Factors Associated with Post-Seasonal Serological Titer and Risk Factors for Infection with the Pandemic A/H1N1 Virus in the French General Population

The CoPanFlu-France cohort of households was set up in 2009 to study the risk factors for infection by the pandemic influenza virus (H1N1pdm) in the French general population. The authors developed an integrative data-driven approach to identify individual, collective and environmental factors associated with the post-seasonal serological H1N1pdm geometric mean titer, and derived a nested case-control analysis to identify risk factors for infection during the first season. This analysis included 1377 subjects (601 households). The GMT for the general population was 47.1 (95% confidence interval (CI): 45.1, 49.2). According to a multivariable analysis, pandemic vaccination, seasonal vaccination in 2009, recent history of influenza-like illness, asthma, chronic obstructive pulmonary disease, social contacts at school and use of public transports by the local population were associated with a higher GMT, whereas history of smoking was associated with a lower GMT. Additionally, young age at inclusion and risk perception of exposure to the virus at work were identified as possible risk factors, whereas presence of an air humidifier in the living room was a possible protective factor. These findings will be interpreted in light of the longitudinal analyses of this ongoing cohort.

科潘流感-法国家庭队列（CoPanFlu-France cohort）于2009年建立，旨在探究法国普通人群感染甲型H1N1流感大流行病毒（H1N1pdm）的相关危险因素。研究团队开发了整合性数据驱动方法，以识别与季后血清学H1N1pdm几何平均滴度（geometric mean titer，GMT）相关的个体、群体及环境因素；同时采用嵌套病例对照分析，明确首季流感感染的危险因素。本次分析共纳入1377名研究对象，涉及601个家庭。普通人群的GMT为47.1（95%置信区间（confidence interval，CI）：45.1~49.2）。经多变量分析发现，大流行流感疫苗接种、2009年季节性流感疫苗接种、近期流感样疾病史、哮喘、慢性阻塞性肺疾病、校内社交接触以及当地居民乘坐公共交通的行为与更高GMT显著相关；而吸烟史则与较低GMT相关。此外，研究纳入时年龄偏小以及工作中接触病毒的风险感知被确定为潜在危险因素；而客厅配备空气加湿器则为潜在保护因素。上述研究结果将结合该正在进行的队列研究的纵向分析结果进一步阐释。