Chikungunya virus mutation, Indonesia, 2011.

To the Editor: Chikungunya virus (CHIKV) is a single-stranded, positive-sense RNA virus of ≈11.8 kb molecules (1) belonging to the family Togaviridae and genus Alphavirus. Genotypes of CHIKV include Asian, East/Central/South African (ECSA), and West African. CHIKV is endemic to Africa, southern Asia, and Southeast Asia and frequently causes debilitating but nonfatal illness.