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Researchers identify new H5N1 subclade in India
A genetic analysis of H5N1 avian influenza isolates from February 2011 poultry outbreaks in India's Tripura state shows the introduction of a new clade to the area, researchers reported in Public Library of Science (PLoS) One. Until 2009, outbreaks in India and Pakistan were linked to 2.2 clade viruses. The first 2.3.2.1 clade virus was detected in South Asia in 2010 in Nepal; however, investigators found that 2.3.2.1 clade viruses responsible for the Tripura outbreaks are distinct from the ones found earlier in Nepal. When they compared their findings with phylogenetic data from the WHO, they concluded that the new clade circulated in Myanmar, then spread to Bangladesh and India through land-based poultry or migratory birds. The group said it's important to monitor whether the new 2.3.2.1 clade is replacing the previous 2.2 clade in South Asia or is cocirculating with it. They warned that cocirculation of H5N1 subclades in a highly populated area such as South Asia increases the risk of evolving H5N1 strains.
Excerpt from Plos article
I wonder if this novel strain is associated with the crow deaths in India?
Feb 20 PLoS One abstract http://www.plosone.org/article/fetchArticle?articleURI=info%3Adoi%2F10.1371%2Fjou rnal.pone.0031844
A genetic analysis of H5N1 avian influenza isolates from February 2011 poultry outbreaks in India's Tripura state shows the introduction of a new clade to the area, researchers reported in Public Library of Science (PLoS) One. Until 2009, outbreaks in India and Pakistan were linked to 2.2 clade viruses. The first 2.3.2.1 clade virus was detected in South Asia in 2010 in Nepal; however, investigators found that 2.3.2.1 clade viruses responsible for the Tripura outbreaks are distinct from the ones found earlier in Nepal. When they compared their findings with phylogenetic data from the WHO, they concluded that the new clade circulated in Myanmar, then spread to Bangladesh and India through land-based poultry or migratory birds. The group said it's important to monitor whether the new 2.3.2.1 clade is replacing the previous 2.2 clade in South Asia or is cocirculating with it. They warned that cocirculation of H5N1 subclades in a highly populated area such as South Asia increases the risk of evolving H5N1 strains.
Excerpt from Plos article
The WHO report on antigenic and genetic characteristics of zoonotic influenza viruses and development of candidate vaccine viruses for pandemic preparedness (http://www.who.int/influenza/resourc...ate.pdf) also reveals isolation of clade 2.3.4.2 viruses in Myanmar and Bangladesh which showed reduced reactivity with post-infection ferret antisera against the clade 2.3.4 viruses. Continued circulation of the H5N1 viruses of various subclades which are more adapted to land based poultry in a highly populated region such as South Asia might lead to evolution of pandemic strains with devastating consequences. Hence, there is an urgent need for faster sharing of data in public domain or through bilateral/international agencies for better management of control of the virus spread and its evolution in South Asia.
Feb 20 PLoS One abstract http://www.plosone.org/article/fetchArticle?articleURI=info%3Adoi%2F10.1371%2Fjou rnal.pone.0031844
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