A new #reassortant clade 2.3.2.1a #H5N1 highly pathogenic #avian #influenza virus causing recent #outbreaks in #ducks, geese, #chickens and turkeys in #Bangladesh (Transbound Emerg Dis., abstract)

[Source: US National Library of Medicine, full page: (LINK). Abstract, edited.]

Transbound Emerg Dis. 2019 Jun 6. doi: 10.1111/tbed.13264. [Epub ahead of print]

A new reassortant clade 2.3.2.1a H5N1 highly pathogenic avian influenza virus causing recent outbreaks in ducks, geese, chickens and turkeys in Bangladesh.

Nooruzzaman M1, Mumu TT1, Hasnat A1, Akter MN1, Rasel MSU1, Rahman MM1, Parvin R1, Begum JA1, Chowdhury EH1, Islam MR1.

Author information: 1 Department of Pathology, Faculty of Veterinary Science, Bangladesh Agricultural University, Mymensingh, 2202, Bangladesh.

 

Abstract

A total of 15 dead or sick birds from 13 clinical outbreaks of avian influenza in ducks, geese, chickens and turkeys in 2017 in Bangladesh were examined. The presence of H5N1 influenza A virus in the affected birds was detected by RT-PCR. Phylogenetic analysis based on full length gene sequences of all eight gene segments revealed that these recent outbreaks were caused by a new reassotant of clade 2.3.2.1a H5N1 virus, which had been detected earlier in 2015 during surveillance in live bird markets (LBMs) and wet lands. This reassortant virus acquired PB2, PB1, PA, NP and NS genes from low pathogenic avian influenza viruses mostly of non-H9N2 subtypes but retained HA, NA and M genes of the old clade 2.3.2.1a viruses. Nevertheless, the HA gene of these new viruses was 2.7% divergent from that of the old clade 2.3.2.1a viruses circulated in Bangladesh. Interestingly, similar reassortment events could be traced back in four 2.3.2.1a virus isolates of 2013 from backyard ducks. It suggests that this reassortant virus emerged in 2013, which took two years to be detected at a broader scale (i.e. in LBMs), another two years until it became widely spread in poultry and fully replaced the old viruses. Several mutations were detected in the recent Bangladeshi isolates, which are likely to influence possible phenotypic alterations such as increased mammalian adaptation, reduced susceptibility to antiviral agents and reduced host antiviral response.

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KEYWORDS: Bangladesh; H5N1 HPAIV; clade 2.3.2.1a; domestic poultry; new reassortant

PMID: 31168925 DOI: 10.1111/tbed.13264

Keywords: Avian Influenza; H5N1; H9N2; Reassortant Strain; Poultry; Bangladesh.

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Giuseppe Michieli

I am an Italian blogger, active since 2005 with main focus on emerging infectious diseases such as avian influenza, SARS, antibiotics resistance, and many other global Health issues. Other fields of interest are: climate change, global warming, geological and biological sciences. My activity consists mainly in collection and analysis of news, public services updates, confronting sources and making decision about what are the 'signals' of an impending crisis (an outbreak, for example). When a signal is detected, I follow traces during the entire course of an event. I started in 2005 my blog ''A TIME'S MEMORY'', now with more than 40,000 posts and 3 millions of web interactions. Subsequently I added an Italian Language blog, then discontinued because of very low traffic and interest. I contributed for seven years to a public forum (FluTrackers.com) in the midst of the Ebola epidemic in West Africa in 2014, I left the site to continue alone my data tracking job.