目的 了解人感染H7N9禽流感流行病学特点,探寻人感染H7N9禽流感病毒的可能来源。方法 根据《安徽省人感染H7N9禽流感病例调查(2017年版)》,对阜阳市2014～2017年确诊的7例人感染H7N9禽流感病例进行流行病学调查。采集活禽交易场所相关标本,检测H7核酸。分析患者的临床特点,暴露风险因素,关闭活禽交易市场,对疫情的影响。结果 7例患者中男性6例,年龄中位数58岁,55岁及以上者5例。病例分布在4个县区的7个不同乡镇,职业以农民居多(3/7);发病时间集中在冬春季节,发病到就诊时间间隔中位数为1 d(0~3 d),发病到使用抗病毒药物时间中位数为4.5 d(3~6 d)。7例患者均有活禽接触或活禽市场暴露史,休市后活禽市场外环境标本H7N9核酸阳性率明显下降(χ 2_趋势=11.92,P=0.001)。密接人员中未发现感染病例。结论 活禽接触或暴露活禽市场是人感染H7N9禽流感的主要危险因素。采取活禽交易休市措施,有助于控制人感染H7N9禽流感疫情。

Objective To understand the epidemiological characteristics of the patients infected with avian influenza A(H7N9) virus,and explore possible sources of the virus. Methods 7 cases infected with avian influenza A(H7N9) virus and its related factors were investigated and analyzed from 2014 to 2017, according to investigation using questionnaire for the patients infected with avian influenza A (H7N9) virus of Anhui province (2017 edition). The relevant samples from the trading market of live poultry were collected to detect H7 nucleic acid. The clinical characteristics, risk factors and the impact of closing live poultry trading market on the epidemic were analyzed. Results 6 cases were male. The Median age of the 7 patients was 58 years old. Five cases were over 55 years old(71.43%). The cases were distributed in 7 different townships in 4 counties. They were mostly farmers (3/7).The onset time was concentrated in the winter and spring. The median of time interval between onset and treatment was 1 day (0~3 d).The median of the interval between the time of onset and taking the antiviral drugs was 4.5 days (3~6 d). All 7 patients had exposure to live poultry or live poultry market. After shutdown, the positive rate of H7N9 nucleic acid in the external environment of live poultry market decreased significantly(χ 2_{thend=11.92,P=0.001). Conclusion Live poultry exposure or exposure to live poultry market is a major risk factor for human infection with H7N9 avian influenza. Closing the live poultry market could help control the infection of H7N9 avian influenza.}