doi:10.1038/nindia.2012.87 Published online 20 June 2012
Researchers have identified new genetic mutations in the chikungunya virus and tracked its ancestral presence with the maximum diversity circulating in the western Indian state of Maharashtra. They have also tracked the trend of chikungunya spread in India since its first report in 1963 and its subsequent reappearance in 2005.
The researchers worked on the Chikungunya strain from the 2010 outbreak in New Delhi. Blood samples were drawn from 289 patients, who were clinically suspected to have chikungunya over a period of three months since the onset of the outbreak and their viral RNA was sequenced.
The researchers found two novel mutations in the structural proteins E1 and E2 — E1 K211E and E2 V264A — in all Delhi isolates.
Virus sequences from eight other states of India were analyzed along with the Delhi sequences to map the genetic diversity of the virus within the country. "We identified distinct molecular signatures of the different genotypes of chikungunya virus revealing emergence of a new signature in the New Delhi clade", the researchers write.
Statistical analyses and construction of evolutionary path of the virus within the country also revealed gradual spread of one specific strain all over the country.
The authors of this work are from: International Centre for Genetic Engineering and Biotechnology, New Delhi; Vardhman Mahavir Medical College & Safdarjung Hospital, New Delhi and Insect Resistance Group, International Centre for Genetic Engineering and Biotechnology, New Delhi, India.