Last data update: May 06, 2024. (Total: 46732 publications since 2009)
Records 1-3 (of 3 Records) |
Query Trace: Poh MK[original query] |
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Unusually high mortality in waterfowl caused by highly pathogenic avian influenza A(H5N1) in Bangladesh
Haider N , Sturm-Ramirez K , Khan SU , Rahman MZ , Sarkar S , Poh MK , Shivaprasad HL , Kalam MA , Paul SK , Karmakar PC , Balish A , Chakraborty A , Mamun AA , Mikolon AB , Davis CT , Rahman M , Donis RO , Heffelfinger JD , Luby SP , Zeidner N . Transbound Emerg Dis 2015 64 (1) 144-156 Mortality in ducks and geese caused by highly pathogenic avian influenza A(H5N1) infection had not been previously identified in Bangladesh. In June-July 2011, we investigated mortality in ducks, geese and chickens with suspected H5N1 infection in a north-eastern district of the country to identify the aetiologic agent and extent of the outbreak and identify possible associated human infections. We surveyed households and farms with affected poultry flocks in six villages in Netrokona district and collected cloacal and oropharyngeal swabs from sick birds and tissue samples from dead poultry. We conducted a survey in three of these villages to identify suspected human influenza-like illness cases and collected nasopharyngeal and throat swabs. We tested all swabs by real-time RT-PCR, sequenced cultured viruses, and examined tissue samples by histopathology and immunohistochemistry to detect and characterize influenza virus infection. In the six villages, among the 240 surveyed households and 11 small-scale farms, 61% (1789/2930) of chickens, 47% (4816/10 184) of ducks and 73% (358/493) of geese died within 14 days preceding the investigation. Of 70 sick poultry swabbed, 80% (56/70) had detectable RNA for influenza A/H5, including 89% (49/55) of ducks, 40% (2/5) of geese and 50% (5/10) of chickens. We isolated virus from six of 25 samples; sequence analysis of the hemagglutinin and neuraminidase gene of these six isolates indicated clade 2.3.2.1a of H5N1 virus. Histopathological changes and immunohistochemistry staining of avian influenza viral antigens were recognized in the brain, pancreas and intestines of ducks and chickens. We identified ten human cases showing signs compatible with influenza-like illness; four were positive for influenza A/H3; however, none were positive for influenza A/H5. The recently introduced H5N1 clade 2.3.2.1a virus caused unusually high mortality in ducks and geese. Heightened surveillance in poultry is warranted to guide appropriate diagnostic testing and detect novel influenza strains. |
Multiple reassortment events among highly pathogenic avian influenza A(H5N1) viruses detected in Bangladesh.
Gerloff NA , Khan SU , Balish A , Shanta IS , Simpson N , Berman L , Haider N , Poh MK , Islam A , Gurley E , Hasnat MA , Dey T , Shu B , Emery S , Lindstrom S , Haque A , Klimov A , Villanueva J , Rahman M , Azziz-Baumgartner E , Ziaur Rahman M , Luby SP , Zeidner N , Donis RO , Sturm-Ramirez K , Davis CT . Virology 2014 450-451 297-307 In Bangladesh, little is known about the genomic composition and antigenicity of highly pathogenic avian influenza A(H5N1) viruses, their geographic distribution, temporal patterns, or gene flow within the avian host population. Forty highly pathogenic avian influenza A(H5N1) viruses isolated from humans and poultry in Bangladesh between 2008 and 2012 were analyzed by full genome sequencing and antigenic characterization. The analysis included viruses collected from avian hosts and environmental sampling in live bird markets, backyard poultry flocks, outbreak investigations in wild birds or poultry and from three human cases. Phylogenetic analysis indicated that the ancestors of these viruses reassorted (1) with other gene lineages of the same clade, (2) between different clades and (3) with low pathogenicity avian influenza A virus subtypes. Bayesian estimates of the time of most recent common ancestry, combined with geographic information, provided evidence of probable routes and timelines of virus spread into and out of Bangladesh. |
Microevolution of highly pathogenic avian influenza A(H5N1) viruses isolated from humans, Egypt, 2007-2011
Younan M , Poh MK , Elassal E , Davis T , Rivailler P , Balish AL , Simpson N , Jones J , Deyde V , Loughlin R , Perry I , Gubareva L , Elbadry MA , Truelove S , Gaynor AM , Mohareb E , Amin M , Cornelius C , Pimentel G , Earhart K , Naguib A , Abdelghani AS , Refaey S , Klimov AI , Donis RO , Kandeel A . Emerg Infect Dis 2013 19 (1) 43-50 We analyzed highly pathogenic avian influenza A(H5N1) viruses isolated from humans infected in Egypt during 2007-2011. All analyzed viruses evolved from the lineage of subtype H5N1 viruses introduced into Egypt in 2006; we found minimal evidence of reassortment and no exotic introductions. The hemagglutinin genes of the viruses from 2011 formed a monophyletic group within clade 2.2.1 that also included human viruses from 2009 and 2010 and contemporary viruses from poultry; this finding is consistent with zoonotic transmission. Although molecular markers suggestive of decreased susceptibility to antiviral drugs were detected sporadically in the neuraminidase and matrix 2 proteins, functional neuraminidase inhibition assays did not identify resistant viruses. No other mutations suggesting a change in the threat to public health were detected in the viral proteomes. However, a comparison of representative subtype H5N1 viruses from 2011 with older subtype H5N1 viruses from Egypt revealed substantial antigenic drift. |
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