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DRINKING WATER AND LEGIONNAIRES' DISEASE
Citation:
Dufour, A. AND W. Jakubowski. DRINKING WATER AND LEGIONNAIRES' DISEASE. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/D-82/285 (NTIS PB82239302).
Description:
Pneumonia outbreaks caused by Legionella species recently have been epidemiologically linked to potable water distribution systems in hospitals and hotels. Showerheads were confirmed as the immediate source of the Legionella in many of the outbreaks, however, the organism also was isolated from other parts of the water distribution systems, such as water taps and storage tanks. Legionella also have been isolated from building water distribution systems in the absence of the disease and this has led to questions about the need to disinfect all systems in which the organism is found. In disease outbreak situations, where the requirement for disinfection is appropriate, chlorination appears to be the method of choice. Chlorine 'shock' treatment (50 mg/L free chlorine for short periods) followed by continuous chlorination (1-2 mg/L free chlorine) was effective for eliminating Legionella from plumbing systems. High temperature (60C for 72 hours) was partially effective for removing most of the Legionella for 1 to 2 month periods. Ozone and ultraviolet irradiation were not effective. The role of potable water as a vehicle for the transmission of Legionella species is ambiguous, since the organisms have not been isolated from mains delivering water to buildings whose potable water plumbing systems have yielded the organism. Recommendations for the control of Legionella that are consistent with the current state of our knowledge of this pathogen are discussed.