Contamination of avian influenza virus in alive poultry markets and related factors in winter and spring in Chengdu

Objective To understand the contamination of avian influenza virus in alive poultry markets in winter and spring in Chengdu and identify the related factors, so as to provide scientific evidence for the prevention and control of human infection with avian influenza virus. Methods Sampling was conducted in alive poultry markets of 5 districts and counties, and face to face questionnaire survey was conducted among the stalls owners. RT-PCR was used to detect A, subtype H5, H7 and H9 avian influenza virus nucleic acid by using the samples collected and 2 test and Binary logistic regression analysis were performed. Results A total of 255 samples were collected and detected. The positive rate of avian influenza A virus was 51.0%(130/255), while the positive rates of H5, H9, cross contamination of H5 and H9 and other subtype viruses were 11.0%(28/255), 22.4%(57/255), 9.8%(25/255), and 7.8%(20/255) respectively. No subtype H7 virus positive samples were found. Influential factors analysis showed that the positive rate of A,subtype H9, cross contamination of H5 and H9, and other subtype viruses were higher in February than in March(P0.05). Stalls with depilating machines had a higher positive rate of A, subtype H5 and H9 viruses than those without such machines(P0.05). The positive rates of other subtype viruses were higher in stalls collecting poultry blood for sale than those discharging poultry blood into sewage and in wholesale markets than in retail markets, respectively (P0.05). 6.4%(5/78) of the owners wore masks during the operation, and 11.5%(9/78) of them wore gloves. Conclusion To prevent human infection with avian influenza virus, it is necessary to improve the operation procedure of slaughtering, conduct regular disinfection and market suspension as well as health education.