Center for Improvement in Healthcare Quality Newsletter
July 2022

CIHQ-ARS Article

Environmental Water Sampling and Testing to Reduce the Risk of a Legionnaires’ Disease Outbreak

An article provided Hyperion Biotechnology
Healthcare facilities know the importance of following water management plans (WMP) to reduce the risk of Legionella in a facility’s water system. Legionella bacteria can grow in plumbing systems and spread through water sources such as showers, faucets, decorative fountains, and cooling towers. When droplets of water or mist containing Legionella spread in the air, people can breathe it in. Not all people who inhale the bacteria will become ill with Legionnaires’ disease. For those who do get sick, the CDC reports that 1 in 10 people will die from the disease. More alarming for healthcare facilities, the CDC states, “For those who get Legionnaires’ disease during a stay in a healthcare facility, about 1 out of every 4 will die.” Because healthcare facilities serve at-risk and vulnerable populations, their patients may be more susceptible to illness. People at increased risk include:
  • Age 50 years or older
  • Have underlying health conditions and weakened immune systems
  • Current or former smokers
For accreditation compliance, healthcare facilities must adhere to The Center for Medicare & Medicaid Services’ (CMS) “Requirement to Reduce Legionella Risk in Healthcare Facility Water Systems to Prevent Cases and Outbreaks of Legionnaires’ Disease (LD)” (Memo #17-30-Hospitals/CAHs/NHs). Further, The Center for Improvement in Healthcare Quality (CIHQ) Accreditation Standards for hospitals (Effective April 2022) requires facilities to implement a water management program that includes environmental testing and documenting the results of testing. Additional Legionella risk management resources are available from the Centers for Disease Control and Prevention (CDC). The CDC publishes helpful information for reducing the risk of Legionnaires’ disease outbreaks, including guidelines for routine Legionella environmental water sampling.
While serving patients who may be at a higher risk of getting sick if exposed to Legionella bacteria, healthcare facilities need to continuously manage their WMPs to ensure patient safety. Exposure to Legionella causes illness; Legionnaires’ disease does not spread from person to person. According to a March 2021 report, the CDC determined that almost all Legionnaires’ disease outbreaks could have been prevented with more effective water management. To verify the effectiveness of a WMP, validation needs to occur. The only way to determine if a WMP is working to reduce Legionella growth and spread is to conduct routine environmental water sampling and testing. Routine sampling provides benefits such as the following:
  • A baseline for monitoring water system
  • Validation that WMP is working
  • Early detection of a Legionella issue to enable action before it becomes an infestation
  • Cost savings. Routine testing is affordable compared to the cost of a Legionnaires’ disease outbreak. Costs include the risk to patients’ health, investigations to determine the source, protection of patients during investigations, and remediation to get rid of the bacteria.
Including a Legionella water sampling plan in healthcare facility water management programs provides another monitoring tool to ensure staff and patient safety. Collecting samples and sending them to a certified laboratory that follows CDC testing or ISO 11731 methods will provide complete results to healthcare facilities. With a laboratory report showing no detection of Legionella, healthcare facilities have confirmation that all other actions to reduce the risk of Legionella are working.


Centers for Disease Control and Prevention (CDC)
CDC Legionella Control Toolkit
CDC Routine Legionella Testing
The Centers for Medicare & Medicaid Services: Requirement to Reduce Legionella Risk in Healthcare Facility Water Systems to Prevent Cases and Outbreaks of Legionnaires Disease (LD)
Center for Improvement in Healthcare Quality (CIHQ)