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The Illinois Department of Veterans’ Affairs and the Illinois Department of Public Health (IDPH) have confirmed an outbreak of Legionnaires’ disease in residents at the Illinois Veterans’ Home - Quincy. See IDPH’s news release and Legionnaires’ disease information.

The California Department of Corrections and Rehabilitation (CDCR), along with the Marin County Public Health Department and California Correctional Health Care Services, are continuing the investigation of the source of Legionnaires’ disease at San Quentin State Prison. See CDCR’s Legionnaires’ disease case update.

When it comes to Legionella bacteria, outbreaks occur when two or more people become ill in the same place at about the same time, such as patients in hospitals. Hospital buildings have complex water systems, and many people in hospitals already have illnesses that increase their risk for Legionella infection.

Other outbreaks have been linked to aerosol (mist) sources in the community, or with cruise ships and hotels, with the most likely sources being hot tubs, cooling towers (air-conditioning units from large buildings), and water used for drinking and showering.

Cruise ship

Processing Legionella Samples Obtained During Outbreaks

The Procedures for the Recovery of Legionella from the Environment manual describes the procedures currently used by the CDC to process environmental samples obtained during investigations of legionellosis outbreaks. It includes information on the collection and concentration of water samples, preparation of samples for bacteriologic examination, formulas for media, and sources for reagents.