The Pan American Health Organization has released new clinical guidelines aimed at improving the management of severe yellow fever cases and strengthening the capacity of healthcare workers across the Americas.
The new guidance is designed to support timely, life-saving care for patients affected by Yellow fever, which can trigger outbreaks with high numbers of infections and deaths in a short period.
According to PAHO, there is currently no specific treatment for yellow fever, making early detection of suspected cases, close monitoring of high-risk patients, and timely referral to intensive care units critical to reducing complications and saving lives.
“This guideline provides evidence-based clinical recommendations to support decision-making and improve the care of severe yellow fever cases,” said Ángel Rodríguez. “It also serves as a key tool to strengthen preparedness and response across health services in the Americas.”
The new guidance complements PAHO’s 2023 clinical management guidelines and forms part of the organisation’s broader response to a public health emergency recorded between 2024 and 2025, when the average case fatality rate for yellow fever reached about 45 percent.
The updated recommendations include guidance on case detection, diagnosis, severity classification, initial management, and comprehensive patient care.
Yellow fever is caused by a virus from the Flavivirus genus and is transmitted through mosquito bites. In jungle environments, transmission typically involves mosquitoes from the Haemagogus and Sabethes genera, while urban transmission can occur through Aedes aegypti and Aedes albopictus. Severe infections can progress rapidly and may lead to complications such as acute liver failure requiring intensive medical care.
The disease has re-emerged as a growing public health concern in recent years. Since 2024, outbreaks have been reported in several South American countries, including areas outside the traditional Amazon basin, indicating an expansion of risk zones.
In 2025, 346 confirmed cases and 143 deaths were reported across seven countries: Bolivia, Brazil, Colombia, Ecuador, Guyana, Peru, and Venezuela. In the first seven weeks of 2026, 34 additional cases and 15 deaths were recorded in Bolivia, Colombia, Peru, and Venezuela.
While there is no specific treatment, vaccination remains the most effective prevention method. A single dose of the yellow fever vaccine provides lifelong immunity, and most recent cases have occurred among unvaccinated individuals.
PAHO said it will continue supporting countries in strengthening surveillance, expanding vaccination coverage among at-risk populations, and improving health systems’ ability to detect and manage severe cases early.
The organization noted that the new guidelines aim to provide healthcare teams with practical, evidence-based tools to standardize care and reduce deaths associated with the disease as climate and environmental factors increase outbreak risks across the region.
