Journal article
Unusually High Mortality in Waterfowl Caused by Highly Pathogenic Avian Influenza A(H5N1) in Bangladesh
National Veterinary Institute, Technical University of Denmark1
Section for Epidemiology, National Veterinary Institute, Technical University of Denmark2
Centers for Disease Control and Prevention3
University of Florida4
International Centre for Diarrhoeal Diseases Research5
University of California at San Diego6
Ministry of Fisheries and Livestock7
Institute of Epidemiology, Diseases Control and Research8
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.
Language: | English |
---|---|
Year: | 2017 |
Pages: | 144-156 |
ISSN: | 18651682 and 18651674 |
Types: | Journal article |
DOI: | 10.1111/tbed.12354 |
ORCIDs: | Haider, Najmul |
Bangladesh Clade 2.3.2.1a Duck Goose H5N1 subtype Histopathology Immunohistochemistry Influenza A virus Outbreaks SDG 3 - Good Health and Well-being
Adolescent Adult Aged Animals Chickens Child Disease Outbreaks Ducks Female Geese Humans Influenza A Virus, H5N1 Subtype Influenza in Birds Influenza, Human Male Middle Aged Phylogeny Poultry Diseases Sequence Analysis, DNA Young Adult clade 2.3.2.1a duck goose histopathology immunohistochemistry influenza A virus outbreaks