Assessment of poultry rearing practices and risk factors of H5N1 and H9N2 virus circulating among backyard chickens and ducks in rural communities.

Ariful Islam1,2,3 Shariful Islam2,3 Emama Amin2,3 Shahanaj Shano2,3 Mohammed Abdus Samad4 Tahmina Shirin3 Mohammad Mahmudul Hassan5 Meerjady Sabrina Flora3,6
Affiliations 6 institutions
  1. Centre for Integrative Ecology, School of Life and Environmental Science, Deakin University, Australia.
  2. EcoHealth Alliance, New York, New York, United States of America.
  3. Institute of Epidemiology, Disease Control and Research (IEDCR), Mohakhali, Dhaka, Bangladesh.
  4. National Reference Laboratory for Avian Influenza, Bangladesh Livestock Research Institute (BLRI), Savar, Bangladesh.
  5. Queensland Alliance for One Health Sciences, School of Veterinary Science, University of Queensland, Queensland, Australia.
  6. Directorate General of Health Services, Mohakhali, Dhaka, Bangladesh.

Abstract

The avian influenza virus (AIV) causes significant economic losses by infecting poultry and occasional spillover to humans. Backyard farms are vulnerable to AIV epidemics due to poor health management and biosecurity practices, threatening rural households' economic stability and nutrition. We have limited information about the risk factors associated with AIV infection in backyard poultry in Bangladesh. Hence, we conducted a cross-sectional survey comprising epidemiological and anthropological investigations to understand the poultry rearing practices and risk factors of AIV circulation among backyard poultry in selected rural communities. We sampled 120 poultry from backyard farms (n = 30) of the three selected communities between February 2017 and January 2018. We tested swab samples for the matrix gene (M gene) followed by H5, H7, and H9 subtypes using real-time reverse transcriptase-polymerase chain reaction (rRT-PCR). We applied multivariable logistic regression for risk factor analysis. Furthermore, we conducted an observational study (42 hours) and informal interviews (n = 30) with backyard farmers to record poultry-raising activities in rural communities. We detected that 25.2% of the backyard poultry tested positive for AIV, whereas 5% tested positive for H5N1 and 10.8% tested positive for H9N2. Results showed that scavenging in both household garden and other crop fields has higher odds of AIV than scavenging in the household garden (AOR: 24.811; 95% CI: 2.11-292.28), and keeping a cage inside the house has higher odds (AOR:14.5; 95% CI: 1.06-198.51) than keeping it in the veranda, cleaning the cage twice a week or weekly has a higher risk than cleaning daily (AOR: 34.45; 95% CI: 1.04-1139.65), dumping litter or droppings (AOR: 82.80; 95% CI: 3.91-1754.59) and dead birds or wastage (AOR: 109.92, 95% CI: 4.34-2785.29) near water bodies and bushes have a higher risk than burring in the ground, slaughtering and consuming sick birds also had a higher odd of AIV (AOR: 73.45, 95% CI: 1.56-3457.73) than treating the birds. The anthropological investigation revealed that household members had direct contact with the poultry in different ways, including touching, feeding, slaughtering, and contacting poultry feces. Poultry is usually kept inside the house, sick poultry are traditionally slaughtered and eaten, and most poultry raisers do not know that diseases can transmit from backyard poultry to humans. This study showed the circulation of H5N1 and H9N2 virus in backyard poultry in rural communities; associated with species, scavenging area of the poultry, location of the poultry cage, the practice of litter, wastage, droppings, and dead bird disposal, and practice of handling sick poultry. We suggest improving biosecurity practices in backyard poultry and mass awareness campaigns to reduce incidences of AIV in household-level poultry farms in rural communities in Bangladesh.

Supporting text Virus Host Location
Influenza A Virus, H5N1 Subtype 300 Influenza A Virus, H9N2 Subtype 71 Influenza in Birds 341 Poultry Diseases 74 Animals 1948 Chickens 146 Cross-Sectional Studies 35 Ducks 81 Humans 1440 Poultry 112 Risk Factors 34 RNA-Directed DNA Polymerase 1 Rural Population 5 Water 2

Evidence records

6 total
Zoonotic Surveillance
6 records · 2 evidence types
Evidence type
4 records
OVE6420
Key finding

H5N1 avian influenza virus RNA was detected in backyard chickens and ducks in Bangladesh by rRT-PCR.

Virus
Host
Location
Supporting text

We detected that 25.2% of the backyard poultry tested positive for AIV, whereas 5% tested positive for H5N1 and 10.8% tested positive for H9N2.

Method
real-time reverse transcriptase-polymerase chain reaction (rRT-PCR)
Sample type
swab samples
Geographic raw
Bangladesh
Country inferred
BGD
OVE6421
Key finding

H9N2 avian influenza virus RNA was detected in backyard chickens and ducks in Bangladesh by rRT-PCR.

Virus
Host
Location
Supporting text

We detected that 25.2% of the backyard poultry tested positive for AIV, whereas 5% tested positive for H5N1 and 10.8% tested positive for H9N2.

Method
real-time reverse transcriptase-polymerase chain reaction (rRT-PCR)
Sample type
swab samples
Geographic raw
Bangladesh
Country inferred
BGD
OVE6422
Key finding

Avian influenza virus (AIV) RNA was detected in 25.2% of backyard poultry in Bangladesh by rRT-PCR.

Virus
Host
Location
Supporting text

We detected that 25.2% of the backyard poultry tested positive for AIV, whereas 5% tested positive for H5N1 and 10.8% tested positive for H9N2.

Method
real-time reverse transcriptase-polymerase chain reaction (rRT-PCR)
Sample type
swab samples
Geographic raw
Bangladesh
Country inferred
BGD
OVE6425
Key finding

In rural Bangladesh, household members had direct contact with backyard poultry infected with H5N1 and H9N2 avian influenza viruses, indicating potential risk of animal-to-human spillover.

Virus
Host
Location
Supporting text

The avian influenza virus (AIV) causes significant economic losses by infecting poultry and occasional spillover to humans. The anthropological investigation revealed that household members had direct contact with the poultry in different ways, including touching, feeding, slaughtering, and contacting poultry feces. Poultry is usually kept inside the house, sick poultry are traditionally slaughtered and eaten, and most poultry raisers do not know that diseases can transmit from backyard poultry to humans. This study showed the circulation of H5N1 and H9N2 virus in backyard poultry in rural communities in Bangladesh.

Method
field observation | interviews | rRT-PCR detection of H5N1 and H9N2 subtypes
Geographic raw
Bangladesh
Evidence type
2 records
OVE6423
Key finding

Circulation of H5N1 virus in backyard poultry in rural communities of Bangladesh was associated with poultry species and husbandry practices such as scavenging area, cage location, and waste disposal.

Virus
Host
Location
Supporting text

This study showed the circulation of H5N1 and H9N2 virus in backyard poultry in rural communities; associated with species, scavenging area of the poultry, location of the poultry cage, the practice of litter, wastage, droppings, and dead bird disposal, and practice of handling sick poultry.

Method
cross-sectional survey | real-time reverse transcriptase-polymerase chain reaction (rRT-PCR) | multivariable logistic regression | observational study | informal interviews
Sample type
swab samples
Geographic raw
rural communities | Bangladesh
Country inferred
BGD
OVE6424
Key finding

Circulation of H9N2 virus in backyard poultry in rural communities of Bangladesh was linked to poultry species and rearing conditions including scavenging area, cage location, and disposal of litter and dead birds.

Virus
Host
Location
Supporting text

This study showed the circulation of H5N1 and H9N2 virus in backyard poultry in rural communities; associated with species, scavenging area of the poultry, location of the poultry cage, the practice of litter, wastage, droppings, and dead bird disposal, and practice of handling sick poultry.

Method
cross-sectional survey | real-time reverse transcriptase-polymerase chain reaction (rRT-PCR) | multivariable logistic regression | observational study | informal interviews
Sample type
swab samples
Geographic raw
rural communities | Bangladesh
Country inferred
BGD