Epidemiological Alert Chikungunya and Oropouche in the Americas Region - 28 August 2025

During 2025, outbreaks of chikungunya have been reported in several regions of the world, including Europe and Asia, some of them large in scale. In the Americas Region, several countries have reported an increase in cases. In addition, autochthonous cases of Oropouche continue to be reported in six countries in the Region, including areas outside the historical zones of transmission. Given this situation, the Pan American Health Organization/World Health Organization (PAHO/WHO) urges Member States to strengthen epidemiological and laboratory surveillance, ensure adequate clinical management, and reinforce vector control actions for these two diseases in order to mitigate the risk of outbreaks and reduce complications and deaths.