中国2013-2017年人感染H7N9禽流感的流行病学特征

Epidemiology of human infection with avian influenza A（H7N9） virus in China, 2013-2017

目的 对我国人感染H7N9禽流感的流行病学特点进行分析，为H7N9禽流感的预防控制提供依据。方法 以2013年3月至2017年4月公开发表的人感染H7N9禽流感数据为对象，利用Excel 2007软件对数据进行统计学分析，描述其三间分布、暴露史及聚集性。结果 中国共确诊人感染H7N9禽流感病例1 416例，死亡559例，病死率为39.5%，2016年病例最少（127例），病死率最高（57.5%）；报告病例前三位的省份主要是浙江、广东、江苏；发病年龄M＝55岁，男女性别比为2.3∶1，男性病例远多于女性。66%的病例在发病前确定有活禽相关暴露史，31%的病例暴露情况不详，仅有3%的病例无相关活禽暴露史。共发生35起家庭聚集性病例，共涉及72例病例，占总发病例数的5%。结论 H7N9禽流感疫情有较明显的季节分布及区域分布特点；存在有限的家庭聚集性；感染病例多与禽类接触有关。

Objective To understand the epidemiological characteristics of human infection with avian influenza A （H7N9） virus in China, and provide evidence for the prevention and control of human infection with H7N9 virus. Methods The published incidence data of human infection with H7N9 virus in China from March 2013 to April 2017 were collected. Excel 2007 software was used to perform the analysis. The characteristics of distribution of the disease, exposure history, cluster of the disease were described. Results By the end of April 2017, a total of 1 416 cases of human infection with H7N9 virus were confirmed in China, including 559 deaths, the case fatality rate was 39.5%. In 2016, the case number was lowest （127 cases）, with the highest fatality rate （57.5%）. The first three provinces with high case numbers were Zhejiang, Guangdong and Jiangsu. The median age of the cases was 55 years and the male to female ratio was 2.3：1. Up to 66% of cases had clear live poultry exposure history before illness onset, 31% of cases had unknown exposure history and only 3% of the cases had no live poultry exposure history. There were 35 household clusters （5 in 2013, 9 in 2014, 6 in 2015, 5 in 2016, 10 in 2017）, which involved 72 cases, accounting for 5% of the total cases. Conclusions The epidemic of human infection with H7N9 virus in China during 2013-2017 had obvious seasonality and spatial distribution. There was limited family clustering. Infection cases were mostly related to poultry contact.