Objective This study aims to analyze the surveillance results of avian influenza viruses in the external environment in Zhong County of Chongqing from 2018 to 2023,and to provide a basis for evaluating the risk of avian influenza outbreak in Zhong County.Methods Wipe samples were collected from two locations(large-scale poultry farms/households and urban and rural live poultry markets)and three types(feces,cages,tablet surfaces)in Zhong County from 2018 to 2023.RT-PCR was used to detect subtypes of influenza A virus(H5,H7,H9 subtype,etc.).Data were organized by using Excel 2013 and statistical analysis was conducted by using SPSS 22.0.Differences in classification data rates were analyzed by using the x2 test with an test level ofα=0.05.Results A total of 864 avian influenza virus surveillance samples were collected from the external environment in Zhong County of Chongqing from 2018 to 2023,of which 506 were positive for type A,with a positive rate of 58.56％.The positive rate decreased from 77.78％in 2018 to 42.36％in 2023,showing a statistically significant downward trend(x2Trend=75.504,P＜0.001).The positivity rate of the H9 subtype was 46.53％,while the positive rates of non-H5/H7/H9 subtypes were 10.42％,the H5 subtype was 6.37％,and the H5+H9 mixed type was 3.94％.Among the two types of venues,12 samples from large-scale poultry farms(households)were collected,and no avian influenza A virus was detected;852 samples were collected from urban and rural live poultry markets,with a positive rate of 59.39％.Among the three types of external environmental samples,the surface wiping samples of cages had the highest positive rate(64.24％),followed by wiping samples from slaughtered or placed poultry chopping boards(59.03％)and feces(52.43％).There was a statistically significant difference in the positive rate of Type A among different sample types(x2=8.309,P=0.016).Samples from different quarters all tested positive for avian influenza virus,with the highest positive rate of Type A in the fourth quarter(68.98％).However,there was no statistically significant difference in the positive rate of Type A in different quarters(x2=2.894,P=0.089).Conclusions From 2018 to 2023,the positive rate of Type A in the external environment in Zhong County of Chongqing,showed a downward trend,but it remains relatively high and H9 subtype was predominantly remained.It is necessary to strengthen the health education and publicity for practitioners,so that to improve their awareness and prevention of avian influenza and reduce the risk of human infection with avian influenza.
维普
万方数据
