四川省阿坝州5例人感染H7N9禽流感病例流行病学特征分析

目的 分析阿坝州2017年人感染H7N9禽流感病例的流行病学特征，为该州制定禽流感预防和控制策略提供依据。方法 对阿坝州2017年报告的5例人感染H7N9禽流感病例按照国家卫生计生委下发的《人感染H7N9禽流感疫情防控方案（第三版）》进行调查，使用Excel 2007、SPSS 17.0进行数据统计分析。结果 阿坝州2017年首次出现人感染H7N9禽流感疫情，共有5例人感染H7N9禽流感确诊病例，死亡3例，病死率为60.00%。男2例，女3例，男女性别比为0.67∶1。其中，最小年龄51岁，最大年龄76岁，平均年龄60.8岁，年龄中位数57岁。病例均有活禽农贸市场暴露史。病例报告县农贸市场外环境标本阳性率较未报告病例县农贸市场高，差异有统计学意义(χ2 = 6.73，P＜0.05)。结论 阿坝州此次疫情地区分散，时间集中，农贸市场禽类暴露是感染的危险因素。采取关闭活禽市场能明显控制疫情发展；病例以散发为主，目前暂无足够的证据支持病毒在人与人之间传播。

Epidemiological characteristics of 5 cases of human infection with avian influenza A (H7N9) virus in Aba of Sichuan

Objective To analyze the epidemiological characteristics of H7N9 avian influenza in Aba in 2017, and thus to provide evidence for developing prevention and control strategies of influenza A(H7N9) virus. Methods An investigation was conducted in accordance with the Programme for Prevention and Control of Human Infection by H7N9 Avian Influenza issued by National Health and Planning Commission， and data were statistically analyzed by Excel 2007 and SPSS 17.0. Results The first epidemic of human infection by H7N9 avian influenza of Aba in 2017. A total of 5 persons were infected by H7N9 avian influenza, and 3 died,the fatality rate was 60%. There were 2 males and 3 females, and the sex ratio was 0.67:1. The youngest patient was 51 years old, the oldest was 76 years old, the average age was 60.8 years old, the median age was 57 years old. All the cases had histories of alive poultry market exposures. The H7N9 virus positive rate was higher the county of reported cases market environment exposed samples than the county of unreported cases market environment exposed samples. The difference was statistically significant(χ2=6.73, P<0.05). Conclusion The outbreak of H7N9 avian influenza in Aba affects scattered areas and time concentrated. Farmer's market poultry exposure is a risk factor for infection. The suspension of the alive poultry trade could effectively control the outbreak. The infection mainly occurred sporadically，and by far no sufficient evidence to support that the virus spread from person to person.