Objective To monitor and analyze the avian influenza virus contamination in the environment outside the poultry-related places in Guangxi, and to assess the risk of human infection with avian influenza viruses, so as to provide a scientific basis for the prevention and control of avian influenza in Guangxi.
Methods From 2021 to 2022, environmental samples from 5 kinds of poultry-related sites were collected monthly in 14 cities of Guangxi. The real-time fluorescent quantitative RT-PCR method was used to detect the nucleic acids of generic influenza A viruses, and H5, H7, and H9 subtypes of avian influenza virus. The detection results of avian influenza virus in the environment of the poultry-related sites in Guangxi were collected for retrospective analysis. SPSS 22.0 was used for data analysis, and the chi-square test was used to compare the rates.
Results From 2021 to 2022, a total of 5 960 environmental samples were collected in 14 cities, of which 3 918 were positive for influenza A virus nucleic acid, with a positive rate of 65.74%; Among the positive samples, 281 were positive for H5 subtype (7.17%), 2 508 were positive for H9 subtype (64.01%), 552 were positive for H5+H9 subtype (14.09%), 577 were positive for type A but not H5/H7/H9 (14.73%), and no subtype H7 was detected. The positive rate of influenza A in poultry related environment samples was higher throughout the year in Guangxi; except for Wuzhou, which had a similar number of H5, H9, and A non-H5/H7/H9 subtypes, the H9 subtype was predominantly detected in other cities. There was significant variability in positive rates among different regions, with the highest being in Hezhou City (90.32%, 653/723) and the lowest in Yulin City (28.96%, 75/259). The positive rate of different specimen types ranged from 50.32% to 74.94%. There were statistically significant differences in the positive rates of samples from different types of samples (χ2=163.08, P<0.001), different months (χ2=172.69, P<0.001), different regions (χ2=498.86, P<0.001), different monitoring sites (χ2=370.01, P<0.001).
Conclusions There is severe contamination of avian influenza virus in the poultry-related environment in Guangxi, predominantly with the H9 and H5 subtypes. Therefore, the relevant authorities in Guangxi should strengthen the monitoring, management, and disinfection of poultry-related premises.