TY - JOUR
T1 - Patterns of avian influenza A (H5) and A (H9) virus infection in backyard, commercial broiler and layer chicken farms in Bangladesh
AU - Gupta, Suman Das
AU - Hoque, Md Ahasanul
AU - Fournié, Guillaume
AU - Henning, Joerg
N1 - Funding Information:
This study was supported by the BALZAC research programme ‘Behavioural adaptations in live poultry trading and farming systems and zoonoses control in Bangladesh' (BB/L018993/1) and is 1 of 11 programmes supported by the Zoonoses and Emerging Livestock Systems, a joint research initiative between the Biotechnology and Biological Sciences Research Council, the Defence Science and Technology Laboratory, the Department for International Development, the Economic and Social Sciences Research Council, the Medical Research Council and the Natural Environment Research Council. In particular, we would like to acknowledge the support from local CVASU BALZAC research team for helping with the sample collection and processing. We thank all farmers for their participation in the research. All farmers involved in this study were informed about the diagnostic results of birds sampled in their flocks. The first author of this publication was supported by Australian Government through an Australian Government Research Training Program Scholarship.
Publisher Copyright:
© 2020 Blackwell Verlag GmbH
PY - 2021/1
Y1 - 2021/1
N2 - In order to control Highly Pathogenic Avian Influenza (HPAI) H5N1 and Low Pathogenic Avian Influenza (LPAI) H9N2 virus spread in endemically infected countries, a detailed understanding of infection patterns is required. We conducted cross-sectional studies in Bangladesh in 2016 and 2017, on 144 backyard, 106 broiler and 113 layer chicken farms. Although all sampled birds were negative for H5 virus by RT-PCR, H5 antibodies were detected in unvaccinated birds on all three farming systems. Higher H5 antibody prevalence was observed in ducks raised on backyard farms, 14.2% (95% CI: 10.0%–19.8%), compared to in-contact backyard chickens, 4.2% (95% CI: 2.8%–6.1%). The H5 antibody prevalence was lower in broiler chickens, 1.5% (95% CI: 0.9%–2.5%), compared to layer chickens, 7.8% (95% CI: 6.1%–9.8%). H9 viruses were detected by RT-PCR in 0.5% (95% CI: 0.2%–1.3%) and 0.6% (95% CI: 0.3%–1.5%) of broilers and layers, respectively, and in 0.2% (95% CI: 0.0%–1.2%) of backyard chickens. Backyard chickens and ducks showed similar H9 antibody prevalence, 16.0% (95% CI: 13.2%–19.2%) and 15.7% (95% CI: 11.3%–21.4%), which was higher compared to layers, 5.8% (95% CI: 4.3%–7.6%), and broilers, 1.5% (95% CI: 0.9%–2.5%). Over the course of a production cycle, H5 and H9 antibody prevalence increased with the age of backyard and layer chickens. Usually, multiple ducks within a flock were H5 antibody positive, in contrast to backyard chickens, broilers and layers where only individual birds within flocks developed H5 antibodies. Our findings highlight low virus circulation in healthy chickens of all production systems in Bangladesh, which is in contrast to high virus circulation reported from live bird markets. Data generated in this project can be used to adopt risk-based surveillance approaches in different chicken production systems in Bangladesh and to inform mathematical models exploring HPAI infection dynamics in poultry from the source of production.
AB - In order to control Highly Pathogenic Avian Influenza (HPAI) H5N1 and Low Pathogenic Avian Influenza (LPAI) H9N2 virus spread in endemically infected countries, a detailed understanding of infection patterns is required. We conducted cross-sectional studies in Bangladesh in 2016 and 2017, on 144 backyard, 106 broiler and 113 layer chicken farms. Although all sampled birds were negative for H5 virus by RT-PCR, H5 antibodies were detected in unvaccinated birds on all three farming systems. Higher H5 antibody prevalence was observed in ducks raised on backyard farms, 14.2% (95% CI: 10.0%–19.8%), compared to in-contact backyard chickens, 4.2% (95% CI: 2.8%–6.1%). The H5 antibody prevalence was lower in broiler chickens, 1.5% (95% CI: 0.9%–2.5%), compared to layer chickens, 7.8% (95% CI: 6.1%–9.8%). H9 viruses were detected by RT-PCR in 0.5% (95% CI: 0.2%–1.3%) and 0.6% (95% CI: 0.3%–1.5%) of broilers and layers, respectively, and in 0.2% (95% CI: 0.0%–1.2%) of backyard chickens. Backyard chickens and ducks showed similar H9 antibody prevalence, 16.0% (95% CI: 13.2%–19.2%) and 15.7% (95% CI: 11.3%–21.4%), which was higher compared to layers, 5.8% (95% CI: 4.3%–7.6%), and broilers, 1.5% (95% CI: 0.9%–2.5%). Over the course of a production cycle, H5 and H9 antibody prevalence increased with the age of backyard and layer chickens. Usually, multiple ducks within a flock were H5 antibody positive, in contrast to backyard chickens, broilers and layers where only individual birds within flocks developed H5 antibodies. Our findings highlight low virus circulation in healthy chickens of all production systems in Bangladesh, which is in contrast to high virus circulation reported from live bird markets. Data generated in this project can be used to adopt risk-based surveillance approaches in different chicken production systems in Bangladesh and to inform mathematical models exploring HPAI infection dynamics in poultry from the source of production.
KW - antibody prevalence
KW - H5
KW - H9
KW - HPAI
KW - infection pattern
KW - virus prevalence
UR - http://www.scopus.com/inward/record.url?scp=85087657476&partnerID=8YFLogxK
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U2 - 10.1111/tbed.13657
DO - 10.1111/tbed.13657
M3 - Article
C2 - 32639112
AN - SCOPUS:85087657476
SN - 1865-1674
VL - 68
SP - 137
EP - 151
JO - Transboundary and Emerging Diseases
JF - Transboundary and Emerging Diseases
IS - 1
ER -