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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
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. Webster
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)