The French Health Protection Agency (InVS) warns against Legionella outbreaks

In an official statement dated July 2004, the French Health Protection Agency called for vigilance with regards to the risk of Legionella outbreaks during summer 2004. In 2003, 1044 legionella cases were recorded in France and 129 patients died. Moreover, more than half of these cases occurred during summer. This call for vigilance was consolidated by information disseminated during the 19th session of the European Working Group on Legionella Infections (EWGLI), where a British speaker had stressed that a clear increase in the number of cases declared this year was expected due to improvement of the diagnostics and recording circuits. In Europe, the threshold of 5000 cases declared could be exceeded, which represents a clear increase compared with the 1242 cases declared in 1993. Legionella are often present, at low concentrations, in natural water sources. Contamination occurs through the respiratory tract, by inhalation of contaminated water droplets. There are many sources of contamination, including cooling towers, but a major source is the water distribution systems in large buildings such as hotels and hospitals. Nevertheless, often, the source is not identified. The implementation of suitable control measures depends on rapid detection and description of cases.