Genomic epidemiology of chikungunya virus in Guangdong, China

Sequencing 1,264 chikungunya virus genomes from the 2025 Guangdong outbreak (>25,000 confirmed cases) traces the epidemic to a single Reunion-associated ECSA lineage introduction in late April–early May 2025 and reveals contrasting spatial dispersal between the Foshan and Jiangmen epidemic waves.