Colombia's Yellow Fever Outbreak Faces Ecoepidemiological Challenges

The World Health Organization has recently reconfirmed that the mosquito-transmitted yellow fever virus has become endemic in various countries in the Americas, including the Republic of Colombia.

Yellow fever was once mainly sylvatic in remote Colombian regions throughout the 20th century.

However, the 21st century has seen the re-emergence of yellow fever in endemic zones, and it has spread to populated areas, raising the risk of urban outbreaks in 2025 due to ecoepidemiological shifts, as noted by Carlos A. Alvarez-Morenoa and Alfonso J. Rodriguez-Moralesb.

As of early June 2025, there have been 104 cases and 45 deaths this year, most occurring in the Tolima Department.

In 2024, 23 cases of yellow fever were reported in Colombia, with 13 deaths.

The expanding vaccine-preventable yellow fever outbreak highlights the persistent threat and tests Colombia's public health resilience and preparedness.

Published by The Lancet on June 13, 2025, this Correspondence stated that the Colombian Government has declared a health and economic emergency in several affected regions in response to the recent surge in cases.

Despite vaccines and technical expertise, barriers remain, such as low rates of adult vaccination, difficult access in high-risk areas, restricted operations in conflict zones, and mistrust in rural and Indigenous groups.

The most pressing challenge is to achieve sustained and adequate vaccination coverage, particularly among adults in rural, jungle, and border areas.

In conclusion, the authors wrote, 'A strong, equitable, community-centred approach is crucial. Key priorities include improving surveillance, risk communication, and equitable vaccine access—especially for underserved, high-risk groups—to prevent the spread and reduce the disease burden.'

When visiting yellow fever outbreak areas in Colombia in 2025, the health ministries of the United States, the United Kingdom, and Canada recommend obtaining a vaccination at least one month before departure.