Legionnaires' disease in long-term care facilities: overview and proposed solutions.

Pneumonia is a leading cause of morbidity and mortality in nursing home patients. In acute care hospitals, there is considerable evidence to indicate that Legionnaires' disease is a significant cause of nosocomial pneumonia, the source of which is the potable water system. A relatively limited amount of data exists as to the role of Legionnaires' disease as a cause of pneumonia acquired in long-term care residents. Several lines of evidence suggest that Legionnaires' disease may be an important but underrecognized cause of pneumonia in long-term care residents. These include reports of outbreaks, prospective studies of community-acquired pneumonia that include nursing home patients, and prospective studies of individual long-term care facilities linking Legionnaires' disease to colonization of the potable water system with Legionella. Multiinstitutional studies combining environmental and clinical surveillance for Legionella are needed to further confirm the relationship between colonization of potable water and the occurrence of disease in the long-term care facilities. Until these studies are completed, it is recommended that individual facilities undertake annual sampling of the potable water system for Legionella, coupled with introduction of the rapid Legionella urinary antigen test should L. pneumophila serogroup 1 be found.