Zika Virus Dr Conor Doherty

Transcription

1 Zika Virus Dr Conor Doherty

2 Zika Virus Single stranded RNA enveloped icosahedral virus Flavivirus (e.g. dengue, yellow feve er) First described in Zika forest in Uganda in 1947 Initial enzootic monkey mosquitoo monkey cycle with only occasional transmission to humans Since 2007 mosquito human mosquito cycle and more human cases Since 2013 more cases notes in French Polynesia and Latin America

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4 Current Zika Virus epidemiology i Reported Zika virus cases have accelerated rapidly in the Americas in late 2015/early 2016 Guillain Barre congenital microcephaly Causallink link not confirmed ECDC 2016

5 Clinicallyi ll Incubation period is 3 12 days Mild self limiting illness of 4 7 days fever, headache, conjunctivitis, rash, myalgia, arthralgia Upto 80% asymptomatic

6 Diagnostics Detection of viral RNA in acute phase samples Testing through Rareandand Imported Pathogens Lab Viraemia tends to be transient and serology produces inconclusive results due to cross reactions with other similar viruses.

7 Microcephaly & Brazi il 2015 Health authorities in Salvador (Bahia) reported 14, 835 cases of exanthematous disease between een February and June ne states have reported a total of 3893 cases of congenital microcephaly since October 2015 the great majority (87.39%) of cases have been reported from the NorthEast region cases per year that were reported between 2010 and 2014 Public Health Emergency of International Concern (PHEIC) by WHO on 1 February.

8 ZIKV can cross the placental l barrier Evidence of Zika Virus Infection in Brain and Placental Tissues from Two Congenitally Infected Newborns and Two Fetal Losses by RT PCR (MMWR Weekly / February 19, 2016 / 65(06); ) ) tissues samples from two newborns (born at 36 and 38 weeks gestation) with microcephaly who died within 20 hours of birth and two miscarriages (fetal losses at 11 and 13 weeks) from mothers all four mothers had clinical signs of Zika virus infection, including fever and rash, during the first trimester of pregnancy, but did not have clinical signs of active infection at the time of delivery ormiscarriage Zika Virus Associated with Microcephaly (NEJM Feb ) TOP at 32 weeks of woman who developed clinica ally NIKV compatible illness at 13 weeks in Brazil demonstrated microcephaly, agyria, hydrocephalus, calcification & inflammation and ZIKV on RT PCR.

9 HPS ZIKV is suspected to cause severe birth defects in children if pregnant women are infected The risk is likely to be highest during the first two trimesters of pregnancy. The main risk is in Latin America, in particular Brazil Public Health lthengland d(phe) (PHE), CDC (USA) and PHAC (Canada) have issued highly cautious guidance advising women who are, could be, or could become pregnant to cons ider avoiding travel to countries where ZIKV is circulating

10 Currently (18 th Feb) Seven (7) imported cases of ZIKV disease have been reported in the United Kingdom in association with the current outbreaks. 2 probable cases of sexual transmission reported in USA SNBTS introduced 28 day deferral for donors who have visited Zika affected countries from Friday 5th Feb, in common with other UK blood services. RCOG/RCM/PHE/HPS Interim guidance Feb 16

11 RCOG/RCM/PHE/HPS Interim guidance - Feb 16