Risk factors associated with infectious bursal disease in commercial chickens in Bangladesh.

To identify risk factors associated with infectious bursal disease (IBD) in commercial chickens in Bangladesh, we conducted a matched case-control study on 32 commercial farms affected with IBD and 96 IBD unaffected farms taking flock size (1000 vs. >1000 birds) and location of the farms (whether it is in rural or urban area) as matching variables. Epidemiological data from case and control farms were collected through the use of a pretested questionnaire, and analyzed by matched-pair analysis and multivariable conditional logistic regression. In the multivariable analysis, the variables 'receive visitors on the farm premises' (odds ratio [OR]=4.49; 95% confidence interval [CI]=1.50-13.42; p=0.007), 'purchase live poultry from the open market' (OR=7.59; 95% CI=2.69-21.45; p=<0.001), 'workers live outside the farms premises' (OR=5.89; 95% CI=1.87-18.60; p=0.002) and 'access of vendor vehicles on the farm premises' (OR=5.19; 95% CI=1.39-19.31; p=0.014) were identified as risk factors for IBD in commercial chicken farms. The proper management of the risk factors along with knowledge of the disease could help to reduce the incidence of IBDV infection in commercial chickens in Bangladesh.