Zika Virus – An update Dr S Anuradha, Gold Coast Public Health Unit

What is Zika Virus?  Zika is a RNA virus of the Flavivirus family  Spreads to people primarily through the bite of an infected Aedes species mosquito (vector)  Vectors are the same as for dengue virus, Aedes aegypti (N & C Qld and some SW Qld) and Aedes albopictus (Torres Strait).

Zika – Clinical Context  Short, mild illness; 80% asymptomatic  Low grade Fever  Arthralgia (small joints) ~swelling  Headaches (retro-orbital), muscle pains  Conjunctivitis, maculo-papular rash  Tiredness, weakness

Zika - Clinical Context  Incubation Period: May be up to 10 days  Infectious Period: Unknown  No treatment nor vaccine yet  Differential Diagnosis (Zika is milder)

Historical - From

Global Update Between 1 Jan 2007 and 17 Feb 2016, 48 countries and territories have reported local transmission of Zika virus DoH website for list of countries: shing.nsf/Content/ohp-zika-countries.htm

Association with birth defects and neurological disorders  Increase in the cases of microcephaly (Brazil & French Polynesia)  Increase in cases of Guillain-Barré syndrome (GBS) (atleast 5 countries)

Public Health Emergency  WHO declared a Public Health Emergency of International Concern (PHEIC) on 1 February 2016  WHO declared that “Surveillance for microcephaly and GBS should be standardized and enhanced, particularly in areas of known Zika virus transmission and areas at risk of such transmission ”

Birth defects: the defence  Microcephaly is a measurement, not a syndrome  Reports mainly from NE Brazil, not elsewhere  Poverty, pesticides, other factors?  Birth cohort showing high rate before Zika (but steep rise in severe cases after)

What’s the risk of microcephaly?  Background rate ~5 per 100,000 births  Brazil, 2015 ~4700 (max) cases in 2.9M births  That would be 162 per 100,000  If ~1.5M infections in population 200M  At same attack rate~ 21,000 affected pregnancies Risk (pregnancy with Zika) could be 3% – 15% Uncertainties:  Can silent infections damage fetus?  Stage of pregnancy? Cofactors?  What about breast-feeding?

Association with birth defects and neurological disorders  Circumstantial relationship??  Clinical and Epidemiological information is emerging fast  Case-control study using 100 cases of microcephaly currently underway

Australia Update  In Australia there have been 27 cases notified, with the first in 2012  The first case of Zika notified in Queensland was in 2014  As at 15 Feb 2016, Qld’s total is 18 cases  7 in 2014  4 in 2015  7 in 2016

Country of acquisition  All cases notified in Qld were acquired overseas  In 2016, cases were acquired from Samoa (3) and Tonga (3) Country of acquisition Number of notifications in Qld Cook Islands7 Samoa3 Tonga3 Vanuatu2 El Salvador1 Solomon Islands1

Qld Zika notifications  In 2016 one pregnant woman has been notified.  Most reported in SEQ Hospital and Health Service Number of Notifications Gold Coast4 Metro South4 Townsville3 West Moreton3 Metro North2 Mackay1

Minister’s Round Table  03 February Qld. Health Minister met with health experts and other stakeholders  Recognition that greatest risk for local transmission is in north Queensland Ministerial priorities:  Research  Laboratory testing capability  Community engagement  Local government engagement with mosquito surveillance and control

The specific vector  Elderly ♀ Aedes aegypti  Day biting, shy, fussy, travels ≤ 200m  Hides indoors, under furniture, dark surfaces  Extrinsic Incubation period: days  Infective for life  Not a bush mozzie

Getting ready- Receptive area  Encourage Eliminate Dengue (wolbachia mosquitoes) participation  Vector control at home using interior residual spray (IRS) (90% dengue protection to occupants)  Zappers, coils, daytime / dusk clothing (legs, feet) and repellents  DEET, pyrethroids, methoprine safe in pregnancy

Eliminate Breeding Sites

Targeted insecticides

Surveillance  Early detection is key to preventing and managing outbreaks  Labs in Townsville to test for Zika virus from March 2016

Testing for Zika  Returned from Zika country + sick  Returned from Zika country + Pregnant, (sick or not)  Test early for the virus (PCR: days)  Pregnant: urine PCR can be positive up to 2 weeks  Semen?  Serology (testing for antibodies IgG & IgM)

Testing for Zika in Pregnancy Symptomatic Pregnant Women  H/o place of travel and date of symptom onset  Test for Zika + others relevant travel- related illness  Recommended specialist ID advice to discuss DD

Testing for Zika in Pregnancy Asymptomatic Pregnant Women  H/o dates/duration/place of travel  H/o mozzy bites  Blood collected at initial presentation irrespective of time of exposure  If presents < 2 weeks of exposure, blood collected held at lab for future testing

Diagnostic tests

Sexual Transmission  Zika virus has been found in saliva or urine for more than one week after blood clears  Two cases of probable sexual transmission reported so far – both from men  Seminal fluid positive for virus for 9 weeks after onset of symptoms – so duration of infectivity currently unknown  No evidence that an infected woman can transmit Zika virus through sex

Sexual Transmission Recommendations for men who have recently travelled to areas with ongoing Zika virus transmission  Pregnant partner - Use condoms consistently or abstain from sexual activity for the duration of pregnancy  Confirmed Zika infection and non pregnant partner - Use condoms consistently or abstain from sexual activity for 3 months

Travel advice  Pregnant, contemplating pregnancy… “Don’t go to the listed countries”  No sexual partners  Safe sex throughout pregnancy semen may be positive for 2 months +  Mosquito avoidance  Insect repellants, clothes, bednet (daytime)

Unknowns??  Real link to microcephaly, adult GBS?  Sensitivity and Specificity of tests?  Asymptomatic transmission?  Rate, duration of sexual transmission?  Low level circulation (Dengue endemic countries)?

Updates Qld Health website alerts/health-alerts/zika/  Communicable disease control guidance  The Australian Government Department of Health Contact Public Health Unit on or

Thank you

Dengue outbreaks

A. aegypti distribution