India’s deadly swine flu outbreak that has killed more than 1,200 people since December may have acquired mutations making it even more dangerous than the previously circulating strains of H1N1 influenza, warns a just-released MIT study.
The MIT findings, published in the March 11 issue of Cell Host & Microbe, contradict previous reports from Indian health officials that the strain has not changed from the version of H1N1 that emerged in 2009 and has been circulating around the world ever since.
The study, led by MIT’s Indian-American professor of biological engineering Ram Sasisekharan, found that “the recent Indian strains carry new mutations in the hemagglutinin protein that are known to make the virus more virulent”.
“One of the new mutations is in an amino acid position called D225, which has been linked with increased disease severity. Another mutation, in the T200A position, allows hemagglutinin to bind more strongly to glycan receptors, making the virus more infectious,” an MIT release said.
Sasisekharan and research scientist Kannan Tharakaraman are said to have compared the genetic sequences of the two strains to the H1N1 strain that emerged in 2009, killing more than 18,000 people worldwide between 2009 and 2012.
Hemagglutinin, the release explained, binds to glycan receptors found on the surface of respiratory cells, and the strength of that binding determines how effectively the virus can infect those cells.
Stating that very little scientific data is available about the new strain, the researchers have urged better surveillance to track the outbreak and to help scientists to determine how to respond to this influenza variant.
The authors say that in the past two years, genetic sequence information of hemagglutinin from only two Indian strains has been deposited into publicly available influenza databases, making it difficult to determine exactly which strain is causing the new outbreak, and how it differs from previous strains.