National Institute for Public Health and the Environment (RIVM), PO box 1 3720 BA, Bilthoven, the Netherlands.
Antimicrob Resist Infect Control. 2012 Sep 21;1(1):30. doi: 10.1186/2047-2994-1-30.
To guide policy and control measures, decent scientific data are needed for a comprehensive assessment of epidemiological, clinical and virological characteristics of the First Few hundred (FF100) cases. We discuss the feasibility of the FF100 approach during the 2009 pandemic and the added value compared with alternative data sources available.
The pandemic preparedness plan enabled us to perform a case-control study, assessing patient characteristics and risk factors for experiencing symptomatic influenza A(H1N1)2009 infection and providing insight into transmission. We assessed to what extent timely and novel data were generated compared to other available data sources.
In May-December 2009, a total of 68 cases and 48 controls were included in the study. Underlying non-respiratory diseases were significantly more common among cases compared to controls, while a protective effect was found for frequent hand washing. Seroconversion was found for 7/30 controls (23%), and persisting high titers for 4/30 controls (13%). The labour-intensive study design resulted in slow and restricted recruitment.
The findings of our case-control study gave new insights in transmission risks and possible interventions for improved control. Nevertheless, the FF100 approach lacked timeliness and power due to limited recruitment. For future pandemics we suggest pooling data from several countries, to enable collecting sufficient data in a relatively short period.
为了指导政策和控制措施，需要有良好的科学数据，才能全面评估 2009 年大流行中最初数百例（FF100）病例的流行病学、临床和病毒学特征。我们讨论了在 2009 年大流行期间采用 FF100 方法的可行性，以及与其他可用数据源相比的附加值。
大流行防范计划使我们能够开展病例对照研究，评估出现有症状的甲型 H1N1 2009 流感感染的患者特征和危险因素，并深入了解传播情况。我们评估了与其他可用数据源相比，及时和新颖的数据生成程度。
2009 年 5 月至 12 月期间，共纳入 68 例病例和 48 例对照。与对照组相比，病例组中存在潜在的非呼吸道疾病明显更为常见，而经常洗手则具有保护作用。30 名对照者中有 7 人（23%）出现血清转化，4 人（13%）的持续高滴度。劳动密集型的研究设计导致招募缓慢且受限。
我们的病例对照研究结果提供了有关传播风险和可能的干预措施的新见解，以改善控制效果。然而，由于招募人数有限，FF100 方法缺乏及时性和效力。对于未来的大流行，我们建议从几个国家汇集数据，以便能够在相对较短的时间内收集足够的数据。
