Washington, DC, February 4, 2025 (PAHO) – The Pan American Health Organization (PAHO) has issued an epidemiological alert with respect to yellow fever in the Americas due to the recent increase in human cases confirmed in several countries of the region and a change in the geographical distribution of the disease.
This increase has been observed in the last months of 2024 and the first weeks of 2025. In total, 61 cases of yellow fever were confirmed in 2024, with 30 resulted in death. This number exceeds the 58 reported cases of yellow fever, including 28 deaths, between 2022 and 2023 in Bolivia, Brazil, Colombia and Peru. In January of this year, 17 additional cases were reported, with seven deaths.
While in 2024, cases were mainly concentrated in the Amazon region of Bolivia, Brazil, Colombia, Guyana and Peru, in 2025, the disease has begun to spread to areas outside this area, particularly the state of São Paulo, Brazil and The department of Tolima, Colombia. Peru has also reported a fatal case. Paho warns that other countries could also be affected.
Yellow fever is a severe viral disease that can be fatal, especially in its most serious form. This increase in cases highlights the urgent need to intensify efforts to prevent the spread of the virus, strengthen clinical management (with an emphasis on early detection and treatment of severe cases) and improve epidemiological surveillance in high -risk areas.
Paho remembers that vaccination remains one of the most effective tools to prevent and control yellow fever. In 2024, most of the informed cases were in people who had not been vaccinated. In this sense, the PAHO urges countries to continue strengthening their vaccination programs and to take appropriate measures to inform and protect travelers who go to high -risk areas.
Given the changes in the transmission patterns of the virus, the PAHO emphasizes the need to maintain active surveillance, particularly in areas close to the affected areas, to detect any early suspicious case and guarantee appropriate isolation and treatment.
Key recommendations:
- Improved surveillance: quickly detect any suspicious case, even in areas not traditionally affected.
- Universal vaccination: Make sure at least 95% of people in high -risk areas are vaccinated.
- Laboratory diagnosis: Make virological diagnoses through PCR during the first 7 to 10 days of illness, or IGM Elisa in the convalescent phase, with careful interpretation due to cross reactivity in areas with other circulating flavivirus.
- Clinical management: Strengthen early detection and specialized monitoring of serious patients as a key measure to save lives.
- Preparation for outbreaks: Check and update the inventory of national and subnational vaccines to plan a rapid emergency response.
Since 1970, yellow fever has resurfaced as a threat to public health in the Americas. The disease is endemic in 13 countries and territories in the region, causing outbreaks and deaths. In 2014, the virus spread beyond the Amazon basin. Some attribute this spread to changes in the interaction between monkeys, mosquitoes and humans.
PAHO continues to closely monitor the situation to provide the most up -to -date information and best practices to mitigate the impact of the disease, guarantee a coordinated response between the countries of the region and offer technical and strategic support for prevention and control of yellow fever .
