Sporadic community-acquired Legionnaires' disease in France: a 2-year national matched case-control study

Epidemiol Infect. 2008 Dec;136(12):1684-90. doi: 10.1017/S0950268807000283. Epub 2008 Jan 23.


Legionnaires' disease (LD) is an aetiology of community-acquired bacterial pneumonia in adults, with a high case-fatality ratio (CFR). We conducted a matched case-control study to identify risk factors for sporadic, community-acquired LD. Cases of sporadic, community-acquired and biologically confirmed LD, in metropolitan France from 1 September 2002 to 31 September 2004, were matched with a control subject according to age, sex, underlying illness and location of residence within 5 km. We performed a conditional logistic regression on various host-related factors and exposures. Analysis was done on 546 matched pairs. The CFR was 3.5%. Age ranged from 18-93 years (mean 57 years), with a 3.6 male:female sex ratio. Cases were more likely to have smoked with the documentation of a dose-effect relation, to have travelled with a stay in a hotel (OR 6.1, 95% CI 2.6-14.2), or to have used a wash-hand basin for personal hygiene (OR 3.5, 95% CI 1.6-7.7) than controls. Tobacco and travel have been previously described as risk factors for LD, but this is the first time that such a dose-effect for tobacco has been documented among sporadic cases. These findings will provide helpful knowledge about LD and help practitioners in identifying patients at high risk.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Case-Control Studies
  • Community-Acquired Infections / epidemiology
  • Environment
  • Female
  • France / epidemiology
  • Humans
  • Legionnaires' Disease / epidemiology*
  • Leisure Activities
  • Male
  • Middle Aged
  • Multivariate Analysis
  • Risk Factors
  • Smoking
  • Travel
  • Young Adult