Strengthening Vector Control Against Chikungunya and the Expansion of Oropouche in Latin America

The Pan American Health Organization (PAHO) has issued an epidemiological alert due to localized outbreaks of chikungunya and the sustained circulation of the Oropouche virus in several countries across the Americas. In this context, it is noted that the simultaneous occurrence of arboviral diseases could increase the risk of complications and fatalities, especially among the most vulnerable populations.

Chikungunya outbreaks have most severely impacted South America, with Bolivia, Brazil, and Paraguay being the most affected nations, in addition to some regions of the Caribbean. As of August 9, over 212,000 suspected cases and 110 deaths have been reported in 14 countries, with more than 97% of infections concentrated in South America. Although this represents a decline compared to 2024, infection hotspots still persist.

PAHO has identified the presence of two genotypes of the chikungunya virus: the Asian genotype and the East-Central-South African genotype. The latter has been detected in at least four countries, raising concerns about its possible adaptation and the transmission dynamics it could entail.

Meanwhile, the Oropouche virus, primarily transmitted by the midge Culicoides paraensis, has shown noteworthy geographical expansion. In the first seven months of 2025, over 12,700 confirmed cases have been reported in eleven countries, including endemic cases in Brazil, Colombia, Cuba, Panama, Peru, and Venezuela. This virus, which has traditionally been confined to the Amazon region, has reached areas that had never been affected before, underscoring the need to strengthen epidemiological and entomological surveillance.

Both viruses lack specific treatments or vaccines, making it a priority to focus on prevention through vector control and personal protection. PAHO has urged an intensification of diagnosis in the early stages of symptoms and the enhancement of clinical capacities to manage acute cases and their potential complications, such as encephalitis or Guillain-Barré syndrome.

Additionally, community involvement and the implementation of intersectoral strategies are essential for controlling populations of Aedes aegypti and Culicoides paraensis. This includes actions like eliminating breeding sites, weeding, and draining areas with stagnant water. PAHO calls on countries in the region to carry out coordinated and proactive actions to contain the spread of these emerging diseases.