A Legionnaires’ disease outbreak linked to UW Hospital’s water system has infected 14 people with the pneumonia-like bacteria, and three have died, a hospital official said Monday.
The deaths were of patients who had other serious, life-limiting health conditions, spokeswoman Lisa Brunette said.
One patient remains in the hospital for ongoing treatment of serious health conditions, and 10 patients have been discharged and are doing well, Brunette said.
Lab testing of three of the patients has confirmed that their strain of Legionella bacteria is the same strain previously found in the hospital’s water system, Brunette said. Other patients could not provide samples for testing.
Extensive chlorination of the water system, performed last month after the outbreak was discovered, continues to work as anticipated, with tests finding the expected reduction in the bacteria, Brunette said.
Dr. Nasia Safdar, medical director of infection control at UW Hospital, said last month that the outbreak appeared to be linked to a decision to reduce water flow at the hospital during low-demand times. That can make the water system more vulnerable to infectious bacteria, she said. Regular flow has resumed, she said.
Legionnaires’ spreads in airborne droplets from hot water. The bacteria, which can be found at low levels in tap water, is mostly problematic for people with chronic diseases or who are already ill.
Until last month, UW Hospital hadn’t had any cases of Legionnaires’ acquired at the hospital in 23 years, hospital officials said. Safdar attributed that to a copper-silver ionization system that disinfects the water.
Nationwide, about 6,100 cases of Legionnaires’ disease were reported in 2016, according to the Centers for Disease Control and Prevention. That figure is likely an underestimate, as many cases go undiagnosed.
About one in 10 people who get sick from Legionnaires’ disease will die, the CDC says. Among people infected at hospitals, nursing homes and other health care facilities, roughly one in four will die.
Legionnaires’ is named for a 1976 outbreak at an American Legion convention in Philadelphia that hospitalized more than 200 people and killed 34.