Yellow Fever

Tourists at Iguazu Falls on the border of Brazil and Argentina

Yellow fever is an illness spread by the bite of an infected mosquito.

Yellow fever virus is spread in tropical and subtropical areas of Africa and South America. Travel-Associated cases are rarely reported in the United States.

Anyone who travels to areas where yellow fever is spread is at risk of getting the illness, but people who spend more time outdoors are at a higher risk of being bitten by an infected mosquito. It is important to take preventive steps when traveling to areas with yellow fever, especially in areas with ongoing outbreaks. Some preventive steps you can take are getting the yellow fever vaccine, wearing protective clothing, using insect repellents, and using mosquito netting.

For more tips, please visit our Mosquito Bite Prevention page. For country-specific travel information and recommendations, visit the CDC (Center for Disease Control and Prevention's) Traveler's Health page.

About yellow fever

Provider information

Questions about illnesses spread by mosquitoes? Contact us!

Phone: 608-267-9003 | Fax: 608-261-4976

Last revised July 3, 2025