一例人H9N2禽流感病例触发的禽间禽流感紧急流行病学调查

An Emergency Epidemiological Investigation of AI in Poultry Triggered by a Human Case of H9N2 AI

2021年9月,A省B市出现一例人H9N2禽流感病例。为了解禽间是否存在禽流感病原,确定该病例的感染来源,防止出现禽间疫情,对该病例家附近区域内的家禽养殖场户、集中屠宰点和农贸市场开展了H9亚型禽流感紧急流行病学调查,对该病例居住地和就读学校间区域内的家禽养殖户、屠宰点和农贸市场以及B市所有家禽养殖场户进行禽流感疫情排查,均未发现可疑病例。对该病例居住社区内养殖场户、农贸市场和活禽临时集中屠宰点进行第一轮家禽咽/泄殖腔拭子和环境样品采样检测,结果均为H9亚型禽流感阴性;在第二轮采样检测中,活禽临时集中屠宰点8家屠宰摊位的16份鸡拭子检测为H9亚型禽流感阳性。经疫情排查和采样检测,认为本地家禽发生H9亚型禽流感疫情的风险较低,该病例通过家禽感染的可能性较小,但不能排除通过野禽感染的可能,病原通过屠宰点和农贸市场由外地传入散播的风险较高。建议加强家禽屠宰点、农贸市场等高风险场所的清洗、消毒和疫情排查,做好家禽养殖场的禽流感防控,切断人-禽间的禽流感传播途径。

In September 2021,a human case of H9N2 avian influenza(AI)occurred in B City of A City. In order to recognize the AI virus carrying status in poultry,find out the infection source,and to prevent any possible outbreak in poultry,an emergency epidemiological investigation on H9 subtype AI was carried out in poultry farms/households,centralized slaughtering points and farmers’ markets in the area where the case was exposed. No suspicious case was found in the above premises between the residence of the case and the school even all poultry farms in B City. The first round of AI detection of poultry pharyngeal cloacal swabs and environmental samples was carried out in the farms,farmers’ markets and temporary centralized slaughtering points in the community where the case lived,and all results were negative;for the second round,16 chicken swabs collected from 8 stalls of the temporary centralized slaughtering points were confirmed to be positive for H9 subtype AI. It was considered that,through investigation and sampling detection,the risk of occurrence of H9 subtype AI in local poultry was relatively low,and the case was not more likely to be infected via poultry,but the risk of pathogen introduced from other regions through slaughtering points and farmers’ markets and then spreading was relatively high. It was thus recommended to strengthen the cleaning,disinfection and inspection for poultry slaughtering points,farmers’ markets and other high-risk premises,to make efforts to prevent and control the disease in poultry farms,and to cut off any possible routes between human and poultry.