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."
Pittsburgh VA spokesman David Cowgill refused to answer any questions about the allegations by Dr. Stout and Dr. Yu.
It was Dr. Stout and Dr. Yu, who now run a private laboratory and consulting business, who originally chose to install the copper-silver system in the hospital in 1993. The VA also has, without Dr. Yu and Dr. Stout's input, added two other copper-silver systems in hospital expansions in 2009 and 2011.
Dr. Stout and Dr. Yu say they were told that VA officials were aware they had problems with the copper-silver system as early as June -- four months before they knew they had an outbreak -- when they called in an outside consultant, Pittsburgh-based Enrich Products Inc., to look at the system.
Enrich recommended in July that the VA make immediate adjustments to the copper-silver levels -- which were haphazard in prior test results, showing up both much higher and lower than recommended levels, an inside source said. But the consultant wasn't called back to make the adjustments until October, the source said, at about the time the VA first realized it might have an outbreak.
In late October VA Pittsburgh called the federal Centers for Disease Control and Prevention to help analyze the problem, according to CDC officials.
Enrich operations manager Aaron Marshall said he could not comment about any consulting work his company has done.
Mr. Cowgill of the VA would not provide any specifics about why the VA believes the copper-silver ionization system failed or why it called Enrich this past summer.
On Nov. 16, when Pittsburgh VA confirmed that it had a Legionnaires' outbreak, it said in a news release that its copper-silver ionization system "may not be as effective as previously thought," and it was switching its water disinfection over to a chlorination system "to ensure better control."
Alicia Demirjian, the CDC epidemic intelligence service officer who worked on the outbreak in Pittsburgh, was surprised to hear that Pittsburgh VA already has determined that the ionization system was the culprit in the outbreak since its investigation is not yet completed.
"We're not sure if the ionization system was working properly," said Dr. Demirjian, who was also aware that the VA called in Enrich this past summer. "We're not sure if the copper or silver were at the right levels."
Legionnaires' disease got its name in 1976, when many people who went to a Philadelphia convention of the American Legion suffered from an outbreak of the disease.
About 8,000 to 10,000 people each year are hospitalized with the disease, but the CDC and other experts believe many more cases occur each year that go undiagnosed as simple pneumonia or other afflictions. Legionnaires' can be fatal in 5 to 30 percent of cases, depending on who it strikes and where it is acquired.
The copper-silver ionization system was originally created as an alternative to keep swimming pools clean of bacteria, as a replacement for chlorine systems. It kills Legionella -- the bacterium found in the natural environment that causes Legionnaires' disease -- by regularly dispersing minute quantities of copper and silver into water systems.
It is the combination of the copper and silver that studies show make the system effective in killing Legionella, although there is widespread dispute in the scientific community about what disinfection system is the best at preventing the spread of Legionnaires' disease.
The CDC, for example, recommends the type of chlorination system that Pittsburgh VA said on Friday that it is switching to.
The CDC said it is still waiting to see how many cases ultimately will be traced to the water system at the University Drive hospital.
Testing on the first four cases did not confirm a tie to the hospital's water system until Nov. 16, when the hospital stopped using its water and began emergency disinfection procedures. Because the disease has an incubation period up to 14 days, more cases could arise for another six days.
"As long as they're not using the water and we know it's not a source of transmission," there should not be any more cases after Nov. 30, Dr. Demirjian said. "So, we'll have to wait a little longer."
Sean D. Hamill: email@example.com or 412-263-2579.