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Infection preventionists who have put water management programs on the back burner could be in a world of pain if they encounter a case of Legionnaires’ disease — let alone an outbreak.
Public health officials and other authorities may show up on site with a demand for data and documents that may not be immediately available, warned Frank Sidari, PE, BCEE, technical director of the Special Pathogens Laboratory in Pittsburgh.
“They will ask, ‘Do you have a recent risk assessment? Are you following a water management plan?’” he said recently in Minneapolis at the annual conference of the Association for Professionals in Infection Control and Epidemiology. “If the answer is ‘no,’ they may say you must put together a water management plan and a risk assessment. And it is due by Friday.”
The scenario got the attention of the IPs in attendance, but it is not out of the realm of possibility. Last year, the Centers for Medicare & Medicaid Services issued a memo mandating that:
“All covered facilities have water management policies to reduce the risk of growth and spread of Legionella and other opportunistic pathogens in building water systems. … Conduct a risk assessment to identify where Legionella and other opportunistic waterborne pathogens could grow and spread in the water system.”1
Facilities that are not in compliance in these areas could get dinged by a surprise visit or one prompted by the report of a Legionella infection. This can be labor-intensive, as you may have to hire a consultant, conduct risk assessments, and implement water safety programs under time constraints. Instead of a preferred stance of proactive measures, you are now responding retroactively under the pressure of public health scrutiny.
“As soon as there is a case, they will wonder if you have done any water sampling,” Sidari said. “They will want you to submit this, and it usually goes well beyond proactive testing. When you are testing on your own, you can take a few samples from a few locations. Once [CMS] becomes involved, you may have to collect all sorts of samples.”
Making matters worse, you may end up “chasing zero,” as inspectors look for the presence of Legionella in any and all samples.
“Being proactive avoids all this,” he said.
To avoid this painful scenario, form a water management team and develop a plan for detecting and mitigating risk of Legionella to your patients. (See related story, page 105.)
“To do a good risk assessment, you really need to understand if you have Legionella growing in your building, what type, and how extensive is the colonization,” he said.
This may result in recommendations for short- or long-term actions to manage the risk.
“From the engineering side, risk assessment looks at your water system to understand if it is operating properly,” he said. “Is there some wing where you can’t get hot water to work? So, the risk assessment not only looks at Legionella, but how your water system is operating.”
Another aspect of risk assessment is the vulnerability of the patients using the water system. As IPs are aware, the primary threat to high-risk patients is developing pneumonia after inhaling Legionella in aerosolized water from, for example, a shower, sink, or water feature like a fountain.
As part of a water management plan, begin a periodic water testing program for Legionella, knowing that Legionella pneumophila is the species responsible for more than 90% of infections. L. pneumophila has 15 serogroups, but the one that causes the most disease is L. pneumophilia serogroup 1.
“Testing can help you determine what kind of Legionella may be in your water system,” Sidari said. “Serogroup 1 is a concerning one for disease.”
Still, the CDC recommends using a testing method capable of detecting all types of Legionella.
“Standard culture is the gold standard,” he said. “Order cultures for your environmental samples. It gives you all the information you need, and it is capable of detecting all Legionella species.”
It is also important to ensure the right clinical tests are being performed on patients, including the urinary antigen test that picks up L. pneumophila serogroup 1.
While virtually any building water system could contain Legionella, roughly speaking only about half of them do. That means you need to test to see if your building has Legionella, but periodic testing can be done at select distal sites, he said. There is no established threshold of Legionella in a given water sample that predicts disease. A dose rate for the pathogen to manifest as disease has not been established.
Rather, the key is the frequency of the pathogen detected in distal sites and water outlets throughout the supply system. The benchmark that has emerged in the literature, and is now codified in New York state law, is 30% of hot water supply sites testing positive for Legionella. Greater than 30% of outlets positive corresponds with increased risk of disease, he said.
“So, the more frequently people are exposed to Legionella, the chance for disease increases,” Sidari said.
This underscores why eliminating all Legionella from the entire water system is not necessary to prevent disease. However, hospitals performing Legionella environmental testing with an eye on the 30% benchmark are more likely to prevent cases of hospital-acquired Legionnaires’ disease, he said.
“Your mission should be to prevent Legionnaires’ disease,” he said. “You can have a positive result here and there [in the water system], but staying under that 30% threshold has been shown to prevent disease.”
Constant vigilance is required because intricate hospital plumbing systems seem almost designed to grow Legionella.
“If you told me as an engineer to design a reactor to grow Legionella, I would put together a building,” Sidari said. “Lots of pipes, lots of places for biofilm, sediment, and corrosion. Lots of warm water systems great for Legionella to grow in.”
In addition, there have been some unintended consequences with “green” efforts to conserve water and the massive shift away from soap and sinks to ubiquitous alcohol hand rub dispensers in hospitals. The water flow is slowed, and some sink water faucets are rarely used. Depending in part on the efficacy of your municipal water system treatment, these factors could contribute to Legionella growth. To assess risk, test the hot water at key sites by collecting a sample right when you turn it on.
“The first draw of hot water gives you the idea of the worst risk,” Sidari recommended. “Take that from representative locations in each of your water systems. If you just have one water system, you can spread out your samples.”
For example, tests of water containing Legionella show a 98% positive at first draw, declining to 69% positive after the water has run for two minutes, he said. Similarly, test equipment like ice machines at “worst-case,” which could mean right before the next scheduled maintenance.
“You don’t want to sample your ice machine right after you clean it,” he said. “What is the worst quality of water samples? Right before you service.”
These measures will prevent cases of Legionella and give you evidence of a proactive program to show the powers that be, whether inspectors or hospital administration.
“If you are not looking for Legionella and not actively putting together a water safety program, you can have a problem sneak up on you,” Sidari said.
“Most of the time when I get a call it is from somebody who has a case or an outbreak. They have not been testing their water. They do not have a water safety program and have not been proactive.”
Financial Disclosure: Peer Reviewer Patrick Joseph, MD, reports that he is a consultant for Genomic Health Reference Laboratory, Siemens Clinical Laboratory, and CareDx Clinical Laboratory. Senior Writer Gary Evans, Editor Jesse Saffron, Editor Jill Drachenberg, Nurse Planner Patti Grant, RN, BSN, MS, CIC, and Editorial Group Manager Terrey L. Hatcher report no consultant, stockholder, speaker’s bureau, research, or other financial relationships with companies having ties to this field of study.