Mao Chen, Wu Xin-Yin, Fu Xiao-Hong, Di Meng-Yang, Yu Yuan-Yuan, Yuan Jin-Qiu, Yang Zu-Yao, Tang Jin-Ling
School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong, Hong Kong, China (Hong Kong).
J Med Internet Res. 2014 Sep 25;16(9):e221. doi: 10.2196/jmir.3763.
In early 2013, a new type of avian influenza, H7N9, emerged in China. It quickly became an issue of great public concern and a widely discussed topic on the Internet. A considerable volume of relevant information was made publicly available on the Internet through various sources.
This study aimed to describe the outbreak of H7N9 in China based on data openly available on the Internet and to validate our investigation by comparing our findings with a well-conducted conventional field epidemiologic study.
We searched publicly accessible Internet data on the H7N9 outbreak primarily from government and major mass media websites in China up to February 10, 2014. Two researchers independently extracted, compared, and confirmed the information of each confirmed H7N9 case using a self-designed data extraction form. We summarized the epidemiological and clinical characteristics of confirmed H7N9 cases and compared them with those from the field study.
According to our data updated until February 10, 2014, 334 confirmed H7N9 cases were identified. The median age was 58 years and 67.0% (219/327) were males. Cases were reported in 15 regions in China. Five family clusters were found. Of the 16.8% (56/334) of the cases with relevant data, 69.6% (39/56) reported a history of exposure to animals. Of the 1751 persons with a close contact with a confirmed case, 0.6% (11/1751) of them developed respiratory symptoms during the 7-day surveillance period. In the 97.9% (327/334) of the cases with relevant data, 21.7% (71/327) died, 20.8% (68/327) were discharged from a hospital, and 57.5% (188/327) were of uncertain status. We compared our findings before February 10, 2014 and those before December 1, 2013 with those from the conventional field study, which had the latter cutoff date of ours in data collection. Our study showed most epidemiological and clinical characteristics were similar to those in the field study, except for case fatality (71/327, 21.7% for our data before February 10; 45/138, 32.6% for our data before December 1; 47/139, 33.8% for the field study), time from illness onset to first medical care (4 days, 3 days, and 1 day), and time from illness onset to death (16.5 days, 17 days, and 21 days).
Findings from our Internet-based investigation were similar to those from the conventional field study in most epidemiological and clinical aspects of the outbreak. Importantly, publicly available Internet data are open to any interested researchers and can thus greatly facilitate the investigation and control of such outbreaks. With improved efforts for Internet data provision, Internet-based investigation has a great potential to become a quick, economical, novel approach to investigating sudden issues of great public concern that involve a relatively small number of cases like this H7N9 outbreak.
2013年初，一种新型禽流感H7N9在中国出现。它迅速成为公众高度关注的问题，并在互联网上引发广泛讨论。通过各种渠道，大量相关信息在互联网上公开。
本研究旨在基于互联网上公开的数据描述中国H7N9疫情，并通过将研究结果与一项开展良好的传统现场流行病学研究进行比较，验证我们的调查。
我们主要从中国政府和主要大众媒体网站搜索截至2014年2月10日的关于H7N9疫情的公开互联网数据。两名研究人员使用自行设计的数据提取表独立提取、比较并确认每例确诊H7N9病例的信息。我们总结了确诊H7N9病例的流行病学和临床特征，并与现场研究的结果进行比较。
根据截至2014年2月10日更新的数据，共识别出334例确诊H7N9病例。中位年龄为58岁，67.0%（219/327）为男性。中国15个地区报告了病例。发现了5个家庭聚集性病例。在有相关数据的16.8%（56/334）的病例中，69.6%（39/56）报告有动物接触史。在1751名与确诊病例密切接触的人中，0.6%（11/1751）在7天监测期内出现呼吸道症状。在有相关数据的97.9%（327/334）的病例中，21.7%（71/327）死亡，20.8%（68/327）出院，57.5%（188/327）情况不明。我们将2014年2月10日前以及2013年12月1日前的研究结果与传统现场研究的结果进行比较，后者的数据收集截止日期与我们的相同。我们的研究表明，除了病死率（2014年2月10日前我们的数据为71/327，21.7%；12月1日前我们的数据为45/138，32.6%；现场研究为47/139，33.8%）、发病至首次就医时间（分别为4天、3天和1天）以及发病至死亡时间（分别为16.5天、17天和21天）外，大多数流行病学和临床特征与现场研究相似。
我们基于互联网的调查结果在疫情的大多数流行病学和临床方面与传统现场研究相似。重要的是，公开的互联网数据对任何感兴趣的研究人员开放，因此可以极大地促进此类疫情的调查和控制。随着互联网数据提供工作的改进，基于互联网的调查有很大潜力成为一种快速、经济、新颖的方法，用于调查像此次H7N9疫情这样涉及病例数量相对较少的、引发公众高度关注的突发问题。
