Travel-associated Legionnaires disease in Europe in 2009.

A total of 818 cases of Legionnaires' disease with onset of illness in 2009 were reported from 22 European and two non-European countries to the European Surveillance Scheme for Travel-Associated Legionnaires' Disease (EWGLINET). This is a decrease of 52 cases compared with 2008 and 129 fewer than in 2007 - the peak year of reporting to date. A total of 794 (97.1%) cases were reported as confirmed and 24 as presumptive cases. Outcome of illness was reported for 561 (68.6%) cases. Of these cases 28 (5%) were reported to have died. More than half, of the cases in 2009 (n=469, 57.3%) were reported within 20 days of symptom onset. Cases visited 53 countries and were infected in all months of the year, with a peak in September (n=146). By country of residence of the cases, the United Kingdom (UK) reported the highest number of cases (n=173). Italy reported the second highest number of cases (n=169) and was also the country associated with the most cases by country of infection (n=209). A total of 88 new clusters (75 in Europe and 13 outside Europe) were detected in 2009 and were associated with 196 cases. The largest cluster occurred in Italy and involved seven cases. Without the scheme's international database, thirty three (37.5%) of the newly detected clusters would not have been identified. In 49 of the accommodation sites with clusters of cases, environmental samples were found to be positive for Legionella spp. Details of 10 sites were published on the European Working Group for Legionella Infections (EWGLI) website for failure to return information on the status of environmental investigations.