Special Pathogens Laboratory was launched as an LLC in 2007.

Prior to going private, SPL was designated a special reference microbiology laboratory housed at the Pittsburgh VA Medical Center from 1981 to 2006. The initial funding for the unit was provided by VA Central Office in response to endemic hospital-acquired Legionnaires’ disease at the hospital. Hospital-acquired Legionnaires’ disease was a major problem for this healthcare system during the early 1980s; approximately 25 cases occurred per year. At this time, little was known about prevention of hospital-acquired Legionnaires’ disease and the treatment of the potable water system.

Under the direction of Victor L. Yu, MD and Janet E. Stout, PhD, who continue to lead SPL today, the interdisciplinary and cooperative efforts of the staff from Infectious Disease, Infection Control, engineering, and the Special Pathogens Laboratory, lead to measures that controlled Legionella within the potable water system resulting in the complete elimination of hospital-acquired Legionnaires’ disease.

The keystone of this effort was culturing the water distribution system for the Legionella bacteria; unfortunately, a practice currently not recommended by the Centers for Disease Control and Prevention.

Our core group of dedicated scientists took this proactive approach to controlling this waterborne pathogens to the national level. Working with infection control practitioners and the Allegheny County Health Department, we produced guidelines (the first ever in the United States) for controlling Legionella in healthcare facilities. The outcome of this proactive approach was a significant reduction in the number of cases of hospital-acquired Legionnaires’ disease in Allegheny County (Squier 2005 Am. J. Infection Control). 

Research Firsts

SPL researchers made the seminal discoveries for the Legionnaires' disease that are the standard today. Our list of clinical and environmental firsts include: 


  • Devised methods for diagnosis of Legionella

  • Identified patients who were infected

  • Described symptoms of disease

  • Designing and conducting the randomized study for FDA approval of azithromycin (Pfizer) for treatment of Legionella infections and community-acquired pneumonia.

  • Provided the laboratory support for the clinical studies that led to FDA approval of levofloxacin (Ortho-McNeil) for treatment of Legionella infections.

  • Educated healthcare providers to assess patients for LD and order appropriate tests 

  • Monitored for nosocomial LD as part of the infection control surveillance program.

  • Participated in the development of new antimicrobial therapies for Legionnaires’ disease.  


  • First to link Legionella in the hospital's potable water system with Legionnaires' disease in patients

  • Developed the formulation of selective differential media for culture isolation of Legionella, prior to that the bacteria couldn't be detected on standard media

  • Pioneered control methodologies aimed at the prevention of Legionnaires’ disease including heat and flush, chlorine, chlorine dioxide, copper-silver ionization, ultraviolet light, and monochloramine
  • Describing the transmission link between the environmental source and the patient.

  • Developing mechanisms for decontaminating the environmental source.