Surveillance of avian influenza in alive poultry markets in urban and rural areas in Shiyan, Hubei, 2011-2012

Objective To understand the circulation of avian influenza virus (AIV) in Shiyan, Hubei province, and provide evidence for the prevention and control of human infection with AIV. Methods Two surveillance sites were set up in urban area of Shiyan and in Yunxian county, and 210 out-environment samples (washing water, filthy water, feces, cover of cage, etc.) were collected from these surveillance sites from 2011 to 2012 to detect nucleic acid of AIV, the positive samples were further detected for H5, H7, H9 and N1 nucleic acid with real-time PCR. Results The viral nucleic acid detection rates of AIV, H5, H7, H9 and N1 were 47.62%, 19.52%, 0, 34.76% and 17.62% respectively. The AIV detection rate was highest in washing water and lowest in feces. Most positive samples were from chickens, only small number of them were from pigeons and ducks. The detection rates of AIV, subtype H5 and H9 were low in spring and autumn but high in summer and winter. The detection rate of subtype H5 was lower than subtype H9. The detection rates of AIV, subtype H5, H9 and N1 were higher in the urban area of Shiyan than in Yunxian. Conclusion AIV, including subtype H5 and H9, circulated in poultry in alive poultry markets in Shiyan, so it is necessary to take active prevention and control measures to prevent and control human infection with AIV.