Contamination status of avian influenza virus in external environment and the levels of H5N6, H7N9 and H9N2 antibodies in poultry-exposed population in Jiaxing City
Abstract：Objective To investigate the distribution of avian influenza virus in external environment in Jiaxing City and its infection status in poultry-exposed population so as to provide a scientific basis for effectively preventing and controlling human infection with avian influenza. Methods Real-time RT-PCR assay was used to detect the nucleic acid of influenza A virus from 3,115 external environmental samples collected in Jiaxing City from March, 2013 to April, 2016, and then multiple RT-PCR assay and specific H5, H7 and H9 primers were employed to analyze the subtypes of the positive samples.Haemagglutination inhibition (HI) test was used to detect antibodies against H5N6, H7N9 and H9N2 viruses in sera collected from 140 poultry-exposed workers in Jiaxing City in April, 2015 and April, 2016. Results The overall positive rate of avian influenza A virus was 18.11%. The positive rates of subtypes H5, H9 and H7 were 0.64%, 3.21% and 5.07% respectively. In addition, 74specimens with mixed-subtype contamination were detected in the 3,115 external environmental samples, and the positive rate of mixed subtype H9/H7 reached 1.86%. The circulation of influenza A virus and subtype H7 was active during winter and spring in the external environment; moreover, the positive rate of avian influenza virus in urban and rural live poultry markets was significantly higher than those of other places. The positive rates of influenza A virus and subtype H7 in the samples from cutting boards and poultry cleaning wastewater were significantly higher than those of other sample types. Among the 140 serum samples detected, only 5 (3.57%) were H9N2 virus positive, and no samples with positive H5N6 and H7N9 viruses were found. Conclusions Contamination of avian influenza viruses of H5, H9 and H7 subtypes did exist in external environment in Jiaxing City in 2013-2016, and a few patients with asymptomatic infection caused by H9N2 avian influenza virus were proved to exist in the poultry-exposed population. The results suggest that there is a possibility of becoming infected with avian influenza virus if people have a history of poultry contact and exposure to live poultry markets; and hence, it is necessary to strengthen health education among the key population and intensify surveillance of avian influenza virus in the key districts so as to prevent and control human infection with avian influenza virus.
亓云鹏,顾伟玲,富小飞,谢亮,何培彦,查亦薇,周晚玲. 嘉兴市外环境禽流感病毒污染状况及职业暴露人群H5N6、H7N9和H9N2抗体水平调查[J]. 实用预防医学, 2018, 25(4): 417-420.
QI Yun-peng, GU Wei-ling, FU Xiao-fei, XIE Liang,HE Pei-yan,ZHA Yi-wei,ZHOU Wan-ling. Contamination status of avian influenza virus in external environment and the levels of H5N6, H7N9 and H9N2 antibodies in poultry-exposed population in Jiaxing City. , 2018, 25(4): 417-420.
2018, Vol. 25 
