What is Legionnaires Disease?
Legionnaires' disease is a severe form of pneumonia caused by Legionella bacteria, which live in warm, stagnant water systems. It is contracted by inhaling aerosolized contaminated water, not directly from person to person. Symptoms include high fever, cough, shortness of breath, and muscle aches, appearing 2-14 days after exposure. Treatment requires prompt antibiotics, as it can be fatal if not treated timely.
Legionnaires' disease was identified in 1976 after a mysterious pneumonia outbreak sickened over 180 people (killing 29) attending an American Legion convention at a Philadelphia Hotel. The Centers of Disease Control (CDC) identified the previously unknown Legionella pneumophila bacteria, which thrived in the hotel’s air conditioning cooling tower.
Legionella bacteria exist naturally in water and soil, but they cause infection when they colonize, multiply and aerosolize from man-made water systems, such as cooling towers, hot tubs, and plumbing. Legionella can spread via medical equipment that uses nonsterile water or generates aerosols. High-risk devices include respiratory therapy equipment (nebulizers, CPAP/BiPAP machines), hydrotherapy baths, ice machines, and dental equipment. Proper sterilization, using distilled/sterile water, and following manufacturer cleaning instructions are important to prevent this disease.
Healthcare facilities have implemented water management programs using the American Society of Hospital Engineers (ASHE) guidelines that incorporate best practices for water management to prevent such diseases in healthcare. This involves monitoring water temperatures, chlorine availability, the circulation of water through all areas including the flushing of dead ends of plumbing and performing cultures of water at various points within a healthcare facility. In addition, Infection Prevention does monitor for laboratory results for any patients with legionella results.
Prevention of legionella at home can be done by draining garden hoses and avoiding leaving waterfilled hoses lying in the sun. Use the type of water recommended by your in-home medical equipment or healthcare provider. This includes humidifiers, CPAP or BiPAP machines, and neutralizers, always follow the manufacturer’s instructions for cleaning and use. Follow the advice from your healthcare provider if they recommend using sterile water. Replace all water filters regularly, including whole-house water filters, and point of use filters (tap or refrigerator water/ice makers). Regularly check the chlorine level in your pool or hot tub because chlorine will kill Legionella. People who are at higher risk should avoid using devices that recirculate water, such as decorative fountains, where Legioenlla can grow.
Consider raising your hot water heater temperature to between 130-140° F. Hotter water kills Legionella but also increases the risk of hot water burns. You can mix hot and cold water at the tap before use to avoid injury.
Flush your hot water heater twice a year and follow the manufacturer’s recommendations for maintenance. Also, consider a water softener if you have hard water. A water softener will stop the buildup of scale in your piping that can provide a breeding ground for Legionella.
If you develop any pneumonia symptoms, please contact your PCP for medical evaluation and follow-up.