Exploring Risk Factors for Avian Influenza A Virus in Poultry: A Cross-Sectional Study in Dhaka Division, Bangladesh

Avian influenza virus (AIV) significantly affects both commercial and backyard poultry by causing high mortality rates or diminishing egg production, while also posing public health risks. We conducted a cross-sectional study in live bird markets (LBMs), as well as in backyard and commercial poultry farms located in Dhaka (Savar), Gazipur (Gazipur Sadar), and Tangail (Mirzapur) in Bangladesh. Seventy-seven swab samples were obtained from backyard chickens (tracheal swabs=20), commercial chickens (tracheal swabs=34), and environmental swabs from LBMs (n=23) between January and February 2020. Using real-time rRT-PCR, we detected an overall prevalence 22.8% (17/77) for AIV, with specific rates of 16.67% (95% CI: 5.64-34.72) in Tangail, 30.43% (95% CI: 13.21-52.92) in Savar, and 20.83% (95% CI: 7.13-42.15) in Gazipur. We conducted a multivariate logistic regression analysis to identify potential risk variables related with AIV and determined that sample sources, management of sick and dead chickens, and housing systems significantly contribute to AIV infections. The identified risk factors for AIV infection included sampling sources (commercial chicken - AOR: 1.16; 95% CI: 0.2859-4.7615; LBMs - AOR: 2.04; 95% CI: 0.5840-7.13), management of sick chickens (sold - AOR: 2.04; 95% CI: 0.58-7.13, eaten - AOR: 1.16; 95% CI: 0.28-4.76), management of dead chickens (throw in bushes - AOR: 1.60; 95% CI: 0.52-4.89), and housing systems (caged- AOR: 1.29; 95% CI: 0.20-8.30), all of which were statistically significant (p<0.05). In conclusion, AIV is prevalent in various farming practices and LBMs. Consequently, regular monitoring of AIV is strongly advised to assess the current status of AIV in Bangladesh.