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Summary of Legionnaires' disease cases in France in 2014In 2014, 1,348 cases of Legionnaires' disease were reported through the notifiable disease reporting system in France. The incidence rate in mainland France was 2.0 per 100,000 inhabitants. The number of cases in 2014 was slightly higher than in 2013, when 1,262 cases were reported.The “west-to-east” geographic gradient in the incidence rate of reported Legionnaires’ disease cases remained pronounced, and the highest age- and sex-standardized incidence in 2014 was found in Franche-Comté at 4.6 per 100,000 inhabitants, with Burgundy ranking third among regions at 3.1 per 100,000 inhabitants. The median age of cases was 63 years [min-max: 9–102 years], and the male-to-female ratio was 2.7. Incidence increased with age. The majority (67%) of cases occurred during the second half of the year, with a peak in July and August. Only 17 cases (1%) were not hospitalized. The disease course was known for 95% of cases, and the case fatality rate was 9.5% (122 deaths), significantly lower than in 2013 (12.2%, p < 0.03). The median time between the onset of initial clinical symptoms and notification to the Regional Health Agency (ARS) was 6 days. Ninety-eight percent of cases were confirmed, and detection of soluble urinary antigens was the primary diagnostic method used. The majority of cases (97.5%) involved Legionella pneumophila serogroup 1 (Lp1) (1,305/1,339). In 25.3% of cases (n=341), a strain was isolated, a percentage identical to that of 2013 (25.6%). The majority (98% = 334/341) were L. pneumophila strains, including 314 Lp1 and 20 belonging to other serogroups. Although a slight increase in the number of Legionnaires' disease cases was observed in 2014 compared to 2013, this report shows overall stability in the data. The "west-east" geographic gradient in incidence rates observed in recent years is currently the subject of a multifactorial study that could help explain these disparities in Legionnaires' disease incidence across the region. It is important that the proportion of cases in which strains are isolated continues to increase in order to improve our ability to identify sources of contamination and document clusters of cases. This proportion in Burgundy remains below the national average, with only 16% of cases in which a strain was isolated, whereas in Franche-Comté it is above the national average at 42%.