Objective To investgate the infection of H5N1 avian influenza virus in occupational exposure crowds and the avian influenza virus distribution in the environment of Nanchong City.

Methods The serum samples were collected from occupational exposure crowds from 2014 to 2015, and H5N1 antibody was detected by hemagglutination inhibition test (HI). The nucleic acid of avian influenza viruses (Flu A) from environmental samples was detected by the real -time PCR method, which we collected cages, feces and sewage from live poultry markets, poultry slaughter markets, poultry farms, and wild bird habitats.

Results All of the 160 tests for serum H5N1 antibody from occupational exposure crowds were negative. While in 160 environment samples, there were 31 (16.32%) positive cases of avian influenza A virus, including 18 (9.47%) H5 positive cases, 10 (5.26%) H9 positive cases, 3 (1.58%) untyped positive cases. There was statistically significant difference between different sample types, different environment of monitoring points, different monitoring places, and different seasons (χ2=37.43, 8.67, 30.57, 30.44; P<0.05).

Conclusions The antibody-positive sample of type A avian influenza virus (H5N1) was not found among occupational exposure crowds. There were type A avian influenza virus in all the collected samples and monitoring areas of Nanchong city. We suggest that the relevant government departments to publicize knowledge of avian influenza. It also plays an important role to strengthen the supervision of trading and slaughter markets and the monitoring of the environment.