Objective  To understand the contamination of avian influenza virus in the poultry related environment and the infection of avian influenza virus in population with occupational exposure to avian influenza virus in Zhejiang form 2016 to 2020, and provide evidence for the prevention and control of human infection with avian influenza.

  Methods  Real time fluorescence quantitative PCR was used to detect the nucleic acid of influenza A virus in the poultry related environment samples. The positive samples were tested for nucleic of subtype H5, H7 and H9 of avian influenza virus. The antibodies to influenza A (H5N6), (H7N) and (H9N2) viruses in the serum of population with occupational exposure were detected by hemagglutination inhibition test (HI). The detection results were statistically analyzed by descriptive statistics.

  Results  From 2016 to 2020, a total of 10 106 positive samples of influenza A virus were detected (24.6%), including 525 subtype H5 positive samples (1.28%), 1137 subtype H7 (2.77%) positive samples and 3634 subtype H9 positive samples (8.84%), in the poultry related environment in Zhejiang, and there were H5+H7, H5+H9, H7+H9, H5+H7+H9 co- positive samples. The positive samples of avian influenza A virus were detected in the samples from urban and rural live poultry markets, poultry packinghouses, areas with multi-scattering raising-households, households with large-scale poultry breeding, and wild migratory bird habitats, the highest positive rate was in the surface swabs of chopping board (48.33%). The proportion of avian influenza virus positive samples was higher in winter and spring, One H5N6 positive and 9 H9N2 positive samples were detected in 2888 serum samples from population with occupational exposure in urban and rural live poultry markets, poultry packinghouses, areas with multi-scattering raising-households and households with large-scale poultry breeding, but mainly in urban and rural live poultry markets.

  Conclusion  The avian influenza viruses detected in Zhejiang mainly belonged to subtype H9, subtype H5 was detected every year, subtype H7 was mainly detected in 2016 and 2017, there were co-positive samples, there was a risk of virus recombination. The latent infections of H5N6 and H9N2 viruses were found in the population with occupational exposure, so it is necessary to strengthen the prevention and control of human infection with avian influenza virus, improve health education and surveillance for avian influenza virus.