pregnancy outcomes in women infected with Chlamydia trachomatis.
In my closing remarks I commented on the quality and diversity of the speakers and the first-class talks they had just presented. I reiterate
my comments and sincere thanks to the speakers for their time and invaluable
contribution and also to our corporate sponsors BD, Roche and bioMerieux for their
continued support.
Saturday night’s “Conference Dinner” was a relaxed outdoor Territorian Feast held on
the lawns poolside featuring a special guest presentation by well-known local
astronomer with the aid of his telescope.
Fantastic contributions by the speakers, excellent delegate networking and generosity
of the sponsors combined with the pleasant and relaxed atmosphere made for an
excellent meeting that I think was enjoyed by all. We now look forward to the next
TriState meeting in three years with some discussion as to alternating between Alice
Springs and Darwin. I encourage you to attend as this truly is a unique and rewarding
networking & learning experience!
Rod Bowman
Chair, TriState 2008 Organising Committee
ASM 2009 Perth
6 – 10 July 2009
&
Perth Convention Centre WA
www.asm2009.org
Invitation
You are invited to attend the Perth 2009 Annual Scientific Meeting &
Exhibition to help ASM celebrate its 50th Golden Jubilee Year!
The conference will provide many opportunities for you to stay
up to date with the latest technology, industry practices and global
issues. NSAC and the Scientific Program Committee have been
working hard to produce a program that is relevant to all Divisions
across the Society and also thought provoking.
A S M ’ s 5 0 t h G o l d e n J u b i l e e Ye a r !
over the coming months – stay tuned for the Early Bird Registration
Society for Microbiology will co-sponsor a special guest speaker for
and abstract submission announcements so that you don’t miss
the meeting, Professor Rita Colwell, a world-renowned authority
these important deadlines.
on microbiology and climate change and past President of the
American Society for Microbiology.
We look forward to seeing you in Perth next year!
Professor Bonnie Bassler – Rubbo Orator
Rod Bowman | Chair, ASM 2009 Perth Local Organising
Professor of Molecular Biology, Princeton University, Princeton,
Committee
New Jersey USA
Scientific Program
The Rubbo Oration is the key plenary session of the ASM Scientific
Meeting honouring the contribution of Dr Sydney Rubbo to the
society and microbiology more generally. The evening plenary
is followed by supper and is supported by the University of
Melbourne, Rubbo Trust.
July 2009 will see Perth host a world class gathering of eminent
microbiologists to discuss various issues of current relevance
to the microbiological community. The range of topics to be
discussed and the high quality of the invited speakers ensures that
the meeting will likely attract many senior hospital and laboratory
scientists and medical staff as well as researchers and teachers from
all aspects of the microbiology community. We anticipate 800+
delegates to attend the conference and the exhibition will provide
a perfect opportunity to see the latest industry and technical
advancements.
The Social Program Committee are also working hard to bring you
enjoyable and relaxing functions to stimulate and continue your
networking. Especially exciting elements to the Social Program are
being planned to celebrate ASM’s achievement of 50 years and we
would love for you to come and celebrate with us!
The theme of “Reflection and Direction” acknowledging both
the Society’s 50th birthday, and future directions in the field of
microbiology. The American Society of Microbiology has agreed to
co-sponsor a special guest speaker as it formally acknowledges and
celebrates our 50th anniversary with us.
The new Perth Convention Centre is a purpose-built world class
facility nestled between the beautiful Swan River, the city centre
and King’s Park. The centre and its immediate surrounds offer
some excellent locations and environments for trade focussed
opportunities.
Perth’s location puts it us easy reach of our Pacific Rim colleagues
and we will be encouraging their attendance ensuring an even
wider networking platform.
Once again, discounted accommodation rates have been negotiated
with a variety of hotels and apartments within walking distance to
the convention centre.
Visit the website for full conference information as this is developed
Introduction
The conference will bring you some of the respected Microbiologists
in the world as keynote speakers. ASM 2009 Perth will feature
presenters from a range of sub-disciplines in microbiology that
will provide a unique opportunity to experience several plenary
sessions of world class standard.
Keynote Speakers
Professor Rita Colwell, USA
Chairman, Canon US Life Sciences, Distinguished Professor,
University of Maryland, College Park
Distinguished Professor, Johns Hopkins University, Bloomberg
School of Public Health
To acknowledge and celebrate ASM’s Golden Jubilee, the American
The Perth 2009 Rubbo Oration will be delivered by Dr Bonnie
Bassler, Professor of Molecular Biology at Princeton University.
Professor Bassler is a world authority on mechanisms of quorum
sensing in bacteria (how bacteria “talk” to each other) and was
awarded a MacArthur Fellowship in 2002 and elected to the
National Academy of Sciences in 2006 in recognition of her work.
Further, the delivery of her presentations is made in such a way
that captures the complete imagination and involvement of her
audience. This will be a function not to be missed.
Dr Rino Rappuoli – Bazeley Orator (sponsored by CSL)
Vice President & Chief Scientific Officer, Vaccines Research, Chiron
Vaccines, Sienna, Italy
Dr Rappuoli is credited with co-founding the field of “cellular
microbiology”, a discipline which combines cell biology and
microbiology and has pioneered the genomic approach to vaccine
development called “reverse vaccinology”. Dr Rappuoli has been
involved in pandemic influenza preparedness activities for many
years, including the production and clinical testing of potential
pandemic vaccines.
Dr Thomas Ksiazek – Snowdon Lecturer (sponsored by
AAHL, CSIRO)
Chief, Special Pathogens Branch, Division of Viral and Rickettsial
Diseases, National Centre for Infectious Disease, Centers for
Disease Control, Atlanta, Georgia
Dr Ksiazek has worked as a veterinary microbiologist at stations
around the world for the US Navy, US Air Force and then the
US Army at the Defense Assessment Division at Fort Detrick,
Maryland. His military career saw numerous academic awards and
Army, Navy and Air Force Commendation Medals. He took up his
current position as Chief Special Pathogens Branch, Centers for
Disease Control, Atlanta Georgia in 1991 after 20 years of active
Plenary Presentation: Climate, oceans, infectious disease and
human health - A new perspective
Symposia Topics:
Metagenomics and environment
Validating probiotic functionality in clinical and animal trials
Out of left field: the microbiology of the Australian rhizosphere
Current topics in food microbiology
Biological threat assessment
Microbial Informatics
Prevention of biofilms on medical devices
Culture media
Water microbiology
Vibrio
Division 4 – Microbial Genetics, Physiology & Pathogenesis
David Stephens - Professor of Microbiology and Immunology,
Emory University School of Medicine
Plenary Presentation: Vaccine design focussing on selected innate
immunity pathways and adjuvants
duty service. Dr Ksiazek has authored and co-authored over 200
publications in his career.
Associate Professor Elizabeth Harry – ASM 2009 Fenner
Lecturer
University of Technology Sydney
Associate Professor Harry has been awarded the prestigious ASM
Frank Fenner Award for 2009 and has a long standing interest in the
subject of bacterial cell division.
Opening Ceremony
Professors Barry Marshall and John Mackenzie will present joint
plenary sessions for the Opening Ceremony.
Professor Barry Marshall
Nobel Laureate (Physiology and Medicine, 2005)
Professor of Clinical Microbiology, University of Western Australia
Co-Director, Marshall Centre for Infectious Disease Research and
Training
Professor Barry Marshall is an Australian physician and is known
world-wide for his role in the demonstration of Heliocobacter
pylori being the primary cause of stomach ulcers. He has received
numerous other prestigious awards for his ground -breaking
research and was awarded a Companion of the Order of Australia
in 2007.
Division 2 - Virology
Susan Gottesman - Chief of Biochemical Genetics, Laboratory of
Molecular Biology, National Cancer Institute, National Institutes
of Health
Ian Lipkin - Professor of Epidemiology, Columbia University
Mailman School of Public Health
Plenary Presentation: Small RNAs and the Bacterial Stress
Response
Plenary Presentation: Pathogen Discovery
Symposia Topics:
Mechanisms of gene regulation in bacteria
Innate immune response to microbial products
How microbial genomics informs novel approaches to vaccine
design
Parasite/Host interactions
Nuts and bolts: how protein structure relates to function in the
microbial world
Bacterial/Host interactions
Microbial evolution
Paradigms in microbial pathogenesis
Building a home- the cell wall
Moving home- biofilms and motility
Mycobacteria
Diane Griffin - Professor and Chair in Molecular Microbiology and
Immunology, Johns Hopkins Bloomberg School of Public Health
Plenary Presentation: Alphavirus
Determinants of outcome
encephalomyelitis
-
Symposia Topics:
Gastroenteritis
Parvoviruses
Emerging threats
Virus-Host Interactions
Viral encephalitis
Enteroviruses
Animal viruses
Respiratory viruses
Molecular epidemiology / surveillance
HIV
To Be Announced
The following dates and details will be announced over the coming
weeks:
Division 3 – General, Applied & Environmental
Microbiology
•
R egistration – Early Bird rates & deadline, discounted ASM
member and student rates
Professor John Mackenzie
Honorary Professor, University of Queensland
Curtis Suttle - Professor of Earth & Ocean Sciences, University of
British Columbia
•
A bstract Submission – deadline date, submission categories
and how to submit
Professor Mackenzie is a past President of the ASM and has held
many other positions in international microbiology societies.
Recently “retired”, Prof Mackenzie maintains a keen involvement in
many projects and is a world authority on arboviral infections.
Plenary Presentation: The virosphere - The largest reservoir of
unexplored diversity on the planet
•
Social Program – function details & ticket costs
•
Local Perth Accommodation – room descriptions & rate, how
to book
Invited International Speakers
International speakers invited by the four Divisions of NSAC are
listed below followed by the proposed range of symposia to be
presented by each division.
Division 1 – Medical & Veterinary Microbiology
Ellen-Jo Baron - Professor of Pathology, Stanford University School
of Medicine
Plenary Presentation: Diagnostic Microbiology - The Future is
NOW
Lance Peterson - Professor and Director, Clinical Microbiology
and Infectious Diseases Research Division, Evanston Northwestern
Healthcare
Plenary Presentation: The emerging role of the diagnostic
laboratory in infection control
Symposia Topics:
Anaerobes
Clostridium difficile
Meningococcal disease
Laboratory diagnosis of respiratory tract infections
MRSA
Pneumococcal disease
Mycology
Laboratory diagnosis of genital tract infections
Tropical medicine
Robert Hancock - Professor of Microbiology and Immunology,
University of British Columbia
Plenary Presentation: Antibiotic resistance and how to overcome it
Details will published to the conference website –
www.asm2009.org
Rita Colwell - Professor of Microbiology and Biotechnology,
University of Maryland
Conference Organisers – Australian Society for
Microbiology
Under the Microscope
Diagnosis and treatment of herpes simplex
virus (HSV) infection in the newborn
Cheryl A Jones
Discipline of Paediatrics and Child
Health, University of Sydney, NSW
Centre for Perinatal Infection
Research, The Children’s Hospital
at Westmead, Westmead NSW 2145
Tel (02) 9845 3382
Fax (02) 9845 3389
Email [email protected]
Neonatal herpes simplex virus (HSV) disease is a rare but
sometimes highly lethal infection. The reported incidence
in Australia is approximately four cases per 100,000
live births 1. HSV type 2 (HSV-2) is the predominant
serotype that causes infection in the newborn in the
United States 2, whereas in Australia 1 neonatal infection
is usually caused by HSV type 1 (HSV-1), most likely
due to greater prevalence of oral and genital HSV-1
disease in this country 3. Diagnosis of neonatal infection
requires a high index of clinical suspicion as signs are
non-specific, and is usually confirmed by isolation of
HSV from skin vesicle or detection of HSV DNA in the
cerebrospinal fluid, blood or surface swab. Treatment
requires intravenous aciclovir for 14-21 days depending
on the form of disease.
Presentation and route of infection
a term infant typically on Day 3-5 of life. SEM disease carries a
very low to no risk of mortality, but carries a high risk of spread
to the central nervous system if untreated with antiviral therapy
and a risk of neurological impairment in late infancy. Neonatal
HSV encephalitis has a high mortality rate which is significantly
reduced by prompt initiation of systemic antiviral therapy, but
survivors have a high risk of neurological sequelae. Multi-organ
HSV disease in the newborn is also often lethal, even with
antiviral therapy 4.
The strongest risk for vertical transmission of HSV is primary
genital infection during late pregnancy 5, 6. Some studies suggest
that genital HSV-1 disease is more readily transmissible to the
neonate than HSV-2, but this requires confirmation 6. If virus is in
the genital tract at delivery, invasive obstetric procedures such as
instrument deliveries and fetal scalp electrodes increase the risk
of transmission to the newborn 6.
The diagnosis of neonatal herpes
Clinical features
The presenting features of neonatal HSV infection are nonspecific, which may result in missed or delayed diagnosis. Typical
skin vesicles may be absent in up to 30% of infected infants,
particularly in those with encephalitis or multi-organ disease.
Fever is only present in just under half of the infected infants.
Systemic disease may manifest as lethargy, seizures, jaundice or
respiratory distress.
Laboratory diagnosis
Viral culture, PCR and direct immunofluorescence
The majority (85%) of infants become infected with HSV at the
time of delivery by passage through an infected birth canal. A
further 10% acquire the infection from contact with infectious
lesions, usually on the hands or lips of a caregiver after delivery.
The remaining 5% of HSV infected infants have a congenital
infection, i.e. become infected in utero by transplacental spread
of virus.
Specimens that should be collected from an infant with suspected
neonatal HSV disease include cerebrospinal fluid (CSF), surface
swabs from skin vesicles, conjunctiva, nasopharynx and rectum,
and blood for full blood count, liver function tests, and coagulation
studies (if systemic disease is suspected). Central nervous system
imaging (computer tomographic scan or magnetic resonance
imaging) and chest radiographs may also be indicated.
Congenital HSV infection presents with distinct manifestations
at birth – usually eye abnormalities, skin scarring, microcephaly
and sometimes central nervous system calcification on imaging.
Perinatal HSV infection, acquired at the time of delivery or in
the postnatal period, may present in three ways. Disease may be
confined to the skin, eye, or mouth (SEM disease), to the central
nervous system alone, or the infection can present with multiorgan ‘septic shock’ with or without encephalitis.
Surface swabs may be analysed by viral culture and/or polymerase
chain reaction (PCR) for HSV DNA. HSV induces a typical
cytopathic effect in 2-4 days on cell monolayers which can be
subsequently serotyped. Rapid confirmation of HSV infection
can be obtained by direct immunofluorescence of surface swabs
that have been plated on to a glass slide. The sensitivity of this
technique is only 40-50%, so a negative result does not exclude
the diagnosis 2.
Neonatal HSV pneumonitis is a highly lethal variant of
disseminated infection which presents as respiratory distress in
CSF from neonates should be analysed for cell count and
biochemistry, and should always be set up for viral culture in
194
MICROBIOLOG Y A U STRA LIA • N OV EM BER 2008
Under the Microscope
addition to PCR; positive CSF cultures have been reported in up
to 20% of infants with neonatal HSV disease in contrast to the low
yield obtained from adults with HSV encephalitis 7. The sensitivity
of HSV PCR in the CSF is reportedly lower for neonatal herpes
(71–100%) than for adults with HSV encephalitis (>95%) 8. The
rate of detection of HSV DNA in the CSF decreases in most cases
after infants have been on antiviral therapy for over a week 9. A
repeat CSF specimen should be performed at the end of therapy
to confirm the absence of HSV DNA, which can be associated
with early relapse and late neurological sequelae. Some groups
have used quantitative HSV PCR on CSF samples to provide
prognostic information in adults with HSV encephalitis, with
an HSV viral load >100 copies/ml being associated with poor
neurological outcome 10. This is not in routine clinical use, and
similar studies have yet to be conducted in neonates.
PCR assays for HSV DNA have also been performed on blood from
infants with neonatal HSV infection. HSV DNA was detected in
PBMC or plasma from 60-70% of infected infants in one study 11.
Serology
Type specific IgM or IgG serology for HSV has a limited role in
the acute diagnosis of HSV infection in the neonate. Only 40% of
infants develop HSV-type specific IgM responses in neonates and
their response is usually too slow to guide therapy 2. Serology
may play a role in counselling parents postnatally as to the origin
of neonatal HSV disease as most women who deliver an infant
with neonatal HSV disease are unaware of their own genital HSV
disease until the infant is diagnosed 6. Serology may also assist in
the diagnosis of nosocomial infections.
Routine antenatal type specific serology is controversial and
probably not indicated in countries with low HSV-2 seroprevalence
like Australia 12-15. However, it may play a role in isolated cases for
counselling serodiscordant couples about risks of vertical HSV
transmission in future pregnancies.
The treatment of the neonatal HSV disease
Current recommendations for antiviral therapy for neonatal
HSV disease are listed in Table 1. Clinical trials have confirmed
that vidarabine and aciclovir are equally efficacious in reducing
mortality from neonatal HSV disease 16; however, intravenous
aciclovir has become the standard therapy because it has less
toxicity and is easier to administer. The duration of therapy
depends on the type of neonatal HSV disease. Infants with SEM
disease should be treated for 14 days, whereas infants with
disseminated infection, encephalitis or where a lumbar puncture
has not been performed, should be treated for 21 days.
Katoomba
Blue Mountains, NSW
7 – 9 May 2009
www.virusesinmay.com
Annual intensive clinical virology update for clinicians, scientists and trainees in this discipline
Australia’s only meeting focused specifically on the clinical, diagnostic and management aspects of viral infections.
Program themes include:
• Principles of clinical virology
• Congenital infection, paediatric infection and vaccination
• Blood borne viruses and hepatitis
Invited speakers include:
•
Associate Professor Cheryl Jones, Children’s Hospital Westmead
•
Emeritus Professor Yvonne Cossart, University of Sydney
•
Professor Richard Strugnell, Microbiology University of Melbourne
•
Professor William Rawlinson, Virology Prince of Wales Hospital
•
Dr Carl Kirkwood, Royal Children’s Hospital Melbourne
•
Philip Cunningham , NSW State Reference Library for HIV/AIDS
•
Professor David Isaacs, Immunology & Infectious Diseases, Children’s
•
Dr Peter Robertson, Microbiology Prince of Wales Hospital
•
Associate Professor Alison Kesson, Children’s Hospital Westmead
•
Dr David Smith, PathWest Laboratory Medicine
•
Dr Nham Tram, Centenary Institute of Cancer
•
Dr Mike Catton, VIRDL
•
Associate Professor Stephen Riordan, Gastrointestinal & Liver Unit
•
Dr Jeffrey Post, Infectious Diseases Physician Prince of Wales Hospital
Prince of Wales Hospital
•
plus other speakers still to be confirmed
•
Hospital Westmead
•
Professor Robert Booy, National Centre for Immunisation Research &
Surveillance
Dr Monica Lahra, University of Sydney
See website for preliminary scientific program & invited speakers. Discount accommodation rates at conference venue available for delegates
Discount registration available to ASM members & full-time students – Early Bird registration opportunity
Convenors: Professor William Rawlinson – Director, Virology Division Microbiology Dept, Prince of Wales Hospital NSW
Dr Monica Lahra – Dept Immunology & Infectious Diseases, University of Sydney
Conference Organisers – Australian Society for Microbiology www.virusesinmay.com
M I CROB I O L O G Y A U S T RALIA • NOVE MB E R 2 0 0 8 195
Under the Microscope
The dose and duration of IV aciclovir for neonatal HSV disease has
been increased over the last decade to 60mg/kg/day, administered
in three equal doses in order to reduce disease progression and
mortality from disseminated infection or encephalitis. These
changes have not been formally studied in randomised controlled
trials due to the low frequency of the condition, but were
reported in an open label study to result in increased survival for
infants with disseminated HSV disease and to reduce long-term
neurological sequelae compared to historical controls 17. Infants
on high dose aciclovir should have their neutrophil counts and
hydration monitored throughout therapy, and dose should be
adjusted for renal function.
Other antiviral agents are not generally used to treat neonatal
HSV disease. Foscarnet has been used in neonates with severe
viral disease, or on the rare occasion where aciclovir resistance
is suspected. Oral aciclovir should not be used for the acute
treatment of neonatal HSV disease due to low bioavailability
and the failure to achieve adequate CNS concentrations that will
inhibit viral replication. There are no current data available about
the use of oral antiviral preparations with better bioavailability for
the treatment of this condition.
Suppressive antiviral therapy to prevent long-term neurological
sequelae from neonatal HSV disease has been trialled 18. However,
this practice is associated with a high rate of drug induced
neutropenia, and isolated reports of late CNS recurrences on
therapy and isolation of aciclovir-resistant mutants, so is not
routinely recommended 18-20.
The use of antiviral therapy in pregnant women or their partners
to prevent vertical transmission of HSV disease is reviewed
elsewhere 21, 22.
Conclusion
Neonatal HSV disease remains an uncommon but important
cause of infant death and childhood neurological morbidity. As
clinical signs at presentation are non-specific, and a history of
maternal genital disease often absent, diagnosis requires a high
index of clinical suspicion and prompt laboratory investigation.
Table 1. Aciclovir therapy for neonatal HSV disease.
References
1.
Jones, C.A. et al. (2008) Neonatal HSV disease in Australia. Report of Australian
Paediatric Surveillance Unit, 2005-2006, p.24.
2.
Whitley, R. (2007) Herpes simplex viruses. In: Fields Virology (5th ed). (Knipe,
D.M., and Howle, P.M., eds). p.2502-2576, Philadelphia (PA): Wolster KluwerLippincott Williams & Wilkins.
3.
Malkin, J.E. (2004) Epidemiology of genital herpes simplex virus infection in
developed countries. Herpes 11, Suppl 1, 2A-23A.
4.
Whitley, R. et al. (1991) Predictors of morbidity and mortality in neonates with
herpes simplex virus infections. The National Institute of Allergy and Infectious
Diseases Collaborative Antiviral Study Group. N. Engl. J. Med. 324, 450-454.
5.
Brown, Z.A. et al. (2003) Effect of serologic status and Cesarean delivery on
transmission rates of herpes simplex virus from mother to infant. JAMA 289,
203-209.
6.
Brown, Z.A. et al. (1991) Neonatal herpes simplex virus infection in relation
to asymptomatic maternal infection at the time of labor. N. Engl. J. Med. 324,
1247-1252.
7.
Tyler, K.L. Herpes simplex virus infections of the central nervous system:
encephalitis and meningitis, including Mollaret’s. Herpes 2004; 11 Suppl 2,
57A-64A.
8.
Kimura, H et al. (1991) Detection of viral DNA in neonatal herpes simplex virus
infections: frequent and prolonged presence in serum and cerebrospinal fluid.
J. Infect. Dis. 164, 289-293.
9.
Kimberlin, D. (2004) Herpes simplex virus, meningitis and encephalitis in
neonates. Herpes 11 Suppl 2, 65A-76A.
10. Domingues, R.B. et al. (1998) Application of competitive PCR to cerebrospinal
fluid samples from patients with herpes simplex encephalitis. J. Clin. Microbiol.
36, 2229-2234.
11. Diamond, C. et al. (1999) Viremia in neonatal herpes simplex virus infections.
Pediatr. Infect. Dis. J. 18, 487-489.
12. Wilkinson, D. et al. (2000) HSV-2 specific serology should not be offered
routinely to antenatal patients. Rev. Med. Virol. 10, 145-153.
13. Brown, Z.A. (2000) HSV-2 specific serology should be offered routinely to
antenatal patients. Rev. Med. Virol. 10, 141-144.
14. Copas, A.J. et al. (2002) An evidence based approach to testing for antibody to
herpes simplex virus type 2. Sex Transm. Infect. 78, 430-434.
15. Lafferty, W.E. (2002) The changing epidemiology of HSV-1 and HSV-2 and
implications for serological testing. Herpes 9, 51-55.
16. Whitley R. et al. (1991) A controlled trial comparing vidarabine with aciclovir
in neonatal herpes simplex virus infection. Infectious Diseases Collaborative
Antiviral Study Group. N. Engl. J. Med. 324, 444-449.
17. Kimberlin, D.W. et al. (2001) Safety and efficacy of high-dose intravenous
aciclovir in the management of neonatal herpes simplex virus infections.
Pediatrics 108, 230-238.
18. Kimberlin, D.W. et al. (1996) Administration of oral aciclovir suppressive
therapy after neonatal herpes simplex virus disease limited to the skin, eyes
and mouth: results of a phase I/II trial. Pediatr. Infect. Dis. J. 15, 247-254.
19. Levin, M.J. et al. (2001) Development of aciclovir-resistant herpes simplex virus
early during the treatment of herpes neonatorum. Pediatr. Infect. Dis. J. 20,
1094-1097.
Type of neonatal HSV disease
Duration of therapy
Skin, eye, mouth
14 days
Central nervous system
21 days*
Disseminated infection
21 days*
21. Hollier, L.M. and Wendel, G.D. (2008) Third trimester antiviral prophylaxis
for preventing maternal genital herpes simplex virus (HSV) recurrences and
neonatal infection. Cochrane Database Syst. Rev. Issue 1. Art. No.: CD004946.
DOI: 10.1002/14651858.CD004946.pub2.
LP not performed at diagnosis
21 days*
22. Jones, C.A. Vertical transmission of genital herpes: prevention and treatment
options. Pediatr. Drug. (in press).
Dose: 60mg/kg/day divided into three equal doses and
given every 8 hours intravenously as 1 hour infusion
* Duration should be extended if HSV DNA PCR remains
positive at the end of therapy.
196
20. Fonseca-Aten, M. et al. (2005) Herpes simplex virus encephalitis during
suppressive therapy with aciclovir in a premature infant. Pediatrics 115, 804849.
Cheryl Jones in a paediatric infectious diseases specialist who runs an
outpatient service dedicated to the diagnosis, management and treatment
of congenital and perinatal infections, and heads the Centre for Perinatal
Infection Research to investigate the epidemiology and pathogenesis of
these infections.
MICROBIOLOG Y A U STRA LIA • N OV EM BER 2008
Under the Microscope
Respiratory infections in the newborn
Michael D Nissen
Theo Sloots
Queensland Paediatric Infectious
Diseases Laboratory
Department of Infectious Diseases
Sir Albert Sakzewski Virus
Research Centre
Royal Children’s Hospital
Brisbane QLD 4029
Tel (07) 3636 8654
Email [email protected]
Queensland Paediatric Infectious
Diseases Laboratory
Department of Infectious Diseases
Sir Albert Sakzewski Virus
Research Centre
Royal Children’s Hospital
Brisbane QLD 4029
Tel (07) 3636 8833
Email [email protected]
It is well recognised that acute respiratory tract infection
(ARTI) occurs commonly in children younger than 5
years of age, with pneumonia being the most serious
complication 1. The greatest risk of death from pneumonia
in childhood is in the neonatal period 2; it is estimated
that pneumonia contributes to between 0.75-1.2 million
neonatal deaths annually, accounting for approximately
10% of global child mortality 3. Of all neonatal deaths due
to pneumonia, 96% occur in the developing world 4.
ARTIs in neonates can be classified as congenital or neonatal in
origin, and are defined by the timeframe in which the infection or
pathogen has been acquired. Congenital pneumonias are usually
part of a transplacental infection, while neonatal pneumonias
can evolve from intrauterine or postnatal acquisition. Neonatal
pneumonia is classified as early or late onset 2. Early onset neonatal
pneumonia, in general, is defined as a clinical presentation in
the first 48 hours up to 1 week of life, while late onset neonatal
pneumonia occurs in the following 3 weeks.
Congenital and neonatal pneumonias are often a difficult disease
to identify and treat. Clinical manifestations are generally nonspecific, sharing respiratory and a range of non-inflammatory
processes. Laboratory findings also have limited value, with
attempts to identify specific microbes often unsuccessful due
to difficulty in their recovery from intrapulmonary sites without
contamination. In addition, many organisms are primarily
uncultivable or uncultivable due to antimicrobial therapy.
Bacterial respiratory pathogens
The pathogens commonly associated with neonatal and
congenital pneumonia include numerous bacteria, fungi and
viruses (Table 1). Bacterial pneumonia derived from infected
amniotic fluid or colonisation of the birth canal is linked with
maternal chorioamnionitis and fetal asphyxia. It is assumed that
asphyxia leads to fetal gasping and aspiration of infected amniotic
fluid. This hypothesis is based on the histological finding of
M I CROB I O L O G Y A U S T RALIA • NOVE MB E R 2 0 0 8 amniotic fluid and/or maternal white blood cells in the affected
neonatal lungs 2. The bacterial aetiology of neonatal pneumonia
is also influenced by nosocomial infection in neonatal intensive
care units. High rates of Streptococcus pneumoniae have been
reported in late onset neonatal pneumonia in some areas of the
world 5.
Atypical bacterial pathogens, for example Chlamydia
trachomatis, are well recognised as agents of late onset
pneumonia causing infection at 1-3 months of age. The ability to
now perform C. trachomatis polymerase chain reaction (PCR)
testing on nasopharyngeal or endotracheal aspirates from infants
with neonatal pneumonia has increased the rate of detection
of this pathogen. It is assumed that C. trachomatis contributes
significantly to neonatal pneumonia in countries where untreated
sexually transmitted diseases in women are common. In addition,
Bordetella pertussis may present as an early onset or late onset
pneumonia, and is most commonly associated with close contact
with an infected parent, siblings, relative or healthcare worker.
Other atypical bacteria that have been associated with pneumonia
or pneumonitis in the neonate are Ureaplasma urealyticum and
Ureaplasma parvum, Treponema pallidum, Mycobacterium
tuberculosis and Listeria monocytogenes 5.
A persistent neonatal pneumonia associated with a rapidly
progressive presentation of congenital HIV infection has been
previously described in two Southern Africa studies 6, 7. Coinfections with M. tuberculosis, syphilis and cytomegalovirus were
common and realistically contributed to the clinical presentation.
Congenital HIV infection also increases the fatality risk from
neonatal respiratory distress syndrome and sepsis associated
with S. pneumoniae and Staphylococcus aureus.
Viral respiratory pathogens
Viral neonatal pneumonias can either be associated with
intrauterine, early onset or late onset pneumonias, and may
be acquired from the birth canal (e.g. herpes simplex virus –
197
Under the Microscope
HSV), infected siblings, parents and/or healthcare workers with
or without nosocomial involvement (e.g. respiratory syncytial
virus). HSV is usually transmitted during delivery through an
infected maternal genital tract and respiratory symptoms are
normally associated with multi-organ disease. Transplacental
transmission of virus and hospital-acquired spread from one
neonate to another by hospital personnel or family may account
for 15% of cases. Mothers of neonates with HSV infection tend
to have no history or symptoms of genital infection at the time
of delivery.
The role of respiratory viruses (respiratory syncytial virus,
influenza viruses, parainfluenza viruses, adenovirus and human
metapneumovirus) in neonatal pneumonia is well described by
retrospective reports 8 and is associated with seasonal late onset
pneumonia where viral diagnostic techniques are accessible.
Nosocomial outbreaks of respiratory viruses in neonatal nurseries
and co-infections with respiratory syncytial virus and human
metapneumovirus have also been described 9.
Diagnosis of neonatal respiratory infections
To diagnose neonatal respiratory infection, chest x-rays should
be performed in any patient with respiratory abnormalities, and
blood should be collected for culture in all cases of neonatal
pneumonia. While the yield from blood cultures is low, blood, if
possible, should be collected prior to antibiotic therapy to guide
second-line treatment in the event of first-line antibiotic failure.
Blood cultures collected simultaneously with endotracheal tube
aspirates in mechanically ventilated neonates may also assist in
determining the significance of endotracheal tube colonisation.
Conventional bacteriologic culture is used most widely and
is currently most helpful in diagnosing neonatal pneumonia.
The culture of fungi, viruses, Ureaplasma urealyticum, and
other unusual organisms often requires different microbiologic
processing but may be warranted in suggestive clinical settings.
A number of factors may interfere with the ability to cultivate a
likely pathogen from the sites noted, including (but not limited
to): pretreatment with antibiotics that limit in vitro but not
in vivo growth; contaminants that overgrow the pathogen;
pathogens that do not replicate in currently available culture
systems; sampling of an inappropriate site; and patients in whom
the process is inflammatory but not infectious, such as with
meconium aspiration.
Techniques that may help overcome some of these limitations
include antigen detection, serologic tests, nucleic acid probes and
PCR-based assays. Particularly in the diagnosis of viral respiratory
pathogens, molecular methods have significantly enhanced our
ability to diagnose these infections. Additionally, these sensitive
assays have led to the recognition of new viruses associated
with the human respiratory tract, including in neonates, yet the
significance of these as agents of disease remains unclear 10.
Conclusion
In summary, the global impact of neonatal pneumonia is
significant, with a complex epidemiology and aetiology compared
to the pneumonias in older children. Management and prevention
strategies for neonatal pneumonia cross multiple levels of the
population and health care provision, and have broader based
effects that are sometimes difficult to measure.
Table 1. Pathogens associated with congenital and neonatal pneumonia.
Bacteria
Serratia spp.
Fungii
Acinetobacter spp.
Staphylococcus aureus
Candida albicans
Enterobacter aerogenes
Staphylococcus epidermiditis
Pneumocystis jiroveci
Enterococcus spp.
Streptococcus pneumoniae
Atypical microorganisms
Escherichia coli
Streptococcus viridans group
Group A Streptococcus (S. pyogenes)
Viruses
Group B Streptococcus (S. agalactiae)
Herpes simplex virus
Listeria monocytogenes
Group D & G streptococci
Human adenoviruses
Mycobacterium tuberculosis
Haemophilus influenzae (non-typable)
Human cytomegalovirus
Treponema pallidum
Klebsiella spp.
Human immunodeficiency virus
Ureaplasma urealyticum
Morganella spp.
Human metapneumovirus
Ureaplasma parvum
Neisseria meningitidis
Influenza A & B viruses
Proteus spp.
Parainfluenzae viruses 1, 2 & 3
Pseudomonas aeruginosa
Respiratory syncytial virus
Bordetella pertussis
Chlamydia tracheomatis
Salmonella spp.
198
MICROBIOLOG Y A U STRA LIA • N OV EM BER 2008
Under the Microscope
The growing prevalence of antibiotic resistance to common and
affordable antibiotics will eventually impact on the morbidity and
mortality rates for neonates, especially in the developing world,
and emphasises the importance of the continuing development
of universal maternal and preventative health programmes.
References
1.
Arnold, J.C. et al. (2006) Human bocavirus: prevalence and clinical spectrum at
a children’s hospital. Clin. Infect. Dis. 43, 283-288.
2.
Duke, T. (2005) Neonatal pneumonia in developing countries. Arch. Dis. Child.
Fetal. Neonatal. Ed. 90,F211-F219.
3.
The Child Health Research Project (1999) Reducing perinatal and neonatal
mortality: report of a meeting Baltimore, Maryland. Baltimore, 3, 6-12.
4.
Black, R.E. et al. (2003) Where and why are 10 million children dying every
year? Lancet 361, 2226-2234.
5.
Nissen, M.D. (2007) Congenital and neonatal pneumonia. Paediatr. Respir. Rev.
8, 195-203.
6.
Pillay, T. et al. (2001) Severe, rapidly progressive human immunodeficiency
virus type 1 disease in newborns with co-infections. Pediatr. Infect. Dis. J. 20,
404-410.
7.
Aiken, C.G. (2004) HIV-1 infection and perinatal mortality in Zimbabwe. Arch.
Dis. Child. 67, 595-599.
8.
Roe, M. et al. (2003) Respiratory viruses in the intensive care unit. Paediatr.
Respir. Rev. 4, 166-171.
9.
Semple, M.G. et al. (2005) Dual infection of infants by human metapneumovirus and
human respiratory syncytial virus is strongly associated with severe bronchiolitis.
J. Infect. Dis. 191, 382-386.
10. Sloots, T.P. et al. (2008) Emerging respiratory agents: new viruses for old
diseases? J. Clin. Virol. 42, 233-243.
P r e l i m i n a r y
Michael Nissen (BMedSc, MBBS, FRACP, FRCPA) is director of infectious
diseases at the Royal Children’s Hospital, Brisbane, unit director (medical)
of the Queensland Paediatric Infectious Diseases (QPID) Laboratory, and
clinical microbiologist overseeing the Serology, Virology and Molecular
(SVM) Unit of Pathology Queensland Central based at Royal Brisbane
Hospital, Brisbane. Michael’s research interests include the characterisation
and discovery of respiratory viruses such as WU and KI polyoma viruses,
human metapneumovirus, bocavirus, coronaviruses NL-63 and HKU1, and
new rhinovirus variants. He is also a chief investigator on three NHMRC
project grants including one examining the viral aetiology of indigenous
otitis media (OM).
Michael was a clinical research associate and post-graduate fellow in the
Department of Molecular Microbiology and Pediatrics at the Washington
University School of Medicine, St Louis and St Louis Children’s Hospital,
USA from 1996-1999, and the recipient of the Connaught Laboratories Inc.
Fellowship in Infectious Diseases from the Infectious Diseases Society of
America. He currently holds academic appointments with the School of
Biomolecular and Physical Sciences, Griffith University, and the Biological
and Chemical Sciences Faculty, University of Queensland, Brisbane.
Theo Sloots (PhD, GCM, MASM) has more than 25 years’ experience
in medical microbiology and is currently the unit director (research) at
the Queensland Paediatric Infectious Diseases (QPID) Laboratory of the
Royal Children’s Hospital, Brisbane, as well as consultant virologist to
Pathology Queensland Central. Research at the QPID Laboratory has focused
on examining the significance of human metapneumovirus as a newly
recognised respiratory pathogen, and the discovery of new viral agents
associated with respiratory disease in children. Theo is a chief investigator on
three separate research project grants funded by the NHMRC, and also holds
academic appointments with the Biological and Chemical Sciences Faculty,
University of Queensland, and the School of Biomolecular and Physical
Sciences, Griffith University, Brisbane.
A n n o u n c e m e n t
IV Mycology MasterClass 2009
Hamilton Island QLD
2009
Friday 30 – Saturday 31 October 2009
Plus: Satellite Workshop for Laboratory Staff – Sunday 1 November 2009
Back by popular demand – places are strictly limited and will sell-out in advance!
Mark these dates in your diary now! Registration opens – Feb 2009
Advanced Medical Mycology Course for specialists and trainees in Infectious Diseases, Microbiology, Haematology
& Intensive Care Medicine and for Laboratory Scientists/Technicians specialising in Medical Mycology
Discount registration available to financial members of ASM, ASID and HSANZ
Specially discounted accommodation rates on Hamilton Island have been negotiated for delegates
Website Launch – February 2009
Convenor: Associate Professor David Ellis, Mycology Unit – Women’s & Children’s Hospital, Adelaide SA
Conference Organisers: Australian Society for Microbiology
M I CROB I O L O G Y A U S T RALIA • NOVE MB E R 2 0 0 8 199
Under the Microscope
Pathogenesis of cytomegalovirus (CMV)
infection in pregnancy
Gillian M Scott, Alicia Steller, Shu Wang,
Karen WW Teng and Sharon SW Chow
Virology Division, Department of Microbiology
SEALS, Prince of Wales Hospital
Randwick NSW 2031
School of Biotechnology and Biomolecular Sciences,
Faculty of Science and School of Medical Sciences,
Faculty of Medicine
University of New South Wales NSW 2052
Tel (02) 9382 9096
Fax (02) 9382 8533
Email [email protected]
Cytomegalovirus (CMV) infection during pregnancy can
have devastating effects on the developing fetus. Maternal
CMV infection can affect the fetus in two ways: firstly by
transmission to, and replication in, fetal tissue resulting
in direct damage to developing organs; or, less well
recognised, through cellular changes that potentially
affect placentation and transfer of nutrients and gases to
the developing fetus.
Congenital CMV infections occur in approximately 0.5-2% of births
and 10-15% of these infections will be symptomatic, resulting in
petechiae, jaundice, hepatosplenomegaly, chorioretinitis or more
severe manifestations such as cytomegalic inclusion disease
(CID) and stillbirth 1, 2. As such, CMV has become the leading
viral cause of congenital malformation in newborns now that
rubella vaccination is universally available. More than half of
CMV-infected infants who are symptomatic at birth are also
at risk of long-term sequelae such as learning difficulties or
sensorineural hearing loss 1, 2. Symptomatic congenital infections
are usually the result of CMV transmission in the first trimester of
pregnancy. Fortunately, a larger percentage of children infected
with CMV during pregnancy will remain asymptomatic. Less well
recognised is the percentage of miscarriage and preterm births
that may result from CMV infections in pregnancy. The reasons
for these differences in outcome are unknown, but CMV strain
variation, co-infections, host immunity and altered host cellular
responses are suspected of playing a role.
Congenital CMV infection and maternal
immunity
CMV infection of the placenta and fetus most often results from
primary infection of the mother. CMV transmission is therefore
facilitated by an immunologically naïve host, allowing the virus to
replicate to high titres in the infected mother, and disseminate
and cross the placenta before a sufficient immune response is
mounted. Low avidity antibodies with poor neutralising activity
200
are generated following primary CMV infection and the presence
of these antibodies in the first 20 weeks of pregnancy is a strong
predictor for congenital transmission of CMV 3. Conversely, high
avidity antibodies are produced much later through the process
of immune maturation but provide greater neutralising ability
and protection against CMV transmission. This explains why
hyperimmune globulin therapy is able to reduce the incidence
of congenital transmission when given to women with primary
CMV infections 4.
A mature cellular immune response is also important in limiting
CMV dissemination and controlling reactivation from latency.
Despite this, secondary CMV infections in the mother have also
been shown to contribute to a small but significant percentage
of congenital transmission, suggesting CMV-specific maternal
immunity is not always protective, particularly when a different
strain of the virus is acquired 5. These factors have implications
for the design of potential vaccines that must protect against
infections with different CMV strains and provide a sustained
humoral and cellular immune response during pregnancy. A
DNA vaccine containing plasmids encoding the CMV pp65
phosphoprotein (a primary target of the host CD4+ and CD8+
T-cell response) and envelope glycoprotein gB (which elicits a
strong T-cell response and neutralising antibodies) has recently
shown promise in phase I clinical trials in CMV seronegative
adults 6. However, like many candidate vaccines before it,
enhanced CMV immunity in CMV seropositive individuals could
not be achieved.
Transplacental transmission of CMV
The human placenta is the primary route for transmission of
CMV from mother to fetus 7-9. Maternal viraemia can result in
spread of virus to the placenta, which serves as a reservoir for
CMV replication and subsequent transmission to the fetus. The
placenta offers some protection against congenital transmission,
MICROBIOLOG Y A U STRA LIA • N OV EM BER 2008
Under the Microscope
consistent with our observations of CMV detection in placenta
tissue without concomitant infection of the corresponding fetus
or newborn. For CMV congenital infection to occur, the virus
must negotiate a complex pathway across the placenta that
involves a number of different cell types. The exact process of
CMV transplacental transmission is not fully understood, but
recent studies are providing valuable insights into the potential
mechanisms and transmission routes of virus from mother to
fetus.
CMV productively infects primary syncytiotrophoblasts in
Transmission of congenital CMV is dependent upon passage
through specialised cells of the placenta called cytotrophoblasts.
These cells have specific functions depending on their location
within the placenta. Villous cytotrophoblasts located at the
surface of floating chorionic villi act as progenitor cells for the
formation of an outer multinucleate syncytiotrophoblast layer.
This syncytiotrophoblast layer is in direct contact with maternal
blood in the intervillous space and normally acts as a conduit
for exchange of nutrients and gases for the developing fetus.
Extravillous cytotrophoblasts arrange into columns of anchoring
chorionic villi that attach to the uterine wall. Cells at the base
of these columns further differentiate to become invasive
cytotrophoblasts that enter the interstitium of the uterus and the
uterine vasculature, diverting and increasing maternal blood flow
to the placenta. Potential transmission routes of CMV across the
placenta therefore involve passage through syncytiotrophoblasts
of the chorionic floating villi and/or infection of extravillous
cytotrophoblasts of anchoring villi.
Transmission of infectious virus is dependent on the virion-
We typically observe CMV DNA within syncytiotrophoblasts
of CMV-infected placentae (Figure 1), with CMV also detected
within underlying cytotrophoblasts, stromal cells and endothelial
cells lining fetal vessels within the floating chorionic villi 9. This
suggests that CMV can enter the fetal circulation by transfer from
maternal blood across the syncytiotrophoblast layer to infect
underlying cytotrophoblasts, before transmission through the
stromal layer to fetal vessels.
culture 10, but evidence that active CMV replication occurs
within syncytiotrophoblasts in utero is limited. Examination of
biopsies taken from early trimester placenta suggests that CMV
is transported across the syncytiotrophoblast layer by receptormediated transcytosis of virion-antibody immune complexes
utilising the pathway normally used to transfer maternal IgG for
passive immunity 11.
immune complex containing low avidity, rather than high avidity,
antibodies 11. It is hypothesised that virion-immune complexes
consisting of high avidity antibodies are transported intact
across the syncytiotrophoblast layer, but are endocytosed by
macrophages within the chorionic floating villi or internalised
by underlying cytotrophoblasts. Conversely, CMV virions in
complexes with low avidity antibodies are thought to be released
when they reach the cytotrophoblast layer, and therefore able
to go on and infect other cells and fetal blood vessels within
the chorionic villi. This hypothesis is consistent with the higher
incidences of congenital CMV transmissions that occur in the
presence of low avidity maternal antibodies 3.
Evidence also exists for the transmission of CMV across the placenta
through infection of invasive extravillous cytotrophoblasts of the
anchoring villi from the maternal decidua
. This route also
12, 13
appears to be a complex and lengthy pathway for transplacental
transmission of the virus, but may be relevant in the early stages
of gestation where the placenta is undergoing rapid changes.
The effect of CMV infection on placental
development
CMV is known to induce changes in the expression of cellular
proteins of infected cells and subvert many cellular pathways to
Figure 1: CMV localisation in the human placenta. CMV was detected by in situ PCR (purple) in syncytiotrophoblast (ST) cells
(purple) lining placental floating villi (FV) (a). In normal pregnancy, the syncytiotrophoblast layer allows for transfer of nutrients
from maternal blood in the intervillous space (IVS) to fetal blood vessels (FB). Control in situ PCR carried out on the same tissue
demonstrates the reaction is specific for CMV (b).
M I CROB I O L O G Y A U S T RALIA • NOVE MB E R 2 0 0 8 201
Under the Microscope
advance or promote viral replication. It is therefore conceivable
that CMV infection of the differentiating and supporting cells of
the placenta can have deleterious effects on placentation and
fetal development. Indeed, there is increasing evidence that CMV
infection can indirectly affect the developing fetus by altering the
process of placentation and causing pathological changes to the
placenta in the early stages of pregnancy.
Early cytotrophoblast invasion of the uterine decidua is critical to
the establishment and maintenance of a functioning placenta, and
a number of proteins are known to be important in this process,
including cellular growth factors, integrin receptors and matrix
metalloproteinases 14. KAI1, a metastatis suppressor protein, is
expressed by decidual cells at the uterine-placental interface, and
thought to promote invasion of the endometrium by extravillous
cytotrophoblasts 15. We have demonstrated increased expression
of KAI1 in the decidua of CMV-infected placenta (Figure 2),
suggesting CMV may interfere with the communication between
invading fetal cytotrophoblasts and cells of the maternal decidua
that is thought to regulate placental development.
In addition to this, CMV infection of extravillous cytotrophoblast
cells directly interferes with their differentiation towards
invasiveness, metalloproteinase-9 secretion and epithelial growth
factor expression 16. We are currently investigating the extravillous
trophoblast infectivity of low-passage CMV strains isolated from
maternal urine and congenitally infected infants to determine the
differential effects of strain variation and identify the viral genes
essential for replication in cytotrophoblast cells.
The role of inflammatory cytokines
The role of cytokines in congenital CMV infection is only now being
elucidated. Some groups have shown even UV-inactivated CMV
can elicit the release of inflammatory cytokines and apoptosis in
syncytiotrophoblast cells, suggesting cytokine mediated damage
of the syncytiotrophoblast layer as a potential mechanism for
CMV infection of placental villi and transmission to the fetus 17.
Likewise, changes in fetal cytokine production in response to
CMV infection may also have a role in the pathogenesis of CMVinduced fetal damage.
We have observed changes in the level of certain pro- and antiinflammatory cytokines, including interleukin-6, in the amniotic
fluid of CMV-infected fetuses. These changes have correlated with
cytokine expression in extravillous trophoblasts and epithelia of
the amniotic membrane (Figure 3). Further experiments are
underway to determine whether observed changes in fetallyderived cytokine levels are similar to changes in CMV-infected
placental tissue at different stages of gestation, and to correlate
these with histopathological tissue damage.
Animal models for the study of congenital CMV
transmission
The investigations of human CMV congenital infection described
above are helping to elucidate the mechanisms of transplacental
CMV transmission but there are obvious ethical and practical
limitations to in vivo studies of human CMV pathogenesis.
Human CMV is highly host restricted and will only infect humans
and human cell lines, and animal models are therefore required
to study CMV infection in vivo.
There are many animal homologues of human CMV, but
only a few of these have been extensively studied. Guinea
pigs and rhesus macaques are similar to humans in terms
of placental architecture and congenital CMV infection, but
use of these animal models is limited in terms of availability,
practicality and what we know about guinea pig and rhesus
CMV in general 18, 19. Much more detailed knowledge is available
regarding the pathogenesis, immunology and genetics of
murine CMV infection in mice 20-22, and murine models are
used extensively to advance our understanding of human
placental development and other factors affecting pregnancy
outcomes 23, 24. Transplacental transmission of murine CMV
from immunocompetent mice to fetal pups has not been
previously demonstrated, although congenital infection of
fetal pups can occur when murine CMV is injected directly to
murine placentas 25.
Figure 2: Up-regulation of KAI1 protein in CMV-infected tissue at the uterine-placental interface. Increased expression of KAI1
protein (brown) in the decidual cells (D) at the uterine-placental interface of CMV-positive placental tissue (a) compared with
CMV-negative tissue (b), as determined by immunohistochemical analysis. The placenta is anchored to the maternal decidua by
the fetal anchoring villi (AV).
202
MICROBIOLOG Y A U STRA LIA • N OV EM BER 2008
Under the Microscope
Developments in the small animal models of guinea pig and
mice are likely to be seen in the near future. These models will
complement ongoing investigations of human CMV and assist
with identification of therapies and vaccines for prevention of
CMV transplacental transmission and congenital infection.
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an overview of progress in the characterization of guinea pig cytomegalovirus
(GPCMV). J. Clin. Virol. 25, S37-49.
19. Kuhn, E.M. et al. (1999) Immunohistochemical studies of productive rhesus
cytomegalovirus infection in rhesus monkeys (Macaca mulatta) infected with
simian immunodeficiency virus. Vet. Pathol. 36, 51-56.
20. Rawlinson, W.D. et al. (1996) Analysis of the complete DNA sequence of murine
cytomegalovirus. J. Virol. 70, 8833-8849.
21. Tsutsui Y. et al. (2005) Neuropathogenesis in cytomegalovirus infection:
indication of the mechanisms using mouse models. Rev. Med. Virol. 15, 327345.
22. Smith, L.M., et al. (2008) Laboratory strains of murine cytomegalovirus are
genetically similar to but phenotypically distinct from wild strains of virus. J.
Virol. 82, 6689-6696.
23. Georgiades, P. et al. (2002) Comparative developmental anatomy of the murine
and human definitive placentae. Placenta 23, 3-19.
24. Malassine, A. et al. (2003) A comparison of placental development and
endocrine functions between the human and mouse model. Human Reprod.
Update 9, 531-539.
25. Li, R.Y. and Tsutsui, Y. (2000) Growth retardation and microcephaly induced
in mice by placental infection with murine cytomegalovirus. Teratology 62,
79-85.
Dr Gillian Scott completed her PhD on cytomegalovirus antiviral susceptibility
and resistance in 2004 and is now a postdoctoral scientist in the Department
of Microbiology, SEALS at Prince of Wales Hospital and conjoint lecturer at
the University of New South Wales. She has continued her research of CMV
susceptibility to current and potential antiviral agents as well as investigations
of CMV pathogenesis in liver transplantation and congenital infection.
Alicia Steller, Shu Wang and Karen Teng are currently honours students at
the University of New South Wales conducting research into CMV congenital
infection at Prince of Wales Hospital. Alicia intends to pursue a career in
science following completion of her studies, Shu will continue her medical
studies at UNSW, and Karen intends to continue as a PhD student next year.
Sharon Chow is a UNSW PhD student in the final stages of her studies into
maternal and fetal immunological responses to congenital CMV infection.
The majority of her research is conducted in the virology research lab at
Prince of Wales Hospital under the supervision of Prof William Rawlinson
in collaboration with Prof Cheryl Jones from the Children’s Hospital at
Westmead.
Figure 3: IL-6 expression in amniotic membranes. IL-6 expression (brown) is localised to the extravillous trophoblasts (ET)
and amniotic epithelium (AE) of fetal amniotic membranes (a). Immunohistochemistry negative control (no primary antibody)
carried out on tissue from the same individual indicates IL-6 detection is specific (b).
M I CROB I O L O G Y A U S T RALIA • NOVE MB E R 2 0 0 8 203
Under the Microscope
Pathogenesis of malaria in pregnancy
Stephen J Rogerson
Steven R Meshnick
Department of Medicine
(RMH/WH), The University of
Melbourne, Post Office Royal
Melbourne Hospital
Parkville VIC 3050
Tel (03) 8344 3259
Fax (03) 93471863
Email [email protected]
Department of Epidemiology,
University of North Carolina
School of Public Health
Chapel Hill, NC USA 27599-7435
Tel (1) 919-966-7414
Fax (1)919-966-0584
Email [email protected]
Even though we have good tools to prevent and treat
susceptibility to malaria, resulting in more prevalent and higher-
malaria, it remains a tragically common disease in poor
density infection, and a relative loss of gravidity-dependent
countries, especially in Africa. Pregnant women are
immunity 8. In low transmission areas, women of all gravidities
particularly susceptible to malaria, causing anaemia and
are affected.
poor birth outcomes. There is marked sequestration of
Placental pathology
Plasmodium falciparum-infected erythrocytes (IEs) in
the placenta, but the pathogenesis of malaria in pregnancy
is still incompletely understood. Both intermittent
preventive therapy and insecticide-impregnated bed nets
are effective protective measures, but new measures are
also needed.
P. falciparum causes three specific changes in the placenta.
IEs containing mature trophozoite and schizont parasite stages
accumulate in the intervillous spaces (the lake-like structures
through which maternal blood circulates), sometimes to very high
densities 9. Placental malaria may be accompanied by intervillous
infiltrates of monocytes and macrophages, some containing
Epidemiology
malaria pigment (hemozoin). Finally, hemozoin may also be seen
Malaria causes maternal anaemia and contributes to an estimated
10,000 maternal deaths each year 1. Moreover, malaria infections
result in 75,000-200,000 low birth weight babies each year,
due to combinations of preterm delivery and fetal growth
in fibrin deposits, and these pigmented fibrin deposits can persist
after resolution of episodes of infection. Each of these changes
(parasites, monocytes, or pigmented fibrin) has been associated
with poor birth outcomes.
restriction 2, 3. The most dangerous form of malaria for pregnant
Sequestration of IE plays an important role in all P. falciparum-
women is P. falciparum; P. vivax infections also cause poor
associated pathology. In the brain and other viscera, ICAM-1 and
birth outcomes .
CD36 are the primary ligands for IE. In the placenta, in contrast,
4
Pregnant women are at greater risk of malaria infection and of
symptomatic malaria disease than non-pregnant adults for several
IE adhere to chondroitin sulphate A (CSA) and hyaluronic
acid, which are expressed by syncytiotrophoblast that line the
placental intervillous spaces 10, 11.
reasons 5. First, they are more attractive to mosquitoes 6. Second,
once infected, parasite burdens are higher in pregnant women
Placental IE express variant surface antigens (VSAs), which
than in non-pregnant adults. This may be because pregnancy
mediate cytoadherence. The major VSAs are the PfEMP1 (P.
weakens the host immune response to parasites and because
falciparum erythrocyte membrane protein 1) receptors, coded
large numbers of parasites sequester in the placenta.
for by plasmodial var genes. One var gene, var2csa, appears to
be responsible for CSA binding. Deletion of var2csa largely or
In areas of high transmission, such as much of sub-Saharan Africa,
completely abolishes CSA adhesion 12, 13, placental isolates usually
malaria is most frequent in first pregnancies , and this gravidity
transcribe high levels of var2csa 14, 15, and levels of antibody to
dependent susceptibility is a key feature of disease epidemiology.
VAR2CSA recombinant proteins correlate with protection in
Prevalence of infection peaks early in pregnancy (between
some subgroups 16, 17. Thus, VAR2CSA may be a promising vaccine
13-16 weeks) , declining towards term. HIV infection increases
candidate.
7
5
204
MICROBIOLOG Y A U STRA LIA • N OV EM BER 2008
Under the Microscope
Malaria may evade the host immune response in the placenta
Kinshasa, the effects of malaria were most evident in
by altering the response. Placental malaria causes increased
undernourished
synthesis of inflammatory cytokines like TNF, interleukin-2 and
supplementation has been shown to improve birth weight 24, and
interferon γ 18-20. Increased placental TNF has been associated
it may be that combined nutritional and malaria interventions
with low birth weight and anaemia 18, 21. Some of the mechanisms
would give optimal fetal protection from growth restriction.
by which malaria may result in premature delivery or fetal growth
restriction are illustrated in Figure 1 22.
mothers
23
.
Maternal
macronutrient
Timing of infection and fetal growth restriction
Few studies have attempted to examine the relationship
Undernutrition and malaria
between malaria infection during pregnancy and pregnancy
Maternal nutrition before and during pregnancy is another
outcome. Figure 2 illustrates the relationship between
important determinant of birth weight. In a recent study in
fetal
growth,
gestation,
and
timing
of
currently-used
Figure 1. Potential pathogenic mechanisms by which placental malaria affects placental function and results in intrauterine
growth retardation or preterm delivery. Reproduced with permission 22.
IRBC – infected red blood cell; CSA – chondroitin sulfate A; IUGR – intrauterine growth retardation; PTD – preterm delivery.
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M I CROB I O L O G Y A U S T RALIA • NOVE MB E R 2 0 0 8 205
Under the Microscope
interventions 22, 25. Presently, it is unknown whether infection early
in pregnancy may compromise ultimate fetal growth potential,
although one study suggests this may be the case 26.
Malaria and the neonate
Newborns in areas of high malaria transmission are relatively
protected from malaria in early life, although the mechanisms
are not fully understood 27, 28. Cord blood infection is commonly
detected, especially when sensitive molecular diagnosis is
used
, but symptomatic neonatal infection is rare in
29, 30
endemic areas 31.
Contributing factors may include innate mechanisms (including
fetal haemoglobin and p-amino benzoic acid-deficient breast
milk), cultural ones (swaddling of newborns, decreasing their
exposure), transplacental transfer of protective antibody
,
32, 33
and priming of neonatal responses by transplacental transfer
Prevention of malaria in pregnant women
of parasites or their products 34, 35. In case reports from the US,
Effective and affordable ways to protect pregnant women from
newborns of non-immune women have developed severe febrile
malaria are discussed in the article by Heather Jeffery in this issue.
illness due to P. falciparum or P. vivax malaria 36. The apparent
Unfortunately, only 2-50% of pregnant women in malaria-endemic
rareness of similar cases in babies of semi-immune women
area currently sleep under bednets and relatively few women
suggests a central protective role for transplacental antibody
receive the recommended intermittent preventive treatment
, possibly
(IPT) 39. Additionally, due to the emergence of resistance, new
increasing susceptibility of children of HIV-infected mothers to
IPT regimens are needed. Such drugs will need to be evaluated
malaria.
closely for safety in pregnancy, as well as for efficacy and, because
transfer. HIV infection interferes with this process
37,38
Figure 2. Relationship between timing of IPT, fetal growth rates, and potential vulnerability of mother and fetus to deleterious
effects of malaria.
The fetal growth rate varies over the course of pregnancy, peaking at about 36 weeks (blue curve). In the context of moderate
SP resistance, IPTp (vertical green arrows) may or may not clear infection, and offer a shortened period of prophylaxis against
reinfection (attached horizontal black arrows) 25. Reinfection during the period of vulnerability may affect fetal growth (double
headed arrow). The effects of malaria early in pregnancy (dotted arrow) on fetal growth are less well understood. Reproduced
with permission 22.
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MICROBIOLOG Y A U STRA LIA • N OV EM BER 2008
Under the Microscope
drug pharmacokinetics can change radically in pregnancy, it will
be important to ensure optimal dosing regimes.
Conclusions
Our understanding of the pathogenesis of malaria in pregnancy
has improved significantly in recent years, but important gaps
remain. Many challenges remain in developing and implementing
interventions to protect pregnant women from malaria. A
recently inaugurated Malaria in Pregnancy Consortium , funded
40
by the Gates Foundation and EDCTP, will accelerate progress in
protecting pregnant women and their infants from malaria.
Acknowledgements
SJR is supported by the NH&MRC of Australia and by the Malaria
in Pregnancy Consortium. SRM is supported by the NIH. We
thank Sarah Landis for the prototype of Figure 1.
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expression and its relationship to intrauterine growth retardation. J. Infect. Dis.
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22. Rogerson, S.J., Mwapasa, V. and Meshnick, S.R. (2007) Malaria in pregnancy:
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77(6_Suppl): 14-22.
23. Landis, S.H. et al. (2008) Impact of maternal malaria and under-nutrition on
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in a birth cohort of children less than one year of age in Ghana, detected by
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infections with Plasmodium falciparum, P. malariae, and P. ovale in Kenya. J.
Infect. Dis.182, 558-563.
30. Kamwendo, D.D. et al. (2002) Plasmodium falciparum: PCR detection and
genotyping of isolates from peripheral, placental, and cord blood of pregnant
Malawian women and their infants. Trans. Royal Soc. Trop. Med. Hyg. 96, 145149.
31. Fischer, P.R. (2003) Malaria and newborns. J. Trop. Pediat. 49, 132-134.
32. Branch, O.H. et al. (1998) A longitudinal investigation of IgG and IgM antibody
responses to the merozoite surface protein-1 19-kiloDalton domain of
Plasmodium falciparum in pregnant women and infants: associations with
febrile illness, parasitemia and anemia. Am. J. Trop. Med. Hyg. 58, 211-219.
33. Hviid, L. and Staalsoe, T. (2004) Malaria immunity in infants: a special case of a
general phenomenon? Trends Parasitol. 20, 66-72.
34. Malhotra, I. et al. (2005) Distinct Th1- and Th2-Type prenatal cytokine
responses to Plasmodium falciparum erythrocyte invasion ligands. Infect.
Immunity 73, 3462-3470.
35. King, C.L. et al. (2002) Acquired immune responses to Plasmodium falciparum
merozoite surface protein-1 in the human fetus. J Immunol 168, 356-364.
36. Hulbert, T.V. (1992) Congenital malaria in the United States: report of a case
and review. Clin Infect Dis 14, 922-926.
37. de Moraes-Pinto, M.I. et al. (1996) Placental transfer and maternally acquired
neonatal IgG immunity in human immunodeficiency virus infection. J. Infect.
Dis. 173, 1077-1084.
38. de Moraes-Pinto, M.I. et al. (1998) Placental antibody transfer: influence of
maternal HIV infection and placental malaria. Arch. Dis. Childhood 79, F202205.
39. White, N.J. (2005) Intermittent presumptive treatment for malaria. PLoS Med.
2, e3.
40. http://www.mip-consortium.org/
15. Duffy, M.F. et al. (2006) Transcribed var genes associated with placental malaria
in Malawian women. Infect. Immun. 74, 4875-4883.
16. Salanti, A. et al. (2004) Evidence for the involvement of VAR2CSA in pregnancyassociated malaria. J. Exp. Med. 200, 1197-1203.
17. Tuikue Ndam, N.G. et al. (2006) Dynamics of anti-VAR2CSA immunoglobulin G
response in a cohort of Senegalese pregnant women. J. Infect. Dis. 193, 713-720.
18. Fried, M. et al. (1998) Malaria elicits type 1 cytokines in the human
placenta: IFN-g and TNF-a associated with pregnancy outcomes. J. Immunol.
160, 2523-2530.
19. Moore, J. et al. (1999) Immunity to placental malaria. I. Elevated production of
interferon-g by placental blood mononuclear cells is associated with protection
in an area with high transmission of malaria. J. Infect. Dis. 179, 1218-1225.
M I CROB I O L O G Y A U S T RALIA • NOVE MB E R 2 0 0 8 Steven Meshnick is professor of epidemiology and of microbiology and
immunology at the University of North Carolina, Chapel Hill, USA. He uses
molecular epidemiology to understand the prevention and pathogenesis of
malaria in pregnancy, antimalarial drug resistance and HIV mother-to-child
transmission.
Stephen Rogerson is associate professor in the Department of Medicine,
University of Melbourne. His research interests include the pathogenesis,
immunity and prevention of malaria in pregnancy, and the interaction
between HIV and malaria infections.
207
In Focus
Goal setting and reality:
maternal, perinatal and childhood malaria
Parasites and transmission
Heather Jeffery
School Public Health
Edward Ford Building
University of Sydney &
Royal Prince Alfred Hospital
Newborn Care, Sydney NSW
Tel 0402 223 840
Email [email protected]
The protozoan, viral and bacterial infections of malaria,
human immunodeficiency virus (HIV) and tuberculosis
(TB) cause over 5.5 million deaths each year 1. This
burden of disease is largely concentrated in the same
geographical regions, related to vector distribution, their
association with poverty and the vulnerability of HIV
infected people to both malaria and TB.
This paper is a review of the devastating effects of malaria in
the most susceptible hosts – pregnant women and children.
Importantly, a recent technical report from the WHO indicates
that rapid coverage and sustained efforts with evidence-based
interventions would have a major impact on reducing malarial
mortality and morbidity in a relatively short time. Global
eradication will require newly developed tools and research
directed to prevention, diagnosis and treatment 2.
Epidemiology
Malaria in pregnancy is a major cause of maternal and perinatal
infection, death and morbidity. In low income countries, most
deaths in 2002 (>1 million) occurred in children less than 5
years and accounted for over 90% of all malarial deaths 1 and
approximately 10% of the 10.6 million deaths in children of
this age 3. A recent systematic analysis of maternal deaths in a
tertiary referral hospital in Maputo, Mozambique, challenges
global estimates that most maternal deaths are attributable
to direct, pregnancy-related causes. The authors conducted a
prospective study (2002-2004) of 139 of the 179 maternal deaths
and found that infectious diseases accounted for half of all deaths
and included malaria, HIV and TB 4. An estimated 50 million
pregnancies and more than 40% of all births worldwide occur in
endemic malarious areas of the tropics and subtropics, including
most tropical regions of sub-Saharan Africa, south-east Asia and
Latin America 5.
208
Malaria is caused by an intracellular protozoan parasite of the
genus Plasmodium. Five species infect humans – P. falciparum,
P. vivax, P. ovale, P. malariae and the morphologically similar
P. knowlesi. Infected female Anopheles mosquitoes transmit
malaria parasites person-to-person and are more attracted to
pregnant than non-pregnant women 6. Increased recognition
of vertical transmission from mother to fetus either during
pregnancy or delivery has been documented in endemic areas
with a prevalence rate of up to 32% 7. Spread can also occur
from transfusion of infected blood or via infected needles.
Transmission of malaria by breast feeding does not occur.
P. falciparum is the most lethal malarial parasite with mortality
and morbidity concentrated on pregnant mothers and young
children, due to the severity of syndromes such as cerebral
malaria, pulmonary oedema and profound anaemia 8, 9. Secondary
effects of maternal malaria include suppression of immune
responses to vaccination, e.g. tetanus toxoid, and reduction
in placental transfer of specific antibodies to the fetus, e.g.
respiratory syncytial virus, measles, pneumococcus 8.
Maternal, perinatal and childhood morbidity
and mortality
Pregnant women in endemic (stable or high transmission) areas
are usually asymptomatic but develop anaemia and, if severe,
both maternal morbidity and mortality may be increased. The
risk of adverse maternal and perinatal outcome is greater during
first pregnancies, younger age and for all gravida women who are
HIV positive 10. In epidemic (unstable or low transmission) areas,
consequences of infection are more severe and the risk is similar
across parity. Non-immune pregnant women are at high risk of
cerebral malaria, hypoglycaemia, pulmonary oedema, severe
haemolytic anaemia and perinatal death 11. Risk of stillbirth may
be increased seven-fold in unstable areas 12. Symptoms and signs
(fever, chills, headache, sweats, vomiting) are non-specific.
Adverse effects on pregnancy (anaemia) and pregnancy
outcomes (stillbirth, abortion, low birth weight (LBW),
prematurity, intrauterine growth reduction (IUGR), perinatal
mortality, infant anaemia) are directly related to the extent of
placental malaria and partly to the degree of maternal anaemia
and fever 11, 13, 14. Congenital malaria may present as fever,
anaemia, jaundice, hepatosplenomegaly and early death 15.
The morbidity due to malaria is extensive, as LBW, IUGR and
preterm infants are at increased risk of neonatal death and
impaired cognitive development attributable to prenatal and
MICROBIOLOG Y A U STRA LIA • N OV EM BER 2008
In Focus
postnatal causes. Included in the latter are unrecognised and
untreated hypoglycaemia in resource poor settings. Further,
approximately 7% of children who survive cerebral malaria due
to P. falciparum have permanent neurological impairment and
others have learning difficulties which adversely affect school
performance 16. Similarly, recurrent fever and anaemia due to
malaria are exacerbated by drug resistance so that children
remain parasitaemic and anaemic, contributing to ill health and
impaired school performance.
susceptibility of pregnant women to malaria 19. Placental malaria
Placental malaria
accuracy 21. Additionally, several laboratory tests exist; most
In malaria-endemic areas, placental malaria, characterised by
parasitised red cells in placental blood in the intervillous space,
is a more common finding than parasites in the peripheral
circulation of the mother, who is often asymptomatic due to
acquired partial immunity. The only species shown to colonise
the placenta is P. falciparum. A search for biomarkers to identify
placental inflammation has so far established that maternal
peripheral blood level of interleukin-10 at a cut off of 15pg/mL has
80% sensitivity and 84% specificity to detect placental malaria 17.
Severe maternal and neonatal mortality and sequelae are related
to placental inflammation due to malaria 18. The parasitised cells
in the placenta express unique variant surface antigens and lack
of immunity to these antigens, combined with acquired changes
in cell mediated immunity in pregnancy, explain some of the
also increases the risk of mother-to-child HIV transmission,
emphasising the role of malarial prevention for both malaria and
HIV infection in improving perinatal and infant outcomes 20.
Diagnosis
Light microscopy of thick and thin Giemsa-stained blood
smears is the gold standard for diagnosis. Further, rapid antigen
detection provide rapid results in 2-10 minutes, with variable
accurate and most expensive are tests using PCR to detect
parasite nucleic acids. Finally, serology detects antibodies
indicating past infection, either by indirect immunofluorescence
(IFA) or ELISA.
Treatment
Prompt appropriate treatment of pregnant women with malaria
requires early and effective case management in malarious areas
together with screening and appropriate treatment of anaemia.
Increasing resistance to efficacious drugs with a well established
safety profile in pregnancy such as sulfadoxine-pyrimethamine
has led to recommendations that artemisinin combination
therapy (ACTs) are the most cost-effective strategy for control of
malaria in sub-Saharan Africa 22. Their effect is rapid and reliable,
Figure 1. In-patient malaria cases, out-patient laboratory-confirmed cases and in-patient non-malaria cases by month, all ages
2001-2007, Rwanda 33.
M I CROB I O L O G Y A U S T RALIA • NOVE MB E R 2 0 0 8 209
In Focus
with >95% efficacy for artesunate-mefloquine, artemetherlumefantrine and dihydroartemisinin-piperaquine 23.
(RR 0.62, 95% CI 0.50-0.78), LBW (RR 0.55, 95% CI 0.43-0.70) and
perinatal death (RR 0.73, 95% CI 0.53-0.99) 28.
In pregnancy, when malaria is uncomplicated, WHO currently
recommends ACTs as first choice for second and third trimesters
(and if breast feeding) and oral quinine for 7 days in the first
trimester 24, 25. CDC updates treatment options, depending on
location, for non-immune travellers 26.
Recent research has similarly shown that treatment of infants
at the time of routine immunisation at 2, 3 and 9 months
reduced clinical malarial episodes by 60% and severe anaemia
by 50% 29. Current recommendations include use of sulfadoxinepyrimethamine with close monitoring of safety for infants where
the burden of disease is high and drug resistance low 30.
Prevention
Non-immune pregnant women are advised to avoid malaria
endemic areas. In general, chemoprophylaxis is not recommended
in areas with <10 reported cases of P. falciparum malaria per
1000 inhabitants per year 27. In endemic areas in Africa, WHO
recommends a triple approach (the first three points below) for
prevention and control in pregnant women 24.
Intermittent preventive treatment (IPT)
Intermittent preventive treatment (IPT) of at least two doses
of antimalarial drugs should be given to all pregnant women
at antenatal visits in areas of stable transmission. The relative
risk (RR) of routine chemoprophylaxis (such as sulfadoxinepyrimethamine) for pregnant women (low parity) in endemic
malarial areas indicates significant reduction in severe anaemia
Insecticide-treated bed nets (ITNs)
Insecticide-treated bed nets (ITNs) are recommended as early in
pregnancy as possible and postpartum 24. In pregnant women in
Africa, ITNs reduced placental malaria in all pregnancies (RR 0.79,
95% CI 0.63-0.98). They also reduced LBW (RR 0.77, 95% CI 0.610.98) and fetal loss in the first to fourth pregnancy (RR 0.67, 95%
CI 0.47-0.97) 31. ITNs are highly effective in reducing childhood
morbidity and all cause mortality from malaria by 20% and halve
episodes of malaria 32. About 5.5 lives can be saved each year for
every 1000 children protected with ITNs. This equates to 0.5
million child deaths prevented each year in sub Saharan Africa.
Recent review of investment in malaria control in four African
countries found strong initial evidence that the combined effect
of long-lasting insecticidal-treated bed nets (LLINs) and ACTs to
Figure 2. In-patient malaria and non-malaria cases in children <5 years old, January 2001 – November 2007, 19 in-patient
facilities, Rwanda 33.
210
MICROBIOLOG Y A U STRA LIA • N OV EM BER 2008
In Focus
all children <5 and all households was associated with a >50%
decline of inpatient malaria deaths in Rwanda (66% reduction
children <5 years) and Ethiopia (51%) (Figures 1 & 2) 33.
Case management
Case management and appropriate treatment for febrile malaria
and anaemia (see treatment).
Prevention/prophylaxis for pregnant travellers
The CDC also recommends prevention/prophylaxis for pregnant
travellers 34 and lists drugs that are safe and those that are unsafe
in pregnancy 35.
Vaccines
stable and unstable transmission in Ethiopia during a non-epidemic year. J. Inf.
Dis. 187, 1765-1772.
13. Steketee, R.W. (2003) Pregnancy, nutrition and parasitic diseases. J. Nutr. 133,
1661S-1667S.
14. Poespoprodjo, J.R. et al. (2008) Adverse pregnancy outcomes in an area
where multidrug-resistant Plasmodium vivax and Plasmodium falciparum
infections are endemic. Clin. Infect. Dis. 46, 1374-1381.
15. Fischer, P.B. (2003) Malaria and newborns. J. Trop. Ped. 49, 132-134.
16. Holding, P.A. et al. (1999) Cognitive sequelae of severe malaria with impaired
consciousness. Trans. Royal Soc. Trop. Med. Hyg. 93, 529-534.
17. Kabyemela, E.R et al. (2007) Maternal peripheral blood level of IL-10 as a
marker for inflammatory placental malaria. Malaria J. 7, 26-32.
18. Brabin, B. et al. (2004) The sick placenta: the role of malaria. Placenta 25, 359378.
19. Rogerson, S.J. et al. (2007) Malaria in pregnancy: linking immunity and
pathogenesis to prevention. Am. J. Trop. Med. Hyg. 77, 14-22.
20. Brambhatt, H. et al. (2008) J. AIDS 47, 472-476.
The difficulties associated with mosquito control and drug
resistance to the parasite, together with the large burden of
disease due to malaria, have provoked intense research for a
suitable vaccine. Currently there is no effective, licensed vaccine,
although phase III trials are underway 8, 36. The pre-erythrocytic
vaccine RTS,S has demonstrable protection against severe
malaria in children for 18 months and clinical malaria episodes
in adults 37.
23. Nosten, F. and White, N.J. (2007) Artemisinin-based combination treatment of
falciparum malaria. Am. J. Trop. Med. Hyg. 77, 181-192.
Conclusion
26. www.cdc.gov/travel
The global public health need, attributable to the economic and
social burden of malaria 38, the current situation and the research
and development needs are outlined by Guerin et al. 36. Research
to address the disease burden, in children and pregnant women
in particular, vector control, vaccine development, deployment of
rapid tests adapted to field situations and effective combination
drugs are essential priorities to reduce malaria and prevent
escalation of the disease 36.
References
1.
Revised Global Burden of Disease (GBD) 2002 Estimates. World Health Report
2004. http://www.who.int/healthinfo/bodgbd2002revised/en/index.html
2.
Global Malaria control and elimination: report of a technical review. World
Health Organisation 2008, p.1-47.
3.
Bryce, J. et al. (2005) WHO estimates of the causes of death in children. Lancet
365, 1147-1152.
4.
Menendez, C. et al. (2008) An autopsy study of maternal mortality in
Mozambique: the contribution of infectious diseases. PloS Medicine 5, e44e47.
5.
Steketee, R. et al. (2001) The burden of malaria in pregnancy in malariaendemic areas. Am. J. Trop. Med. Hyg. 64, 28-35.
6.
Lindsay, S. et al. (2000) Effect of pregnancy on exposure to malaria mosquitoes.
Lancet 355, 1972.
7.
Menendez, C. and Mayor, A. (2007) Congenital malaria: the least known
consequence of malaria in pregnancy. Sem. Fetal Neonatal Med. 12, 207-213.
8.
Duffy, P.E. (2003) Maternal immunization and malaria in pregnancy. Vaccine 21,
3358-3361.
9.
Planche, T. and Krishna, S. (2005) The relevance of malaria pathophysiology to
strategies of clinical management. Curr. Opin. Inf. Dis. 1895, 369-375.
10. ter Kuile, F. et al. (2004) The burden of co-infection with human
immunodeficiency virus type 1 and malaria in pregnant women in sub-Saharan
Africa. Am. J. Trop. Med. Hyg. 71, 41-54.
11. van Geertruyden, J.-P. et al. (2004) The contribution of malaria in pregnancy to
perinatal mortality. Ann. Trop. Med. Hyg. 71, 35-40.
21. http://www.wpro.who.int/rdt
22. Morel, C. et al. (2005) Cost effectiveness analysis of strategies to combat
malaria in developing countries. BMJ, DOI:10.1136/bmj.38639.702384.AE.
24. World Health Organisation (2004) A strategic framework for malaria prevention
and control during pregnancy in the African region. Brazzawille: WHO Regional
Office for Africa, AFR/MAL/04/01.
25. WHO Guidelines for the treatment of malaria 2006. http://www.who.int/
malaria/docs/TreatmentGuidelines2006.pdf
27. Petersen, E. (2004) Malaria chemoprophylaxis: when should we use it and what
are the options? Exp. Rev. Antiinfective Ther. 2, 119-132.
28. Garner P and Gülmezoglu AM. (2002) Drugs for preventing malaria in pregnant
women. Cochrane Database Syst. Rev. 2006, Issue 3. Art. No.: CD000169. DOI:
10.1002/14651858.CD000169.pub2
29. Schellenberg, D. et al. (2001) Intermittent treatment for malaria and anaemia
control at time of routine vaccinations in Tanzanian infants: a randomised,
placebo-controlled trial. Lancet 357, 1471-1477.
30. WHO Report of the technical expert group meeting on intermittent preventive
therapy in infancy, Geneva, 2007, p.1-12.
31. Gamble, C. et al. (2006) Insecticide-treated nets for preventing malaria in
pregnancy. Cochrane Database Syst. Rev., Issue 2. Art. No.: CD003755. DOI:
10.1002/14651858.CD003755.pub2
32. Lengeler, C. (2004) Insecticide-treated bed nets and curtains for preventing
malaria. Cochrane Database Syst. Rev. Issue 2. Art No.: CD000363.pub2.
DOI:10.1002/14651858.CD000363.pub2.
33. WHO Global Malaria Program Surveillance, Monitoring and Evaluation Unit.
(2008) Impact of long-lasting insecticidal-treated nets and artemisinin-based
combination therapies measured using surveillance data in four African
countries.
34. http://www.cdc.gov/malaria/risk_map/
35. http://wwwn.cdc.gov/travel/contentMalariaPregnantPublic.aspx
36. Guerin, P. et al. (2002) Malaria: current status of control, diagnosis, treatment,
and a proposed agenda for research and development. Lancet Infect. Dis. 2,
564-573.
37. Graves, P. and Gelband, H. (2002) Vaccines for preventing malaria (preerythrocytic). Cochrane Database Syst. Rev. 2006, Issue 4. Art. No.: CD006198.
DOI: 10.1002/14651858.CD006198
38. Sachs, J. and Malaney, P. (2002) The economic and social burden of malaria.
Nature 415, 680-685.
Heather Jeffery (PhD, MPH, MBBS, FRACP) has had extensive experience as a
clinical neonatologist and more recently trained and worked in maternal and
perinatal public health in middle and low-income countries. She has wideranging experience with perinatal and childhood malaria in the endemic
regions in Malaysia in the 1980s. She currently is professor of international
maternal and child health, School of Public Health, University of Sydney.
12. Newman, R.D. et al. (2003) Burden of malaria during pregnancy in areas of
M I CROB I O L O G Y A U S T RALIA • NOVE MB E R 2 0 0 8 211
In Focus
Infection and preterm birth
Vaginal flora
Helen McDonald
Women’s & Children’s Hospital
72 King William Road
North Adelaide SA 5006
Tel (08) 8161 6725
Email [email protected]
Preterm birth (PTB) before 37 weeks’ gestation remains
an important cause of perinatal morbidity and mortality,
despite modern advances in obstetric and neonatal
care. The causes of spontaneous PTB are multi-factorial;
however, infection has been implicated as a significant
cause of both PTB and late miscarriage, often with no
visible signs or symptoms.
The most common source for microorganisms gaining access
to the uterine cavity and placenta is the lower genital tract,
although it is unclear under what circumstances these organisms
ascend into the amniotic cavity causing preterm labour, often
with chorioamnionitis. It is thought preterm labour may also
be initiated by a cascading cytokine host response to vaginal
pathogens. Abnormal vaginal flora is more likely to cause
ascending infection and preterm labour than normal lactobacillary
flora. Bacterial vaginosis (lack of normal vaginal lactobacilli with
overgrowth of mixed anaerobic bacteria) in early pregnancy has
been consistently associated with a two-fold or more increase in
PTB rate.
Since antibiotic treatment usually eradicates bacterial vaginosis,
a number of randomised, controlled trials have been undertaken
to determine whether treatment during early/mid-pregnancy
would lower the PTB rate. However, meta-analysis of these trials
showed that treatment, while effectively eradicating bacterial
vaginosis, failed to decrease the risk of PTB. Studies indicate that
treatment earlier in pregnancy may be more successful.
Other vaginal microorganisms, such as genital mycoplasmas,
have also been implicated in adverse pregnancy outcome. Group
B Streptococcus and Escherichia coli are well-known causes of
neonatal sepsis, and group B Streptococcus is a major pathogen
in unexplained late miscarriage. Recent studies have focused
on identifying women who are at highest risk of infectionassociated PTB, for whom preventive treatment may be more
beneficial. Genetic studies have identified gene polymorphisms
in immunoregulatory genes which influence susceptibility to
chorioamnionitis and PTB. Maintenance/restoration of normal
lactobacillary flora is important in prevention of PTB.
212
The vaginal flora constitutes a dynamic and complex ecosystem,
with many different aerobic and anaerobic organisms present
at any one time and at different concentrations. Lactobacillus
spp., including the important hydrogen peroxide-producing
lactobacilli, are the dominant species in normal vaginal flora,
maintaining the vaginal pH between 4.0-4.5. During pregnancy
the vaginal flora changes as a result of the substantial hormone
increases during the first trimester; the concentration of
lactobacilli is ten-fold higher in pregnant women.
Microbiological findings in preterm labour
Comprehensive case-control studies revealed that two groups of
bacteria, bacterial vaginosis organisms (Gardnerella vaginalis
and Bacteroides spp.), and an enteropharyngeal group (E. coli,
Klebsiella spp. and Haemophilus influenzae/parainfluenzae),
were significantly more common in the genital tract of women
in preterm labour (often with chorioamnionitis) than labour at
term 1-3 (Table 1).
In placental and amniotic fluid studies, these and other pathogens
such as Group B Streptococcus were significant causes of
chorioamnionitis 4, and Group B Streptococcus and E. coli are
well-known as major causes of neonatal sepsis. Ureaplasma
urealyticum is more common in women with ruptured
membranes, and is a cause of chronic respiratory disease in
very low birth weight neonates 5. The earlier the gestation of
PTB, the stronger are the statistical associations between these
organisms and adverse pregnancy outcome. Invasive maternal
infection with Listeria monocytogenes is known to carry a high
risk of preterm labour, although the pathogenesis is not due to
ascending lower genital tract flora but is generally bloodborne
from gastrointestinal infection.
Microbiological findings in early pregnancy
and risk of PTB
Prospective vaginal flora studies of women in early pregnancy
have shown significant associations between carriage of certain
microorganisms and increased risk of PTB and preterm prelabour
rupture of membranes 6 (Table 1). The most consistent finding
has been the association between PTB and bacterial vaginosis
(or bacterial vaginosis organisms) in early pregnancy 7, 8. Unlike
the findings of studies in labour, there was no association
between vaginal carriage of enteropharyngeal organisms in early
pregnancy and increased risk of PTB 9.
Symptomatic bacterial vaginosis is characterised by a grey, watery
vaginal discharge, often with a fishy odour. Microbiologically,
bacterial vaginosis is described as an imbalance of vaginal flora with
a reduction or absence of lactobacilli, and an overgrowth of mixed
anaerobic flora, including G. vaginalis and often Mycoplasma
hominis and Mobiluncus spp. (Figure 1). However, 50% of
pregnant women with bacterial vaginosis are asymptomatic. Why
these organisms multiply, many of which are normally present in
small concentrations in the vagina, while the usually prevalent
MICROBIOLOG Y A U STRA LIA • N OV EM BER 2008
In Focus
lactobacilli decrease, is not clear. The role of hydrogen peroxideproducing lactobacilli appears to be important in preventing
overgrowth of anaerobes in normal vaginal flora 10.
Other organisms in pregnancy have also been associated with
increased risk of PTB and adverse pregnancy outcome such as
heavy vaginal carriage/overgrowth of group B Streptococcus 11, M.
hominis 12 (usually with bacterial vaginosis present), Trichomonas
vaginalis 13 and cervical Chlamydia trachomatis 12 and Neisseria
gonorrhoeae. It has been known for many decades that
asymptomatic bacteriuria is associated with adverse pregnancy
outcome 14. Screening and treatment for asymptomatic bacteriuria
at the first antenatal visit is routine in obstetric protocols in the
western world. However, Candida albicans is not associated with
increased risk of adverse pregnancy outcome.
Intervention studies
To determine if the risk of infection-associated PTB can be
reduced, many studies of antibiotic treatment of bacterial
vaginosis, using metronidazole or clindamycin during early to
mid-pregnancy, have been undertaken. The Cochrane Database
of Systematic Reviews 15 reports a meta-analysis of randomised,
placebo-controlled trials of antibiotic treatment of bacterial
vaginosis in pregnancy. Although antibiotic therapy was effective
in eradicating bacterial vaginosis, there was little evidence that
screening and treating all pregnant women with asymptomatic
bacterial vaginosis would prevent PTB and its consequences.
The gestation of treatment (early rather than mid pregnancy)
appears to be important. In the five trials using treatment before
20 weeks, the use of antibiotics showed a significant reduction
in risk of PTB 15.
It is known that women with a previous PTB are at higher risk
of a subsequent PTB. Screening and treatment for bacterial
vaginosis in early pregnancy has been advocated in these women
since several trials have shown a significant reduction in PTB in
this group. Although a recent meta-analysis did not confirm this,
there was a reduction in the risk of preterm prelabour rupture of
membranes in two trials 15.
Intermediate vaginal flora
Recent studies have focused on women with abnormal or
‘intermediate’ vaginal flora (by Gram-stain microscopy) not
fitting the description of bacterial vaginosis. This intermediate
flora is characterised by a reduction in normal lactobacilli, but
overgrowth is by aerobic facultative pathogens not usually found in
bacterial vaginosis 16 (mainly group B streptococci or occasionally
intestinal microorganisms such as E. coli, enterococci). Unlike
bacterial vaginosis, vaginal leukocytosis is present. Several studies
have shown an increased risk of adverse pregnancy outcome in
women with intermediate flora. Two trials of antibiotic treatment
of women with intermediate flora in early pregnancy found a
significantly lower risk of PTB before 37 weeks 15.
Table 1. Vaginal microorganisms and adverse pregnancy outcome.
Organism
Risk of preterm birth:
Sampled in
Sampled in
midtrimester
labour
Risk of preterm prelabour rupture of membranes:
Sampled in
Sampled in
midtrimester
labour
Bacterial vaginosis
++
++
+
G. vaginalis*
+
+
Bacteroides / Prevotella spp.* ++
+
M. hominis*
+
U. urealyticum
+
Group B Streptococcus*
+
+/–
+/–
+†
E. coli
+
Klebsiella spp.
+
+
H. influenzae ∆
+/–
+/–
C. trachomatis
+
+
N. gonorrhoeae
+
+
T. vaginalis
+
+
Asymptomatic bacteriuria
++
+/–
+/–, +, ++ General indication of strength of association and/or number of studies with significant findings
* When present in heavy concentrations
† In late miscarriage
∆ Cause of amnionitis but uncommon
M I CROB I O L O G Y A U S T RALIA • NOVE MB E R 2 0 0 8 213
In Focus
Midtrimester miscarriage
The association between intra-uterine infection and
late miscarriage (16-24 weeks’ gestation) has been largely
unrecognised. In a study of placentas and fetuses in
unexplained late miscarriage, group B Streptococcus was
the most significant pathogen recovered, especially in
women with intact membranes 17. The remaining spectrum of
microorganisms recovered was similar to that found in preterm
labour at later gestations such as bacterial vaginosis organisms
(Bacteroides/Prevotella spp., G. vaginalis), S. anginosus and
U. urealyticum. There were no clinical signs suggestive of
infection in 70% of women in this study, yet microorganisms
were found in 62% of cases (placenta and/or fetus), and 61%
had histological evidence of chorioamnionitis.
Identification of women at high risk of PTB
Since the host response to the presence of microorganisms
may vary, studies of cytokine/inflammatory responses have
been undertaken. Women with immunoregulatory gene
polymorphisms which affect their inflammatory response to
certain microorganisms may be at increased risk of adverse
pregnancy outcome. Studies of cytokine gene polymorphisms
have shown interleukin-10 (IL-10 -1082A/-819T/-592A) and
mannose binding lectin (MBL2 codon 54Asp) single nucleotide
polymorphisms were independently associated with histological
chorioamnionitis and PTB before 29 weeks 18.
Pregnant women with periodontal disease may have a higher
risk of PTB due to the potential to seed the bloodstream with
mouth flora 19.
closely related Lactobacillus species of the vagina. Studies of
changes in vaginal flora after treatment with metronidazole
showed L. iners was the first Lactobacillus to colonise the vagina
post treatment 21, suggesting L. iners is a dominant part of the
vaginal flora when the flora is in a transitional stage.
Further studies using molecular tools are needed to elucidate the
role of Lactobacillus species in maintaining normal vaginal flora.
Studies of the effects of Lactobacillus phages which may decimate
Lactobacillus populations, are also needed. Treatment of bacterial
vaginosis may require not only antibiotics capable of eradicating
anaerobic bacteria but also Lactobacillus suppositories 22 to
re-establish the normal flora, so essential in preventing infectionassociated PTB.
References
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Maintenance of normal lactobacillary flora
11.
Maintenance of normal lactobacillary flora is of primary
importance to a healthy vagina and reduction of PTB. Studies
of Lactobacillus species indicate L. crispatus, L. iners, L. gasseri
and L. jensenii are most likely to be part of the normal flora in
a healthy vagina 20. L. iners deserves close scrutiny, as it was not
found in earlier studies due to its peculiar culture requirements,
and phenotypic methods have not been able to separate the
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
Figure 1. Gram-stain of bacterial vaginosis including
Mobiluncus (Gram-variable curved rods).
214
McDonald, H.M. et al. (1991) Vaginal infection and preterm labour. Br. J. Obstet.
Gynaecol. 98, 427-435.
Krohn, M.A. et al. (1997) Vaginal colonization by Escherichia coli as a risk
factor for very low birth-weight delivery and other perinatal complications. J.
Infect. Dis. 175, 606-610.
Krohn, M.A. et al. (1991) Vaginal Bacteroides species are associated with
preterm delivery in women with preterm labour. J. Infect. Dis. 164, 88-93.
Hillier, S.L. et al. (1991) Microbiologic causes and neonatal outcomes
associated with chorioamnion infection. Am. J. Obstet. Gynecol. 165, 955-961.
Kafetzis, D.A. et al. (2004) Maternal colonization with Ureaplasma urealyticum
promotes preterm delivery: association of the respiratory colonization or
premature infants with chronic lung disease and increased mortality. Clin.
Infect. Dis. 39, 1113-1122.
McDonald, H.M. (1997) The role of vaginal flora in normal pregnancy and in
preterm labor. In Preterm Labour, (Murdo, E. G., Lamont, R.F. and Romero, R.,
eds) p.65-83.
Hillier, S.L. et al. (1995) Association between bacterial vaginosis and preterm
delivery of a low-birth-weight infant. The Vaginal Infections and Prematurity
Study Group. New Engl. J. Med. 333, 1737-1742.
McDonald, H.M. et al. (1992) Prenatal microbiological risk factors associated
with preterm birth. Br. J. Obstet. Gynecol. 99, 190-196.
McDonald, H.M. et al. (1994) Changes in vaginal flora during pregnancy and
association with preterm birth. J. Infect. Dis. 170, 724-728.
Hillier, S.L. et al. (1993) The normal vaginal flora, H2O2-producing lactobacilli and
bacterial vaginosis in pregnant women. Clin. Infect. Dis. 16(Suppl 4), S273-281.
Regan, J.A. et al. (1996) Colonization with group B streptococci in pregnancy and
adverse outcome. VIP Study Group. Am. J. Obstet. Gynecol. 174, 1354-1360.
Polk, B.F. et al. (1989) Association of Chlamydia trachomatis and Mycoplasma
hominis with intrauterine growth retardation and preterm delivery. Am. J.
Epidemiol. 129, 1247-1257.
Cotch, M.F. et al. (1987) Trichomonas vaginalis associated with low birth
weight and preterm delivery. The Vaginal Infections and Prematurity Study
Group. Sex. Transm. Dis. 24, 353-360.
Romero, R. et al. (1989) Meta-analysis of the relationship between asymptomatic
bacteriuria and preterm delivery/low birth weight. Obstet. Gynecol. 73, 576-582.
McDonald, H.M. et al. (2007) Antibiotics for treating bacterial vaginosis in
pregnancy. Cochrane Database Syst. Rev. 1, CD000262.
Ison, C.A. and Hay P.E. (2002) Validation of a simplified grading of Gram-stained
vaginal smears for use in genitourinary medicine clinics. Sex. Transm. Infect.
78, 413-415.
McDonald, H.M. and Chambers H.M. (2000) Intrauterine infection and
spontaneous midgestation abortion: Is the spectrum of microorganisms similar
to preterm labour? Infect. Dis. Obstet. Gynecol. 8, 220-227.
Annells, M.A. et al. (2005) Polymorphisms in immunoregulatory genes and the
risk of histologic chorioamnionitis in Caucasoid women: a case control study.
BMC Pregnancy Childbirth 5, 2.
Xiong, X. et al. (2006) Periodontal diseases and adverse pregnancy outcomes:
a systematic review. Brit. J.Obstet. Gynaecol. 113, 135-143.
Vasquez, A. et al. (2002) Vaginal Lactobacillus flora of healthy Swedish women.
J Clin Microbiol. 40, 2746-2749.
Ferris, M.J. et al. (2007) Cultivation-independent analysis of changes in
bacterial vaginosis flora following metronidazole treatment. J. Clin. Microbiol.
45, 1016-1018.
Larsson, P.G. et al. (2008) Human lactobacilli as supplementation of clindamycin
to patients with bacterial vaginosis reduce the recurrence rate: a 6-month,
double-blind, randomized, placebo-controlled study. BMC Women’s Health 8, 3.
Helen McDonald is an emeritus microbiologist, Women’s & Children’s
Hospital, North Adelaide, where she was the chief medical scientist,
Diagnostic Microbiology Laboratories, until her retirement in 2004. Prior to
merger with the Adelaide Children’s Hospital she was the microbiologist in
charge of the Queen Victoria Hospital Microbiology Laboratories (1976-1995),
and during this time she gained her Gr.DipHA, FASM and PhD. Her major
research interests are the role of vaginal flora/infection in PTB and neonatal
sepsis, and vaginal microbicides for prevention of HIV acquisition.
MICROBIOLOG Y A U STRA LIA • N OV EM BER 2008
Under the Microscope
Mother-to-child transmission of HIV:
positive impacts
of HIV from mother to child became the basis for studies on
strategies for interrupting transmission 4.
Pamela Palasanthiran
Senior Staff Specialist and
Conjoint Senior Lecturer, UNSW
Department of Immunology and
Infectious Diseases
Sydney Children’s Hospital
High Street, Randwick
Tel (02) 9382 1508
Fax (02) 9382 1580
Email pamela.palasanthiran@
SESIAHS.health.nsw.gov.au
Mother-to-child-transmission (MTCT) of HIV remains
the major mode of paediatric HIV infection. Advances
in the prevention of MTCT over the past decade and
a half represent a major public health achievement.
Strategies to prevent MTCT are now the standard of care
for countries rich enough to afford the interventions. As
such, perinatally acquired HIV in countries like the USA
and Europe is now a rare event.
With clearly documented declines in MTCT rates in
resource rich countries, the focus is shifting towards any
downsides of these strategies in pregnant women and for
fetuses exposed in utero to antiretroviral (ARV) drugs and
to infants postnatally. Cumulative evidence still supports
the benefits of these strategies in preventing MCTC of
HIV, with continued benefits for HIV pregnant women
and their infants, and with minimal adverse outcomes.
Knowledge of HIV infection status in pregnancy is
critical for identifying the need for MTCT prevention.
However, antenatal testing rates to identify HIV infected
women is variable and an area that warrants attention.
The overwhelming challenge in the 21st century is up
scaling the availability of MTCT interventions in resource
poor areas where more than 90% of the world’s HIV
infected children now reside, and to develop optimal
MTCT regimens that can be practically adopted in these
settings.
The milestones leading to the current successful MTCT
intervention programmes has been a journey over more than
2 decades. The first was the recognition that the human
immunodeficiency virus was not limited to transmission
among the homosexual population but was also acquired via
heterosexual contact, and transmissible from infected women
to infants 1. The identification of risk factors associated with
MTCT transmission, including the first report from Australia
documenting the role of breast milk as a significant mode of HIV
transmission 2,and more recently, the estimates of the timing of
MTCT transmission3 have set the stage for studies on methods
to interrupt transmission. The major risk factors associated
with MTCT transmission viz. virus burden to which the child is
exposed, duration of exposure and factors facilitating transfer
M I CROB I O L O G Y A U S T RALIA • NOVE MB E R 2 0 0 8 In 1994, the landmark trial on the use of the first licensed ARV,
zidovudine (AZT), to prevent the transmission of HIV from
mother to infants was halted early. Preliminary findings were so
overwhelmingly in favour of its efficacy that continuing the study
was unethical. PACTG 076 was a three part ARV approach to the
interruption of HIV transmission from mother-to-child where
pregnant women received AZT from 14 weeks of gestation, then
intravenously during labour followed by 6 weeks of AZT to the
infant. MTCT transmission was reduced by two thirds (from
22.6% to 8%) 3, 5.
Since then, progress has been such that the three proven
intervention strategies regarding ARV use to decrease maternal
viral load antenatally and postnatal ARVs to infants – a component
of which may be post-exposure prophylaxis, minimising duration
of exposure to HIV by cesarean section before labour and before
rupture of membrane and avoiding continued postnatal exposure
to HIV by formula feeding infants – now achieves a phenomenally
low rate of MTCT transmission. Historical MTCT rates of 20-30%
are now in the order of 1-2% 6-9. The success of these measures
in resource rich settings has been measurable and sustained.
Perinatal HIV incidence in the USA has fallen by about 95% since
1992 10, similar to patterns in the UK and Ireland, and a selected
Italian cohort 6-10.
It appears that, overall, the benefits continue to outweigh
potential risks 11. HIV does not adversely affect the clinical
course of women 12. Combination therapy with highly active
antiretroviral therapy (HAART) during pregnancy is efficacious,
with the majority of women achieving viral suppression 13. Recent
medium-term follow-up supports evidence for healthy maternal
survival after use of ARVS during pregnancy, be it zidovudine
monotherapy or HAART 14. Longer follow-up to 21 years in
an Italian cohort is in further support of this 8. Concerns that
ARVs are associated with prematurity has not been a consistent
finding 15. Whilst concerns about mitochondrial toxicity in infants
exposed to zidovudine in utero have been raised, evidence from
large clinical trials do not support a significant risk of severe
congenital anomalies, increase in malignancy or impaired growth
and development in children exposed in utero to ARVs 16.
However, strategies to prevent transmission can only
be implemented if the diagnosis of HIV infection is known
antenatally. Routine antenatal screening for HIV infection has
long been a controversial issue, with those who argue against
routine antenatal testing basing concerns on human rights issues,
impact of false-positives results, the adequacy of counselling and
appropriate post-test care of the woman 17.
In Australia, paediatric HIV has always been rare. However, of
concern is that children diagnosed with perinatal infection in the
MTCT prevention era (post-1994) reflect missed opportunities
for prevention strategies due to the lack of an antenatal diagnosis
in pregnant HIV infected women. National surveillance data from
1994-2003 report a total of 206 perinatal exposures identified, 34 of
215
Under the Microscope
which resulted in an HIV infected child. A disturbing proportion,
68% (23/34) of infants, were offspring of women whose HIV
diagnosis was not made antenatally (Table 1). Cumulative data
from 1982 – 2006 on the number of perinatally infected children
in Australia show a substantial increase in mother-to-childtransmission rates if HIV infection is made postnatally compared
to antenatally, reflecting the missed opportunities for prevention
of MTCT (Figure 1).
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From Positive Pregnancy, a resource booklet for pregnant
women living with HIV. Paediatric HIV Service, Sydney
Children’s Hospital, Randwick, revised 2008.
:V\YJL!(\Z[YHSPHU7HLKPH[YPJ:\Y]LPSSHUJL<UP[":[H[LHUK;LYYP[VY`OLHS[OH\[OVYP[PLZ
Figure 1: Perinatal HIV infection in Australia (1982 – 2006),
by year of birth and timing of mother’s HIV diagnosis.
Acknowledgement: Ann McDonald, National Centre in HIV
Epidemiology and Clinical Research (NCHECR).
The Royal Australian and New Zealand College of Obstetricians
(RANZCOG) recommend routine testing (a ‘universal testing’
approach) as part of antenatal care, whilst the 2006 National
HIV testing policy recommends routine testing with essentially
an ‘opt-out’ approach 18. The extent of antenatal HIV screening
in Australia is not known but studies indicate that only 50-60%
of obstetricians offer HIV tests antenatally 19, 20. The variable
rate of antenatal HIV testing is also reflected in other centres in
countries resourced to support testing 8, 21, 22.
Overall, the public health challenge for the 21st century is
up scaling access to workable MTCT prevention strategies in
resource poor settings. Simple, successful interventions could
mean preventing millions of HIV infected infants per year. The
news is somewhat encouraging, for example access to ARVs
for MTCT programmes appear to have increased in recent
estimates, although progress is slow, and access to interventions
still remains dismal in areas of greatest need (Figure2) 23. Recent
focus on how to best to minimise transmission of HIV via breast
milk by feeding practice and ARV regimens may provide part of
a workable solution to impact on the current transmission rates
in countries where infants are dependent on breast feeding for
survival 24.
In summary, the news is good for MTCT of HIV in rich countries
where new cases of paediatric HIV are rare, and the downsides
of these programmes minimal. An identified area of concern
is the missed opportunities to prevent cases of HIV infected
infants in these countries for lack of antenatal testing. Significant
challenges exist for extension of the same success in preventing
children from acquiring HIV in poorer countries.
Figure 2: Percentage of pregnant women living with HIV and
HIV exposed infants receiving antiretroviral prophylaxis for
MTCT from seventy one middle and low income countries,
2004 - 2005 23.
12
10
8
11%
6
8%
7%
4
5%
2
0
HIV positive pregnant
women receiving ARVs
2004
2005
HIV exposed infants receiving ARV
Table 1. No. infected infants in Australia identified by timing of maternal HIV testing 1994-2003 18.
Before birth:
No. exposed No. with HIV
At or after birth:
No. exposed
No. with HIV
Total:
No. exposed
No. with HIV
1994-1995
24
7
20
8
44
15
1996-1997
16
3
10
7
26
10
1998-2001
46
0
7
5
54
5
2002-2003
38
1
1
0
39
1
160
11
45
23
206
34
Total
216
MICROBIOLOG Y A U STRA LIA • N OV EM BER 2008
Under the Microscope
References
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
Centers for Disease Control (1982) Unexplained immunodeficiency and opportunistic
infections in infants: New York, New Jersey, California. MMWR Morb. Mortal Wkly.
Rep. 31, 665-667.
Ziegler, J.B. et al. (1985) Postnatal transmission of AIDS-associated retrovirus from
mother to infant. Lancet 1, 896-898.
Kourtis, A.P. et al. (2006) Mother-to-child transmission of HIV-1: timing and
implications for prevention. Lancet Infect. Dis. 6, 726-732.
McIntyre, J. (2006) Strategies to prevent mother-to-child transmission of HIV. Curr.
Opin. Infect. Dis. 19, 33-38.
Connor, E.M. and Sperling, R.S. (1994) Reduction of maternal-infant transmission of
human immunodeficiency virus type 1 with zidovudine (AZT) treatment. N. Engl. J.
Med. 331, 1173-1180.
European Collaborative Study (2005) Mother-to-child transmission of HIV infection
in the era of highly active antiretroviral therapy. Clin. Infect. Dis. 40, 458-465.
European Collaborative Study (2006) The mother-to-child HIV transmission epidemic
in Europe: evolving in the East and established in the West. AIDS 20, 1419-1427.
Martinelli, P. et al. (2008) Epidemiological and clinical features of pregnant women
with HIV: a 21-year perspective from a highly specialized regional center in southern
Italy. HIV Clin. Trials 9, 36-42.
Townsend, C.L. et al. (2008) Low rates of mother-to-child transmission of HIV
following effective pregnancy interventions in the United Kingdom and Ireland,
2000-2006. AIDS 22, 973-981.
Centers for Disease Control and Prevention (2006) Achievements in public health.
Reduction in perinatal transmission of HIV infection: United States, 1985-2005.
MMWR Morb. Mortal Wkly. Rep. 55, 592-597.
Thorne, C. and Newell, M.L. (2007) Safety of agents used to prevent mother-to-child
transmission of HIV: is there any cause for concern? Drug Saf. 30, 203-213.
Gray, G.E. and McIntyre, J.A. (2007) HIV and pregnancy. BMJ 334, 950-953.
Watts, D.H. et al. (2003) Progression of HIV disease among women following
delivery. J. Acquir. Immune Defic. Syndr. 33, 585-593.
14. Martin, F. et al. (200 6) Pregnant women with HIV infection can expect healthy
survival: three-year follow-up. J. Acquir. Immune Defic. Syndr. 43, 186-192.
15. Kourtis, A.P. et al. (2007) Use of antiretroviral therapy in pregnant HIV-infected
women and the risk of premature delivery: a meta-analysis. AIDS 21, 607-615.
16. Townsend, C.L. et al. (2006) Antiretroviral therapy and congenital abnormalities in
infants born to HIV-1-infected women in the United Kingdom and Ireland, 1990 to
2003. J. Acquir. Immune Defic. Syndr. 42, 91-94.
17. Lo, B. et al. (2000) Ethical issues in early detection of HIV infection to reduce vertical
transmission. J. Acquir. Immune Defic. Syndr. S136-S143.
18. National HIV Testing Policy. (2006) http://www.health.sa.gov.au/PEHS/PDF-files/hivtesting-policy-2006.pdf
19. Giles, M.L. et al. (2004) An audit of obstetricians’ management of women potentially
infected with blood-borne viruses. Med. J. Aust. 180, 328-332.
20. Giles, M.L. et al. (2006) The evidence for a change in antenatal HIV screening policy
in Australia. Med. J. Aust. 185, 217-220.
21. Gruslin, A. et al. (2001) Prenatal HIV screening in a tertiary care centre. Can. J.
Public Health 92, 255-258.
22. Simpson, W.M. et al. (1999) Antenatal HIV testing: assessment of a routine voluntary
approach. BMJ 318, 1660-1661.
23. Interagency Task Team. (2007) Guidance on global scale up of the prevention
of mother to child transmission of HIV. http://www.unicef.org/aids/files/PMTCT_
enWEBNov26.pdf
24. Read, J.S. (2008) Prevention of mother-to-child transmission of HIV through breast
milk. Pediatr. Infect. Dis. J. 27, 649-650.
Dr Pamela Palasanthiran (MBBS, MD, FRACP) is a practising staff specialist
in paediatric infectious diseases and a conjoint lecturer at the University of
New South Wales. Her major interests include perinatal infections and she
specialises in paediatric HIV.
Intrauterine infection:
preterm birth and pulmonary impact
Monica M Lahra
Senior Lecturer
Department of Immunology and
Infectious Diseases, Faculty of
Medicine, University of Sydney,
NSW
Email [email protected]
… chorioamnionitis is a condition that cannot be diagnosed
accurately until after the event, its cause appears multifactorial
and non-specific, and treatment cannot be designed until after
the cause is found – and then it is too late. Where are we going
wrong? There is a long road ahead that must be taken because,
in a time of low perinatal morbidity and mortality, the disorder
is rapidly assuming an important role, if only by default. No
longer is chorioamnionitis merely an interesting finding for
pathologists to demonstrate to their colleagues 1.
This is an excerpt from a letter published anonymously
in the Lancet in 1989. Acute chorioamnionitis is the
histological hallmark of intrauterine infection and remains
today the focus of intense, and increasing, research
interest. This interest is underpinned by the association
of chorioamnionitis with preterm delivery. Extreme
prematurity is the fundamental, unresolved problem in
perinatal medicine, has associated high morbidity and
mortality, and accounts for a significant proportion of the
M I CROB I O L O G Y A U S T RALIA • NOVE MB E R 2 0 0 8 health expenditure in the developed world 2. The preterm
delivery rate is increasing in Australia, from 6.8% in 1991
to 8.1% in 2005 1. Advancement in intensive care practice
has increased survival of very preterm neonates, and this
has meant an increase in diseases that are directly related
to prematurity, such as cerebral palsy and neonatal
chronic lung disease (CLD).
Epidemiology
Histological studies of the placentae of live-born infants
consistently report chorioamnionitis to be most common in
preterm populations, with the highest rates in the lowest
gestational age groups, and the predominance in pregnancies
less than 32 weeks’ gestation. A recent Australian study of 3928
preterm infants between 20 -34 weeks’ gestation demonstrated the
clear inverse relationship between histological chorioamnionitis
and gestation, with the incidence of chorioamnionitis in those
born at 20-24 weeks 66%, decreasing to 16% at 34 weeks 2.
Pathogenesis of intrauterine infection
There are four potential pathways for intrauterine infection.
The first and most common route is ascending infection from
the lower genital tract. Infrequently, infection can occur via
retrograde passage of organisms from the peritoneal cavity
via the fallopian tubes, haematogenously from the maternal
circulation and from invasive antenatal diagnostic procedures,
such as amniocentesis 2.
Ascending intrauterine infection
After overgrowth in the vagina and cervix, organisms gain
access to the space between the amniotic membranes and
the uterus to cause localised inflammation, and this can cause
rupture of the membranes. Further extension of infection may
217
Under the Microscope
follow, and/or the organisms can cross the amniotic membranes
(intact or ruptured) to infect the amniotic fluid. Membrane
rupture can also occur at this point, when there is infection and
inflammation on both sides of the membranes 2. Histologically
this initial inflammatory response to ascending infection is seen
as infiltration of predominantly maternal polymorphonuclear
leucocytes (PMNLs) into the membranes (chorion and amnion).
This is termed chorioamnionitis.
A fetal inflammatory response occurs in response to exposure
of the umbilical cord to infected amniotic fluid. The infecting
bacteria and bacterial products in the amniotic fluid activate the
fetal white cells in the blood vessels in the umbilical cord. This
results in PMNLs migrating from the intravascular space of the
umbilical vessels into the vessel walls, and potentially beyond the
vessel walls to the cord stroma. This fetal inflammatory response
to infected amniotic fluid can occur without fetal infection and
contributes to labour onset and delivery. Less commonly, fetal
infection may occur via by aspiration or ingestion of infected
amniotic fluid. Alternatively, skin or mucous membrane infection
can occur in the fetus after contact with infected amniotic fluid,
with the potential for the development of fetal systemic infection.
It is also possible for fetal infection to occur via spread from the
decidual layers to the intervillous space 2.
Thus the inflammatory responses to ascending intrauterine
infection are of both maternal and fetal origin and occur as
part of a continuum, with the initial inflammatory response of
maternal origin and a fetal inflammatory response subsequent.
This explains the relationship of preterm rupture of membranes
(PROM) with intrauterine infection. Evidence supports the
relationship of intrauterine infection as a likely cause and not an
effect of prematurity and PROM. This hypothesis, based on an
understanding of pathogenesis, is a departure from the earlier
and largely discarded supposition that chorioamnionitis is a
complication of both preterm labour and PROM.
Microbiology
The microbiological findings are discussed in this issue by Dr
Helen McDonald.
Diagnosis
The clinical hallmarks of chorioamnionitis include uterine
tenderness, tachycardia, fever and a raised maternal white cell
count. However, in the majority chorioamnionitis is asymptomatic
until labour onset or rupture of membranes. In the current
clinical setting, histological examination of the placenta, extraplacental membranes and umbilical cord is often the mainstay
of diagnosis.
Clinical implications
Intrauterine infection is known to be associated with the
onset of preterm labour and delivery and with a decreased
incidence of neonatal respiratory distress syndrome (RDS).
RDS occurs in preterm infants because of structural and
functional lung immaturity. RDS occurs in 60-80% infants born
at <28 weeks’ gestation, and 10-15% of infants 32-36 weeks’
gestation at delivery 2. Treatment for RDS includes mechanical
ventilation which can result in lung injury from a combination
218
of barotrauma and oxygen toxicity. This lung injury predisposes
the infant to CLD. Further, there is a reported association
of intrauterine infection and CLD which is controversial and
discussed briefly below. Intrauterine infection is also reported
to be associated with sepsis in the newborn, as are adverse
neurological outcomes which will not be discussed here.
Intrauterine infection and preterm labour
Intrauterine bacterial invasion triggers preterm labour via a
number of interacting pathways 2. The bacterial endo and exotoxins
stimulate the uterine lining (decidua) and fetal membranes
to produce a range of proinflammatory cytokines including
tumour necrosis factor (alpha), interleukin-1, interleukin-6,
interleukin-8 and granulocyte colony stimulating factor. Both the
bacterial products and the proinflammatory cytokines induce
prostaglandin production by the chorioamnion, placenta and
decidua, and recruit and activate PMNLs. These activated PMNLs
synthesise and release a range of bioactive products including
collagenases and elastases that degrade connective tissue 3.
The combined effect of prostaglandins and collaganase and
elastase play a key role in initiation of both labour at term 4,
and preterm labour and delivery 2 via a similar final common
pathway. Increased prostaglandin concentration stimulates
uterine contractions and the collagenases and elastases weaken
the chorioamnionitic membranes and remodel and soften the
cervical collagen 2, 3.
It is thought that spontaneous term labour is initiated via the fetal
hypothalamic-pituitary-adrenal axis (HPA) 4. Studies in humans
indicate that the fetal HPA axis is activated by intrauterine
infection 4. The HPA axis is part of the peripheral stress system.
Interleukin-1, interleukin-6 and tumour necrosis factor (alpha)
independently and, in combination synergistically, activate the
HPA axis during the stress of inflammation.
The end products of HPA activation are glucocorticoids which
inhibit the production and effect of inflammatory cytokines
5
. Glucocorticoids also accelerate maturation of the fetal lung
physiologically, morphologically and biochemically 6. This is the
biological rationale for both the reduction of RDS in the presence
of intrauterine inflammation, and therapeutic maternal antenatal
steroid administration in preterm labour.
Intrauterine infection and pulmonary implications
In 1969 Liggins demonstrated that glucocorticoids decreased
RDS and enhanced survival in preterm lambs 3. Studies have
shown that the presence of chorioamnionitis is associated with
a significant decrease in the incidence of RDS. A very recent
study of preterm newborns investigated the impact of fetal
versus maternal inflammatory responses on the incidence of
RDS. A greater reduction in odds for RDS with found with a fetal
inflammatory response (adjusted OR 0.23, 95% CI 0.15-0.35)
than with a maternal inflammatory response (chorioamnionitis)
(adjusted OR 0.49, 95% CI 0.31-0.78) 4. This indicates a dose
response relationship between the degree of inflammatory
response and reduction in RDS 4.
Early studies showed chorioamnionitis to be associated with
CLD; however, recent studies in the current clinical context have
MICROBIOLOG Y A U STRA LIA • N OV EM BER 2008
Under the Microscope
shown no relationship or a protective effect 3-6. The postulation
that intrauterine infection reduces RDS but increases CLD is
difficult to reconcile biologically, as RDS and its treatment, and
mechanical ventilation and oxygen therapy independently, are on
the causal pathway for CLD 6.
Intrauterine infection, neonatal sepsis and CLD
An immature immune system predisposes the preterm infant to
infection. Neonatal sepsis is defined as early or late onset. This is
because infection occurring early after delivery is often associated
with transmission from the mother (vertical transmission),
whereas late onset neonatal sepsis is generally nosocomially
acquired. Australian multi-centre data show the incidence of late
onset sepsis in infants <1000 grams to be 22.6%, and decreasing
with increasing gestation 7.
There is conflicting evidence regarding the association of
intrauterine infection and neonatal sepsis, regardless of onset.
However, neonatal sepsis has been shown to be an independent
risk factor for CLD. This has significant implications given that the
majority of neonatal sepsis is nosocomially acquired.
Future research
Many questions remain regarding intrauterine infection and its
impact on the fetus and neonate. What is clear is that the most
crucial relate to primary prevention of this disease, and to the
improvement in infection control in the newborn intensive
care.
References
1.
National Perinatal Statistics Unit, AIHWA Australia’s Mothers and Babies (2005)
http://www.npsu.unsw.edu.au/NPSUweb.nsf/page/ps20.
2.
Goldenberg, R.L. et al. (2000) Intrauterine infection and preterm delivery. New
Eng. J. Med. 342, 1500-1507.
3.
Andrews, W.W. et al. (2006) The Alabama preterm birth study: polymorphonuclear
and mononuclear cell placental infiltrations, other markers of inflammation,
and outcomes in 23- to 32-week preterm newborn infants. Am. J. Obstet.
Gynecol. 195, 803-808.
4. Kent, A. and Dahlstrom, J.E. (2004) Chorioamnionitis/funisitis and the
development of bronchopulmonary dysplasia. J. Paediatr. Child Health 40,
356-359.
5.
Redline, R.W. et al. (2002) Placental and other perinatal risk factors for chronic
lung disease in very low birth weight infants. Pediatr. Res. 52, 713-719.
6.
Lahra, M. et al. (2008) Intrauterine inflammation, neonatal sepsis and chronic
lung disease: a 13 year hospital cohort study. Pediatr. In press.
7.
Isaacs, D. et al. (1996) Late-onset infections of infants in neonatal units.
J. Paediatr. Child Health 32, 158-161.
Monica Lahra (BA, MBBS, Dip Paed, FRCPA, MASM) is a medical microbiologist
trained at the Prince of Wales Hospital in Sydney. Her recently submitted
PhD thesis focused on the impact of intrauterine infection on the fetus and
neonate. Her research interests include perinatal infection and infection
in childhood. She has co-authored the chapter The impact of infection in
pregnancy in the 4th edition of Fetal and Neonatal Pathology by JW Keeling
and T Yee Khong (Eds).
Call for Nominations – President-Elect
Associate Professor Keryn Christensen’s term
as Immediate Past President concludes at the
Annual General Meeting which will be held
in July 2009. In accordance with the ASM
Constitution, nominations are invited for the
position of President-Elect of the Society, to
take office in July 2009 following the Annual
General Meeting. The President-Elect will hold
office until the next Annual General Meeting,
to be held in July 2010, at the conclusion of
which he or she will become President.
Candidates for election to the position of
President-Elect shall be Honorary Life Members,
Financial Fellows, Members or Senior Associate
Members of the ASM and be proposed and
seconded by Honorary Life Members, Financial
Fellows, Members or Senior Associate Members
of the Society. Nominations must have the
written consent of the candidate.
Nominations must be received by the ASM
National Office Manager before 5pm Wednesday
31 December 2008. Please use the nomination
for the position of President-Elect form, which
is set out opposite.
M I CROB I O L O G Y A U S T RALIA • NOVE MB E R 2 0 0 8 Nomination for the position of President-Elect of the Australian
Society for Microbiology Inc
We the undersigned wish to nominate:
__________________________________________________________________
of: _______________________________________________________________
for the position of President-Elect of the Australian Society for Microbiology Inc.
Proposer (FASM / MASM / SASM / Honorary Life Member)
Name: ___________________________________________________________
Signature: ________________________________________________________
Seconder (FASM / MASM / SASM / Honorary Life Member)
Name: ___________________________________________________________
Signature: ________________________________________________________
I accept this nomination for the position of President-Elect of the Australian
Society for Microbiology Inc.
Name: ___________________________________________________________
Signature: ________________________________________________________
Date: ________________________________
Address your envelope as follows:
National Office Manager, Australian Society for Microbiology Inc
Suite 23, 20 Commercial Road, Melbourne VIC 3004
Alternatively you may fax your nomination form to the National Office on (03) 9867 8722
219
ASM Affairs
National Scientific Advisory Committee (NSAC)
Divisional Chairs 2011
Call for expressions of interest
Expressions of interest are requested for the following positions
on the National Scientific Advisory Committee (NSAC).
• Provide input and advice to the organisers of the 2010 Annual
• Division 1 Chair (2011)
Medical and Veterinary Microbiology
• Provide scientific advice to the society as a member of NSAC.
• Division 2 Chair (2011)
Virology
• Division 3 Chair (2011)
General, Applied and Environmental Microbiology
Scientific Meeting.
It is envisaged that the divisional representatives will be
researchers and scientists with enthusiasm, good organisational
and communication skills, and broad knowledge and an excellent
or developing reputation in the divisional field.
• Division 4 Chair (2011)
Microbial Genetics, Physiology and Pathogenesis
Fellows, Members, Senior Associate or Associate Members
The successful appointees will have the opportunity to serve a
3 year term of office, concluding at the end of the 2011 Annual
Scientific Meeting, which will be held in Hobart.
honorary positions should submit a brief curriculum vitae (no
The primary responsibilities of the Division Chairs will be to:
Associate Professor Liz Harry (Vice-President, Scientific Affairs)
• Organise the symposium component of the 2011 Annual
Scientific Meeting.
by email to the National Office [email protected]
interested in serving in these exciting and challenging new
more than two pages), together with an appropriate covering
letter to:
by 21 December 2008.
ASM Distinguished Service Award
The Distinguished Service Award recognises outstanding
service of, or contributions by, individuals or organisations to
the Society.
Procedure for nomination
Individual ASM Members or Fellows, Committees or Branches
may nominate individual ASM members or organisations for
a Distinguished Service Award. Nominations should be sent
to the National Office Manager, Michelle Jackson (michelle@
theasm.com.au).
A person or organisation shall not be considered for a
Distinguished Service Award unless the National Office has
received from the proposers:
• a nomination for Distinguished Service Award signed by the
proposer and a seconder, each of whom shall be a Member
or Fellow of the Society; and
Assessment and award
The Executive Committee will review the nominations received
and place those considered acceptable and of sufficient merit
in priority order. The Executive Committee will present a
summary report on nominations received and the names of up
to 10 recommended awardees to National Council. No more
than 10 Distinguished Service Awards shall be awarded in any
one year. Distinguished Service Awards will be announced
at the next Annual General Meeting and the ASM National
Conference.
Closing date for nominations: 30 November of any year.
Acknowledgement: An acknowledgement will be emailed
within 5 business days of receiving your application. If this has
not been received, please contact Michelle Jackson at the ASM
National Office on (03) 9867 8699.
• a statement summarising the nominee’s major contribution
to the Society.
220
MICROBIOLOG Y A U STRA LIA • N OV EM BER 2008
ASM Affairs
New ASM Life Member, Ruth Bishop AO
Ruth Bishop is a graduate in microbiology from the University
of Melbourne. Her long-term research career, based at the
Department of Gastroenterology at the Royal Children’s Hospital
Melbourne, and later at the Murdoch Children’s Research Institute,
Melbourne, focused initially on qualitative and quantitative
studies of gut flora, in particular of the small intestine in children
with a variety of malabsorptive diseases including coeliac disease,
cystic fibrosis, sugar malabsorption and short-gut syndrome.
In 1971 she combined with paediatricians Rudge Townley
and Graeme Barnes in research aimed at understanding the
pathophysiology of severe acute gastroenteritis in young children.
This research showed that the duodenum of these children
was acutely inflamed, indicating the presence of an ‘unknown’
infectious agent. In 1973 she led a team, including paediatrician
Geoff Davidson, electron microscopist Brian Ruck and virologist
Ian Holmes, that discovered a ‘new’ virus (now called rotavirus)
in duodenal tissue and faeces from children admitted to hospital
with severe dehydrating gastroenteritis.
Ruth has subsequently pursued the goal of preventing this
serious infection that still kills more than half a million children
each year worldwide. Careful immunological, epidemiological
and virological studies within Australia, and globally via her
role in chairing several WHO Committees and as Director of a
WHO Collaborating Laboratory, have influenced international
development of rotavirus vaccines. It is a tremendous local
outcome of the worldwide program that oral rotavirus vaccines
were introduced into the routine immunisation schedule for
all Australian children from July 2007. The Group continues
to develop a cheap, affordable Australian candidate rotavirus
vaccine aimed at use in developing countries.
Ruth has been the recipient of many awards including the
University of Melbourne Selwyn-Smith Prize for Clinical Research
(1978), The Clunies Ross National Science and Technology Award
(1998), The Children’s Vaccine Initiative Award (Geneva, 1998)
Royal Children’s Hospital Gold Medal (1994), and Honorary
Fellowship of the Royal Australasian College of Physicians (2008).
Ruth was made a Life Member of the Australian Society for
Microbiology in July 2008.
Ruth Bishop AO, DSc, PhD
Senior Principal Research Fellow
Murdoch Children’s Research Institute
Royal Children’s Hospital, Flemington Rd, Parkville VIC 3052
Tel (03) 9345 5062
Fax (03) 9345 6240
Email [email protected]
Obituaries
Graeme Laver
ASM member Dr Graeme Laver has died in London at the age of
79. Graeme’s research on the influenza virus spanned a period
of more than 30 years. His work at the John Curtin School
of Medical Research, ANU, helped develop the anti-flu drug
Relenza. In 1996, Graeme was awarded the Australia Prize for
excellence in the field of pharmaceutical design. Graeme was
very much a public figure and his lectures at ASM meetings often
attracted media attention. His last contribution to Microbiology
Australia was in the special influenza (November 2006) issue.
This contribution was another interesting perspective on the
origins of pandemic influenza.
Milton RJ Salton, FRS
Milton Salton received his BAgSci degree in 1945 from the
University of Sydney. In 1948, Salton was awarded a CSIRO
fellowship for postgraduate study at Cambridge, receiving a
PhD in 1951 and subsequently a ScD. At Cambridge he began
his pioneering studies that led to the discovery of the bacterial
cell wall. He continued these investigations during postdoctoral
studies at the University of California. In 1956, Salton was
appointed as a Reader of Chemical Bacteriology at the University
of Manchester. In 1961 he returned to the University of New
M I CROB I O L O G Y A U S T RALIA • NOVE MB E R 2 0 0 8 South Wales as the Foundation Professor of Microbiology. In 1964,
he was recruited by Severo Ochoa, NL to head the Microbiology
Department at New York University School of Medicine. He
remained there for over 25 years as Professor and Chairman until
his retirement in 1991.
Many of Salton’s seminal papers on the bacterial cell wall were
published in the 1950s and early 1960s. In a paper published in
Nature in 1952, Salton showed that the cell wall is the substrate
for lysozyme action in Micrococcus lysodeicticus, and between
1951 and 1961 he published a series of eight papers with the
common title Studies of the bacterial cell wall. These and other
publications helped to explain why bacteria either do or don’t take
up the Gram stain and also laid the basis for the understanding
of the mechanism of action of penicillin on bacterial cell wall
synthesis. His later work at NYU focused on both the physical and
biochemical elucidation of the unique macromolecular structure
of the bacterial cell wall and the multiple functions it served.
The above was extracted from an article written by Joel D
Oppenheim and Jan Vilcek (New York University School of
Medicine, New York), and published in the American Society for
Microbiology’s Microbe Magazine.
221
ASM Affairs
IUMS 2008
Microbiologists met where East meets West – Istanbul, Turkey
biotechnology and biobusiness symposium. Invited speakers Dr
Stuart Cordwell (University of Sydney) and Dr Wieland Meyer
(Westmead Hospital, Sydney) talked on the Comparative surface
proteomics and glycoproteomics of virulent Campylobacter
jejuni and MLST typing in Crytococcus neoformans species
respectively. At the virology congress, fascinating developments
in viral genomes and bioinformatics as well as emerging viral
pathogens were covered; Dr TuckWeng was the representative
from Australia.
Bosphorus Bridge
View of Golden-Horn from the Congress Centre.
Meetings of the three divisions of the International Union
of Microbiological Societies (IUMS) – hosted by the Turkish
Microbiological Society, the Society for Microbial Ecology and
the Society of Chemotherapy – took place in Istanbul, Turkey in
August. The meeting started with the XII International Congress of
Bacteriology and Applied Microbiology and the XII International
Congress of Mycology (5-9 August 2008) and was followed by
the XIV International Congress of Virology (10-15 August 2008).
Prof. Michael Hecker (Germany), Prof. Mariana Viviani (Italy)
and Prof. Robert Lamb (USA) chaired the programmes for
the bacteriology, mycology and virology divisions respectively.
Australia was represented in the international advisory boards for
all of the three divisions of the IUMS.
Current IUMS President Prof. Karl-Heinz Schleifer (Germany) and
Chairman of the Turkish National Organising Committee Prof.
Özdem Ang welcomed the participants at the opening ceremony
while the screen was filled with beautiful views of Istanbul and
Turkish folk dancers performed on the stage.
Australia was represented in significant numbers of participants
chairing symposia or delivering oral and poster presentations.
Prof. Hatch Stokes represented the ASM and Prof. David Ellis
attended the Mycology Division Committee meetings which
took place throughout the conference. Current Chair of the
IUMS mycology division Prof. Graham Fleet (UNSW) chaired the
Food mycology symposium and Prof. Barbara Howlett (University
of Melbourne) gave the keynote lecture on Mechanisms of
fungal pathogenesis in plants and animals. The symposium
Interactions in the microbial world was chaired by Prof.
Steffan Kjelleberg (UNSW), and Dr Ipek Kurtböke (USC) chaired
the Actinobacteria: an unexhausted source for biodiscovery,
222
All three Congresses captured recent advances ranging from
metabolic engineering, functional genomics/pathogenomics,
physiological proteomics, and systems microbiology to
biotechnology and applied microbiology expanding towards
bioenergy. They also covered the evolving global landscape
to biosafety and pathogen security practices as well as the
emerging pathogens. Other highlights included Antibiotics and
pathogenicity, chaired by Prof. Julian Davies (Canada) and Bergey
plenary session: taxonomy of prokaryotes, chaired by Prof.
James Staley (USA) and Prof. Karl-Heinz Schleifer (Germany).
In the symposium organised by the World Federation of Culture
Collections, Facing the transition from culture collections to
biological resource centre was discussed. Current international
progress included in that symposium again provided impetus
for us to provide support towards formal recognition of the
Australian Microbial Resources Research Network. On a personal
note, I was delighted to greet my Australian colleagues in
beautiful Istanbul where I grew up.
Full details of the Congress programme and names of the
Australian participants can be viewed at http://www.iums2008.
org/. The next IUMS will be in Sapporo, Japan in 2011.
Ipek Kurtböke
University of the Sunshine Coast, QLD
Ipek Kurtböke, David Ellis & Hatch Stokes sailing on the
Bosphorus at the congress dinner.
Prof. J Martin and Prof. P Liras of Spain with Ipek Kurtböke at
the Actinobacteria symposium.
MICROBIOLOG Y A U STRA LIA • N OV EM BER 2008
What’s On
2008-2010 meetings
Contributions listing relevant meetings are welcome. Please send to: [email protected]
2008
12 November 2008
Food Science Australia, Brisbane QLD
Food Microbiology Seminar Series:
Tales from the Green Book
Gary Grohman (Enviro Path) on Ch.22 – Viruses
Sofroni Eglezos, Series Coordinator & ASM Food Micro SIG
Tel (07) 3848 3622
Email [email protected]
4-7 December 2008
Foshan, China
2nd Annual World Congress of Gene-2008 (WCG 2008):
Decoding Life for Human Health
The tradition of the conference dates back to 3 years ago in
Dalian, China, which brought together five Noble Prize Laureates
and more than 3000 participants to celebrate the discovery of the
double helix.
www.bitlifesciences.com/wcg2008
2009 – Golden Jubilee Year
22-25 February 2009
Baltimore, MD, USA
7th ASM Biodefense and Emerging Diseases Research Meeting
25-28 March 2009
Cypress Lakes Resort, Hunter Valley NSW
ASID 2009 – Australasian Society for Infectious Diseases
(ASID) Annual Scientific Meeting
10-13 May 2009
Buenos Aires, Argentina
VTEC 2009 – 7th International Symposium on Shiga Toxin
(Verocytotoxin) – Producing Escherichia coli Infections
www.vtec2009.com.ar
17-21 May 2009
Philadelphia, PA, USA
109th General Meeting of American Society for Microbiology
www.asm.org
21-25 June 2009
Hamilton Island QLD Australia
10th International Symposium on
Double-Stranded RNA Viruses
Coordinators: Barbara Coulson & John Taylor
www.dsrna2009.org
28 June – 2 July 2009
Goteborg, Sweden
FEMS 2009 – Third Congress of European Microbiologists:
Microbes and Man – Interdependence and Future Challenges
www2.kenes.com/fems-microbiology/Pages/home.aspx
6-10 July 2009
Perth Convention Centre, Perth WA
ASM 2009 Perth – Annual Scientific Meeting & Exhibition
Australia’s largest microbiology event for 2009
celebrating ASM’s 50th Golden Jubilee Year.
Chair, Local Organising Committee: Rod Bowman
Chair, Scientific Programme Committee: Harry Sakellaris
Conference Management: Australian Society for Microbiology
Contact: Janette Sofronidis, Conference Manager
www.asid.net.au
30 March – 2 April 2009
Harrogate International Centre, UK
SGM 164th Meeting
7-9 May 2009
The Carrington Hotel, Katoomba,
Blue Mountains, NSW
Viruses in May
Australia’s only meeting focused specifically on the clinical,
diagnostic & management aspects of viral infections.
Programme themes:
• Principles of clinical virology
• Congenital infection
• Paediatric infection & vaccination
• Blood borne viruses
• Hepatitis
Convenors: Professor Bill Rawlinson & Dr Monica Lahra
Conference Management: Australian Society for Microbiology
Contact: Meg Lukies, Event Coordinator
www.virusesinmay.com
M I CROB I O L O G Y A U S T RALIA • NOVE MB E R 2 0 0 8 29-31 October 2009
Hamilton Island, QLD
Mycology MasterClass IV
[1 November 2009 – Additional MasterClass Workshop for
laboratory staff]
Convenor: Associate Professor David Ellis
Conference Management: Australian Society for Microbiology
Contact: Janette Sofronidis, Conference Manager
2010
28 June – 1 July 2010
Melbourne Convention and Exhibition Centre,
Melbourne VIC
11th International Symposium on the Genetics of Industrial
Microorganisms
Chair: Ian Macreadie
www.gim2010.org
4-8 July 2010
Darling Harbour Convention Centre, Sydney NSW
ASM 2010 Sydney
223
Who’s Who
Australian Society for Microbiology Incorporated
NATIONAL COUNCIL
EXECUTIVE
President
Prof Hatch Stokes
Past President
Assoc Prof Keryn Christiansen
Vice-President, Scientific Affairs
Assoc Prof Liz Harry
Vice-President, Corporate Affairs
Dr Johnson Mak
BRANCH DELEGATES
ACT/ Ian Carter
NSW
QLD Dr Sandra Hall
SA
Stephen Davies
TAS Dr Louise Roddam
VIC Sue Cornish
WA
Suellen Blackaby
NT (sub branch) Mr Kevin Freeman
Chair, National Scientific Advisory
Committee
Assoc Prof Liz Harry
Chair, National Examinations Board
Prof Peter Coloe
Chair, National Qualifications
Committee
Dr Ruth Foxwell
Convenor, Visiting Speakers Program
Dr Mary Barton
Editor, Microbiology Australia
Prof Ian Macreadie/Mrs Jo Macreadie
Registrar, National Examinations
Board
Assoc Prof Margaret Deighton
Public Officer of the Society
Dr Ruth Foxwell
Executive Officer
Dr Carol Ginns
National Office Manager
Michelle Jackson
Conference Manager
Janette Sofronidis
Event Coordinator &
Registration Services
Meg Lukies
Membership Services
Lina Raco
BRANCH SECRETARIES
ACT/NSW Kerry Varettas
Senior Hospital Scientist
SEALS Microbiology
St George Hospital
Gray Street, Kogarah NSW 2217
Tel (02) 9350 3325
Fax (02) 9350 3349
Email [email protected].
nsw.gov.au
QLD Dr Patrick Blackall
Animal Research Institute
Locked Mail Bag 4
Moorooka QLD 4105
Tel (07) 3362 9498
Email [email protected]
SA Stephen Davies
Women’s & Children’s Hospital
Mycology Section
72 King William Road
North Adelaide
Tel (08) 8161 7365
Email [email protected]
TAS Ms Sarah Foster
LGH, Cnr Franklin and Charles Streets
Launceston TAS 7250
Tel (03) 6348 7670
Email [email protected]
VIC Ms Sue Cornish
Mayfield Education Centre
2-10 Camberwell Road
Hawthorn East VIC 3123
Tel (03) 9811 9012
Email [email protected]
224
WA Miss Nicola Barrett
PathWest Microbiology and
Infectious Diseases
QE2 Medical Centre, SCGH
Hospital Avenue, Nedlands WA 6009
Tel (08) 9224 2444
Email [email protected]
NT (sub branch) Mr Paul Southwell
Royal Darwin Hospital
Microbiology
TIWI NT 8100
Tel (08) 8922 8004
Email [email protected]
CONVENORS OF ASM
STANDING COMMITTEES
ASM Foundation
Dr Ray Akhurst
CSIRO, Division of Entomology
GPO Box 1700, Canberra ACT 2601
Tel (02) 6246 4123
Email [email protected]
BioSafety
Mr Lee Smythe, Supervising Scientist
WHO/FAO/OIE Collaborating Centre
for Reference & Research on Leptospirosis
Queensland Health Scientific Services
39 Kessels Rd, Coopers Plains QLD 4108
Tel (07) 3274 9064 Fax (07) 3274 9175
Email [email protected]
Clinical Microbiology
Dr Stephen Graves
Director of Microbiology
Hunter Area Pathology Service (HAPS)
John Hunter Hosp, Newcastle NSW 2300
Tel (02) 4921 4420
Mobile 0407 506 380
Fax (02) 4921 4440
Email [email protected].
gov.au
Ethics Committee
Emeritus Prof Nancy Millis
University of Melbourne
School of Microbiology, Parkville VIC 3052
Tel (03) 9344 5707
Email [email protected]
National Scientific Advisory
Committee
Assoc Prof Liz Harry
University of Technology Sydney
Inst. for Biotech. of Infect. Diseases
Broadway NSW 2007
Tel (02) 9514 4173 Fax (02) 9514 4021
Email [email protected]
Publications/Editorial Board
Dr Ailsa Hocking
CSIRO, Div Food Science & Technology
PO Box 52, North Ryde NSW 2113
Tel (02) 9490 8520
Email [email protected]
Research Trust Advisory &
Development Committee
Assoc Prof Elizabeth Dax
National Serology Reference Laboratory
4 Fl, Healy Building
41 Victoria Parade, Fitzroy VIC 3065
Tel (03) 9418 1111
Email [email protected]
convenors of asm special
interest groups
Division 1
Antimicrobials
Dr John Merlino
Concord Repatriation General Hospital
Microbiology and Infectious Diseases
Hospital Road, Concord NSW 2173
Tel (02) 9767 6658
Email [email protected]
Mycobacteria
Dr Janet Fyfe
Mycobacterium Reference Laboratory
Victorian Infectious Diseases
Reference Laboratory, 10 Wreckyn Street
North Melbourne VIC 3051
Tel (03) 9342 2617 Fax (03) 9342 2666
Email [email protected]
Mycology
Dr Weiland Meyer, Westmead Hospital
ICPMR CIDMLS Microbiology
Level 2, Room 3114A
Darcy Road, Westmead NSW 2145
Tel (02) 8344 5701
Email [email protected]
Mycoplasmatales
Dr Steven Djordjevic
Elizabeth Macarthur Agricultural Institute
Private Mail Bag 8, Camden NSW 2570
Tel (02) 4640 6426
Email [email protected]
Ocular Microbiology
Dr Carol Lakkis
University of Melbourne
Clinical Vision Research Aust
Crn Cardigan & Keppel St
Carlton VIC 3053
Tel (03) 9349 7420
Fax (03) 9349 7498
Email [email protected]
Parasitology & Tropical Medicine
Dr Andrew Butcher
Senior Medical Scientist
Adjunct Senior Lecturer
University of South Australia
Institute of Medical & Veterinary
Science
The Queen Elizabeth Hospital
Department of Clinical Microbiology &
Infectious Diseases
28 Woodville Road, Woodville SA 5011
Tel (08) 8222 6728
Fax (08) 8222 6032
Email [email protected]
Public Health Microbiology
Dr Geoffrey Hogg
University of Melbourne
Microbiological Diagnostic Unit
Parkville VIC 3052
Tel (03) 8344 5713
Email [email protected]
Clinical Serology & Molecular
David Dickeson
Serology Manager, Centre for Infectious
Diseases & Microbiology Lab Services
Level 3, ICPMR, Westmead Hospital
Westmead NSW 2145
Tel (02) 9845 6861 Fax (02) 9633 5314
Email [email protected].
nsw.gov.au
Veterinary Microbiology
Dr Glenn Browning
The University of Melbourne
Vet Preclinic Centre
Gratton Street, Parkville VIC 3052
Tel (03) 8344 7342
Email [email protected]
Women’s & Children’s Microbiology
Convenor
Dr Suzanne Garland
Royal Children’s Hospital
Microbiology, 132 Grattan Street
Melbourne VIC 3000
Tel (03) 9344 2476
Email [email protected]
Secretary
Mr Andrew Lawrence
Women’s & Children’s Hospital
Microbiology & Infectious Diseases Dept
72 King William Rd, Nth Adelaide SA 5006
Tel (08) 8161 6376
Fax (08) 8161 6051
Email [email protected]
Division 2
Virology
Vacant
Division 3
AquaSIG – Water Microbiology
Mr Simon Rockliff
ACT Health
ACT Government Analytical Laboratories
Micro Section, Locked Bag 5,
Western Creek ACT 2611
Tel (02) 6205 8701 Fax (02) 6205 8703
Email [email protected]
Cosmetics & Pharmaceuticals
Dr Paul Priscott
AMS Laboratories Pty Ltd
8 Rachael Close
Silverwater NSW 2128
Tel (02) 9704 2300
Mobile 0414 772 096
Fax (02) 9737 9425
Email [email protected]
Culture Media
Mr Peter Traynor
Oxoid Australia Pty Limited
20 Dalgleish Street, Thebarton SA 5031
Tel 1800 33 11 63
Email [email protected]
Education
Dr Chris Burke
Degree Coordinator
National Centre for Marine Conservation
and Resource Sustainability
University of Tasmania, Locked Bag 1370
Launceston TAS 7250
Tel (03) 6324 3806
Fax (03) 6324 3804
Email [email protected]
Food Microbiology
Sofroni Eglezos
Technical Manager
EML Consulting Services Qld Pty Ltd
1/148 Tennyson Memorial Avenue
Tennyson QLD 4105
Tel (07) 3848 3622 Fax (07) 3392 8495
Mobile 0410 664 530
Email [email protected]
www.eml.com.au
Laboratory Management
Captain Dennis Mok, MASM
2nd Division, Randwick Barracks
Randwick NSW 2031
Email [email protected]
Microbial Ecology
Dr John Bowman
University of Tasmania Antarctica CRC
GPO Box 252-80, Hobart TAS 7001
Tel (03) 6226 2776
Email [email protected]
Microbial Informatics
AProf Michael Wise
University of Western Australia
Biochemistry M310
35 Striling Highway, Crawley WA 6009
Tel 08 6488 4410
Fax 08 6488 1148
Email [email protected]
Probiotic & Enteric Microbial
Diversity SIG
Dr James Chin, NSW Agriculture
PO Box 128, Glenfield NSW 2167
Tel (02) 4640 6359
Email [email protected]
Rapid Methods
Vacant
Students
Convenor
Si Ming Man
PhD Candidate, School of Biotechnology
& Biomolecular Sciences
University of New South Wales
Sydney, NSW 2052
Tel (02) 9385 3514
Fax (02) 9385 1483
Email [email protected]
Division 4
Molecular Microbiology
Dr Peter Lewis
School of Environmental & Life Sciences
University of Newcastle
Callaghan NSW 2308
Tel (02) 4921 5701
Fax (02) 4921 6923
Email [email protected]
MICROBIOLOG Y A U STRA LIA • N OV EM BER 2008