Health Risk Assessment associated with the yellow fever situation in the Americas Region - 23 May 2025

This rapid risk assessment (RRA) aims to assess the current public health risk associated with the increase in yellow fever cases in 2025 in endemic countries of the Americas Region.

This RRA has been conducted considering the following criteria: (i) the potential risk to human health -including exposure risk, clinical-epidemiological behavior, indicators of magnitude and severity, as well as more detailed risk factors and determinants-, based on the increasing trend in confirmed cases during 2024 and 2025, and the case fatality rate (CFR) which was 50% in 2024 and 40% in 2025; (ii) the risk of dissemination, particularly the potential spread to areas historically classified as low-risk for the disease, including the possibility of a zoonotic wave extending to Panama and other ecological suitable areas ; and (iii) the public health risk on varying capacities for early detection, prevention and control within endemic countries, low vaccine coverage, as well as challenges regarding a scenario of yellow fever vaccine shortage in the Americas Region.

The overall risk associated with the yellow fever situation in the Americas Region, particularly in endemic countries, is classified as ¨High¨ with a ¨High¨ level of confidence based on the available information.