Pan American Health Organization Issues Alert Over Rising Chikungunya Cases in the Americas

Washington, D.C. — The Pan American Health Organization (OPS) issued an epidemiological alert on Thursday due to a sustained increase in chikungunya cases across several countries in the Americas since late 2025 and early 2026. The alert comes as the mosquito-borne virus has resumed transmission in areas that had not reported cases for years.

The regional health body reported that this trend is occurring in regions with the Aedes aegypti mosquito and aligns with expected patterns in endemic zones, though environmental factors like extreme temperatures are boosting vector reproduction. Officials also noted that the persistence of the virus and the circulation of the Asian and East/Central/South African (ECSA) genotypes reinforce the need for sensitive surveillance and prompt response measures.

“Chikungunya spread across the Americas in 2013, and after years of low transmission, we are observing a resurgence, especially in the Intertropical Zone where the Aedes aegypti mosquito is present,” said Sylvain Aldighieri, Director of Communicable Disease Prevention, Control, and Elimination at OPS. “The goal of this alert is for health workers and governments to prepare for potential outbreaks and plan public information campaigns.”

Globally, from January 1 to December 10, 2025, authorities reported 502,264 cases, including 208,335 confirmed infections and 186 deaths across 41 countries and territories. In the Americas, officials recorded 313,132 cases, with 113,926 confirmed, including 170 deaths in 18 countries and one territory during 2025.

While the region overall shows a decrease compared to 2024, some countries in South America and the Caribbean reported increases in specific localities. Since late 2025 and early 2026, authorities identified a sustained rise in cases and renewed transmission in territories that had not reported circulation for several years. Guyana, French Guiana, and Surinam evidenced a resurgence after a decade without reported cases.

Genomic analysis in the Americas identified circulation of the ECSA genotype, without detection of the A226V mutation associated with higher transmissibility by Aedes albopictus. OPS emphasized that the virus’s persistence in endemic areas and its reappearance in previously free territories demands integrated surveillance and continuous preventive actions.

Among its recommendations, the organization urged authorities to intensify epidemiological and laboratory surveillance, include chikungunya in the differential diagnosis of fever and rash alongside measles and other arboviruses, and strengthen health unit capacity to ensure timely diagnosis, classification, and treatment.

OPS advised vector control teams to eliminate breeding sites in zones with higher case reports and areas near health facilities. The public should use repellents, mosquito nets, and clothing covering arms and legs, avoid mosquito exposure in areas with active transmission—especially at dawn and dusk—and assist in removing containers that accumulate water.

Chikungunya is a virus transmitted by Aedes aegypti and potentially Aedes albopictus, which also transmit dengue and Zika. It causes fever and intense joint pain, can lead to chronic conditions with joint involvement for weeks or months in about 60% of cases, and has no specific antiviral treatment. Symptoms are managed with analgesics and antipyretics, while higher-risk groups should be evaluated by health personnel to prevent complications.

OPS indicated it will continue monitoring the situation and providing technical support to countries to strengthen surveillance, patient care, and vector management in the region.