Information for travellers visiting countries with Zika virus transmission
Zika virus is primarily transmitted to people through the bite of infected Aedes mosquitoes, which bite predominantly during the day and early evening. Zika virus can also be transmitted through sex and during pregnancy from mother to foetus. Aedes mosquitoes also transmit dengue, chikungunya, yellow fever, and other viruses. These mosquito-transmitted viruses often circulate in the same geographic areas.
Based on available evidence, WHO advises against any restriction of travel to or trade with countries, areas and territories with Zika virus transmission. However, WHO recommends that pregnant women avoid travel to areas with Zika virus transmission, particularly during outbreaks, based on the increased risk of microcephaly and other severe congenital malformations in infants born to women infected with Zika virus during pregnancy.
As a precautionary measure, some national governments may make public health and travel recommendations to their own populations, based on their assessment of the available evidence and local risk factors.
Before travelling to areas with potential Zika virus transmission
Some areas of the world continue to experience Zika virus outbreaks or ongoing transmission. Other areas have had evidence of prior Zika virus transmission but no recent evidence of transmission, and some have sporadic reported cases or low levels of transmission. Risk of infection may vary in different areas within a country, may vary seasonally, and likely changes over time. Most Zika virus infections have no symptoms or have mild, non-specific symptoms, that may elude detection or reporting. In the absence of large outbreaks, accurate and up-to-date information on risk of Zika virus transmission is therefore limited in many countries and territories. Lack of detection or reporting of Zika virus transmission, therefore, cannot necessarily be equated with evidence that transmission is not occurring.
WHO remains committed to strengthening public health systems for early detection and response to emergence, re-emergence, and global spread of Zika virus infection and its complications. WHO will maintain periodic epidemiologic updates on Zika virus transmission and outbreaks to provide information to countries, healthcare providers and travellers.
WHO recommends that pregnant women, women who may become pregnant within two months of travel, and male travellers whose partner may become pregnant within three months of travel check with their healthcare providers and carefully consider the risks and possible consequences of Zika infection before traveling to areas where there may be Zika virus transmission.
While in areas with potential transmission of Zika virus and other diseases transmitted by Aedes and other day-biting mosquitoes
All travellers should take appropriate measures to reduce the possibility of exposure to mosquito bites during the day and early evening hours and avoid risk of sexual transmission of Zika virus.
To prevent bites from mosquitoes that feed during the day and early evening hours, travellers are advised to:
- wear clothing - preferably light coloured - that covers as much of the body as possible;
- use insect repellents that contain DEET (diethyltoluamide), IR 3535 ((3- [N-butyl-N-acetyl], aminopropionic acid ethyl-ester) or KBR3023 (also called Icaridin or Picaridin). Repellents may be applied to exposed skin or to clothing and must be used in strict accordance with the label instructions. If repellents and sunscreen are used together, sunscreen should be applied first and the repellent thereafter;
- use physical barriers such as regular or mesh screens or insecticide treated netting materials on doors and windows, and keep doors and windows closed; and
- sleep under mosquito nets during the day when Aedes mosquitoes are most active.
To avoid risk of sexual transmission of Zika virus infection, men and women should practice safer sex, including the consistent use of condoms, or abstinence
Upon return home
To prevent the onward transmission of Zika virus, travellers returning from areas with potential transmission of Zika and other mosquito-borne viruses to areas with competent mosquito vectors should continue to use insect repellent for at least three weeks to avoid being bitten and potentially spreading the infection to other people through mosquito bites.
To prevent adverse pregnancy and foetal outcomes due to Zika virus infection, all travellers returning from areas with potential Zika virus transmission should practice safer sex, including through the correct and consistent use of condoms, or consider abstaining from sex for at least three months after the last possible exposure for men, or two months for women travellers. Sexual partners of pregnant women should practice safer sex or abstain for at least the duration of the pregnancy.
Returning travellers who develop symptoms of possible Zika virus infection (e.g. rash, fever, painful joints, red eyes) should contact their healthcare provider, inform their provider of their travel history and receive laboratory testing and clinical care as indicated.
Returning travellers who are pregnant should inform their health care providers of their travel history when seeking care. Routine testing for Zika virus infection in returning travellers who are pregnant, who have no symptoms and no abnormal ultrasound findings, is not recommended at this time.