2009年上海市甲型H1N1流感的流行病学特征分析

Epidemiology of pandemic influenza A (H1N1) in Shanghai

目的分析2009年上海市甲型H1N1流感的流行病学特征,探索疾病流行规律,为进一步完善相关预防控制措施提供科学依据。方法采集病例咽拭子开展甲型H1N1流感核酸检测,并采用流行病学描述方法对2009年5-9月上海市确诊病例开展流行病学研究及相关因素分析。结果2009年5月25日上海市确诊首例甲型H1N1流感病例。截至11月19日24时,上海市共报告1656例确诊病例,重症病例4例,无死亡病例。对最初315例开展流行病学调查,以输入性为主(296例,93.97%),主要来源于澳大利亚(139例,44.13%)和美国(43例,13.65%)。病例的发现主要通过流感监测系统、口岸检疫、发热门诊和集中医学观察点4种途径,发病对象年龄段以10～29岁青少年为主(64.73%),有性别差异(P=0.003)。追踪确诊病例密切接触者共5224人次,包括20名医务人员,无医务人员感染。结论疫情已进入快速增长期,甲流在上海社区间暴发的风险正在日益增加。

Objective To analyze epidemiological characteristics of pandemic influenza A （ H1N1 ） in Shanghai and provide scientific evidence for the further improvement of the control and prevention measures. Methods Throat swabs of the patients were taken to detect nucleic acid of pandemic influenza A （H1N1） virus. Descriptive epidemiological analysis and related risk factor analysis were conducted on the pandemic influenza A （ H1N1 ） cases confirmed in Shanghai during May-September. Results The first case of pandemic influenza A （ H1N1 ） in Shanghai was confirmed on May 25, 2009, and by 24 pm, November 19, 2009, 1656 confirmed cases had been reported in Shanghai, including 4 severe cases, without death. Epidemiological study was performed on 315 confirmed cases reported initially. The vast majority （296, 93.97% ） were imported cases, 139 cases were from Australia （44.13%） and 43 from United States （ 13.65% ）. Since June 29, the reported cases had increased substantially. Most cases were directly identified by following 4 ways： influenza surveillance system, the port quarantine, febrile disease clinic screening and centralized medical observation. Most cases were adolescents and young adults （64.73 % ）. There was gender difference on incidence （P = 0.003 ）. A total of 5224 close contacts were followed up, including 20 health care workers. No infection occurred among health care. workers. Conclusion The epidemic of pandemic influenza A （H1N1） is in rapid spread and there is more potential that the outbreak of pandemic influenza A （H1N1） might occur in the community in Shanghai.