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Zika virus disease

    Overview

    Zika virus is primarily transmitted by the bite of an infected mosquito from the Aedes genus, mainly Aedes aegypti, in tropical and subtropical regions. Aedes mosquitoes usually bite during the day, peaking during early morning and late afternoon/evening. This is the same mosquito that transmits dengue, chikungunya and yellow fever.

    Zika virus is also transmitted from mother to fetus during pregnancy, through sexual contact, transfusion of blood and blood products, and organ transplantation.

    WHO declared a public health emergency of international concern regarding microcephaly, other neurological disorders and Zika virus from February to November 2016. Cases of Zika virus disease declined from 2017 onwards globally; however, Zika virus transmission persists at low levels in several countries in the Americas and in other endemic regions. To date, a total of 89 countries and territories have reported evidence of mosquito transmitted Zika virus infection, however surveillance remains limited globally.

    No vaccine is yet available for the prevention or treatment of Zika virus infection. Development of a Zika vaccine remains an active area of research

    The history of Zika virus

    Symptoms and treatment
    The incubation period (the time from exposure to symptoms) of Zika virus disease is estimated to be 314 days. The majority of people infected with Zika virus do not develop symptoms.

    Symptoms are generally mild including fever, rash, conjunctivitis, muscle and joint pain, malaise, and headache, and usually last for 27 days.

    Complications of Zika virus disease

    Zika virus infection during pregnancy is a cause of microcephaly and other congenital abnormalities in the developing fetus and newborn. Zika infection in pregnancy also results in pregnancy complications such as fetal loss, stillbirth, and preterm birth.  

    Zika virus infection is also a trigger of Guillain-Barré syndrome, neuropathy and myelitis, particularly in adults and older children.

    Research is ongoing to investigate the effects of Zika virus infection on pregnancy outcomes, strategies for prevention and control, and effects of infection on other neurological disorders in children and adults.

    Prevention and control
    Protection against mosquito bites during the day and early evening is a key measure to prevent Zika virus infection. Special attention should be given to prevention of mosquito bites among pregnant women, women of reproductive age, and young children.

    Personal protection measures include wearing clothing (preferably light-coloured) that covers as much of the body as possible; using physical barriers such as window screens and closed doors and windows; and applying insect repellent to skin or clothing that contains DEET, IR3535 or icaridin according to the product label instructions.

    Young children and pregnant women should sleep under mosquito nets if sleeping during the day or early evening.  Travellers and those living in affected areas should take the same basic precautions described above to protect themselves from mosquito bites.

    Prevention of sexual transmission of Zika virus

    Aedes mosquitoes breed in small collections of water around homes, schools, and work sites. It is important to eliminate these mosquito breeding sites, including: covering water storage containers, removing standing water in flower pots, and cleaning up trash and used tires. Community initiatives are essential to support local government and public health programs to reduce mosquito breeding sites.  Health authorities may also advise use of larvicides and insecticides to reduce mosquito populations and disease spread.

    Vector control operations framework for Zika virus

     

    Framework for national surveillance and control plans for Aedes vectors in the Pacific

    Populations in Pacific island countries and areas (‎PICs)‎ remain vulnerable to outbreaks of diseases carried by Aedes mosquitoes for which there...

    Laboratory testing for Zika virus and dengue virus infections: interim guidance

    Zika and dengue viruses remain significant public health threats. These viruses share the same Aedes (Stegomyia) mosquito vectors and geographic...

    Guideline for the clinical diagnosis and treatment of  dengue..., chikungunya

    Evidence-based guidelines are one of the most useful tools for improving public health and clinical practice. Their purpose is to formulate interventions...

    Guideline: infant feeding in areas of Zika virus transmission, 2nd edition

    The objective of this guideline is to provide global, science-informed recommendations on infant feeding in areas of Zika virus transmission. The primary...

    Documents

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    World Health Organization compiled an updated summary of the global epidemiology of Zika virus transmission. A review of global surveillance data and scientific...

    R&D roadmaps are key documents to better understand current and future health threats and identify effective health technologies to save lives.With...

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    In 2016, WHO began a major global initiative to facilitate cross-study analyses of ZIKVrelated studies of pregnant women and their children through both...

    Guidelines