Download 2017 Meeting -Zika Virus GP Update

Zika Virus Update
Gina McAllister, Clinical Scientist
Aspects
• Background: virology
• Epidemiology
• Research
• Public Health recommendations and clinical
algorithms.
• Future: vaccines
• Where to get more information
Moritz U. G. Kraemer and others The global distribution of the arbovirus vectors Aedes aegypti and Ae. albopictus (eLife, 30 June 2015)
Zika cases diagnosed in the UK
As of 28 December 2016 there were 281 travel-associated
cases diagnosed since 2015:
•
144 cases with virus detected [PCR positive].
•
47 cases with antibody evidence indicating recent infection
[seroconversion] and 90 cases that have antibody evidence
highly indicative of recent infection (Zika-specific IgM)
[probable cases].
•
Of the total 281 travel-associated cases reported, seven have
been diagnosed in pregnant women.
•
In addition, one case of likely sexual transmission of Zika
virus infection has been reported in the UK.
Zika Virus Symptoms
Asymptomatic infections are common, only one in four people
infected with ZIKV are believed to develop symptoms.
The disease symptoms are usually mild and last for 2 to 7 days.
Signs and symptoms suggestive of Zika virus infection may include a
combination of the following:
•
Maculo-papular rash (90%)
•
itching or pruritus
•
fever (65%)
•
headache (45%)
•
arthralgia or arthritis (65%)
•
myalgia (48%)
•
Nonpurulent conjunctivitis (55%)
•
lower back pain
•
retro-orbital pain (39%)
•
oedema (19%)
•
vomiting (10%).
PH implications
Imaging
On Examination
Cerebral and cerebellar atrophy
Microcephaly
Cerebral calcifications
Craniofacial disproportion
Ventriculomegaly
Redundant scalp skin
Cortical and white matter abnormalities (eg agyria,
pachygyria, lissencephaly)
Closed anterior fontanelle
Internal hydrocephalus
Exuberant external occipital protuberance
Periventricular cysts
Intrauterine growth restriction
Choroid plexus cyst
Contractures
Blake’s cyst
Talipes
Mega cisterna magna
Umbilical hernia
Vermian dys/agenesis
Hypertonia or spasticity
Callosal abnormalities
Hyperreflexia
Brain stem/spinal cord degeneration
Irritability, convulsions, tremors
Ocular abnormalities (intraocular calcifications, cataracts,
microphthalmia, macular alterations, optic nerve
abnormalities
Hearing and visual abnormalities
Emerging evidence and big unknowns
If there’s a safe time during
your pregnancy to travel to
an area with Zika?
How likely it is that Zika
infection will affect your
pregnancy?
If your baby will have birth
defects if you are infected while
pregnant.
Cauchemez et al. Lancet March 2016
Brasil et al. N Eng J Med 2016
Johansson et al N Eng J Med 2016
How risky is infection in pregnancy?
•Out of the 875 pregnancies with
possible evidence of Zika in the USA
there were 36 (4.1%) infants born with
birth defects and 5 (0.57%)
miscarriages/still births.
•NEJM paper: 29% of 42 pregnant
women with confirmed Zika infection
during pregnancy had adverse
outcomes.
Is there a risky period in pregnancy?
•Lancet paper: Estimated risk of
microcephaly in fetuses and babies born
to mothers infected with the Zika virus in
the first trimester to be 1 in 100, or 1%.
•Modelling suggests microcephaly risk
due to ZIKV infection during the first
trimester might be higher: 0.88 to 13.2%.
Clinical Scenario
• 28 year old female, returned from Jamaica on
Saturday
• Had been on Honeymoon
• O/E Evidence of mosquito bites
• While away had episode of headache, myalgia and
conjunctivitis.
• Partner asymptomatic
“Should I be tested for Zika?”
“How long till we can start trying for a baby?”
Women who are planning pregnancy
After a woman leaves an area with active Zika virus
transmission, it is recommended that she should
avoid becoming pregnant for 8 weeks
• Should also consider partner’s status..
Preventing sexual transmission
If a female partner is at risk of getting pregnant, or is
planning pregnancy, effective contraception is advised to
prevent pregnancy AND condom use is advised during
vaginal, anal and oral sex for a male traveller to reduce the
risk of transmission during travel and for:
• six months after his return from an area with active Zika
virus transmission
or
the remaining duration of pregnancy if he is the partner of a
pregnant woman, regardless of a history of symptoms
suggestive of Zika virus infection.
Women who are already pregnant
Advised to postpone nonessential travel
• If travel is essential, educate about risk as far as
possible.
• Strict bite avoidance day and night is essential.
• Advise use of barrier methods to prevent potential
sexual transmission of ZIKV from a male partner
during travel and throughout the pregnancy.
• On return, early obstetric review is recommended
even if well.
Investigation of patients with current
or previous symptoms
Clinicians should consider Zika virus infection for:
• any patient who has, or has had, a rash illness or fever, or
other symptoms suggestive of Zika virus infection, that
began whilst in any country with active Zika virus
transmission, or within 2 weeks of leaving that country
• any patient presenting with typical Zika-like symptoms
apparently due to sexual transmission in the UK; that is,
there is no history of travel or the symptoms began more
than 2 weeks after travel to a Zika-affected country, and
their sexual partner (especially if male) had travelled within
the last 8 weeks from a country with active Zika virus
transmission.
• If typical Zika-like symptoms develop between 8 weeks and
6 months of a male sexual partner having left a Zika affected
country, the case should be discussed with RIPL
Returned traveller
(or UK visitor)
Current symptoms
consistent with
Zika infection
Previous
symptoms
consistent with
Zika infection
(none now
Never had
symptoms
suggestive of Zika
infection
Pregnant woman
or male partner of
pregnant woman
Serum, EDTA
plasma and urine.
Serum. Also urine
if within 21 days
since symptom
onset.
No testing. Advise
on prevention of
sexual transmission
Other returned
traveller/UK visitor
not in above group
Serum and EDTA
plasma only.
Serum only.
No testing. Advise
on prevention of
pregnancy and
sexual transmission
Investigation of asymptomatic
returned travellers
The Zika virus testing service is currently not available for
individuals who have had no symptoms suggestive of Zika
infection. This includes:
• asymptomatic pregnant women who have travelled from
Zika-affected countries
• asymptomatic returned male travellers whose partners are
currently pregnant
• asymptomatic returned male and female travellers who are
trying to conceive
These individuals should be advised to follow PHE guidance
on prevention of pregnancy and avoidance of sexual
transmission as appropriate.
Date of Travel
Date Returned
Onset date
Gestation
Countries/areas visited
Vaccination History
Women who are already pregnant
The Future
Vaccines
• US National Institute for Allergy and Infectious Disease has
already created vaccine platforms for other flaviviruses
that can be used as a starting point for a Zika vaccine.
• Several vaccine approaches:
• A DNA-based vaccine that uses a strategy similar to a
flavivirus vaccine for West Nile Virus (already tested in
phase 1 trials)
• A live-attenuated Zika vaccine building on a similar
vaccine approach for dengue virus.
Sources of information
• Health Protection Scotland
http://www.hps.scot.nhs.uk/internationalissues/zika.aspx
• ECDC for affected countries
• Any queries call:
• Virology
• Health Protection Team
• Obstetricians