de Lange Marit M A, Meijer Adam, Friesema Ingrid H M, Donker Gé A, Koppeschaar Carl E, Hooiveld Mariëtte, Ruigrok Nel, van der Hoek Wim
National Institute for Public Health and the Environment (RIVM), Centre for Infectious Disease Control Netherlands, P,O, Box 1, 3720 BA Bilthoven, The Netherlands.
BMC Public Health. 2013 Sep 24;13:881. doi: 10.1186/1471-2458-13-881.
During the 2009 influenza pandemic period, routine surveillance of influenza-like-illness (ILI) was conducted in The Netherlands by a network of sentinel general practitioners (GPs). In addition during the pandemic period, four other ILI/influenza surveillance systems existed. For pandemic preparedness, we evaluated the performance of the sentinel system and the others to assess which of the four could be useful additions in the future. We also assessed whether performance of the five systems was influenced by media reports during the pandemic period.
The trends in ILI consultation rates reported by sentinel GPs from 20 April 2009 through 3 January 2010 were compared with trends in data from the other systems: ILI cases self-reported through the web-based Great Influenza Survey (GIS); influenza-related web searches through Google Flu Trends (GFT); patients admitted to hospital with laboratory-confirmed pandemic influenza, and detections of influenza virus by laboratories. In addition, correlations were determined between ILI consultation rates of the sentinel GPs and data from the four other systems. We also compared the trends of the five surveillance systems with trends in pandemic-related newspaper and television coverage and determined correlation coefficients with and without time lags.
The four other systems showed similar trends and had strong correlations with the ILI consultation rates reported by sentinel GPs. The number of influenza virus detections was the only system to register a summer peak. Increases in the number of newspaper articles and television broadcasts did not precede increases in activity among the five surveillance systems.
The sentinel general practice network should remain the basis of influenza surveillance, as it integrates epidemiological and virological information and was able to maintain stability and continuity under pandemic pressure. Hospital and virological data are important during a pandemic, tracking the severity, molecular and phenotypic characterization of the viruses and confirming whether ILI incidence is truly related to influenza virus infections. GIS showed that web-based, self-reported ILI can be a useful addition, especially if virological self-sampling is added and an epidemic threshold could be determined. GFT showed negligible added value.
在2009年流感大流行期间，荷兰通过一个由定点全科医生组成的网络对流感样疾病（ILI）进行常规监测。此外，在大流行期间，还存在其他四个ILI/流感监测系统。为了做好大流行防范准备，我们评估了定点监测系统和其他系统的性能，以确定这四个系统中哪些在未来可能是有用的补充。我们还评估了这五个系统的性能在大流行期间是否受到媒体报道的影响。
将2009年4月20日至2010年1月3日定点全科医生报告的ILI就诊率趋势与其他系统的数据趋势进行比较：通过基于网络的大流感调查（GIS）自我报告的ILI病例；通过谷歌流感趋势（GFT）进行的流感相关网络搜索；因实验室确诊的大流行性流感而住院的患者，以及实验室对流感病毒的检测。此外，还确定了定点全科医生的ILI就诊率与其他四个系统数据之间的相关性。我们还将五个监测系统的趋势与大流行相关报纸和电视报道的趋势进行了比较，并确定了有无时间滞后的相关系数。
其他四个系统显示出相似的趋势，并且与定点全科医生报告的ILI就诊率有很强的相关性。流感病毒检测数量是唯一出现夏季高峰的系统。报纸文章数量和电视广播次数的增加并没有先于五个监测系统活动的增加。
定点全科医疗网络应继续作为流感监测的基础，因为它整合了流行病学和病毒学信息，并且能够在大流行压力下保持稳定和连续性。在大流行期间，医院和病毒学数据很重要，可用于追踪病毒的严重程度、分子和表型特征，并确认ILI发病率是否真的与流感病毒感染有关。GIS表明，基于网络的自我报告ILI可能是一个有用的补充，特别是如果增加病毒学自我采样并能确定流行阈值的话。GFT显示出的附加值可忽略不计。
