Community-wide surveillance of avian influenza virus in poultry markets of Guangzhou in 2018

Objective To study the contamination characters and variation in tendency of avian influenza virus (AIV) in environmental samples from poultry markets in Guangzhou in 2018, so as to provide evidences for the prevention and control of avian influenza. Methods The environmental samples from poultry markets in each community were collected every month. Nucleic acids of AIV subtypes H5, H7 and H9 were detected. The chi-square test was used to compare the positive rates in samples from different types of poultry markets, collected at different time and in samples of different types. Results A total of 18 425 samples were collected. The positive rates of AIV type A and subtypes H5, H7 and H9 were 23.74%, 2.85%, 0.20% and 15.92%, respectively. The positive rates of various types of AIV in non-restricted regions for live poultry trade were higher than those in restricted regions. The differences were statistically significant (P<0.05). AIV type A and subtypes H5 and H9 were detected every month in 2018. Samples with the highest positive rates of AIV in non-restricted and restricted regions were samples of defeathering machine and samples of chopping board and knives, respectively. Conclusions The poultry markets were continuously contaminated by AIV, mainly subtypes H9 and H5. The positive rates of AIV in non-restricted regions were higher those that of restricted regions, suggesting that limitation of live poultry trades could effectively reduce the level of viral contamination in the markets. The restricted regions should be expanded. Key words: Avian influenza; External environment; Surveillance