Epidemiology of the avian influenza A (H7N9) outbreak in Zhejiang Province, China.
Epidemiology of the avian influenza A (H7N9) outbreak in Zhejiang Province, China.
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DOI：
10.1186/1471-2334-14-244
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发表时间：
2014-05-08
影响因子：
3.7
通讯作者：
Chen E
中科院分区：
文献类型：
--
作者：
Gong Z;Lv H;Ding H;Han J;Sun J;Chai C;Cai J;Yu Z;Chen E
中国于2013年3月31日发现了一种新型甲型流感病毒感染，2013年3月25日至9月31日期间，中国12个省份共发现134例病例。其中，浙江省发生46例，患者人数为全国最多。对每例确诊的H7N9病例进行了实地调查。使用标准化问卷收集有关人口统计学、暴露史、临床体征和症状、发病后就诊和护理时间表以及密切接触者的信息。采用描述性统计分析其流行病学和临床特征。采集患者标本，采用真实的时间逆转录聚合酶链反应和病毒培养进行检测。2013年3月31日至9月31日期间，浙江省共发现46例实验室确诊的H7N9流感感染病例，其中29例为男性，17例为女性。患者的中位年龄为61.5岁，76.09%的病例发生在≥50岁的人群中。与其他省份不同，浙江省34.78%的病例为农村居民。11例死亡病例中，男性9例，60岁以上10例，有基础疾病10例。有数据的38例病例中，30例有近期家禽接触史，8例有多次接触史。估计的中位潜伏期为2天，比其他省份的相应数据短。所有病例均住院治疗，从发病到住院的中位时间为5天。发病时的症状包括发烧、咳嗽、咳痰、颤抖、疲劳、肌肉疼痛、恶心、呕吐。只有4.91%的接触者出现呼吸道症状，但他们的样本对H7N9病毒检测呈阴性，表明该病毒没有人际传播。所有病例都是散发的，没有证据表明它们之间存在流行病学联系。不仅在城市地区，而且在农村地区都需要采取控制措施，包括关闭受影响的家禽和屠宰后院家禽，以减少人类H7N9感染风险。
A novel influenza A virus infection was identified on March 31, 2013 in China and a total of 134 cases were identified in 12 provinces of China between March 25 and September 31, 2013. Of these, 46 cases occurred in Zhejiang Province and the number of patients is the largest in China. Field investigations were conducted for each confirmed H7N9 case. A standardized questionnaire was used to collect information about demographics, exposure history, clinical signs and symptoms, timelines of medical visits and care after onset of illness, and close contacts. Descriptive statistics were used to analyze the epidemiological and clinical characteristics. Samples from the patients were collected and tested by real time reverse transcriptase-polymerase chain reaction and viral culture. A total of 46 laboratory confirmed cases of H7N9 influenza infection were identified in the Zhejiang province between March 31 and September 31, 2013 of which 29 were male and 17 were female. The median age of patients was 61.5 years and 76.09% of cases occurred in persons aged ≥50 years old. Unlike other province, 34.78% of cases in Zhejiang Province were rural residents. Among 11 deaths, 9 were male, 10 were older than 60 years old, and 10 had underlying diseases. 30 of 38 cases with available data had a recent history of poultry exposures and 8 cases had multi-exposure history. The estimated median incubation period was two days which was shorter than corresponding data in other provinces. All cases were hospitalized and the median time from illness onset to hospitalization was 5 days. Symptoms at the onset of the illness included fever, cough, expectoration, shivering, fatigue, muscular aches, nausea, vomiting. Only 4.91% contacts developed respiratory symptoms, but their samples were tested negative for H7N9 virus designating lack of human-to-human transmission of the virus. All cases were sporadic and there was no evidence of an epidemiologic link between them. Control measures including closing affected poultry and slaughtering backyard poultry are needed not only in urban areas but also in rural areas to reduce human H7N9 infection risk.