Three heater-cooler units — equipment used to heat and cool patients during heart surgery — tested positive for Legionella bacteria at the University of Washington Medical Center in Seattle, according to a statement from UW Medicine. The news comes after the bacteria infected four patients at the hospital, causing a type of pneumonia known as Legionnaires' disease. Two of the infected patients have died.
The source of the outbreak has been linked to the hospital's water system as bacteria was detected in an ice machine and two sinks in UW Medical Center's cardiac unit in its Cascade Tower. The water system in the Cascade Tower was scheduled to be treated with a high dose of chlorine on Monday evening.
Regarding the possible role of the equipment in the infections, Tina Mankowski, a UW Medicine spokeswoman, said, "Legionnaires' disease has not been previously proven to be transmitted in this fashion." Ms. Mankowski's remarks were made in a statement on Monday, according toThe Seattle Times.
Though the water used to run the heater-cooler units does not come into direct contact with patients, the equipment has been linked to other outbreaks involving pathogens like nontuberculous mycobacteria.
Of the four patients infected at UW Medical Center, two had surgeries involving the heater-cooler units. Similar to certain medical scopes, the design of the heater-cooler devices may prevent thorough disinfection, according to Lawrence Muscarella, PhD, a patient-safety advocate and infection-control consultant.
"These heater-coolers are being used all over the country," Dr. Muscarella told the Seattle Times. "There are literally tens of thousands of people at risk now of having been exposed to NTM and Legionella."
More articles on infection control:
Mumps cases confirmed at 2 SUNY campuses
Legionnaires' disease outbreak in Minnesota town infects 12
Aspirus Wausau Hospital warns patients of whooping cough exposure