Navigate Up
UPMC/University of Pittsburgh Schools of the Health Sciences
Patients and medical professionals may call 1-800-533-UPMC (8762) for more information.

University of Pittsburgh Schools of the Health Sciences

​Study Finds Environmental Monitoring Helps to Predict Risk of Hospital-Acquired Legionnaires Disease

PITTSBURGH, August 22, 2007 A new study spearheaded by the University of Pittsburgh School of Medicine has determined that environmental monitoring of institutional water systems can help to predict the risk of hospital-acquired Legionella pneumonia, better known as Legionnaires disease. Reported recently in the journal Infection Control and Hospital Epidemiology, the 20-hospital study also calls for reconsideration of the current national infection-control policy to include routine testing of hospital water systems for Legionella, the bacterial group associated with Legionnaires.

Only those hospitals that had high levels of Legionella bacteria in their water systems had patients who contracted Legionnaires disease, senior author Victor L. Yu, M.D., professor of medicine at the University of Pittsburgh School of Medicine, said of the study, which involved hospitals in 14 states. Proactive monitoring of the hospital water supply alerted physicians to the hidden risk of Legionnaires disease for their patients.

Legionella bacteria first were identified as causing pneumonia in 1976 following an outbreak among attendees at an American Legion convention at a Philadelphia hotel, resulting in the name Legionnaires disease. With an average fatality rate of 28 percent, Legionnaires is estimated to be responsible for up to 20,000 cases a year in the United States, many of them hospital-acquired. Currently, the U.S. Centers for Disease Control and Prevention recommends that hospitals and other health care institutions monitor patients for pneumonia incidence before doing environmental surveillance of water systems that can harbor the bacteria.

Based in part on our work, and in collaboration with the Allegheny County Health Department and the Three Rivers Association for Professionals in Infection Control, the development of proactive guidelines for hospital-acquired Legionnaires disease prevention has led to the virtual disappearance of this infection in Pittsburgh, said study first author Janet Stout, Ph.D., research assistant professor in Pitts department of civil and environmental engineering. We first reported the connection between hospital water supply and these infections in 1982.

For this investigation, Drs. Yu, Stout and colleagues evaluated samples of hospital system water at 20 facilities across the country from 2000 to 2002. Water samples were retrieved from at least 10 separate sites at each hospital on multiple occasions over the two-year period. When cases of Legionnaires were identified, patient urine and sputum samples from 12 of the hospitals were tested to determine classification of Legionella, which has at least 48 strains.

The researchers found that 14 (70 percent) of hospital water systems tested positive for Legionella species, and that six (43 percent) positive hospitals had high-level colonization. Legionnaires cases were among the 633 patients with hospital-acquired pneumonia whose urine or sputum samples were tested for Legionella bacteria. All were traced to 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, said Dr. Stout, who estimates that 39,000 people have died of Legionnaires since 1982. We think this long overdue approach should be adopted by infection control and infectious disease practitioners nationwide.

This study was based on the Pittsburgh methodology of routine testing of hospital water systems, which also has been adopted by New York, Maryland, France, Germany, Spain, Netherlands, and Italy.

Other authors and members of the Legionella Study Group, are Robert R. Muder, M.D., Sue Mietzner, M.S., and Marilyn M. Wagener, M.S., all of the VA Pittsburgh Healthcare System; Mary Beth Perry, B.S., and Marcus J. Zervos, M.D., both of William Beaumont Hospital, Royal Oak, Mich.; Kathleen deRoos, M.S.N., Dona Goodrich, B.S., William Arnold, M.S., and Marvin Bittner, M.D., all of the VA Medical Center, Omaha, Neb.; Theresa Williamson, M.S., and Sharon L. Camhi, M.D., both of Southern Arizona Healthcare System, Tucson, Ariz.; Ola Ruark, M.S.N., and Anand P. Panwalker, M.D., both of the VA Medical Center, Wilmington, Del.; Christine Treadway, M.S.N., Elizabeth C. Eckstein, M.S.N., and Curtis J. Donskey, M.D., all of the Louis Stokes VA Medical Center, Cleveland, Ohio; Debra Marshall, R.N., VA Medical Center, Dayton, Ohio; Mary Ellen Rafferty, M.S., Stratton VA Medical Center, Albany, N.Y.; Kathleen Sarro, R.N., VA Medical Center, Butler, Pa.; Joann Page, M.S., VA Medical Center, Iowa City, Iowa; Robert Jenkins, B.A., and Minh-Hong Nguyen, M.D., both of the VA Medical Center, Gainesville, Fla.; Gina Oda, M.S., and Mark Holodniy, M.D., both of the VA Palo Alto Health Care System, California; and Kathleen J. Shimoda, R.N., VA Medical Center, Long Beach, Calif.

The study was funded by a Department of Veterans Affairs Merit Review grant.

 

©  UPMC | Affiliated with the University of Pittsburgh Schools of the Health Sciences
Supplemental content provided by A.D.A.M. Health Solutions. All rights reserved.

For help in finding a doctor or health service that suits your needs, call the UPMC Referral Service at 412-647-UPMC (8762) or 1-800-533-UPMC (8762). Select option 1.

UPMC is an equal opportunity employer. UPMC policy prohibits discrimination or harassment on the basis of race, color, religion, ancestry, national origin, age, sex, genetics, sexual orientation, marital status, familial status, disability, veteran status, or any other legally protected group status. Further, UPMC will continue to support and promote equal employment opportunity, human dignity, and racial, ethnic, and cultural diversity. This policy applies to admissions, employment, and access to and treatment in UPMC programs and activities. This commitment is made by UPMC in accordance with federal, state, and/or local laws and regulations.

Medical information made available on UPMC.com is not intended to be used as a substitute for professional medical advice, diagnosis, or treatment. You should not rely entirely on this information for your health care needs. Ask your own doctor or health care provider any specific medical questions that you have. Further, UPMC.com is not a tool to be used in the case of an emergency. If an emergency arises, you should seek appropriate emergency medical services.

For UPMC Mercy Patients: As a Catholic hospital, UPMC Mercy abides by the Ethical and Religious Directives for Catholic Health Care Services, as determined by the United States Conference of Catholic Bishops. As such, UPMC Mercy neither endorses nor provides medical practices and/or procedures that contradict the moral teachings of the Roman Catholic Church.

© UPMC
Pittsburgh, PA, USA UPMC.com