Fig. 2.

Distance matrix cladogram based on CHIKV E1 nucleotide sequences. The analysis included samples from the 2004 to 2007 outbreaks in Kenya, Comoros, Réunion and India, along with historical isolates from the Central/East African (lower clade) and Asian (upper clade) genotypes. Isolates are designated by country of origin, year of isolation, province or city of infection, and strain name or number (e.g. strain 1455/76 isolated from Bangkok, Thailand, in 1975 is designated TH75-BK-1455/75). Unknown data are designated by ‘??’. Isolates sequenced in this study are indicated in bold. Bootstrap values based on 1000 replicates are indicated at the nodes.