Influenza A virus is the most unpredictable global threat, past pandemic witnessed the community swaps happened due to this virus. The recent emergence of H7N9 in China is the result of new and recent reassortmant of Influenza A virus. Emergence of a novel human influenza A virus (H1N1pdm) in 2009 is an unprecedent event of molecular virology. This novel emerged virus affected millions of persons and raised WHO pandemic alert to phase 6. Therefore continuous monitoring is required to have

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... te genome information and to track mutations during course of viral evolution. In present study we investigated acute phase suspected H1N1pdm clinical samples from North India 2012-2013. H1N1pdm virus confirmed positive samples were proceeded for virus isolation in MDCK cells. Complete HA gene was deciphered and phylogenetic analysis of Indian H1N1pdm virus isolate was carried out with respect to globally diversified H1N1pdm virus. CDC Real time RT-PCR revealed 15% positivity for H1N1pdm virus. Complete HA gene sequence characterization of Indian H1N1pdm 2012-2013 virus and their phylogenetic analysis with respect to circulating global viruses revealed continuous circulation of cosmopolitan Clade VII in India. In the course of its evolution, 2009-2013 the virus acquired many mutations and which could be responsible for severity of this virus and emergence of new virus subtypes. India also witnessed high morbidity and mortality reported from all parts of the country. This study clearly indicates that recently reported cosmopolitan clade VII has undergone positive selection in India as well globally revealed continuous circulation of clade VII since 2009. This study of recent H1N1pdm Indian virus isolate will facilitate future epidemiological surveillance in Indian subcontinent and abroad. Fugure 3: Complete HA gene based Bayesian phylogeny H1N1pdm virus 2009-2013. Oseltamivir resistance assay. (A) RT-PCR amplification and RFLP. (B) SYBR green real time RT-PCR amplification plot and dissociation curve. (C) Sequence confirmation of H275Y mutation.