PAHO warns of sustained yellow fever transmission in South America
Yellow fever is a hemorrhagic viral disease endemic in tropical areas of Africa, Central America, and South America.
TL;DR
- Yellow fever is a hemorrhagic viral disease endemic in tropical areas of Africa, Central America, and South America.
- PAHO has issued an alert due to sustained yellow fever transmission, with cases reported in areas outside the Amazon basin since September 2024.
- In 2025, 346 confirmed cases and 143 deaths were reported across seven countries: Bolivia, Brazil, Colombia, Ecuador, Guyana, Peru, and Venezuela.
- The first seven weeks of 2026 saw 34 confirmed cases and 15 deaths in Bolivia, Colombia, Peru, and Venezuela.
- Cases have been detected in non-traditional risk areas, including São Paulo, Brazil, and Tolima, Colombia, since late 2025.
- Urban transmission, facilitated by the Aedes aegypti mosquito, is a growing concern, potentially leading to rapid outbreaks.
- PAHO maintains a high public health risk in the Americas due to increased contagions, a high fatality rate (41% in 2025), and spread to new areas.
- PAHO calls for strengthened surveillance, intensified vaccination, traveler precautions, early detection, timely clinical management, and vaccine stock maintenance.