Risk factors for highly pathogenic avian influenza (HPAI) H5N1 infection in backyard chicken farms, Thailand

► To identify the risk factors of HPAI H5N1 in backyard chicken farms, a case-control study was carried out in Thailand. ► Farming practices and environmental characteristics of the backyard farms were investigated. ► Multivariate analysis highlighted 7 independent risk factors. ► Presence of a pond around the farmhouse and purchase of live chickens were risk factors. ►Using disinfectants to clean poultry areas had a protective effect.