From the U.S. Centers for Medicare and Medicaid Services (CMS):
The bacterium Legionella can cause a serious type of pneumonia called LD in persons at risk. Those at risk include persons who are at least 50 years old, smokers, or those with underlying medical conditions such as chronic lung disease or immunosuppression. Outbreaks have been linked to poorly maintained water systems in buildings with large or complex water systems including hospitals and long-term care facilities. Transmission can occur via aerosols from devices such as shower heads, cooling towers, hot tubs, and decorative fountains.
Examples of these system components and devices include:
Potable Water Non-Potable Water Aerators Air conditioners Bath taps Car washes Bathroom faucets/sinks Centrally-installed misters, atomizers, air washers, and humidifier Drinking fountains Cilled-water return tanks Drinking water Cooling towers Electronic and manual faucets Decorative fountains Eyewash stations Evaporative Condensers Faucet flow restrictors Header Tanks Hot and cold water storage tanks Hot tubs/saunas Ice machines Mashine/utility waters Kitchen faucets/sinks Medical devices (such as CPAP machines, hydrotherapy equipment, bronchoscopes, heater-cooler units) Showerheads and hoses Non-steam aerosol-generating humidifiers Showers Pipes, valves, and fittings Water filters Pools Water heaters Rainwater storage tanks Water-hammer arrestors
Legionella Testing Regulation
In June, 2017, the Centers for Medicare and Medicaid Services published a memorandum titled "Requirement to Reduce Legionella Risk in Healthcare Facility Water Systems to Prevent Cases and Outbreaks of Legionnaires’ Disease.” Healthcare facilities must now develop a water management program to identify areas where Legionella could grow and spread. A critical part of the program is monitoring the effectiveness of the plan. An easy way to monitor the effectiveness of the plan is to collect samples at pre-determined sampling points, and test for Legionella pneumophila. If the results are negative, the plan is working.
The CMS policy memorandum applies to hospitals, critical access hospitals and long-term care facilities. However, it is also intended to provide general awareness for all healthcare organizations, as well as the maintenance staff of any large building.
Legionella Testing at MEL
Maine Environmental Laboratory uses a reliable test method (IDEXX Legiolert) that is comparable to the traditional culture methods, but takes half the time. Confirmed results are available after only 7 days.
Sampling is simple, requiring only certified sterile bottles provided by MEL. Samples do not need to be chilled on their way to the lab, eliminating the need for shipping coolers packed with ice, and the hold time is flexible, though 48 hours or less is preferred. Samples that will not reach the lab within 48 hours should be refrigerated.
How it Works
The method is based on bacterial enzyme activity. An Idexx-patented reagent powder is added to the water sample, mixed thoroughly, and poured into a special 96-well counting tray. The tray is incubated for seven days at 102º F. If Legionella pneumophila bacteria is present in the sample, it's enzymatic reaction with the reagent powder will turn the water brown or cloudy. The method is accurate to 1 organism per 10mL for drinking water and 1 organism per 0.1 mL for non-potable water.
Maine Division of Infectious Disease, "Airborne and Direct Contact Diseases - Legionellosis"
US CDC's "Legionella (Legionnaires' Disease and Pontiac Fever)" (website)
US CDC "Sampling Procedure and Potential Sampling Sites" (6 pg pdf.)
MEL Test Method for Legionella pneumophila
Aqueous (potable and non-potable)
Container: sterile plastic or glass with sodium thiosulfate
Volume: 100 mL minimum
Hold Time: Preferably within 48 hours.
Preservation: Transport at ambient temperature in insulated cooler to protect against extreme heat or cold. Refrigerate if samples will not be analyzed within 24-48 hours of sampling.