• Zika virus is primarily transmitted through mosquito bite. It is found in Mexico, Central America, South America, the Caribbean, tropical areas of Southeast Asia, Oceania, and parts of Africa.
• All travelers may be at risk, as are aid workers and missionary workers. It is particularly dangerous for pregnant women.

Zika virus infection is caused by the Zika virus (ZIKV), which belongs to the Flaviviridae family. The virus is primarily transmitted by infected daytime biting female Aedes aegypti and Aedes albopictus mosquitoes which are typically active from dawn to dusk. There is evidence that Zika virus is also transmitted by other mosquitoes belonging to the Aedes genus. The virus can be transmitted from a pregnant woman to her fetus.

Zika virus is present in Mexico, Central America, South America, the Caribbean, tropical areas of Southeast Asia, Oceania, and parts of Africa. All travelers are at risk. Long-term travelers and aid or missionary workers going to areas where Zika virus is endemic are at greater risk.

Zika virus is associated with neurological complications: Guillain-Barré syndrome (progressive muscle weakness that can lead to temporary paralysis) and microcephaly (decreased head size which may lead to developmental delays) in infants born to pregnant women infected with the virus.

Real-time data on Zika virus outbreaks and transmission is often not available. This is because most people who become infected with Zika virus do not show signs or symptoms. In some countries, reliable reporting and monitoring systems that track virus transmission may not be available. As a result, it is not always possible to convey a country’s current level of risk, but travelers should take precautions wherever risk exists.

All travelers going to areas with Zika virus risk are advised to take mosquito bite precautions, particularly during the daytime. Pregnant women or couples considering pregnancy should consult a healthcare practitioner prior to travel.