Zika virus (ZIKV) infection is spread by day-biting mosquitoes. A small number of cases of sexual transmission of ZIKV have also been reported and there is increasing evidence of transmission from mother to fetus via the placenta.
ZIKV is a flavivirus (similar to dengue) and was first discovered in a monkey in the Zika forest, Uganda in 1947. It is found in parts of Africa, Asia and the Pacific Islands and has recently been reported in Central and South America and the Caribbean. It is likely to spread to new areas in the future. Current outbreaks of ZIKV infection are recorded on our outbreak surveillance section.
All travellers to countries where ZIKV is known to occur are at risk of infection, although determining the actual level of risk is difficult. Travellers who spend a long period in areas where ZIKV is common are at increased risk. However, even short-term visitors may be exposed to the virus.
ZIKV infection is usually a mild and short-lived illness; severe disease is uncommon. Symptoms include: fever, headache, red, sore eyes and conjunctivitis, joint and muscle pain, a rash, itching and swollen joints. There is no specific treatment; rest, fluids and pain relief are recommended to help relieve symptoms. Serious complications and deaths from ZIKV are not common. However, there is now scientific consensus that ZIKV is a cause of microcephaly and other congenital anomalies, and Guillain-Barré syndrome.
Travellers should be aware of the risk of ZIKV in the destination to be visited. Information about ZIKV transmission in affected countries can be found in the ‘Outbreaks’ and ‘Other risks’ section of our Country Information pages.
There is no vaccine to prevent ZIKV infection. Prevention is by minimising mosquito bites; the mosquito that spreads ZIKV is most active in daylight hours. All travellers should be vigilant with insect bite precautions. See also preventing infection by sexual transmission.
Those travelling to regions where ZIKV occurs should ideally seek travel health advice from their GP, practice nurse or a travel clinic at least 4-6 weeks before travel. This is particularly important for those who are pregnant, planning to become pregnant, suffer from a severe, chronic medical condition, or have a medical condition that weakens the immune system. It is recommended that pregnant women should postpone non-essential travel to areas designated as 'high risk' for ZIKV transmission until after pregnancy. They should consider postponing non-essential travel to areas designated as ‘moderate risk’ (see A-Z list) until after pregnancy. See specific advice for travellers in our news item.