RESUMO
Objective To monitor the environmental contamination with avian influenza virus (AIV) in Henan Province. Methods Environmental samples were collected every month from seven moni-toring sites in Henan from 2013 to 2017. Real-time RT-PCR method was performed to detect the nucleic acid of influenza A (Flu A), H5, H7 and H9 viruses in poultry environmental samples. Results A total of 2538 environmental samples were collected and 202 (7. 96％ ) of them were positive for Flu A nucleic acid, including 16 positive for H5 (0. 63％ ), eight positive for H7 (0. 32％ ) and 161 positive for H9 (6. 34％ ). The detection rate of Flu A increased dramatically from 2013 to 2017 except for a small fluctuation in 2015. However, H7 subtype AIV was detected only in 2015 and 2017. The highest detection rate of AIV was in February, followed by that in January. Among different environments, the highest detection rate of Flu A was in live poultry market, which was 13. 69％ , followed by that in poultry slaughtering plant (2. 58％ ) and poultry farm (0. 58％ ). The detection rates of Flu A in swab samples of poultry plucker and cutting board, stool specimens and poultry drinking water were 28. 57％ , 13. 76％ , 5. 70％ and 5. 26％ , respectively.Conclusion Contamination of H5 / H7 / H9 AIV did exist in poultry environment in Henan and was getting worse. Increasingly diversified sources and sale channels were the main causes of serious contamination of AIV. In order to effectively prevent and control human infection with AIV, live poultry in areas where human infection with AIV was confirmed should be blocked and banned to be sold to others areas.