Chikungunya outbreak in China — Foshan City, Guangdong Province, July 2025

A chikungunya fever (CF) outbreak was reported in Foshan City, Guangdong Province, China, in July 2025, marking the largest local transmission event recorded in the country to date. Chikungunya, caused by the chikungunya virus (CHIKV) and transmitted by Aedes mosquitoes, has established itself in more than 110 countries across Asia, Africa, and the Americas. China documented its first imported chikungunya case in 2008, and local outbreaks occurred sporadically in Guangdong, Zhejiang, and Yunnan provinces between 2010 and 2019. The current Foshan event is unprecedented in scale. Between June 16 and July 26, 2025, a total of 4,824 laboratory-confirmed cases were identified across 12 prefecture-level cities in Guangdong; however, Foshan accounted for the overwhelming majority (4,754 cases, 98.5%), with nearly 90% of provincial cases concentrated in the Shunde District. The outbreak peaked on July 19, with 681 new cases recorded in a single day. The median patient age was 44 years, and...