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.

                                  In October 2015, Brazil reported an association between Zika virus infection and microcephaly. Outbreaks and evidence of transmission soon appeared throughout the Americas, Africa, and other regions of the world. To date, a total of 86 countries and territories have reported evidence of mosquito-transmitted Zika infection. 

                                  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

                                  Zika outbreak 2015 - 2016

                                  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

                                   

                                  Majority of infected

                                  have no symptoms

                                  3–14 days

                                  incubation period

                                  The incubation period of Zika ranges from 3 -14 days

                                  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...

                                  WHO guidelines for the prevention of sexual transmission of Zika virus

                                  WHO published interim guidelines on the prevention of sexual transmission of Zika virus in September 2016, based on a limited amount of evidence under...

                                  Guidance framework for testing the sterile insect technique as a vector control tool against aedes-borne diseases

                                  This document is intended to be a comprehensive guide for programme managers tasked with recommending a “go/no-go” decision on testing, full...

                                  Pregnancy management in the context of Zika virus infection

                                  The mosquito vector that carries the Zika virus thrives in warm climates and particularly in areas of poor living conditions. Pregnant women living in...

                                  Guidelines

                                  Our work

                                  Countries and territories with current or previous Zika virus transmission - 5 June 2019

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