ZIKA VIRUS DISEASE, MICROCEPHALY AND GUILLAIN-BARRÉ SYNDROME
As of 27 April, 55 countries and territories report continuing mosquito-borne transmission; for 42 countries this is their first documented Zika virus outbreak (Fig. 1).
Mosquito-borne transmission (Table 1):
42 countries are experiencing a first outbreak of Zika virus since 2015, with no previous evidence of circulation, and with ongoing transmission by mosquitos.
13 countries reported evidence of Zika virus transmission between 2007 and 2014, with ongoing transmission.
Four countries or territories have reported an outbreak since 2015 that is now over:
Cook Islands, French Polynesia, ISLA DE PASCUA – Chile and YAP (Federated States of Micronesia.
Person-to-person transmission (Table 2):
Nine countries have reported evidence of person-to-person transmission of Zika virus, probably via a sexual route.
In the week to 27 April, no additional countries reported mosquito-borne Zika virus transmission. Canada is the latest country to report person-to-person transmission.
Microcephaly and other fetal malformations potentially associated with Zika virus infection or suggestive of congenital infection have been reported in six countries or territories (Table 3). Two cases, each linked to a stay in Brazil, were detected in Slovenia and the United States of America. One additional case, linked to a brief stay in Mexico, Guatemala and Belize, was detected in a pregnant woman in the United States of America.
In the context of Zika virus circulation, 13 countries and territories worldwide have reported an increased incidence of Guillain-Barré syndrome (GBS) and/or laboratory confirmation of a Zika virus infection among GBS cases (Table 4).
Based on research to date, there is scientific consensus that Zika virus is a cause of microcephaly and GBS.
The global prevention and control strategy launched by the World Health Organization as a Strategic Response Framework encompasses surveillance, response activities and research. Key interventions are being undertaken jointly by WHO and international, regional and national partners in response to this public health emergency (Table 5).
WHO has developed new advice and information on diverse topics in the context of Zika virus. WHO’s latest information materials, news and resources to support risk communication, and community engagement are available online.