Download Review of Notifiable Diseases in the South Metropolitan

Review of notifiable
diseases in the South
Metropolitan Health
Service – 2014
Disease Control Section
South Metropolitan Population Health Unit
July 2015
health.wa.gov.au
health.wa.gov.au
Review of notifiable diseases in the South Metropolitan Health Service – 2014.
Disease Control Section - South Metropolitan Population Health Unit.
For enquiries contact:
Disease Control Section
South Metropolitan Population Health Unit
PO Box 546, Fremantle, Western Australia 6959
Phone: (08) 9431 0200
Email: [email protected]
i
Contents
Summary
iv
Introduction
1
Background
1
Notifiable diseases
1
Childhood immunisation
1
Data sources and validity
2
Overview of notifiable diseases
3
Vaccine preventable diseases
6
Pertussis
6
Influenza
8
Hepatitis A
11
Measles
11
Invasive pneumococcal disease
12
Varicella zoster virus
13
Rotavirus
14
Rubella
14
Tetanus
14
Mumps
15
Immunisation rates
16
Vector borne diseases
20
Chikungunya
20
Dengue
20
Ross River virus and Barmah Forest virus
20
Other vector borne diseases
21
Sexually transmitted infections
22
Chlamydia
22
Gonorrhoea
23
Syphilis
24
Blood borne viruses
25
Hepatitis C
25
Hepatitis B
25
Enteric diseases
26
Campylobacterosis
26
Salmonellosis
26
ii
Other enteric diseases
27
Gastroenteritis outbreaks in residential care facilities
27
Other diseases
28
Invasive meningococcal infection
28
Legionellosis
29
Tuberculosis
29
Rabies post-exposure prophylaxis
29
References
30
iii
Summary
There were 11,694 communicable diseases notified in the South Metropolitan Health Service
(SMHS) in 2014. This was an increase of 8.0% from 2013 (10,826 cases) which was primarily
due to an increase in influenza and campylobacteriosis notifications. Chlamydia was the most
commonly notified disease with 4,120 notifications, followed by influenza with 1,673 cases, and
varicella zoster with 1,066 notifications.
Despite relatively high vaccination coverage, pertussis notification rates have increased in
Australia in recent years. The last pertussis epidemic in the SMHS and Western Australia (WA)
peaked in 2011, but a new, higher non-epidemic baseline now seems to have been reached
with 676 cases notified in 2014 in the SMHS, compared to 60 in the pre-epidemic year of 2007,
suggesting there is ongoing transmission of pertussis in the community.
There were 1,673 influenza cases notified in 2014, which was nearly double the number of
cases notified in 2013 (n=856), but similar to the 2012 season (n=1,742).
There were 17 cases of measles notified in the SMHS in 2014 compared with 6 in 2013. This
was part of an Australia wide increase in notifications due to imported measles from Asia, which
was linked to an outbreak in the Philippines. Over three quarters (76%) of SMHS cases
acquired measles overseas and the remaining cases acquired in Australia were all contacts of a
confirmed case who had acquired the disease overseas. This highlights that measles is
essentially a traveller’s disease imported from high prevalence countries.
In 2014 there was one notification of tetanus in an elderly person which was the first case
notified in the SMHS since 1998. Tetanus is an acute, often fatal vaccine preventable disease,
caused by toxin from the organism Clostridium tetani resulting in severe muscle spasms, often
requiring prolonged ventilation.
There was a fall in the proportion of Australian Childhood Immunisation Register (ACIR)
coverage for two year olds who were fully immunised in the September quarter of 2014 in the
SMHS, WA and Australia. This was due to the addition of meningococcal C vaccine, varicella
vaccine and dose 2 of measles, mumps, rubella (MMR) vaccine (replacing dose 1 of MMR
vaccine) to the fully vaccinated calculation for this age cohort.
There has been a steady increase in gonorrhoea notifications in the SMHS since 2010 (n=207).
In 2014 there were 589 cases of gonorrhoea notified in the SMHS, an increase of 35% from
2013 (n=438). Non-Aboriginal males were responsible for most of this increase and, to a lesser
degree, non-Aboriginal females.
In Australia, rabies post-exposure prophylaxis (PEP) is indicated in people who have had
mammalian animal bites or scratches in a geographic location where rabies is known to be
endemic in animal populations (not in Australia), and for people who have been bitten or
scratched by bats in Australia or overseas. The majority of exposures were from mammalian
animals (mostly monkeys but including dogs) during holidays in Bali. There has been an
increase in Australian bat lyssavirus (ABLV) detection in sick and injured bats in the Kimberley
region of WA. In 2014, 11 bats tested positive for ABLV, compared with only one case in WA in
the previous decade.
iv
Introduction
This report provides a summary of notifiable diseases in the South Metropolitan Health Service
(SMHS) of Western Australia (WA) in 2014 and compares these to recent years. It also includes
a report of childhood immunisation rates.
The purpose of this report is to improve the prevention and early detection of notifiable diseases
by informing health-care providers about important local notifiable disease trends.
Background
Notifiable diseases
Under the Western Australian Health Act of 1911, any medical practitioner or nurse practitioner
attending a patient who is known, or suspected, to have a notifiable disease has a legal
obligation to report it to the WA Department of Health (DoH).
All notifiable diseases require notification by a medical practitioner and are entered into the
Western Australian Notifiable Infectious Diseases Database (WANIDD) and cross-checked for
duplication. Some diseases, including suspected meningococcal disease and measles, require
the practitioner to notify the DoH urgently by telephone and these are marked with a on the
notification form. In addition, laboratory notification is mandatory for all notifiable diseases. A
new (green) notification form was produced in August 2014, with some changes to the notifiable
infectious diseases listed.
Communicable disease notifications are used to inform public health interventions and enhance
the prevention and control of these diseases. A full list of current notifiable diseases in WA,
along with case definitions, fact sheets and more, are available at: http://ww2.health.wa.gov.au
under Health Professionals, alerts and notifications.
In the SMHS, notifiable diseases are reported to the South Metropolitan Population Health Unit
(SMPHU) disease control team who are responsible for following up notified cases, as required
by national and state directives, protocols and guidelines. The purpose of notifiable disease
follow up is enhanced surveillance and public health case management and contact tracing,
including provision of prophylaxis to high risk contacts as required for some notifiable diseases.
The aim is to prevent or reduce further cases of notifiable diseases in the population.
Information to support this process is gathered with the assistance of general practice, hospital
staff, pathology department staff and the patient.
Childhood immunisation
The Australian Childhood Immunisation Register (ACIR) was established in 1996 to record
details of vaccinations given to Australian children aged less than seven years. Children are
included on the register at birth, when enrolled with Medicare. Immunisation coverage is
reported quarterly by ACIR for children fully vaccinated in each age group, based on their age
calculated at the end of March, June, September and December each year. The data is a
sample of children from each of three age cohorts, reflecting approximately one quarter of all
children in that one year period.
1
The data reported is as follows:
12 to <15 month report (sample of one year olds): The percentage of children who have
received their scheduled immunisations at 6 months of age.
24 to <27 month report (sample of two year olds): The percentage of children who have
received their scheduled immunisations at 6, 12 and 18 months of age.
60 to <63 month report (sample of five year olds): The percentage of children who have
received their scheduled immunisations at 48 months (4 years) of age.
All prior doses are presumed given.
Data sources and validity
Childhood immunisation data were obtained from the following ACIR reports: State Summary
Coverage, State Summary Aboriginal Coverage, Public Health Unit for WA, Public Health Unit
Aboriginal for WA, Local Government Area for WA and Local Government Area Aboriginal for
WA.
The SMHS and WA notification data for 2014 were obtained from the WANIDD, held by the
Communicable Disease Control Directorate (CDCD), WA DoH. The estimated 2014 population
of the SMHS (945,057 people) and WA (2,532,956 people) were obtained using the Rates
Calculator1 and used to calculate notification rates, which are expressed per 100,000
population. National notification rates for 2014 were obtained from the National Notifiable
Diseases Surveillance System (NNDSS) (Commonwealth DoHA, 2014).
The SMHS notifiable disease data presented in this report were extracted from the WANIDD on
31 March 2015 and are subject to revision. Most data were retrieved from the WANIDD on the
basis of the earliest available date reflecting the date of onset of disease (i.e. the ‘optimal date
of onset’ or ODO). The exceptions were diseases where there may have been considerable
delay between disease onset and diagnosis date. These diseases (non-infectious syphilis,
tuberculosis, leprosy, Creutzfeldt-Jakob disease and unspecified hepatitis B and C) were
retrieved by date of receipt of notification (DOR).
It is important to identify and record Aboriginal2 status for notifiable diseases as Aboriginal
people experience a greater burden of infectious diseases than other Australians. This allows
specific programs introduced to address this, such as targeted immunisation programs, to be
monitored and evaluated.
The ethnicity variable on the WANIDD can be recorded as Aboriginal or Torres Strait Islander,
other or unknown. Ethnicity was recorded as unknown in 8.7% (1,014) of all cases in 2014,
although this was lower for diseases that require public health follow-up and enhanced
surveillance of individual cases, such as gonorrhoea (0.5%) and invasive pneumococcal
disease (1.5%). In this report, cases with unknown ethnicity were assumed to be nonAboriginal. This will underestimate the Aboriginal notification rate if some of those with unknown
status were Aboriginal.
1
The Rates Calculator was created by Dr Jim Codde and is maintained by the Epidemiology Branch, Department
of Health WA. The projection feature of the program was used to obtain 2014 population estimates.
2
The use of the term ‘Aboriginal’ within this document refers to both Aboriginal and Torres Strait Islander people.
2
Overview of notifiable diseases
There were 11,694 communicable diseases notified in the SMHS in 2014. This was an increase
of 8.0% from 2013 (10,826 cases) which was primarily due to an increase in influenza and
campylobacteriosis notifications. The number of influenza notifications nearly doubled, from 856
cases in 2013 to 1,673 cases in 2014, and campylobacteriosis notifications increased by 61%,
from 649 cases in 2013 to 1,045 cases in 2014.
Travellers returning from Bali continue to feature prominently in disease notifications in the
SMHS. The main notifiable infectious disease risks for travellers to Bali are from mosquitoborne (e.g. dengue fever), gastrointestinal (e.g. Salmonella infection) and sexually transmitted
infections (e.g. chlamydia) (CDCD, 2013a).
Figure 1 shows changes in notification rates for selected diseases, by displaying the ratio of the
2014 notification rate to the average notification rate from the previous five years (2009 to
2013). Measles had the highest rate ratio (RR=3.9) between the 2014 notification rate and the
five-year average rate, followed by gonorrhoea and legionellosis (RR=1.7 for both).
The total number of notifications for each disease notified in the SMHS between 2010 and 2014
are presented in Table 1. Only notifiable diseases recorded in the SMHS during that period
have been included. The 2014 crude notification rates for each disease are also presented and
compared to crude state and national rates (where available).
3
Figure 1: Rate ratios comparing the 2014 notification rate for selected diseases to the mean rate
over the period 2009-2013, SMHS
Notes: [1] Diseases with rate ratios <1 had lower notification rates in 2014 than the average rate from 2009-2013, and diseases
with rate ratios >1 had higher notification rates in 2014 than the average rate. [2] Diseases with <10 cases notified in the year
are not shown (except for meningococcal disease and newly acquired hepatitis B). [3] Infectious and non-infectious syphilis are
not shown due to changes in data cleaning during this period. [4] Barmah Forest virus is compared against the average rate
from 2009-12 because of false positive reporting by laboratories in 2013. [5] * indicates diseases for which data were extracted
based on date of receipt of notification (DOR).
4
Table 1: Number of notifications SMHS 2010-2014 & 2014 SMHS, WA & national rates
Number of notifications/year
2010
2011
2012
2013
Blood borne diseases
Hepatitis B (newly acquired)
Hepatitis B (unspecified)*
Hepatitis C (newly acquired)
Hepatitis C (unspecified)*
Hepatitis D
Enteric diseases
Campylobacteriosis
Cholera
Cryptosporidiosis
Hepatitis E
Listeriosis
Paratyphoid fever
Salmonellosis
Shiga/Vero-toxin-prod E. coli
Shigellosis
Typhoid fever
Vibrio parahaemolyticus
Yersiniosis
Sexually transmitted infections
Chlamydia
Gonorrhoea
Syphilis (infectious)
Syphilis (non-infectious)*
Vector borne diseases
Arboviral encephalitis
Barmah Forest virus
Chikungunya
Dengue
Malaria
Typhus (rickettsial disease)
Ross River virus
Schistosomiasis
Vaccine preventable diseases
Hepatitis A
Influenza
Measles
Mumps
Pertussis
Pneumococcal disease (invasive)
Rotavirus
Rubella
Tetanus
Varicella zoster virus
Zoonotic diseases
Leptospirosis
Psittacosis (Ornithosis)
Q fever
Other diseases
Acute rheumatic fever
Creutzfeldt-Jakob disease*
Legionellosis
Leprosy*
Melioidosis
Meningococcal disease (invasive)
Tuberculosis*
2014
2014 notification rate/100,000#
SMHS
WA
National
16
239
22
350
0
9
216
42
347
1
13
227
40
362
1
15
251
46
384
1
9
277
51
388
0
1.0
29.3
5.4
41.1
0.0
0.9
24.9
6.3
39.9
0.1
0.8
28.4
1.7
44.6
0.3
759
0
37
1
1
3
412
2
20
5
0
0
734
1
99
4
2
7
410
0
16
5
4
0
643
0
49
0
5
3
386
0
19
10
5
2
649
0
108
1
1
7
406
0
28
6
6
3
1,045
0
112
0
2
5
393
0
12
6
6
1
110.6
0.0
11.9
0.0
0.2
0.5
41.6
0.0
1.3
0.6
0.6
0.1
117.8
0.0
12.3
0.0
0.2
0.4
50.1
0.1
2.7
0.6
0.6
0.2
126.7
0.0
10.4
0.2
0.3
NA
70.8
0.5
4.6
0.5
NN
NN
3,686
207
19
23
4,418
340
34
27
4,283
415
22
31
4,317
438
15
31
4,120
589
21
20
436.0
62.3
2.2
2.1
451.2
87.4
3.8
2.5
372.1
67.9
8.7
8.5
0
34
6
179
22
5
173
79
2
50
2
135
22
20
247
26
0
90
3
211
15
12
515
15
1
551^
31
168
20
7
516
12
0
17
14
171
18
3
584
41
0.0
1.8
1.5
18.1
1.9
0.3
61.8
4.3
0.0
2.2
1.0
17.8
1.9
0.6
62.9
7.0
0.0
3.2
0.5
6.8
1.4
NN
23.1
NN
10
584
4
7
431
48
209
3
0
731
3
645
5
6
1,498
54
52
7
0
882
6
1,742
2
13
1,212
58
112
1
0
838
5
856
6
13
554
54
99
1
0
1,116
5
1,673
17
11
676
65
148
1
1
1,066
0.5
177.0
1.8
1.2
71.5
6.9
15.7
0.1
0.1
112.8
0.8
209.1
1.7
0.9
69.1
8.3
16.5
0.0
0.0
121.3
1.0
293.3
1.5
0.8
51.3
6.8
NN
0.1
0.0
79.6
3
2
1
0
3
2
1
1
2
1
1
0
1
0
0
0.1
0.0
0.0
0.1
0.1
0.2
0.4
0.2
2.0
0
1
23
0
0
8
46
2
1
27
0
0
2
48
2
0
28
0
2
6
63
1
0
40
1
5
7
47
1
1
46
1
0
7
69
0.1
0.1
4.9
0.1
0.0
0.7
7.3
1.0
0.0
4.8
0.2
0.2
0.7
5.6
NN
NA
1.9
0.0
NN
0.7
5.8
* Data retrieved from WANIDD based on date of receipt of notification (DOR). ^Due to laboratory false positives.
NN = Not notifiable; NA = Data not available at time of reporting
5
Vaccine preventable diseases
There were 3,663 vaccine preventable diseases (VPD) notified in the SMHS in 2014, which was
an increase of 36% from 2013 (n=2,704). This was largely due to a 95% increase in the number
of influenza notifications (from 856 in 2013 to 1,673 in 2014), and a 22% increase in pertussis
notifications (from 554 in 2013 to 676 in 2014).
Pertussis
Pertussis (whooping cough) is a highly contagious, vaccine-preventable respiratory illness
characterised by a paroxysmal cough that can last for many weeks. Infants who are not fully
immunised are most vulnerable to severe disease, which can be complicated by pneumonia
and hypoxic encephalopathy and can occasionally result in death (CDCD, 2011).
The National Immunisation Program provides pertussis containing vaccinations for children at
two, four and six months of age, with booster doses at four years of age and in adolescence.
Despite relatively high vaccination coverage, pertussis notification rates have increased in
Australia in recent years (CDCD, 2012; Pillsbury et al., 2014). Several reasons have been
proposed for this including:
The acellular pertussis vaccine (introduced in Australia in 1999) may be less effective
than the whole cell vaccine which was previously used (Sheridan et al., 2012).
Selection of non-vaccine strains of Bordetella pertussis (Octavia et al., 2012).
Greater availability of more sensitive polymerase chain reaction (PCR) testing
(Kaczmarek et al., 2013).
Greater physician and patient awareness leading to increased testing (CDCD, 2012).
Infants usually acquire pertussis from household contacts, particularly parents (Chuk et al.,
2008; Bisgard et al., 2004) and siblings (Bertilone et al., 2014). To prevent newborns from
acquiring pertussis infection, since early 2015 vaccination has been recommended and is
funded by the WA DoH for pregnant women during their third trimester (from 28 weeks) of every
pregnancy. Parents, grandparents and carers of babies should also consider being immunised
against pertussis (this is not funded).
In the past, pertussis epidemics tended to occur every three or four years (CDCD, 2012). The
last pertussis epidemic in the SMHS and WA peaked in 2011, however a new higher nonepidemic baseline now seems to have been reached, with 554 cases notified in 2013 and 676
cases in 2014, compared to 60 in the pre-epidemic year of 2007 (Figure 2). This suggests there
is ongoing transmission of pertussis in the community.
6
Figure 2: Number of pertussis notifications by quarter, SMHS, 2007 to 2014
900
Number of notifications
800
700
600
500
400
300
200
100
Jan-Mar
Apr-Jun
Jul-Sep
Oct-Dec
Jan-Mar
Apr-Jun
Jul-Sep
Oct-Dec
Jan-Mar
Apr-Jun
Jul-Sep
Oct-Dec
Jan-Mar
Apr-Jun
Jul-Sep
Oct-Dec
Jan-Mar
Apr-Jun
Jul-Sep
Oct-Dec
Jan-Mar
Apr-Jun
Jul-Sep
Oct-Dec
Jan-Mar
Apr-Jun
Jul-Sep
Oct-Dec
Jan-Mar
Apr-Jun
Jul-Sep
Oct-Dec
0
2007
2008
2009
2010
2011
2012
2013
2014
There were nine cases of pertussis in infants aged less than one year. Of these:
Two were aged less than two months, so were unvaccinated as expected with the
current vaccination schedule.
Three were aged between two and six months. Of these, one was age-appropriately
vaccinated and two were partially vaccinated for age.
Four were aged between six and 12 months. Of these, three were fully vaccinated and
one was partially vaccinated.
Five were hospitalised.
In 2014, the highest pertussis notification rates were in adults aged 50 to 84 years, with the
peak occurring among those aged 75 to 79 years (115 per 100,000; n=24). A secondary peak
occurred in children aged 10 to 14 years (94 per 100,000; n=51) (Figure 3). There were 17
notifications of pertussis among Aboriginal people, and nearly half of those (n=8) were children
under 15 years of age.
7
Figure 3: Rates of pertussis notifications by age group, SMHS, 2014
120
100
80
60
40
20
85+
80-84y
75-79y
70-74y
65-69y
60-64y
55-59y
50-54y
45-49y
40-44y
35-39y
30-34y
25-29y
20-24y
15-19y
10-14y
05-09y
0
00-04y
Notification rate per 100,000
140
Age group
Influenza
Influenza is a vaccine preventable disease, and an influenza vaccine is manufactured each year
to cover the likely circulating influenza virus strains (as determined by the World Health
Organisation). Influenza vaccine is funded by the WA DoH for all children aged from six months
to less than 5 years of age. The National Immunisation Program funds influenza vaccine for:
Persons aged 65 years or older.
Aboriginal people aged six months to less than 5 years of age (from 2015), or 15 years
and older.
Individuals aged six months and over with medical risk factors.
Pregnant women in any trimester.
There were 1,673 influenza cases notified in 2014, which was nearly double the number of
cases notified in 2013 (n=856), but similar to the 2012 season (n=1742) and 2009 season
(n=1902) when the influenza A H1N1 pandemic strain was circulating (Figure 4).
Figure 4: Number of influenza notifications by year, SMHS, 2005 - 2014
2,000
Number of notifications
1,800
1,600
1,400
1,200
1,000
800
600
400
200
0
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
8
Influenza is a winter disease, usually peaking in July or August in WA. The pattern of influenza
notifications in 2014 featured a steep rise in notifications, similar to that seen in the 2012
season where notification numbers were also high. In contrast, in 2010, 2011 and 2013
notifications were lower, with a slower rise in notifications prior to the peak (Figure 5).
Figure 5: Number of notifications of influenza by month and year, SMHS, 2010-2014
800
700
Number of notifications
600
500
400
300
200
100
0
2014
2013
2012
2011
2010
In 2014, the rate of influenza notifications in the SMHS was 177 per 100,000, which was lower
than both the state rate and the national rate (209 and 293 per 100,000 respectively). In the
SMHS, the highest rate of influenza notifications was among those aged 75 years and older
(284 per 100,000) (Figure 6). Rates remain high for the 0 to 4 year age cohort (243 per
100,000) despite a funded vaccine program for children aged 6 months to less than 5 years of
age.
9
Figure 6: Rate of influenza notifications by age group and year, SMHS, 2014
350
Notification rate per 100,000
300
250
200
150
100
50
0
In 2014, unspecified influenza A accounted for 36% of notifications, followed by A/H1N1 (33%),
A/H3 (16%) and unspecified influenza B (15%) (Figure 7). The majority of influenza notifications
in people aged 75 years and over were due to unspecified influenza A (40%) or A/H3 (35%).
Figure 7: Percentage of influenza notifications by genotype, SMHS, 2014
15%
36%
16%
33%
A (UNSPECIFIED)
A/H1N1(2009)
A/H3
B (UNSPECIFIED)
10
Public / Population Health Units are responsible for following up influenza outbreaks in
residential care facilities (RCF). Their role is to provide education and infection control advice to
RCFs, to facilitate access to antiviral medication where required, and to monitor the outbreak
through daily line listings of cases notified. In 2014, SMPHU followed up four respiratory
outbreaks in RCFs, one of which was confirmed to be due to influenza. This was a significant
decrease from 2013, when 16 outbreaks were investigated of which nine were due to influenza.
The frequency of RCF outbreaks vary each year, depending on the circulating strain of
influenza virus and the susceptibly of the elderly population to these strains.
Hepatitis A
In the 1990s hepatitis A was responsible for outbreaks among people who inject drugs,
communities of men who have sex with men, residential facilities for disabled people, child care
centres and preschools, Aboriginal communities, and people who had ingested certain
foodstuffs (NHMRC, 2013). In recent years, the number of hepatitis A notifications has fallen to
low levels, and travellers returning from countries with endemic hepatitis A are responsible for
the majority of infections in Australia (NHMRC, 2013; CDCD, 2010a). The National
Immunisation Program provides hepatitis vaccination for Aboriginal children at twelve and
eighteen months of age.
There were five cases of hepatitis A notified in the SMHS in 2014, the same number as in 2013.
One case was a child aged five years and the other four were adults. Three cases acquired the
infection overseas – one in India, one in Somalia and the other in the Philippines. Two cases
were acquired in WA with an unidentified source of infection. All of the cases were unvaccinated
and none of the cases were Aboriginal, which was similar to previous years.
Measles
Measles is highly infectious and a case of measles requires intensive contact tracing and postexposure intervention, which can include immunoglobulin, vaccine, isolation and education.
Many contacts may be immune to measles because of past measles infection or immunisation
with measles containing vaccine (MMR vaccine). People who are regarded as not immune to
measles are those born since 1965 who have not received two doses of measles containing
vaccine.
The National Immunisation Program provides measles containing vaccination for children at
twelve and eighteen months of age. All health care workers born since 1965 should show
immunity to measles – either proof that they have received two doses of measles-containing
vaccine or serological proof of immunity. Travellers to endemic countries should receive
measles containing vaccine prior to travel. If a suspected measles case presents to a health
service, it is important that appropriate testing is arranged, infection control and isolation
procedures are implemented, and that the WA DoH is immediately notified by phone.
There were 17 cases of measles notified in the SMHS in 2014, compared with 6 in 2013. This
was part of an Australia wide increase in measles notifications, with the national rate increasing
from 0.7 per 100,000 (n=158) in 2013 to 1.5 per 100,000 (n=340) in 2014. This outbreak was
due to imported measles from Asia, which has been linked to an outbreak in the Philippines
(CDCD, 2014).
Of the 17 cases in 2014, 71% (n=12) were males and 76% (n=13) were acquired measles
overseas – six in the Philippines, six in Indonesia (five in Bali), and one in India. The four cases
acquired in Australia were all contacts of a confirmed case where disease acquisition had been
11
from overseas. There were no cases with unknown local transmission, highlighting that measles
is essentially a travellers’ disease brought in from high prevalence countries. Fourteen cases
had no record of measles containing vaccine or an unknown vaccination status (including two
infants less than one year old who were not old enough to be vaccinated), two were partially
vaccinated with one dose of vaccine and only one was fully vaccinated with two doses of
vaccine.
Invasive pneumococcal disease
In 2014 there were 65 cases of invasive pneumococcal disease (IPD) notified in the SMHS.
Thirty eight cases (59%) were male. Notifications peaked in winter (June to August), with 29
cases (45%) occurring during this period.
There were ten notifications of IPD among Aboriginal people in 2014. The notification rate for
Aboriginal people (62 per 100,000) was over ten times higher than that for non-Aboriginal
people (5.9 per 100,000).
From 2007 to 2010, there was a steady increase in the notification rate for children aged four
years and under, which may reflect serotype replacement with non-vaccine strains. On 1st July
2011, Prevenar 13® (13vPCV) replaced Prevenar 7® (7vPCV) on the WA Vaccination
Schedule, providing coverage against an extra six serotypes. Since that time, the notification
rate for this age cohort has fallen, and in 2013 it was 8.0 per 100,000, the lowest since data
became available in 2001. However, in 2014 the rate increased to 20 per 100,000 (Figure 8).
Figure 8: Notification rates of invasive pneumococcal disease in children aged 4 years
and under, SMHS, 2006-2014
13vPCV
replaces 7vPCV
12
The 23-valent pneumococcal polysaccharide vaccine is funded for all adults aged 65 years and
older. In this age group, people aged 85 years and over had the highest notification rate for IPD
(33 per 100,000) in 2014 – a 4.7 times higher risk of infection than the general population (6.9
per 100,000).
Varicella zoster virus
Varicella zoster virus (VZV) has been a notifiable disease in WA since July 2006. This followed
the addition of a live attenuated varicella vaccine to the National Immunisation Program in
November 2005 for children aged 18 months, and a catch up program for school children in
year seven from 2006.
In 2014, there were 1,066 notifications of VZV in the SMHS, similar to 2013 (n=1,116). The rate
for VZV in the SMHS was 113 per 100,000, which was 1.4 times higher than the national rate of
80 per 100,000.
Of the 1,066 notifications in the SMHS, 11% were chickenpox (n=122), 43% were shingles
(n=454), and 46% (n=490) were unspecified varicella. Unspecified varicella means the disease
was laboratory confirmed in the absence of clinical information, which makes it hard to interpret
trends in chicken pox and shingles over time. Notifications will underestimate the true incidence
of VZV infection since the majority of infections will be clinically diagnosed by the doctor and
may never be notified (Roche et al., 2002).
Chickenpox affects mainly younger people, and in 2014 the highest notification rate was among
children aged 5 to 9 years (66 per 100,000; n=37). Only one case of chicken pox occurred in a
person over the age of 64 years. In contrast, shingles notifications increased with age, with the
highest notification rate in those aged 80 to 84 years (150 per 100,000; n=26). Similarly,
notification rates for unspecified VZV increased with age, with people aged 70 years and above
having the highest rates (Figure 9).
13
Figure 9: Notification rates for varicella zoster by disease type and age group, SMHS,
2014
160
Notification rate per 100,000
140
120
100
80
60
40
20
VZV Unspecified
Chickenpox
85+
80-84y
75-79y
70-74y
65-69y
60-64y
55-59y
50-54y
45-49y
40-44y
35-39y
30-34y
25-29y
20-24y
15-19y
10-14y
05-09y
00-04y
0
Shingles
Rotavirus
Rotavirus has been notifiable in WA since July 2006, but is not notifiable nationally. Rotavirus
vaccine was introduced for infants in 2007. There were 148 rotavirus cases in the SMHS in
2014, representing a 50% increase in notifications from 2013 (n=99). Over half of the
notifications in 2014 occurred in children under five years of age (55%; n=81).
Rubella
The National Immunisation Program provides rubella containing vaccination for children at
twelve and eighteen months of age. There was one case of rubella notified in the SMHS in
2014. This was acquired in Indonesia by an adult female whose vaccination status was
unknown.
Tetanus
Tetanus is an acute, often fatal vaccine preventable disease, caused by toxin from the organism
Clostridium tetani. It is a rare disease in Australia most common in the elderly due to this age
cohort having a high rate of no prior vaccination or waning immunity from vaccination in the
remote past (NHMRC, 2013). The National Immunisation Program provides tetanus-containing
vaccination as a three dose primary infant schedule, a booster dose for four year olds and
another in adolescence. A booster dose is also recommended, but not funded for those aged 50
years of age.
14
The main presenting symptom is severe muscle spasms. Tetanus is one of the few diseases
that, with a clinically compatible illness, does not require laboratory confirmation to meet the
NNDS case definition (CDCD, 2013).
In 2014 there was one notification of tetanus in an elderly person in the SMHS which was the
first case notified in the SMHS since 1998.Exposure was from a wound sustained during
gardening and they had no known record of a tetanus containing vaccine. They presented to
hospital with classic tetanus symptoms of severe muscle spasms and required prolonged
admission to intensive care and ventilation.
Mumps
In 2012 there was a Perth wide outbreak of mumps which peaked in the first quarter of 2013
(Figure 10). There were 11 cases of mumps notified in the SMHS in 2014, similar to 2013
(n=13).
Figure 10: Number of mumps notifications by quarter, SMHS, 2011-2014
The notification rate for mumps in the SMHS in 2014 was 1.2 per 100,000, which was higher
than both the WA and the national rate (0.9 and 0.8 per 100,000 respectively). In 2014, 64%
(n=7) of mumps cases were male, and all were non-Aboriginal adults (age range 18 to 63
years).
In 2014, three cases acquired mumps overseas (two in Sri Lanka and one in Burma). Of the
eight cases acquired in WA, only one was a confirmed contact of a known case. For the
remaining cases, the source of infection was unknown.
The National Immunisation Program provides mumps-containing vaccination for children at
twelve and eighteen months of age. Only one mumps case could confirm being fully vaccinated
with two doses of mumps-containing vaccine, and two cases had received one dose of vaccine.
15
Immunisation rates
There have been recent changes to the fully vaccinated calculation for the ACIR. In the 12 to
<15 month age cohort, pneumococcal vaccine was added to the fully vaccinated calculation for
the end of September 2013 (date calculated) ACIR quarterly report onwards.
In the 24 to <27 month age cohort, meningococcal C vaccine and varicella vaccine has been
added to the fully vaccinated calculation for the end of September 2014 (date calculated) ACIR
quarterly report onwards. In addition, for this report and onwards, the cohort calculation has also
been amended to calculate dose 2 of MMR vaccine instead of dose 1.
Table 2 shows the percentage of children fully immunised in each age cohort for each quarter of
2014. The data is presented by Local Government Area (LGA), and grouped by Medicare
Locals and Child and Adolescent Community Health (CACH) zones. The final column shows the
number of children in the December cohort. LGAs with small numbers of children, such as East
Fremantle and Waroona, will show greater variability in percentages between years.
Table 3 shows immunisation rates per quarter for 2014 by Medicare Locals, SMHS, WA and
Australia for Aboriginal children and all children. In a three month age cohort at a Medicare
Local level, the number of Aboriginal children may be small so there will be greater variability in
immunisation rates.
16
Table 2: Percentage of children fully immunised in each age cohort by LGA & quarter,
SMHS, 2014
% fully immunised
Local
Age
31-Mar30-Jun30-SepGovernment
group
2014
2014
2014
Area (LGA)
(months)
FREMANTLE MEDICARE LOCAL
South
Cockburn
12-<15
92.9
90.9
92.2
Coastal
24-<27
91.2
92.6
85.5
Zone
60-<63
91.0
91.5
90.6
East Fremantle
12-<15
83.3
83.3
66.7
24-<27
76.0
66.7
66.7
60-<63
94.4
84.9
95.5
Fremantle
12-<15
84.0
83.5
81.6
24-<27
90.7
86.3
81.0
60-<63
91.0
80.8
84.7
Melville
12-<15
88.4
91.1
90.2
24-<27
88.9
92.2
81.4
60-<63
87.4
91.0
89.4
PERTH SOUTH COASTAL MEDICARE LOCAL
South
Mandurah
12-<15
91.1
91.4
92.9
Coastal
24-<27
91.7
92.1
86.6
Zone
60-<63
92.2
90.5
92.8
Murray
12-<15
87.5
89.4
89.2
24-<27
92.8
92.4
86.4
60-<63
93.0
94.0
95.8
Waroona
12-<15
92.9
90.9
83.3
24-<27
71.4
88.9
85.7
60-<63
100.0
84.6
100.0
Rockingham
12-<15
90.9
92.8
90.7
24-<27
86.6
92.3
86.2
60-<63
89.7
88.9
91.5
Kwinana
12-<15
93.8
90.7
90.4
24-<27
91.9
93.4
91.5
60-<63
88.2
89.4
91.8
BENTLEY ARMADALE MEDICARE LOCAL
South
Armadale
12-<15
90.4
88.5
88.9
Coastal
24-<27
93.0
91.3
84.0
Zone
60-<63
91.2
88.9
90.6
Serpentine /
12-<15
96.1
93.9
93.4
Jarrahdale
24-<27
93.1
94.1
84.0
60-<63
93.5
93.8
94.7
Inland
Belmont
12-<15
90.7
86.7
92.2
Zone
24-<27
90.7
90.3
76.8
60-<63
91.3
83.6
88.0
Canning
12-<15
89.2
89.3
90.1
24-<27
91.1
90.2
81.5
60-<63
89.6
88.3
90.6
Gosnells
12-<15
88.8
91.9
90.0
24-<27
90.1
92.9
86.0
60-<63
89.4
89.6
87.3
South Perth
12-<15
84.0
91.8
91.2
24-<27
91.8
89.9
88.3
60-<63
85.7
91.2
94.3
Victoria Park
12-<15
93.3
89.8
91.6
24-<27
92.7
88.6
84.9
60-<63
88.7
90.2
90.3
* CACH Child and Adolescent Community Health
CACH
Zone
31-Dec2014
Number
in cohort
31-Dec-14
92.8
87.4
90.5
90.0
65.0
88.9
86.5
80.5
90.7
90.4
88.3
89.2
375
414
379
10
20
9
89
82
75
272
291
316
88.6
82.9
89.0
89.7
81.1
93.5
90.0
90.0
73.7
92.9
87.0
91.4
87.9
88.5
91.3
210
199
200
68
74
77
10
10
19
493
523
525
141
165
149
90.4
86.4
93.7
96.2
90.1
93.3
90.6
88.4
87.9
90.1
86.0
88.3
87.7
86.4
90.2
87.2
84.0
86.8
87.3
80.0
88.0
345
331
299
78
71
90
159
146
107
342
379
324
446
469
428
117
106
106
134
105
100
17
For all children living in the SMHS, the immunisation rates were lower across all age groups
compared with WA and Australia (Table 3). The drop in coverage in the 24 to <27 month age
cohort, due to the addition of vaccines to the fully vaccinated calculation, can be seen in the
September quarter across the SMHS, WA and Australia (Table 3 and Figure 11).
Table 3: Percentage of Aboriginal and total children fully immunised in each age cohort
by quarter, Medicare Local, SMHS, WA & Australia, 2014
Area
Age
group
months
31-Mar-2014
%
Total*
%
30-Jun-2014
Aborig.^
%
Total*
%
30-Sep-2014
Aborig.^
%
Total*
31-Dec-2014
%
%
%
Aborig.^
Total*
Aborig.^
Fremantle
12-<15
90.3
75.0
89.9
84.2
89.8
77.3
91.2
87.5
Medicare Local
24-<27
89.9
82.6
91.2
94.4
83.2
60.0
86.5
64.7
60-<63
89.7
100.0
90.1
90.9
89.7
92.3
90.0
86.2
Perth South
12-<15
91.4
100.0
91.8
77.3
90.9
75.8
90.9
67.6
Coastal
24-<27
88.9
93.9
92.7
93.5
87.2
95.5
86.0
82.8
Medicare Local
60-<63
90.4
91.3
89.7
92.3
92.2
87.5
90.7
86.5
Bentley
12-<15
89.7
75.0
90.2
70.2
90.4
71.7
89.4
76.7
Armadale
24-<27
91.4
88.0
91.3
86.4
83.7
61.8
86.1
79.3
Medicare Local
60-<63
89.9
87.9
89.0
89.1
89.8
84.8
90.1
84.3
SMHS
12-<15
90.4
79.8
90.6
75.0
90.4
73.9
90.2
74.8
24-<27
90.3
88.6
91.6
89.2
84.6
68.1
86.2
77.9
60-<63
90.1
90.7
89.5
90.3
90.5
85.9
90.3
85.5
12-<15
90.7
83.7
91.7
84.9
90.7
84.9
91.2
82.4
24-<27
91.5
92.4
92.0
92.2
85.1
75.1
86.6
81.9
60-<63
90.3
92.8
90.1
92.2
90.6
91.6
91.0
92.6
12-<15
90.9
86.2
91.5
88.0
90.6
87.4
91.0
87.0
24-<27
92.6
93.2
92.8
92.9
87.3
83.9
87.6
84.4
93.2
93.5
60-<63
91.9
92.2
*Includes both Aboriginal and non-Aboriginal children.
92.2
93.1
92.3
93.7
WA
AUST
^Aboriginal
18
Figure 11: Percentage of children fully immunised in each age cohort by quarter, SMHS,
2013-2014
Table 4 shows that for SMHS children, immunisation rates improved for the 60 to <63 months
age cohort, from 87.9% in 2012, to 88.6% in 2013 and 90.1% in 2014. A similar trend was seen
in WA and Australia. Similarly, the Aboriginal coverage rates for the 60 to <63 months age
cohort increased in the SMHS, WA and Australia.
There was a significant difference in Aboriginal coverage rates in the SMHS compared with the
total childhood population, particularly in the 12 to <15 month age cohort (Table 4). The drop in
coverage for the 24 to <27 month age cohort in 2014 was due to the addition of vaccines to the
fully vaccinated calculation for the September quarter onwards as discussed above.
Table 4: Percentage of Aboriginal and total children fully immunised in each age cohort,
SMHS, WA and Australia, 2012-2014
Region
SMHS
WA
AUSTRALIA
Age
group
% total fully immunised
% Aboriginal fully immunised
(months)
2012
2013
2014
2012
2013
2014
12-<15
89.4
89.1
90.4
75.5
76.3
75.8
24-<27
90.0
89.5
88.2
85.1
87.0
81.6
60-<63
87.9
88.6
90.1
82.5
87.3
88.1
12-<15
90.2
89.9
91.1
78.9
82.5
84.0
24-<27
90.5
90.7
88.8
89.4
90.4
85.7
60-<63
88.9
89.6
90.5
86.9
90.3
92.3
12-<15
91.7
90.3
91.0
86.5
85.7
87.1
24-<27
92.5
92.2
90.1
92.1
91.7
88.7
60-<63
91.2
91.9
92.2
91.0
93.0
93.4
19
Vector borne diseases
There were 848 cases of vector borne diseases notified in the SMHS in 2014, which was a
decrease of 35% from 2013 (n=1,306). The high numbers of Barmah Forest virus reported in
2013 was due to false positive reporting by laboratories.
Chikungunya
Chikungunya is a member of the Alphavirus group, which also includes Ross River virus and
Barmah Forest virus and is a mosquito-borne acute illness. It is endemic in many tropical
regions of the world, reflecting the distribution of Aedes aegypti and Aedes albopictus
mosquitoes. Chikungunya is not endemic in Australia, although there is potential for
transmission in northern Queensland and the Torres Strait Islands, where these mosquitoes are
established (CDCD, 2013b).
Chikungunya became a notifiable disease in WA in May 2008, with initially low numbers of
notified cases between 2009 and 2012. In 2013, the number of chikungunya cases rose to 31,
but in 2014, dropped by 55% to 14 cases. In 2014, the median age was 46 years (range: 26 to
58 years). All cases acquired the infection overseas, the majority in Indonesia (79%, n=11). The
remaining three chikungunya infections were acquired in Sri Lanka (n=1) and an unspecified
location in the Caribbean (n=2).
Dengue
Dengue is also transmitted by Aedes aegypti and Aedes albopictus mosquitoes and is
predominantly acquired from Asian holiday destinations. There is currently no known Aedes
aegypti activity in WA, although prior to the 1930s it existed at least as far south as Harvey.
Activity remains in far north Queensland, so ongoing surveillance for dengue in Australia is
essential (Russell et al., 2009).
There were 171 notifications of dengue in 2014, similar to 2013 (n=168), with all cases acquired
overseas. The main countries of acquisition were Indonesia (77%; n=132), Malaysia (7.0%;
n=12) and Thailand (5.3%; n=9). The SMHS and WA notification rate for dengue notifications
was 18 per 100,000, 2.6 times the national rate of 6.8 per 100,000, reflecting the high proportion
of WA residents who travel to Southeast Asia, particularly Bali (CDCD, 2013a).
Ross River virus and Barmah Forest virus
There were 584 Ross River virus (RRV) notifications in the SMHS in 2014, 13% higher than in
2013 (n=516). Notifications of RRV and Barmah Forest virus (BFV) usually follow a seasonal
pattern, with more disease notified in the summer months. Although this seasonal pattern
occurred in 2014, there was a higher than usual baseline throughout the winter months (Figure
12).
20
Figure 12: Number of Ross River virus notifications by month, SMHS, 2010 - 2014
180
Number of notifications
160
140
120
100
80
60
40
20
0
Jan
Feb
Mar
2010
Apr
May
2011
Jun
Jul
2012
Aug
Sep
2013
Oct
Nov
Dec
2014
Notifications in the Perth metropolitan area tend to be concentrated around the outer suburbs,
close to bushland and water bodies (Environmental Health Directorate, 2012). In the SMHS,
most RRV notifications occurred in postcode 6210 among residents of the Mandurah area,
(22%; n=130).
There were 17 BFV notifications in 2014, a decrease of 81% from 90 cases in 2012 and a
marked decrease from the 551 notifications in 2013. This was due to a high rate of false positive
IgM results associated with a commercial test kit which started in October 2012 and was
resolved by 2014. The notification rate in the SMHS was 1.8 per 100,000, which was lower than
the state and national rates (2.2 and 3.2 per 100,000 respectively).
Other vector borne diseases
In 2014 in the SMHS there were 41 cases of schistosomiasis, over three times the number in
2013 (n=12). This is an overseas acquired infection. There were three notifications of typhus –
one of which was acquired in Bangladesh, and 18 malaria notifications, all of which were
acquired overseas.
21
Sexually transmitted infections
There were 4,750 sexually transmitted infections (STI) notified in the SMHS in 2014 which was
similar to 2013 (n=4,801). Chlamydia accounted for 87% of all STI notifications in 2014.
Chlamydia
There were 4,120 notifications of chlamydia in the SMHS in 2014, which is a decrease of 4.6%
since 2013 (n=4,317). The number of notifications has been essentially stable since 2011,
although the SMHS notification rate (436 per 100,000) and the WA rate (451.2 per 100,000)
remain higher than the national rate of 372 per 100,000.
Females accounted for 57% of chlamydia notifications in the SMHS. The highest age-specific
rate for females occurred in the 20 to 24 year age group (2,287 per 100,000) followed by the 15
to 19 year age group (2,234 per 100,000) . For males the highest age-specific rate was in the
20 to 24 year age group (1,477 per 100,000; Figure 13).
Figure 13: Chlamydia notification rates by age group and gender, SMHS, 2014
Of all chlamydia notifications, 6.2% occurred in Aboriginal people (n=254). The overall rate for
Aboriginal people (1,567 per 100,000) was 3.8 times higher than that for non-Aboriginal people
(416 per 100,000).3 Aboriginal age-specific notification rates were highest in the 15 to 19 year
olds (males: 6,549 per 100,000; females: 5,902 per 100,000).
3
8.4% of notifications were of unknown ethnicity. These were included in the non-Aboriginal cases.
22
Gonorrhoea
There has been a steady increase in gonorrhoea notifications in the SMHS over the last five
years. There were 207 gonorrhoea notifications in 2010, but by 2013 the number of notifications
had more than doubled to 438 notifications. In 2014, the number of notifications increased
again, by 35% to 589. Non-Aboriginal males, and to a lesser degree non-Aboriginal females,
were responsible for this increase (Figure 14). Nearly three quarters of gonorrhoea cases in
2014 were males (74%; n=435).
Figure 14: Number of gonorrhoea notifications by Aboriginality and gender, SMHS, 2009–
2014
In WA, young heterosexual adults account for much of the increase in notifications, which could
indicate a decline in safe sex practices (CDCD, 2013c). In 2014, the highest age-specific rate
for non-Aboriginal males was in the 20 to 24 year age group (245 per 100,000; n=97), followed
by the 25 to 29 year age group (236 per 100,000; n=98). In 2013, the highest age-specific rate
for non-Aboriginal males was also in the 20 to 24 year age group, but the rates were lower (166
per 100,000; n=64). For non-Aboriginal females, the highest age-specific rate in 2014 was also
in the 20 to 24 year age group (84 per 100,000; n=31), but in 2013 it was in the 15 to 19 year
age group (72 per 100,000; n=21) (Figure 15).
In 2014, 9.7% (n=57) of gonorrhoea cases acquired the infection overseas. The most commonly
reported countries of acquisition were Thailand (32%; n=18), Indonesia (18%; n=10), and the
Philippines (14%; n=8). All the overseas acquired cases were non-Aboriginal and 53 (93%)
were males. The overseas acquired cases accounted for 14% of non-Aboriginal male cases and
3% of non-Aboriginal female cases.
23
Figure 15: Age-specific rates of gonorrhoea notifications for non-Aboriginal people by
gender, SMHS, 2013 and 2014
300
Notification rate per 100,000
250
200
150
100
50
0
10-14y 15-19y 20-24y 25-29y 30-34y 35-39y 40-44y 45-49y 50-54y 55-59y 60-65y 65-69y
2014 Male non-Aboriginal
2013 Male non-Aboriginal
2014 Female non-Aboriginal
2013 Female non-Aboriginal
In 2014, the proportion of gonorrhoea notifications among Aboriginal people accounted for 12%
of notifications (n=69), which was a decrease from 2013 where the proportion was 26%
(n=113). However, the notification rates continued to be significantly higher in the Aboriginal
population. Age-specific rates among Aboriginal males peaked in 15 to 19 year olds, at 2,079
per 100,000 (n=20), and rates for Aboriginal females peaked in 20 to 24 year olds at 809 per
100,000 (n=7).
Syphilis
There were 21 notifications of infectious syphilis in the SMHS in 2014. Infectious syphilis is
defined as syphilis of less than two years duration, being primary, secondary or early latent
(Communicable Diseases Network Australia, 2010).
In 2014, all cases of infectious syphilis occurred in non-Aboriginal people, 95% were males
(n=20) and 76% (n=16) were acquired in WA. Nine cases presented with primary syphilis
(chancre), five presented with secondary syphilis (rash or other systemic signs), and seven
presented with early latent syphilis (no signs or symptoms but with definite laboratory evidence
of infection onset within the past two years).
There were 20 cases of non-infectious syphilis (late latent) in 2014. All cases occurred among
non-Aboriginal people and 90% were male (n=18).
24
Blood borne viruses
There were 725 blood borne virus notifications in the SMHS in 2014, which was a slight
increase from 2013 (n=697). Over half of these notifications (54%; n=388) were due to
unspecified hepatitis C.
Hepatitis C
There were 51 cases of newly acquired 4 hepatitis C (5.4 per 100,000) in the SMHS in 2014.
Over three quarters (77%; n=39) of cases were male and 35% (n=18) were Aboriginal. The
notification rate in Aboriginal people was 111 per 100,000, which was over 30 times higher than
the rate among non-Aboriginal people (3.6 per 100,000).
There were 388 cases (41 per 100,000) of unspecified hepatitis C notified in the SMHS in 2014.
Of these, 69% were male (n=266), and 18% (n=69) were Aboriginal. Ethnicity was unknown in
11% (n=44) of unspecified hepatitis C cases, so these cases were analysed as non-Aboriginal
cases. The notification rate for Aboriginal people (426 per 100,000) was more than 12 times
higher than the rate for non-Aboriginal people (34 per 100,000).
Hepatitis B
In 2014, nine cases of newly acquired4 hepatitis B were notified in the SMHS (1.0 per 100,000).
Eight cases (89%) were male and none were Aboriginal. Two cases were acquired overseas (in
Thailand and Cambodia).
There were 277 cases of unspecified hepatitis B (29 per 100,000) in the SMHS in 2014. Of
these, 52% (n=144) occurred in males. Two cases were Aboriginal, although ethnicity was
unknown in a quarter of notifications (n=68).
4
Hepatitis B and C are defined as newly acquired if there is evidence of infection occurring within the last 24
months (CDCD, 2013).
25
Enteric diseases
There were 1,582 enteric notifications in the SMHS in 2014, which is a 30% increase from 2013
(n=1,215), due to an increase in campylobacterosis notifications. Two thirds of all enteric
disease notifications were campylobacterosis and one quarter were salmonella.
Campylobacterosis
There was a significant rise (61%) in campylobacter notifications from 2013 (n=649) to 2014
(1,045 cases), in comparison to the trend over recent years which had shown a decline. The
rise in 2014 was seen across WA, with the state rate increasing from 78 per 100,000 in 2013 to
118 per 100,000 in 2014. However, the campylobacter notification rates for the SMHS (111 per
100,000) and WA (118 per 100,000) were lower than the national rate of 127 per 100,000. The
cause of this is under investigation and at the time of publication had not been ascertained.
The highest rate of campylobacter notifications occurred among people aged 75 to 79 years
(273 notifications per 100,000; n=57) (Figure 16). In 2014, 55% of notifications occurred in
males (n=575). Whether the campylobacter infection was acquired in Australia or overseas was
recorded in 58% of notifications (n=606) and, of these, 165 (27%) acquired their infection
overseas, the majority (64%; n=105) in Indonesia.
Figure 16: Campylobacter notification rates by age group, SMHS, 2014
300
Notification rate per 100,000
250
200
150
100
50
0
Salmonellosis
There were 393 salmonellosis notifications in the SMHS in 2014, similar to the number in 2013
(n=406). Fifty two percent of cases (n=206) were females, and 1.8% (n=7) were Aboriginal. The
highest salmonellosis notification rate was amongst 0 to 4 year olds (107 per 100,000; n=69).
26
Whether the salmonellosis infection was acquired in Australia or overseas was recorded in 75%
of notifications (n=293), and of these, nearly half (n=145) acquired their infection overseas. The
majority of overseas acquired infections were from Indonesia (56%; n=81) and Thailand (12%;
n=18).
Other enteric diseases
There were 112 cryptosporidiosis cases notified in the SMHS in 2014, similar to the number in
2013 (n=108). Whether the infection was acquired in Australia or overseas was recorded in 62%
of notifications (n=69) and, of these, 12 (17%) acquired their infection overseas. Half of the
overseas acquired infections were from Indonesia (n=6).
Six cases of typhoid fever were notified in the SMHS in 2014, the same number as in 2013. All
were acquired overseas; three cases in Indonesia, two in India and one in the Philippines.
There were five cases of paratyphoid fever notified in the SMHS in 2014, a decrease from
seven in 2013. One case acquired the infection in WA and the other four acquired it overseas;
three in India and one in Cambodia.
There were 12 cases of shigellosis in 2014, a decrease of 57% from 28 cases in 2013. Two
thirds of cases (n=8) acquired shigellosis overseas. Of these, three cases acquired the infection
in Indonesia, and one case acquired the infection in each of Cambodia, India, the Cote d’Ivoire,
the UK and an unknown country.
There were six cases of Vibrio parahaemolyticus, four of which occurred in people aged 50
years and older. Three cases were acquired overseas, two in Thailand and one in Indonesia.
There were two cases of listeriosis in the SMHS in 2014, which both occurred in males; one
aged 59 and the other 77 years.
One case of yersiniosis occurred in a 33 year old female, but it was not known where the
infection was acquired.
Gastroenteritis outbreaks in residential care facilities
Public / Population Health Units are responsible for following up gastroenteritis outbreaks in
residential care facilities (RCF). Their role is to provide education and support to RCFs and
monitor the outbreak through daily line listings of cases notified. In 2014, SMPHU followed up
59 gastroenteritis outbreaks in RCFs (compared to 40 in 2013). Of these, where an organism
was identified, the majority of outbreaks were due to norovirus.
27
Other diseases
There were 125 notifications of other diseases in the SMHS in 2014, an increase of 24% from
101 cases in 2013, which was due to an increase in tuberculosis notifications. There was one
notification of leprosy, one of Creuzfeldt-Jakob disease and one of acute rheumatic fever.
Invasive meningococcal infection
There were seven notifications of invasive meningococcal infection in the SMHS in 2014, the
same as in 2013. Two cases were children aged less than one year, one was a child of 7 years
and the other four were adults aged between 20 and 74 years.
Invasive meningococcal infection can present as meningitis or septicaemia or both. There are
several serogroups of Neisseria meningitidis, with serogroups B and C responsible for the
majority of disease in Australia. Most disease in the SMHS and WA has historically been due to
serogroup B (NHMRC, 2013).
Universal meningococcal C vaccination for children 12 months of age was introduced in
January 2003, along with a catch-up program for all children aged from one to 19 years.
Interestingly, despite no vaccine for serogroup B currently on the National Immunisation
Program, there has been a steady decline in the number of cases of serogroup B over the past
decade (Figure 17). Since mid-2014 there has been a licenced meningococcal B vaccine
available in Australia on the private market. This is not funded under the National Immunisation
Program.
Of the meningococcal notifications in 2014, six cases were due to serogroup B and one was
due to serogroup C.
Figure 17: Number of meningococcal notifications by year and serotype, SMHS, 19992014
28
Legionellosis
There were 46 cases of legionellosis notified in the SMHS in 2014, a 15% increase from 2013
(n=40). The notification rates for legionellosis in the SMHS (4.9 per 100,000) and WA (4.8 per
100,000) were more than double the national notification rate of 1.9 per 100,000.
L. longbeachae is the most common species of legionella notified in WA and is associated with
exposure to soils, potting mixes and mulches. L. longbeachae was the cause of 41 of the cases
of legionellosis (89%). The youngest case was 32 years and the oldest 96 years, with a median
age of 65 years. All the cases occurred in non-Aboriginal people.
L. pneumophila is associated with exposure to warm water aerosols containing the bacteria
from environmental sources, such as air conditioning cooling towers, showers, spas, misting or
droplet sprays and fountains. It is a more severe disease then L. longbeachae and can cause
severe pneumonia which often requires intensive care treatment. Five cases of L. pneumophila
occurred in 2014. One was aged 16 years, one was 46 years and the other three were in their
70s. Three of these cases were male and three of the infections were acquired overseas. No
epidemiological link or common environmental exposure source was established for the two
locally acquired cases.
Tuberculosis
There were 69 cases of tuberculosis (TB) notified in the SMHS in 2014, a 47% increase from
2013 (n=47). The SMHS notification rate of 7.3 cases per 100,000 was higher than the WA (5.6
per 100,000) and national (5.8 per 100,000) rates. The majority of TB cases acquired the
infection overseas (84%; n=58).
Rabies post-exposure prophylaxis
In Australia, rabies post-exposure prophylaxis (PEP) is indicated in travellers who have had
mammalian animal bites or scratches in a geographic location where rabies is known to be
endemic in animal populations, and for people who have been bitten or scratched by bats in
Australia or overseas. Rabies PEP requires a course of rabies vaccine and in some cases
rabies immunoglobulin (NHMRC 2013).
Over the last 20 years Australia has had no notifications of rabies in returning overseas
travellers, although there have been three cases of rabies-like illness caused by Australian bat
lyssavirus (ABLV) in Queensland, the last occurring in early 2013.
In December 2008, Indonesian authorities declared that Bali was no longer rabies free after
fatal human cases of rabies were reported (CDCD 2010b). An additional, and very significant,
impact of the increased number of WA residents travelling to Bali has been the provision of
rabies PEP to people who have reported being bitten or scratched by mammalian animals
(mostly monkeys but including dogs) while in Bali (CDCD, 2013a).
In 2014, there was an increase in ABLV detection in sick and injured bats in the Kimberley
region of WA. Eleven bats tested positive for ABLV, compared with only one case in WA in the
previous decade (Wildlife Health Australia, 2015).
In 2014 SMPHU authorised the administration of rabies PEP by SMHS providers to 102 people
(compared with 91 in 2013). Of these, 100 were returned overseas travellers, the majority from
Bali. The predominant animal exposure was monkeys, followed by dogs, then less common
mammals such as squirrels, cats, a rat and a luwak (civet cat). The other two people who
received rabies PEP were exposed to bats within WA (one in the Kimberley and one in Perth).
29
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