Healthcare institutions should develop and implement prevention and control measures to minimize the risk of hospital associated infection related to Legionella and other water borne pathogens in potable water systems.
General Infection Control Guidelines by Authority
ANSI/ASHRAE standard 188-2015 “Legionellosis: Risk Management for Building Water Systems” does require water treatment and does not give recommendations on water treatment methods. They also do not require Legionella water testing and do not give recommendations on Legionella water testing.
Joint Commission states facilities are to develop, implement, and monitor the effectiveness of water management programs to protect patients, visitors, and staff from exposure to waterborne pathogens, including Legionella pneumophila. The Joint Commission assesses accredited organizations to plan, implement and evaluate programs to protect the health and safety of patients. The Joint Commission looks for evidence of compliance. They do not require water treatment and do not give recommendations on water treatment methods. They also do not require Legionella water testing and do not give recommendations on how to do Legionella water testing.
Centers for Disease Control – Guidelines for Prevention of Noscomial Pneumonia defines definite nosocomial cases of Legionella pneumonia are those in which the patient was hospitalized continuously for ≥ 10 days before onset of Legionella infection. Possible cases are those in which patients were hospitalized for 2-9 days prior to onset of Legionella infection.
Centers for Disease Control – Guidelines for Preventing Health-Care-Associated Pneumonia state routine culturing of water systems for Legionella. No recommendations made in health-care facilities that do not have patient-care areas for persons at high risk for Legionella infection. In facilities with hemopoietic stem-cell- and/or solid-organ transplantation programs, periodic culturing can be performed as part of a comprehensive strategy to prevent Legionnaires disease in transplant recipients. CDC states that if culturing is undertaken, no recommendations are made about the optimal methods (i.e., frequency or number of sites) for environmental surveillance cultures in transplant units. Perform corrective measures aimed at maintaining undetectable levels of Legionella in the unit’s water system.
People Most at Risk of Legionella
People most at risk of getting sick from the Legionella bacteria and other water borne pathogens are older people (usually 65 years of age or older), as well as people who are smokers, or those who have a chronic lung disease (like emphysema).
People who have weak immune systems from diseases like cancer, diabetes, or kidney failure are also more likely to get sick from Legionella bacteria and other water borne pathogens. People who take drugs to suppress (weaken) the immune system (like after a transplant operation or chemotherapy) are also at higher risk.
Legionella and Other Water Borne Pathogens Risks
Water borne pathogens of concern are: Mycobacteria, Pseudomonas, Legionella, and water fungi – Aspergilosis may sometimes be waterborne.
Infections with Legionella spp. remain an important cause of nosocomial pneumonia. Mortality of nosocomial Legionella pneumonia has been reported as being up to 40%. Cases of nosocomial Legionella can also be a source of a great deal of negative publicity and litigation for hospitals. Healthcare water systems remain the principal source of nosocomial infections.
Legionella species are intracellular gram- negative pathogens that are commonly found in environmental water sources. Several species including Legionella pneumophila are known to cause both community and healthcare associated pneumonia. Mortality of nosocomial Legionella pneumonia has been reported as being up to 40%. Cases of nosocomial Legionella can lead to negative publicity and litigation for hospitals.
Risks for nosocomial Legionella are increasing as the hospitalized population becomes older, and immunosuppressive treatments become more common. More and more healthcare organizations are beginning to investigate water treatment methods and systems to try and protect patients from Legionella infections and other water borne pathogens even though they are not required. Healthcare organizations should research, explore, and implement methods to control and monitor Legionella and other water borne pathogens in potable water system.
Legionella and other water borne pathogens can be found in domestic cold and hot water systems (via showers, faucets, etc.), cooling towers, dialysis water, decorative fountains, respiratory care equipment, humidifiers, water misters, whirlpool baths, and spas.
Biofilm “communities” thrive in warm water, low velocity water flow conditions, and in “dead legs” of pipes. The older the pipes and rougher the surface (e.g. calcium carbonate deposits from water hardness), the better the environment for the attachment of microbes and formation of biofilm.
Biofilm is a slime layer found on the insides of pipes. It is comprised of secretions from microorganisms and acts like a coral reef for many harmful pathogens. Bacteria such as Legionella collect and reproduce in this slime layer. When pieces of biofilm break off the inside wall of the pipe, they can travel through a faucet or showerhead, where they aerosolize, can be aspirated, and can cause a pulmonary infection.
Potable Water Systems in Healthcare Organizations
Healthcare organizations should research available methods to disinfect hot and cold potable water systems. A selection criterion should be developed to select a disinfection method. The healthcare organization should require that the disinfection method be Environmental Protection Agency (EPA) approved for potable water disinfection. Additional information necessary to select a disinfection method include impact on biofilm, residual effect, by-products, environmental and health effects, impact on equipment and piping, impact on dialysis and laboratory equipment impact on organoleptic properties of treated water.
A potable water disinfection method must be safe for patients, visitors and staff, control and eliminate Legionella and other water borne pathogens, eliminate biofilm, have no impact on dialysis filtration equipment, no impact on laboratory filtration equipment, no impact on corrosion rates, no impact on mechanical equipment and systems.
Using the Environmental Protection Agency (EPA) is critical – EPA list and regulate for use in potable water as a disinfectant, EPA registered under the Federal Insecticide, Fungicide, Rodenticide Act (FIFRA) for potable (cold & hot) water use, EPA established contact time (CT) factor to determine germicidal efficiency of any disinfectant. The CT is established by conducting a germicidal kill test. Environmental effects, health effects, effect on Legionella and bacteria.
Current potable water disinfection methods utilized are super heating of water, chlorination, chloramine, copper/silver ionization, ozone, ultraviolet light, ultraviolet light combined with chemical treatment and chlorine dioxide.
Controlling Legionella with Chlorine Dioxide
Extensive research of current methods for controlling Legionella should be done. Comparing all the disinfecting methods will show that chlorine dioxide (ClO2), which is approved by the EPA for use as a potable water disinfectant under CFR Part 141 – National Primary Drinking Water Regulations is the best choice. Chlorine dioxide comes out being most effective without side effects. Chlorine dioxide is a gas in its native state and is registered as a biocide by the EPA.
Chlorine dioxide is a gas that can be generated chemically or electrolytically from a sodium chlorite solution. Sodium chlorite is approved by the EPA (EPA registration number 5382-43) as a precursor for generating chlorine dioxide as a potable water disinfectant. Chlorine dioxide is a powerful oxidant and kills bacteria via oxidative disruption of cellular processes.
Chlorine dioxide degrades primarily into chlorite ions and into chlorate ions. Chlorine dioxide has been used for many years to treat water in industry and in some municipal water systems. More recently, interest has grown in using it in healthcare settings. Chlorine dioxide is safe and effective for both hot and potable water which can penetrate existing biofilms and inhibit formation of new biofilms.
Results indicate that chlorine dioxide is both safe and effective in the short and long-term at reducing Legionella and other water borne pathogen colonization in healthcare potable water systems. Chlorine dioxide also prevents hospital acquired Legionellosis in high risk populations.
The Johns Hopkins Hospital Use of Chlorine Dioxide
Chlorine dioxide has been effectively used by The Johns Hopkins Hospital for approximately 20 years. Chlorine dioxide has been found to be very effective at controlling and eliminating Legionella and other water borne pathogens. Published documentation also has not indicated any disadvantages. It controls and eliminates Legionella and other water borne pathogens, eliminates biofilm, has no impact on dialysis filtration equipment, no impact on laboratory filtration equipment, no impact on corrosion rates, and no impact on mechanical equipment and systems.
The Hopkins Hospital installed PureLine chlorine dioxide systems over eight years ago in their new 1.6 million square foot building. PureLine’s chlorine dioxide system was developed using state-of-the-art generation technology. The system converts 25% sodium chlorite into nearly pure chlorine dioxide by utilization of EPA recognized water disinfection methods. Legionella and other water borne pathogens have not been detected in over eight years of operation at The Johns Hopkins Hospital. The chlorine dioxide systems continue to control and eliminate Legionella and other water borne pathogens and eliminate biofilm.
The use of an EPA recognized potable water disinfection system such as PureLine chlorine dioxide meets or exceeds current standards established by the CDC and ANSI/ASHRA.
With over 20 years of experience in the manufacture, generation, and application of chlorine dioxide solutions, PureLine specializes in designing and implementing chlorine dioxide treatment solutions utilizing our broad line of proven chlorine dioxide generators and chemical solutions to control and inhibit the growth of mold, mildew, and odor causing bacteria.