Janet Stout, PhD. – Legionella Issues and Answers

Air Date: 1-25-2013| Episode: 271

Dr. Janet E. Stout is director of 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…

Full Description:

Dr. Janet E. Stout is director of 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 pioneering research in Legionella.

Credited as the first to demonstrate the link between Legionnaires’ disease and the presence of Legionella in hospital water systems, her seminal discovery in 1982, shifted the focus from cooling towers to water distributions systems as the primary source for Legionnaires’ disease. This changed the direction of research and expanded the water treatment industry’s approach to controlling Legionella. Since then, Dr. Stout has evaluated every major Legionella disinfection technology used today.

An advocate for prevention, Dr. Stout was instrumental in developing the first U.S. prevention strategy for hospital-acquired Legionnaires’ disease in 1993. Later adopted by the Veteran’s Health Administration and others, the guideline continues to serve as a national model for Legionella prevention.

In addition to Dr. Stout’s numerous research articles published in major medical and scientific peer-reviewed publications, she co-authors the Legionella chapter in Hospital Epidemiology and Infection Control , Harrison’s Principles of Internal Medicine, and the Manual of Clinical Microbiology.

Active in scientific and professional associations, Dr. Stout serves on the Legionella standard committee for the Cooling Technology Institute and on the American Society of Heating, Refrigerating and Air Conditioning Engineer’s committees for Legionella Guideline 12 and the proposed ASHRAE Legionella standard.


Z-Man’s Blog

There’s no doubt, Dr. Stout, knows much about, Legionella

Dr. Janet Stout, is a clinical and environmental microbiologist who is internationally recognized for her pioneering research in Legionella. Her pioneering work shifted the focus from cooling towers to water distribution systems as the primary source for Legionnaire’s disease.

Nuggets mined from today’s interview:

•Legionella is a gram negative bacteria found in warm water.

•Legionella can be inhaled and/or ingested by aspiration and micro-aspiration.

•Legionella came to prominence with the Philadelphia outbreak, in which 100+ became ill and 34 died. Legionnaire’s disease isn’t a new illness, rather a newly identified illness, CDC has identified the organism in tissue samples from the 1940s.

•The Philly outbreak occurred in July; the VA Pittsburgh investigation took place in the winter so Dr. Victor Yu and Dr. Stout searched beyond the water cooling system.

•Legionella was found in 50% of hospitals studied. Legionella was only found in 15%-20% of homes studied.

•Gas fired hot water tanks are more resistant to Legionella colonization than those with electric elements.

•Research into Legionella was hampered until an isolation media was developed.

•Legionella occurs naturally and is found in very low levels in lakes and rivers.

•Think of Legionella as a family tree with over 50 species, 50% of the species are linked to disease, the “bad actor” is legionella pneumophila serogroup 1.

•Legionella enters buildings through fresh water intake. Legionella colonizes in biofilm on warm water. Legionella colonize amoeba.

•Legionella cohabit with other bacteria in biofilm. Biofilms are structured communities of bacteria that are held together by an extracellular matrix consisting of protein and exopolysaccharide. Legionella can be found both intracellular and extracellular.

•Legionella is transported through water system. Plastic plumbing pipe is more hospitable to biofim than copper pipe. Legionella feed upon sediment.

•Legionella is more resistant to chlorine water disinfection, virtually undetectable at low levels and at low water temperatures.

•Misconceptions, both the compromised and uncompromised are susceptible to Legionnaire’s disease. Almost 1/4th of cases are found in uncompromised individuals.

•There is up to 30 to 40% mortality rate among nosocomial Legionnaire’s disease cases, according to some studies.

•All water disinfection systems have pros, cons and limitations. It is important to monitor both Legionella and the disinfectant.

•90% of cases of Legionella are unreported.

•Diagnosis of Legionnaire’s disease requires urine test for antigen or culture of secretions.

•While it is assumed by health authorities that a water treatment plant’s filtration and chlorination will control Legionella, Legionella becomes the building owners responsibility when water enters the building.
Reference resources:

Today’s Music: YouTube Salmonella (Klebsiella, Legionella) GNR

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