Legionella infection and control in occupational and environmental health

This review describes the microbiological characteristics of Legionella species, their habits in the environment, source and route of infection, pathogenesis, symptoms and treatment of legionellosis, and disease outbreaks worldwide. We also describe prevention measures to deal with this organism in the work environment. Particularly in Japan, the present measures and countermeasures against legionellosis are inadequate when compared with those Europe and the United States because occupational and environmental medicine in Japan has not been structured from a microbiological viewpoint. As a result, workplace inspections have not covered cooling towers. We surveyed the cooling towers provided in work environments and in hospitals in Kitakyushu City for contamination by Legionella species. The surveillance definitely revealed that we are surrounded by cooling towers contaminated with Legionella. We conclude that in Japan, occupational and environmental physicians should routinely monitor the water in cooling towers.