Objective To analyze the epidemiologic characteristics of environmental samples of avian influenza virus in Fujian province from 2017 to 2021, and provide a reference for the prevention and control of avian influenza.

Methods Six types of specimens were collected from four types of environments in six cities in Fujian province. And the specimens were subjected to nucleic acid detection for influenza A, subtypes H5, H7 and H9 by fluorescence quantitative PCR, and the results were analyzed statistically with descriptive epidemiological methods.

Results From 2017 to 2021, a total of 4 214 samples were collected from 6 cities, of which the positive rate of avian influenza virus was 41.53%, and the positive rates of H5, H7 and H9 subtypes were 2.33%, 1.16% and 23.16%, respectively. The positive rate for mixed subtypes of H5 and H7 was 0.05%, the positive rate for mixed subtypes of H5 and H9 was 1.83%, the positive rate for mixed subtypes of H7 and H9 was 0.83%, the positive rate for mixed subtypes of H5, H7 and H9 was 0.09%, and the positive rate of A-type unclassified was 12.08%. The difference in avian influenza virus detection among different monitoring places (χ2=517.57, P<0.001), different types of specimens(χ2= 51.58, P<0.001), and different cities (χ2=458.34, P<0.001) was statistically significant. Among different monitoring places, the positive rate of avian influenza virus in urban and rural live poultry markets was the highest. The highest rate of positive detection was found in specimens from the cage surface, cleaning poultry sewage and poultry chopping board surface, with 48.09%, 47.34% and 45.66%, respectively. In terms of different cities, Sanming city had the highest positivity rate (56.00%), while Zhangzhou city had the lowest positivity rate(3.34%). And the positive rate was higher from November to February of the next year and June to August each year.

Conclusions The overall positive rate of avian influenza viruses in Fujian province was relatively high, with H9 subtype accounting for the main proportion. The monitoring of avian influenza viruses in winter, spring and summer should be strengthened. And effective measures should be taken to deal with avian influenza especially in urban and rural live poultry markets.