Tribune-Review, August 22, 2007

National infection control policies should be changed to include regular testing of hospital water systems for bacteria that cause a particularly deadly form of pneumonia, according to a study led by the University of Pittsburgh School of Medicine.

Pitt announced today that a 20-hospital study showed that monitoring institutional water systems can help predict the risk of hospital-acquired Legionella pneumonia, better known as Legionnaires’ disease. The disease was named after it was identified as causing an outbreak of pneumonia in 1976 among attendees at an American Legion convention in Philadelphia.

“Only those hospitals that had high levels of Legionella bacteria in their water systems had patients who contracted Legionnaires’ disease,” Dr. Victor L. Yu, professor of medicine at Pitt and senior author of the study, published in the journal Infection Control and Hospital Epidemiology, said in a statement. “Proactive monitoring of the hospital water supply alerted physicians to the hidden risk of Legionnaires’ disease for their patients.”

Currently the U.S. Centers for Disease Control and Prevention recommends that hospitals and other health care institutions monitor patients for pneumonia before testing water systems for Legionella.

Legionnaires’ has an average fatality rate of 28 percent and is estimated to be responsible for up to 20,000 cases each year in the United States. Pitt’s study involved hospitals in 14 states. Researchers retrieved water samples from at least 10 sites at each hospital on multiple occasions from 2000 to 2002. When cases of Legionnaires’ were identified, patients were tested.

The researchers found that 70 percent of the hospital water systems tested positive for Legionella and 43 percent had high levels of bacteria colonization. All patient cases of Legionnaires’ were traced back to the hospitals with high-level colonization.

“Our study provides much-needed evidence to support a national policy change to include routine environmental surveillance of health care facility water systems along with stringent clinical monitoring of patients,” Janet Stout, a research assistant professor in Pitt’s department of civil and environmental engineering and first author of the paper, said in a statement. “We think this long-overdue approach should be adopted by infection control and infectious disease practitioners nationwide.”