• Legionnaires' Kills Pittsburgh VA Hospital Patient

    December 01, 2012

    Dr. Yu and Dr. Stout believe that this outbreak occurred because since they left the VA, the water treatment system there that had worked so well for so long was mismanaged.

    Dr. Stout said prior to this current outbreak, there was not one case of Legionnaires' disease at the University Drive hospital that was confirmed as being acquired in the hospital since 1997.

    That was four years after she and Dr. Yu had a copper-silver ionization system installed to treat the hospital's water. Two weeks ago the VA declared that the outbreak was due to the failure of the copper-silver system and it was switching to a chlorination system favored by the CDC.

  • Legionella in Nursing Homes and Long-Term Care Facilities

    November 24, 2012

    Drs. Victor L. Yu and Stout most recent publication appeared in the latest issue of the Scandanaivan Journal of Infectious Diseases. In their editorial comment, Legionellosis in nursing homes and long-term care facilities: What the Slovenian experience can teach us, Drs.Yu and Stout note attention is too often focused on aerosol devices and cooling towers when culturing drinking water is the key to finding the true source of Legionella. Plumbing myths and facts regarding Legionella are also explored. Contact us for a copy of the editorial.

  • 5th Case of Legionnaires' Reported at Hospital in Oakland

    November 24, 2012

    The VA Pittsburgh Healthcare System on Thursday confirmed another case of Legionnaires' disease, making it the fifth case tied to an outbreak of the pneumonia-like infection that was spread through the water system at its University Drive Hospital in Oakland.

    Legionnaires' cases are not unheard of in Western Pennsylvania. But the location of this outbreak has grabbed the attention of the medical community because it is the same hospital that used to be home to Victor Yu and Janet Stout, researchers who made many landmark findings about the disease -- including the 1982 discovery that tied the spread of the disease to water systems.

    "It is surprising," said Norman Moore, director of scientific affairs for Maine health products manufacturer Alere Inc. and a Legionnaires' researcher for 17 years. "They're the ones who put together how to find Legionnaires' with testing and other discoveries."

    Dr. Stout and Dr. Yu also contend that the outbreak could have been avoided if the VA had better monitored its copper-silver ionization system, a water disinfection method first installed at the University Drive hospital in 1993 specifically to prevent Legionnaires' disease.

    "The system wasn't performing optimally because it wasn't being managed properly," said Dr. Stout, a Legionnaires' expert who used to work in the VA's laboratory and resigned in 2007 in a dispute with VA's management. Dr. Yu was ousted in 2006 by the VA in that dispute. "I don't take it lightly that veterans at the VA have been harmed needlessly," she said. "It's very preventable."

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  • Legionella and Waterborne Pathogens: What's in Your Reclaimed Water

    May 01, 2012

    Watch Dr. Janet Stout's presentation, Legionella and Waterborne Pathogens: What's in Your Reclaimed Water? at International Association of Plumbing and Mechanical Officials (IAPMO), May 2012.

  • Wet Weather Spawns More Legionnaires' Disease Cases

    October 20, 2011

    According to Dr. Janet Stout "...I've not seen a spike like this that can be explained other than these recent weather events. I've been in touch with public health officials and microbiologists in Ohio, Pennsylvania, and New York and they're all stating the same thing.  Basically that there's been a spike in reported cases of Legionnaires Disease that they haven't seen in the history of reporting."

    Stout concedes that some of the increase may come from doctors diagnosing it better.  But she doubts that explains the whole spike.

    "One thing we've seen over the last several years is this pattern where there's an increased number of cases after these weather events...legionella the bacteria comes into buildings in the incoming cold water.  Legionella are more resistant to the chemicals like chlorine that are in water.  So when you have these water events you might see an increase in the turbidity of water so more nutrients are in the water and legionella takes advantage of that situation to multiply."

    Stout says over her decades of study, she's chagrined to still be talking about basic preventive measures.

    "One of things that I feel very strongly about is that hospitals should be looking to improve the quality of their water so that legionella and other water-borne pathogens are not a threat to those patients...What we would like to see is that water is tested for legionella before any cases occur."

  • Rain, flooding likely led to spike in Legionnaires' disease

    October 17, 2011

    Reports of Legionnaires' disease follow heavy rains.

    According to Janet Stout, director of the Special Pathogens Laboratory in Pittsburgh, legionella bacteria is largely resistant to the chlorine that's used in public water systems to treat water before it is pumped into homes and businesses.

    When heavy rains swamp public water systems, more nutrients and sediments get in the water systems, "so more of the water gets past the gates of disinfectants," she said.

    It didn't help that September temperatures remained warm, since legionella thrive in temperatures of 90-110 degrees, said Stout, whose laboratory bills itself as "The Legionella Experts."

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  • Rapid Climb in Legionnaires' Disease Worries Experts

    September 20, 2011

    Cases of Legionnaire’s disease—a potentially fatal illness caused by waterborne bacteria—have nearly tripled over the past decade, according to a new report from the Centers for Disease Control and Prevention (CDC). This dramatic rise is unprecedented, and scientists aren’t sure why reported cases have increased recently.

    “The bottom line is we’re concerned,” said Dr. Lee Hampton, a medical epidemiologist with the CDC and co-author of the report. “Water consumers and providers need to take preventative measures to protect against this disease.”

    Legionella bacteria cause Legionnaire’s disease and the lesser-known Pontiac fever. Most cases of these two diseases, collectively known as legionellosis, are associated with exposure to contaminated drinking water. While Pontiac fever is uncommon and relatively benign, Legionnaire’s disease is a more serious condition producing pneumonia, high fever and cough. Legionellosis affects between 8,000 and 18,000 people every year nationally, and it is responsible for nearly one third of all outbreaks associated with drinking water.

    The bacteria’s name stems from a 1976 outbreak affecting attendees of an American Legion convention in Philadelphia. Although the bacteria are predominantly found in health care facilities, outbreaks have occurred in apartment complexes, gyms, and hotels. Immuno-compromised patients, the elderly and those with chronic lung disease share an increased risk for infection, but about 20 percent of Legionnaire’s patients are otherwise healthy individuals.

    Reported cases of the disease remained nearly constant during the 1980s and 1990s, suggesting the increase over the past decade may be largely due to an aging population and recent improvements in detection of the disease. Simpler tests for Legionnaire’s disease have proliferated over the past two decades, allowing doctors to more easily distinguish this disease from other forms of pneumonia. Urine antigen tests have become the staple. Between 2005 and 2009, urine antigen tests were used to confirm more than 95 percent of the CDC’s reported cases compared to roughly 70 percent in 1998.

    “A rise in diagnostic testing is the predominant cause of the observed increase in Legionnaire’s disease,” said Janet Stout of the University of Pittsburgh, a microbiologist specializing in Legionella and director of the Special Pathogens Laboratory. “That being said, it appears that environmental conditions are playing a part as well.”

    Over the past month, Stout and her colleagues have observed an uptick in Legionnaire’s cases in the Mid-Atlantic states. This uptick may be associated with recent extreme weather events, such as hurricane Irene, that compromised water quality in municipal systems.

    Environmental factors may also explain the regional variability of Legionnaire’s disease because Legionella bacteria thrive in a warm, humid environment. For instance, differing climates may explain why incidence in the Mid-Atlantic states is more than six times higher than on the West Coast.

    But geographic variability might have more to do with awareness of the disease rather than environmental factors. In the Northeast, Stout said health departments are more likely to publicize the disease, and the population is more familiar with it.

    Regardless, scientists agree that there are important steps that water utilities and consumers can take to protect against Legionella. Legionella can be particularly stubborn—even if the bacteria are undetectable at a treatment plant, they can regrow quickly in the distribution system. Effective secondary disinfectants are critical toward the elimination of Legionella in the water supply.

    Over the past few years, several utilities have seen impressive reductions in Legionella at the tap after introduction of monochloramine as a disinfectant. A CDC-funded report analyzing San Francisco Public Utilities Commission’s conversion to monochloramine found that Legionella rates dropped significantly.  Legionella was found in 72 percent of the studied buildings before the conversion, but only 9 percent of the buildings contained the bacteria after the conversion to monochloramine.

    Monochloramine may not be the answer for all utilities, however. New research has indicated that Legionella may persist even after the introduction of monochloramine into the water supply, according to Stout.

    “Early work on monochloramine was promising,” notes Stout. “But it may not be the silver bullet to the Legionella problem.”

    In addition to treating for Legionella, utilities have a responsibility to inform their consumers about the risks associated with these bacteria. At-risk populations, including the elderly and transplant patients, should be educated on Legionella and preventative measures, said Stout. Boiling drinking water will kill the bacteria, and setting home water heaters to 130 F will prevent the bacteria from colonizing in the plumbing system.

    To improve preventative measures for Legionella, the CDC began active monitoring programs at 10 sites in January. Active monitoring programs should diminish some of the uncertainty surrounding this CDC report, which relied heavily on passive self-reporting by health care professionals. After analyzing this new data, scientists hope to have a better idea of the scope of Legionnaire’s disease.

    © 2011 American Water Works Association  

  • Rain, Flooding Considered in Legionnaires' Disease Cases

    September 15, 2011


    One person remains hospitalized and 10 others are recovering at their residences after an outbreak of Legionnaires disease was discovered at two separate health care facilities in Turtle Creek.

    Dr. Bruce Dixon of the Allegheny County Health Department says the good news is that those affected by the disease appear to be recovering and no new cases have been reported today.
    The LGAR Health and Rehab Center, for example, has now installed a silver-copper ionization system to purify its water. That was recommended by its consulting firm, Special Pathogens Laboratory.

    Dr. Victor Yu, who heads that company, speculates that recent heavy rains and flooding may have played a role since both facilities have their own separate water systems.

    That’s a theory the health department is also investigating.

  • Cooling Tower Study Shows First “Green” Nonchemical Device to Control Bacteria in Water

    August 07, 2011

    Cooling tower operators wanting to rely less on chemicals to treat water-based air conditioning systems may have an environmentally friendly alternative. A “green” nonchemical device (NCD) reduced bacterial growth, including Legionella (the bacterium that causes Legionnaires’ disease) according to a recent study by Special Pathogens Laboratory and the University of Pittsburgh. 

    Cooling tower operators wanting to rely less on chemicals to treat water-based air conditioning systems may have an environmentally friendly alternative. A “green” nonchemical device (NCD) reduced bacterial growth, including Legionella (the bacterium that causes Legionnaires’ disease), according to a recent study by Special Pathogens Laboratory and the University of Pittsburgh.

    The positive results come on the heels of a previous NCD study funded by the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE). Researchers, Janet E. Stout, PhD, Director of Special Pathogens Laboratory, and Radisav D. Vidic, PhD, the William Kepler Whiteford Professor and chair of Civil and Environmental Engineering at Pitt’s Swanson’s School of Engineering, tested five different types of NCDs from different manufacturers in model cooling towers.

    The ASHRAE study found that none of the NCDs (pulsed electric-field, ultrasonic, hydrodynamic cavitation, magnetic) prevented bacteria from growing in the water-cooling systems. In fact, most produced the same or more bacteria as found in untreated water. In this recent study, Stout and Vidic tested a “green machine,” a mechanical water treatment device that relies on an electrolytic process to improve cooling tower performance (H-O-H Water Technology).

    This NCD was evaluated using the same methodology as the ASHRAE study. The results showed that the device removed hardness and alkalinity from the cooling water, and was 100 times more effective in reducing bacteria in the model cooling tower compared to the control, and more effective than all of the previously tested NCDs.

     “The H-O-H device is the first device among the NCDs we’ve tested that showed a bactericidal effect,” says Stout, who is also a research associate professor in civil and environmental engineering at the Swanson school.  “The results also support our scientific method of using model cooling towers to evaluate water treatment devices.”

    Heating and cooling systems constantly exposed to nature provide the perfect environment for microbial growth. When biofilm isn’t controlled, it clogs pipes and promotes the growth of scale, which results in poor performance, slowed cooling and energy loss.

    Ineffective water treatment can allow dangerous bacteria like Legionella to flourish in the cooling systems of hospitals, commercial offices, and other water-cooled buildings. Numerous studies have shown that 40-60 percent of tested water systems contained Legionella.

    Effective water treatment reduces the health risk caused by airborne bacterial emission. To safeguard the public, many organizations that promote industry best practices propose that cooling tower operators validate the effectiveness of water treatment by monitoring for disease causing bacteria.

    According to Stout, “We observed a 1.9 log greater reduction in the total bacteria (HPC) counts in bulk water, and a 2.3 log reduction in Legionella. This data suggests that the H-O-H device may achieve bacterial control that could meet industry standards set by organizations like the Cooling Technology Institute and the Association of Water Technologies. This is a promising sign for cooling tower operators who are environmentally conscious. However, similar experiments on full-sized cooling systems are needed to validate our findings in the model system.”

    While chemicals are most effective in controlling biofilm, corrosion, and deadly bacteria in evaporative air-conditioning systems, the results of this study suggest that a greener solution could become a reality.

  • Water Systems High in Bacteria Pose Serious Safety Threat; WHO, VA Healthcare, ASHRAE Offer Prevention Disinfection Guidelines

    March 09, 2011

    Water in hospitals, hotels, commercial office buildings, and long-term care facilities contain waterborne pathogens, like Legionella, Pseudomonas, and antibiotic resistant bacteria. New guidance documents from the World Health Organization; the Veterans Affairs Healthcare System; the New York Department of Health; and the American Society of Heating, Refrigeration and Air-conditioning Engineers (ASHRAE) give new approaches for disinfection and prevention.

    Water in hospitals, hotels, commercial office buildings, and long-term care facilities contain waterborne pathogens, like Legionella, Pseudomonas, and antibiotic resistant bacteria. If you are elderly or a hospital patient, you are vulnerable to illnesses, like Legionnaires’ disease, which are caused by these bacteria.

    Now, guidance documents developed by the World Health Organization; the Veterans Affairs Healthcare System; the New York Department of Health; and the American Society of Heating, Refrigeration and Air-conditioning Engineers (ASHRAE) offer new methods for disinfection and prevention.

    Faucets, showerheads, drains, humidifiers, and hot tubs provide rich environments for bacteria to colonize. Illness is caused when water is ingested, aerosolized, aspirated, or directly instilled through tubes like feeding tubes.  

    “You’d be surprised at what’s in your water,” says Dr. Janet Stout, director of Special Pathogens Laboratory.  “We want to believe that the water coming from the tap in a hospital or hotel is safe, that assumption is incorrect especially for the elderly, smokers, and anyone whose health is compromised.”

    According to Stout, wherever there is water there should be concern about its quality with respect to waterborne pathogens. One study showed 41 facilities in 18 states reporting a death rate of 34% when hospitalized patients got Legionnaires’ disease from the hospital water. Of those, 88% were acute care hospitals, 12% long-term care and rehabilitation facilities. 

    “Unmonitored levels of bacteria pose a definite threat to public health. Yet for too long there has been a policy of avoidance especially in the case of Legionnaires’ disease where nothing is done until a case is diagnosed or there has been a death,” says Stout, a research assistant professor at the University of Pittsburgh, and leading expert in Legionella detection and disinfection. “These new guidelines offer a preventative approach as well as effective detection and disinfection methods.”

    Stout will lead an educational session for the National Facilities Management and Technology Conference in Baltimore on Wednesday, March 16, 2011.  In “Waterborne Pathogens: Keeping People Healthy in the Building,” she will identify waterborne pathogens in building water systems that pose a risk of infection; review the Do’s and Don’ts for assessing and managing risks from utility water systems; give the status of guidance documents, and the impact on utility system operation and maintenance.