Brazil's Chikungunya Outbreak Centered in the Mountains

Brazil's Ministry of Health (MOH) has been reporting data on the locations of Chikungunya patients for the past three years.

As of March 11, 2025, the MOH reported that most of the 40,000 Chikungunya cases reported this year were found in Sao Paulo (5,714) and Minus Gerias (5,120).

Last year, there were about 265,000 Chikungunya cases and 231 related fatalities in Brazil, located in similar states.

The Chikungunya virus is transmitted to people through the bite of an infected mosquito of the Aedes spp., which are found at beaches and in mountains below seven thousand feet in elevation. 

While the U.S. CDC has not issued a Travel Health Advisory regarding Brazil's ongoing Chikungunya outbreak, it writes, 'There has been evidence of chikungunya virus transmission in Brazil within the last five years.'

Chikungunya vaccination may be considered for seniors, especially those with underlying medical conditions, who may spend at least two weeks (cumulative time) in indoor or outdoor areas where mosquitoes are present in Brazil, or visitors planning to stay in Brazil for a cumulative period of six months or more.

Before departing for Brazil, most travel clinics and pharmacies in the United States offer the U.S. FDA-approved chikungunya vaccine. Valneva SE's IXCHIQ® vaccine has been found safe and effective in various studies.