Surveillance of avian influenza virus in population with occupational exposure and in out-environment in Quzhou, Zhejiang

Objective To understand the infection status of avian influenza virus in poultry and people with occupational exposure in Quzhou, Zhejiang province, and provide evidence for the prevention and control of human infection with avian influenza virus. Methods Totally 132 blood samples collected from people with occupational exposure and 231 out-environment samples were tested for avian influenza A viruses subtype H9 and H5 in Quzhou from 2009 to 2012. Results The overall positive rate of subtype H9 in 132 blood samples was 3.79%, the positive rate in people working in poultry markets was highest (10.53%). No subtype H5 was detected. In out-environment samples, the overall positive rate of avian influenza virus was 23.38%, and the positive rates of subtype H5 and H9 were 3.46% and 17.75% respectively. The positive rate of avian influenza virus was higher in poultry markets than in poultry farms, the difference in positive rate between subtype H5 and subtype H9 had no statistical significance. The positive rate of avian influenza virus in poultry drinking water samples was higher than feces and cage smears. The detection rate of subtype H9 was higher in drinking water samples than in feces and cage smears and in contaminated blood than in feces. The difference in subtype H5 detection rate had no statistical significance. Conclusion The infections of avian influenza A viruses subtype H9 and H5 were detected in poultry in Quzhou. The people engaged in poultry trade are at high risk to be infected. It is necessary to strengthen the prevention and control of human infection with avian influenza virus.