[Source: US National Library of Medicine, full page: (LINK). Abstract, edited.]
Epidemiol Infect. 2018 Jul;146(10):1259-1266. doi: 10.1017/S0950268818001292. Epub 2018 May 21.
Review analysis and impact of co-circulating H5N1 and H9N2 avian influenza viruses in Bangladesh.
Parvin R1, Begum JA1, Nooruzzaman M1, Chowdhury EH1, Islam MR1, Vahlenkamp TW2.
Author information: 1 Department of Pathology,Faculty of Veterinary Science,Bangladesh Agricultural University,Mymensingh 2202,Bangladesh. 2 Faculty of Veterinary Medicine,Center of Infectious Diseases, Institute of Virology, University of Leipzig,An den Tierkliniken 29, 04103 Leipzig,Germany.
Almost the full range of 16 haemagglutinin (HA) and nine neuraminidase subtypes of avian influenza viruses (AIVs) has been detected either in waterfowl, land-based poultry or in the environment in Bangladesh. AIV infections in Bangladesh affected a wide range of host species of terrestrial poultry. The highly pathogenic avian influenza (AI) H5N1 and low pathogenic AI H9N2 were found to co-circulate and be well entrenched in the poultry population, which has caused serious damage to the poultry industry since 2007. By reviewing the available scientific literature, the overall situation of AIVs in Bangladesh is discussed. All Bangladeshi (BD) H5N1 and H9N2 AIV sequences available at GenBank were downloaded along with other representative sequences to analyse the genetic diversity among the circulating AIVs in Bangladesh and to compare with the global situation. Three different H5N1 clades, 2.2.2, 184.108.40.206 and 220.127.116.11, have been detected in Bangladesh. Only 18.104.22.168a is still present. The BD LP H9N2 viruses mostly belonged to the H9 G1 lineage but segregated into many branches, and some of these shared internal genes with HP viruses of subtypes H7N3 and H5N1. However, these reassortment events might have taken place before introduction to Bangladesh. Currently, H9N2 viruses continue to evolve their HA cleavage, receptor binding and glycosylation sites. Multiple mutations in the HA gene associated with adaptation to mammalian hosts were also observed. Strict biosecurity at farms and gradual phasing out of live-bird markets could be the key measures to better control AIVs, whereas stamping out is not a practicable option in Bangladesh. Vaccination also could be an additional tool, which however, requires careful planning. Continuous monitoring of AIVs through systematic surveillance and genetic characterisation of the viruses remains a hallmark of AI control.
KEYWORDS: Avian influenza; Bangladesh; H5N1; H9N2; co-circulation; genetic evolution
PMID: 29781424 DOI: 10.1017/S0950268818001292 [Indexed for MEDLINE]
Keywords: Avian Influenza; H5N1; H7N3; H9N2; Poultry; Wild Birds; Bangladesh.