Janet E. Stout, PhD


Legionella.org provides educational resources for anyone who has been affected by Legionnaires' disease. A nonprofit organization, we provide comprehensive answers to those who are living with the disease, clinicians, to water treatment professionals and others. Founded by internationally recognized authorities in Legionnaires' disease, Legionella.org advocates a proactive approach to prevention. Our information is based on more than 30 years of clinical and environmental research. We share our research for the sole purpose of preventing illness and death.

Janet E. Stout, PhD


Research Associate Professor
University of Pittsburgh Swanson School of Engineering, Department of  Civil and Environmental Engineering
President, Microbiologist, and Director Special Pathogens Laboratory



Dr. Janet E. Stout is the president and director of the Special Pathogens Laboratory, and a research associate professor at the University of Pittsburgh Swanson School of Engineering in the Department of Civil and Environmental Engineering.

A clinical and environmental microbiologist, Dr. Stout is internationally recognized for more than 30 years of research in Legionella-the bacteria that causes Legionnaires' disease. She is credited as the first to demonstrate the link between Legionnaires' disease and the presence of Legionella in hospital water systems.

Her 1982 discovery, published in the New England Journal of Medicine, radically shifted the focus away from cooling towers to water distributions systems as the primary source for  Legionnaries' disease, which fundamentally changed the direction of research and the water treamement industry's approach to disinfection.  For her contributions, the Association of Water Technologies (AWT) awarded Dr. Stout the Ray Baum Award for Water Technologist of the Year for "outstanding contribution to the field of water treatment in improving the understanding of Legionella in industrial water systems."

Dr. Stout's contiuned research in Legionnaires' disease in water systems of homes,
buildings, hospitals, hotels and utility water systems has also been published in medical and scientific peer-reviewed journals. She co-authors the "Legionella" chapter published in Hospital Epidemiology and Infection Control, the Manual of Clinical Microbiology, and UpToDate.com. Currently, on the editorial board of Infection Control and Hospital Epidemiology, Dr. Stout has also served on editorial boards of the International Journal of Environmental Health, the Journal of Clinical Microbiology, and Water Research.

An authoritative source for information on prevention, detection, and control of Legionnaires' disease, Dr. Stout was instrumental in developing the first U.S. prevention strategy for hospital-acquired Legionnaires' disease that now serves as the model for national Legionella guidelines. In addition, Dr. Stout serves on the Legionella standards committees for the America Society of Heating, Refrigerating and Air-Conditioning Engineers' (ASHRAE) Standards 12 and the proposed Legionella standard.

An invited speaker to international and national scientific and professional organizations, Dr. Stout is a member of the American Society for Microbiology, the AWT, the Association for Professionals in Infection Control, the Cooling Technology Institute, and ASHRAE.

Dr. Stout holds a master's degree and PhD in infectious disease microbiology from the University of Pittsburgh, and a BS in biology from Clarion University.



  • Distinguished Research Award for Legionnaires' Disease, National American Legion, 1982.
  • Divisional Lecturer, Nosocomial Infection, American Society for Microbiology, Miami Beach, 1988.
  • Divisional Lecturer, Waterborne Nosocomial Infections, Interscience Conference on Antimicrobial Agents and Chemotherapy, San Diego, CA, 1998.
  • Association of Water Technologies, Water Technologist of the Year, 1999.
  • America Society of Heating, Refrigeration and Air Conditioning Engineers (ASHRAE) Poster Presentation Award, 2002.
  • American Water Works Association Water Quality Conference Poster Presentation Award, 2002.
  • Invited speaker, European Working Group on Legionella Infections (EWGLI), Chamonis, France, 2004
  • Divisional Lecturer, Environmental Aspects of Legionnaires' Disease, 6th International Legionella Symposium, Chicago, IL 2005
  • 2012 Urban Innovation 21 Leadership Award
  • 2012 Distinguished Alumni Award Clarion University


Selected Publications

  • Lin YE, Stout JE and Yu VL. Controlling Legionella in Hospital Drinking Water: An Evidence-Based Review of Disinfection Methods Infection Control and Hospital Epidemiology
    2011 32(2):166-173.
  • Biosafety in Microbiological and Biomedical Laboratories  (BMBL) 5th Edition  U.S. Department of Health and Human Services Centers for Disease Control and Prevention and National Institutes of Health Fifth Edition, Feb 2007.
  • Janet E. Stout, Ph.D. is the author of the newly revised Legionella "Agent Summary" in the 5th Edition of the CDC "Biosafety in Microbiological and Biomedical Laboratories (BMBL)".
  • Drenning SD, Joly JR, JE Stout, Yu, VL. Unexpected similarity of pulsed-field gel electrophoresis patterns of unrelated clinical isolates of Legionella pneumophila, serogroup 1.  J Infect. Dis 183:628-632, 2001.
  • Stout JE, Yu VL.  Legionella in the hospital water supply: a plea for decision-making based on evidence-based medicine.  Infection Control and Hosp. Epid. 22 (11): 670-672, 2001.
  • Singh N, Stout JE, Yu VL.  Legionnaires' disease in a renal transplant recipient: nosocomial or home-grown?  Transplantation 2002; 76(6): 755-756.
  • Lin YE, Vidic RD, Stout JE, Yu VL.  Negative effect of high pH on biocidal efficacy of copper and silver ions in controlling Legionella pneumophila.  J. Appl. Environ. Microbiol.; 68(6); 2711-2715, 2002.
  • Pedro-Botet ML, Stout JE, Yu VL.  Legionnaires' disease contracted from patient homes: the coming of the third plague?  Eur J Clin Microbiol Infect Dis 2002; 21:699 705
  • Squier C, Rihs JD, Risa KJ, Sagnimeni A, Wagener MM, Stout J, Muder, RR, Singh N. Staphylococcus aureus rectal carriage and its association with infections in patients in a surgical intensive care unit and a liver transplant unit.  Infect Cont Hosp Epidemiol 2002; 23: 495-501.
  •  Lin YE, Vidic RD, Stout JE, Yu VL.  Negative effect of high pH on biocidal efficacy of copper and silver ions in controlling Legionella pneumophila.  J. Appl. Environ. Microbiol.; 68(6); 2711-2715, 2002.
  • Stout JE, Yu, VL.   Experience of the first 16 hospitals using copper-silver ionizaton for Legionella control: implications for the evaluation of other disinfection modalities.  Infection Control Hosp. Epid. 2003; 24(8): 563-568.
  • Stout JE, Yu, VL.  Hospital-acquired Legionnaires' disease: new developments.  Curr Opin Infect Dis 2003; 16(4):337-341.
  • Kwak EJ, Husain S, Obman A, Meinke L, Stout JE, Kusne S, Wagener MM, Singh N. Efficacy of galactomannan antigen in the platelia Aspergillus enzyme immunoassay for diagnosis of invasive aspergillosis in liver transplant recipients. J. Clin. Microbiol. 2004;42(1): 435-438.
  • Sidari FP, Stout JE, VanBriesen JM, Bowman AM, Grubb D, Neuner A, Wagener MM,  Yu VL.  Chlorine dioxide as a disinfection method for Legionella control.  J Amer Water Works Assoc. 2004; 96: 111-119.
  • J.E. Stout and R.R. Muder.  Legionella in Residential Water Systems.  ASHRAE Journal. 2004 ; 46 :52-54.
  • Yu VL,  Greenberg, RN, Zadeikis, N, Stout, JE, Kashab MM, Olson WH, Tennenberg AM,.  Levofloxacin efficacy in the treatment of community-acquired Legionellosis.  Chest 2004; 125:2135-2139.
  • Stout, JE and Muder, RR.  Legionella in Residential Water Systems.  ASHRAE Journal. 2004 ; 46 : 52-54.
  • Stout, JE, Sens K, Mietzner S, Obman A, Yu, VL.  Comparative activity of quinolones, macrolides, and ketolides against Legionella species using in vitro broth dilution and intracellular susceptibility testing. Int J Antimicrob Agents 2005; 25:302-307.
  • Squier CL, Stout JE, Krystofiak S, McMahon J, Wagener MM, Dixon B. Yu VL.  A proactive approach to prevention of healthcare-acquired Legionnaires' disease:  the Allegheny County (Pittsburgh) experience.  Am. J. Infect. Control 2005; 33(6): 360-367.
  • Sheffer PJ, Stout JE, Wagener MM, Muder RR.  Efficacy of new point-of-use filter for preventing exposure to Legionella and waterborne bacteria.  Am. J. Infect. Control. 2005; 33(5) Suppl. 1: S20-S25.
  • Muder RR, Brennen C, Rihs JD, Wagener MM, Obman A, Stout JE, Yu VL.  Isolation of Staphylococcus aureus from urinary tract: association of isolation with subsequent staphylococcal bacteremia.  Clin Infect Dis 2006; 142(1): 46-50.
  • Stout JE, Muder RR, Mietzner S, Wagener MM, et al.  Role of environmental surveillance in determining risk for hospital-acquired Legionnaires' disease: a national survey with clinical correlations.  Infect Control Hosp Epidiol. 2007 (In Press).