ObjectiveTo understand the environmental contamination with avian influenza virus(AIV) in Yunnan Province from 2015 to 2021.
MethodsSix types of environmental samples(cage swabs, chopping board swabs, poultry faeces, sewage for cleaning poultry and drinking water for poultry) were collected from five types of bird related sites in 16 areas. The nucleic acid of avian influenza virus type A(flu A) was detected by Real-time PCR. The H5, H7 and H9 subtypes were further detected in flu A nucleic acid positive samples.
ResultsA total of 11033 environmental samples were detected from 2015 to 2021 in Yunnan, and 2951 (26.75%) of these samples were positive for flu A with the majority of H9 subtype(2164 samples). The positive rates of samples in urban and rural live poultry markets and live poultry wholesale markets were both high(36.08% and 35.06%). Among the six types of external environment samples, the positive rate of the sewage for cleaning poultry was the highest(45.50%), followed by chopping board swabs(35.06%). The top three areas of positive rates for flu A were Baoshan, Wenshan and Nujiang in Yunnan Province.
ConclusionsThe pollution of avian influenza virus in the external environment is still serious in Yunnan.