Yellow Fever Outbreak Alert Issued for the Americas

With the unexpected increase in human cases of yellow fever in the Americas region between the end of 2024 and the beginning of 2025, the Pan American Health Organization / World Health Organization (PAHO/WHO) issued an Epidemiological Alert.

Today, these health agencies stated, 'The risk of (continued) yellow fever outbreaks is high in the Americas Region.'

As of February 3, 2025, this Alert revealed that between epidemiological week (EW) 1 and EW 4 of 2025, 17 confirmed human cases of yellow fever (YF) had been reported in three countries in the Region, seven of which were fatal.

These cases have been reported in Brazil, Colombia, and Peru.

Additionally, Guyana has reported three laboratory-confirmed cases in 2025.

Furthermore, if projections are fulfilled, this YF outbreak may impact countries such as Argentina and Paraguay.

Last year, 61 human cases of yellow fever were confirmed in the Americas Region, of which 30 were fatal.

The PAHO/WHO calls on Member States with areas at risk to take the necessary actions to ensure that travelers visiting places where yellow fever outbreaks occur and vaccination is recommended are appropriately informed on how to prevent this mosquito-transmitted disease.

The PAHO/WHO wrote, 'It is essential that countries achieve vaccination coverage of at least 95% in populations in at-risk areas, in a homogeneous manner, and that health authorities ensure that they have a strategic reserve inventory that allows them to maintain routine vaccination and, at the same time, respond effectively to possible outbreaks.

"This report from PAHO and WHO serves as a reminder to travelers planning a visit to South America in 2025 of the importance of vaccinating against yellow fever because infection can lead to death in up to 60% of cases," stated Jeri Beales, MSN, RN.

"Thankfully, the yellow fever vaccine has proven highly effective, although some people with certain health conditions may not be eligible for vaccination."

"Keep in mind, if you plan to transit between multiple countries while in South America, the yellow fever vaccine may be required, and you need to bring the official yellow fever vaccination record with you, added Beales, the leader of Destination Health Clinic, a Boston-area travel health provider specializing in health education and vaccination for international travelers.

In February 2025, certified travel clinics and pharmacies in the United States will offer yellow fever vaccines to international travelers visiting these countries.

Moreover, Brazil's Ministry of Health recently warned international travelers about a potential need for a yellow fever vaccine booster dose.