Chikungunya Outbreaks

Publisher Website
Google Scholar
Abstract
In their Perspective article on outbreaks of chikungunya fever, Charrel et al. (Feb. 22 issue)1 suggest that the recent outbreak in India2 could have been caused by the same viral strain that caused the Indian Ocean outbreak.3 Recent data do not support this speculation.4,5 We previously described sequence microheterogeneity in the viruses causing the Indian Ocean outbreak.4 We have compared E1 sequences from viruses involved in the Indian and Indian Ocean outbreaks ( Figure 1 ).4,5 The strains differed only in a single nucleotide change (T321C), which was found in all Indian Ocean isolates. Isolates from India retained the ancestral T321 nucleotide present in all other African and Asian strains, making it unlikely that the outbreak in India was caused by a strain originating from the Indian Ocean outbreak. Nevertheless, in contrast to sequences from all other available chikungunya viruses, the Indian and Indian Ocean isolates shared two nucleotide changes: A306G and C384T. These shared derived characters indicate common ancestry. The strain isolated from Yawat, India, in 20005 retained the ancestral nucleotide at both positions but had a distinctive T468C change, arguing against a direct link between this strain and the strain implicated in the 2005–2006 Indian outbreak.

This publication has 9 references indexed in Scilit: