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

Abstract

Background 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. Methods 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. Results 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. Conclusions 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.

Epidemiology and molecular characterization of avian influenza A viruses H5N1 and H3N8 subtypes in poultry farms and live bird markets in Bangladesh

“…This study investigated the risk factors associated with influenza A, specifically H5 subtype prevalence. The present study detected influenza A viruses in waterfowl, chicken, turkey, and pigeon, similar to previously reported data 34 – 36 . We screened avian samples and found evidence of H3, H5, and H9 viruses in the tested samples, albeit with specific patterns.…”

Epidemiology and phylodynamics of multiple clades of H5N1 circulating in domestic duck farms in different production systems in Bangladesh

“…Our study also showed that detecting AIV and A/H5 is higher in sick ducks than in apparently healthy ducks. Previous studies in Bangladesh and other countries have reported similar results for ducks and poultry birds ( 2 , 70–73 ). Even though ducks can secrete large quantities of a deadly virus without manifesting any outward signs of disease, H5N1 can cause the birds to have breathing difficulties such as gaping (mouth breathing), nasal snicking (coughing sound), sneezing, gurgling, or rattling.…”

Prevalence and risk factors for avian influenza virus (H5 and H9) contamination in peri-urban and rural live bird markets in Bangladesh

“…AIV is a public health concern in the countries like Bangladesh, where people and poultry are in frequent contact without adequate biosecurity measures in place ( 32 ). LBMs are a significant source of AIV circulation, mutation, and spillover to humans or other wildlife.…”

“…As more people turn to LBMs as a source of protein in Bangladesh ( 28 ), robust risk characterization is essential to inform targeted public health interventions at this interface. However, most studies about the risk of AIV biosecurity are conducted in urban areas and communities ( 7 , 29 – 32 ). The risk of AIV spillover in peri-urban and rural areas remains poorly understood.…”