2018-2021年湖南省长沙市活禽市场外环境禽流感病毒监测以及禽类职业暴露人群血清学分析

Surveillance for avian influenza virus in external environment of live poultry markets and serological analysis in population with occupational exposure in Changsha,Hunan,2018-2021

目的 了解2018—2021年湖南省长沙市活禽市场外环境禽流感病毒的分布特点、污染情况以及职业暴露人群的血清学检测结果,为人感染禽流感防控和政策制定提供科学依据。方法 2018年1月1日至2021年12月31日,收集长沙市活禽市场外环境样本,采用实时荧光反转录聚合酶链式反应法检测禽流感病毒核酸,血清样本采用马血球血凝抑制实验(HI)检测血清中的H5N6、H7N9抗体,火鸡血球检测血清中H9N2抗体。运用SPSS 19.0软件对数据进行统计分析,比较不同样本类型、不同地区以及不同监测时间阳性率的差异。结果 2018—2021年共采集活禽市场外环境样本813份,禽类职业人员血清样本150份,禽流感病毒平均阳性率为64.58%,其中2019—2021年阳性率逐年升高,其中H9型254份,为阳性检出数量最多的型别。6类不同类型的样本中,笼具表面擦拭样本的阳性率最高(79.03%),禽类咽拭子最低(10.00%)。岳麓区的禽流感病毒阳性率最高,占94.67%。在时间分布上,平均阳性率最高的是第四季度(67.50%),最低的是第三季度(57.82%),呈夏季阳性率低于冬季的情况。禽类职业暴露人员血清学检测中检出1份H9N2抗体阳性样本。不同类型样本、不同地区的禽流感病毒阳性率差异有统计学意义(P<0.05)。结论 长沙市活禽市场外环境禽流感病毒阳性检出型别主要为H9型。冬季为高发期,职业暴露人群中存在H9N2隐性感染的情况。活禽市场内交易、运输和人员流动是禽流感跨种传播的高风险因素,应将活禽市场作为禽流感防控重点场所,持续开展禽流感病毒监测以防止禽流感病毒在人际间传播。

Objective To understand the distribution and contamination of avian influenza virus in the external environment of live poultry markets and analyze the serological test results of population with occupational exposure in Changsha, Hunan province, from 2018 to 2021, and provide evidence for the prevention and control of human infection with avian influenza virus and policy-making. Methods From January 1, 2018 to December 31, 2021 in Changsha, the external environmental samples of live poultry markets were collected and detected for avian influenza virus nucleic acid by real-time reverse transcription polymerase chain reaction, and horse blood cell hemagglutination inhibition test(HI) was used to detect H5N6and H7N9 antibodies in serum samples, and turkey blood cell was used to detect H9N2 antibodies in serum samples. Software SPSS 19.0 was used to analyze the data and compare the positive rates of different samples, at different areas and at different times. Results From January 1, 2018 to December 31, 2021, a total of 813 external environmental samples of live poultry markets and 150 serum samples of people with occupational exposure to poultry were collected in Changsha. The average positive rate of avian influenza virus in the external environment of live poultry markets was 64.58% in Changsha from 2018 to2021, the annual positive rate showed an increasing trend from 2019 to 2021, and 254 samples were positive for subtype H9,accounting for the highest proportion. Among the six different types of sample, the positive rate in cage surface swabs was highest(79.03%), and the positive rate in poultry throat swabs was lowest(10.00%). Among the districts and counties in Changsha, Yuelu had the highest positive rate of avian influenza virus(94.67%). In terms of time distribution, the average annual positive rate was highest in the fourth quarter(67.50%), and lowest in the third quarter(57.82%), the positive rate was lower in summer than in winter. From 2018 to 2021, one H9N2 antibody positive sample was detected in the serological test for the population with occupational exposure to poultry.There were significant differences in the positive rate of avian influenza virus among different types of samples and different areas (P<0.05).Conclusion The main subtype of avian influenza virus was H9 in the external environment of live poultry market in Changsha during 2018-2021.Winter was the season with high detection rate,and there was H9N2 recessive infection in population with occupational exposure.Trading,transportation and personnel flow in live poultry markets were high-risk factors for the cross-species spread of avian influenza virus.Live poultry markets should be regarded as a key places for avian influenza prevention and control,and continuous surveillance for avian influenza virus should be carried out to prevent the spread of avian influenza virus in human.