Has estimation of numbers of cases of pandemic influenza H1N1 in England in 2009 provided a useful measure of the occurrence of disease?
Has estimation of numbers of cases of pandemic influenza H1N1 in England in 2009 provided a useful measure of the occurrence of disease?
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DOI：
10.1111/j.1750-2659.2011.00259.x
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发表时间：
2011-11-01
影响因子：
4.4
通讯作者：
Watson, John M.
中科院分区：
文献类型：
--
作者：
Evans, Barry;Charlett, Andre;Watson, John M.
背景流感活动的监测指标通常为英格兰提供了可靠的比较趋势数据。然而，在2009年流感大流行期间，由于对风险的认识和卫生保健提供系统的变化，这些指标在监测活动趋势或与往年比较方面变得不那么可靠。开发了一种方法来估计因感染大流行性流感病毒而发生的流感样疾病（ILI）病例数。方法与结果：以就诊人数为基础，估计英国每周的病例数；估计社区中寻求精神卫生保健的个人比例；这些人在实验室检测中呈阳性的比例。据估计，在英格兰两波大流行活动期间发生了近80万例（范围为37.5万至160万）有症状的ILI病例。据估计，第二波疫情中发生的病例比第一波更多。这些结果低估了感染的总数，因为它们不包括无症状感染，也不包括那些不符合ILI病例定义的轻度疾病。尽管如此，病例数估计数提供了流感活动趋势的有用指标，每周数据在媒体报道中被广泛使用。虽然各国的监测方法不同，但综合现有数据来源以产生病例数总体估计的方法可以更广泛地应用于提供比较数据。
Background Surveillance indicators of influenza activity have generally provided robust comparative trend data for England. These indicators became less reliable, however, for monitoring trends in activity, or comparisons with previous years, during the influenza pandemic in 2009 because of changes in the perception of risk and changes in the systems of healthcare delivery. An approach was developed to estimate the number of cases of influenza-like illness (ILI) occurring because of infection with pandemic influenza virus.Methods and findings The number of cases was estimated each week in England on the basis of total number of patients consulting healthcare services with ILI; estimates of the proportion of individuals in the community experiencing an ILI-seeking health care; and the proportion of these positive on laboratory testing. Almost 800 000 cases (range 375 000-1.6 million) of symptomatic ILI cases were estimated to have occurred over the course of the two waves of pandemic activity in England. More cases were estimated to have occurred in the second wave than in the first.Conclusions These results underestimate the total number of infections as they do not include asymptomatic infections nor those with mild illness not meeting the definition of a case of ILI. Nevertheless, the case number estimates provide a useful indicator of the trend in influenza activity and weekly data were extensively used in media reports. Although surveillance methods differ between countries, the approach of synthesising available data sources to produce an overall estimate of case numbers could be applied more widely to provide comparative data.