Approximately 6,000 cases of Legionnaires’ disease (LD) were reported in the United States in 2015. The Centers for Disease Control and Prevention (CDC) found that 76% of these cases could be traced back to healthcare facilities. Of those cases, 80% were linked to long-term care facilities, 18% were linked to hospitals and 2% were linked to both.
During a 2017 media briefing, CDC Acting Director Anne Schuchat M.D. stated, “Legionnaires’ disease in healthcare facilities is widespread, deadly and preventable.”
LD outbreaks are commonly associated with hospitals and long-term care facilities due to their complex water distribution systems and other aerosol-generating devices along with having a large number of people who are more susceptible to the disease.
Common Sources of Infection
Legionnaires’ disease is caused by the bacterium Legionella. Although the bacterium can be found naturally in freshwater environments, it can become a health concern when it grows and spreads at high concentrations in man-made water systems.
Legionella grows best in warm, stagnant water. Some of the potential growth sites for the bacterium that can be found in healthcare facilities include:
- Potable water systems
- Potable water outlets, especially those in or near patient rooms
- Cooling towers and evaporative condensers
- Humidifiers (e.g., nebulizers)
- Decorative fountains
- Irrigation equipment
- Fire sprinkler systems (if recently used)
- Whirlpools and spas
Increased Risk Factors
While most healthy people exposed to Legionella do not get Legionnaires’ disease, there are others who are more susceptible to infection. People with an increased risk of contracting LD include those aged 50 or older, current or former smokers, and those with a chronic disease or weakened immune system. The CDC reported that 88% of the Legionnaires’ cases in 2015 occurred in patients older than 60.
Prevention and Risk Reduction
The key to preventing Legionnaires’ disease is to inhibit the growth of Legionella. Legionella water management programs are the current industry standard for managing Legionella growth in large buildings in the United States (ASHRAE Standard 188, 2015). These guidelines are available for those who maintain and manage building water systems, including systems for potable (water for drinking and showering), non-potable, and recreational water, and may be found at:
https://www.ashrae.org/resources--publications/bookstore/ansi-ashrae-standard-188-2015-legionellosis-risk-management-for-building-water-systems
Some healthcare facilities are required to have water management policies and procedures in place. The Centers for Medicare and Medicaid Services (CMS) recently announced that Medicare-certified healthcare facilities, including hospitals, critical access hospitals and long-term care facilities are expected to develop and implement water management programs to reduce the growth and spread of Legionella.
Water Management Program Considerations
It is recommended that all healthcare facilities, including those not participating in the Medicare program, consider implementing a Legionella water management program. For the water management program to be effective, it is recommended that the program include the following activities.
- Conduct a facility risk assessment to identify where Legionella could grow and spread in the facility water system.
- Implement a water management program that considers the ASHRAE industry standard and includes control measures such as:
- Physical controls
- Temperature management
- Disinfectant level control
- Visual inspections
- Environmental testing for pathogens
- Specify testing protocols and acceptable ranges for control measures, and document the results of testing along with corrective actions taken when control limits are not maintained.
Additional help with designing and implementing a new Legionella water management program or evaluating an existing program is available through the CDC. Their free toolkit, “Developing a Water Management Program to Reduce Legionella Growth & Spread in Buildings: A Practical Guide to Implementing Industry Standards” is available online.
Decorative Fountains
Ornamental water fountains can promote relaxation and stress relief to sick patients. They can also provide an ideal environment for Legionella to grow.
Healthcare facilities with patients susceptible to Legionnaires’ disease should be aware of the risks associated with locating an ornamental water feature in any area which may be used by high risk patients. The CDC states that all healthcare facilities should “avoid placing decorative fountains and fish tanks in patient-care areas” and “ensure disinfection and fountain maintenance.” 1
Additionally, healthcare organizations with ornamental water features should include testing the water for Legionella levels in their risk management plans. It is recommended that facilities test the water for Legionella quarterly to ensure the bacterium levels are consistently less than 1 cfu (colony forming unit). If testing verifies the desired levels are being consistently maintained over the course of one year, testing frequency can then be reduced to annually.
Conclusion
The growth and spread of Legionella can lead to outbreaks of Legionnaires’ disease. Because Legionella cases are most commonly associated with healthcare facilities, it is especially important for healthcare organizations to understand their Legionella risk. Developing an effective Legionella water management program can help healthcare organizations reduce Legionella growth and spread in their buildings and prevent the development and transmission of Legionnaires’ disease.
Centers for Disease Control and Prevention. (2003, June 6). Guidelines for environmental infection control in health-care facilities: recommendations of CDC and the Healthcare Infection Control Practices Advisory Committee (HICPAC). MMWR. Morbidity and Mortality Weekly Reports. Retrieved from https://www.cdc.gov/mmwr/preview/mmwrhtml/rr5210a1.htm
Soda, E.A., Barskey, A.E., Shah, P.P., et al. Vital Signs: Health Care–Associated Legionnaires’ Disease Surveillance Data from 20 States and a Large Metropolitan Area — United States, 2015. MMWR Morb Mortal Wkly Rep 2017;66:584–589. DOI: http://dx.doi.org/10.15585/mmwr.mm6622e1.htm
Barbaree, J.M., Gorman, G.W., Martin, W.T., Fields, B.S., & Morrill, W.E. (1987, Jul). Protocol for sampling environmental sites for legionellae. Applied and Environmental Microbiology, 53(7): 1454–1458. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC203891/
