关键词: H7N9禽流感, 流行特征, 分析

Abstract: Objective To describe and analyze the epidemiological characteristics of human infection with avian influenza A(H7N9) virus, so as to provide evidence for developing disease control measures. Methods Epidemiological analysis was conducted on 17 laboratory confirmed cases of human infection with H7N9 virus in Jinhua city, Zhejiang. Results A total of 17 cases of human infection with avian influenza A(H7N9) virus, 10 males and 7 females, were reported from 2014 to 2016,with 10 fatalities(58.82%). A total of 7 cases were <50 years old(including 1 death), 10 cases were ≥ 50 years old(including 9 death). Winter was the high-occurrence season for avian influenza A(H7N9), and cases were mainly farmers from countryside. Epidemiological survey indicated that 17 cases had the histories of exposure to live poultry or poultry markets. In total, 167 samples were collected from external environments which associated with cases epidemiologically, with the positive rate of 39.52%. A household clustering of human infections with avian influenza A (H7N9) virus involving 2 children occurred in February 2014. Epidemiological investigation showed that the later cases were more likely to be exposed to alive poultry, but the possibility of person to person transmission could not be ruled out. Among 17 cases, 5 were mild cases, 12 severe cases. The severe cases were complicated with other primary diseases (75.00%) and ≥ 50 years old(91.67%), with the fatality rate of 83.33%. Conclusion It is necessary to emphasize the market management of live poultry in rural areas in the future. We should strengthen training of community-level medical personnel and improve the sample detection rate for influenza-like case, so that the cases can be early diagnosed and treated as well as reduce the fatality rate.

Key words: Avian influenza A(H7N9), Epidemic characteristics, Analysis