Friday, August 30, 2013

CDC Emerging Infectious Diseases: Antigenic and Molecular Characterization of Avian Influenza A(H9N2) Viruses, Bangladesh

Volume 19, Number 9—September 2013

Research

Abstract

Human infection with avian influenza A(H9N2) virus was identified in Bangladesh in 2011. Surveillance for influenza viruses in apparently healthy poultry in live-bird markets in Bangladesh during 2008–2011 showed that subtype H9N2 viruses are isolated year-round, whereas highly pathogenic subtype H5N1 viruses are co-isolated with subtype H9N2 primarily during the winter months. Phylogenetic analysis of the subtype H9N2 viruses showed that they are reassortants possessing 3 gene segments related to subtype H7N3; the remaining gene segments were from the subtype H9N2 G1 clade. We detected no reassortment with subtype H5N1 viruses. Serologic analyses of subtype H9N2 viruses from chickens revealed antigenic conservation, whereas analyses of viruses from quail showed antigenic drift. Molecular analysis showed that multiple mammalian-specific mutations have become fixed in the subtype H9N2 viruses, including changes in the hemagglutinin, matrix, and polymerase proteins. Our results indicate that these viruses could mutate to be transmissible from birds to mammals, including humans.


Karthik Shanmuganatham, Mohammed M. Feeroz, Lisa Jones-Engel, Gavin J.D. Smith, Mathieu Fourment, David Walker, Laura McClenaghan, S.M. Rabiul Alam, M. Kamrul Hasan, Patrick Seiler, John Franks, Angie Danner, Subrata Barman, Pamela McKenzie, Scott Krauss, Richard J. Webby, and Robert G. WebsterComments to Author 
 
Author affiliations: St. Jude Children’s Research Hospital, Memphis, Tennessee, USA (K. Shanmuganatham, D. Walker, L. McClenaghan, P. Seiler, J. Franks, A. Danner, S. Barman, P. McKenzie, S. Krauss, R.J. Webby, R.G. Webster); Jahangirnagar University, Dhaka, Bangladesh (M.M. Feeroz, S.M.R. Alam, M.K. Hasan); University of Washington, Seattle, Washington, USA (L. Jones-Engel); Duke-NUS Graduate Medical School, Singapore (G.J.D. Smith, M. Fourment); Duke Global Health Institute, Durham, North Carolina, USA (G.J.D. Smith)
 

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