Mayor's Office

Gen. Co. Health Dept. Issues Reminder about Risks of Legionnaires’ Disease

(June 6, 2018) — The Genesee County Health Department (GCHD) would like to remind residents of the risk of Legionnaires’ disease as temperatures begin to increase. While Legionnaires’ can occur at any time of year, more illness is reported in summer and early fall. Legionnaires’ disease is a respiratory infection characterized by the bacteria Legionella. A milder form of the illness is called Pontiac fever. Legionnaires’ symptoms include cough, shortness of breath, fever, muscle aches, headaches, and sometimes diarrhea and mental changes. Pontiac fever has similar symptoms but does not progress to pneumonia. Antibiotics are highly effective against Legionella bacteria. To date in 2018, there have been eight cases reported in Genesee County.

Legionella bacteria are found naturally in the environment (rivers, lakes, streams), but can also be found in man-made water supplies that aerosolize water, such as cooling towers, hot water tanks, humidifiers, nebulizers, showers, hot tubs, and decorative fountains. Filtering water does not remove Legionella bacteria.

People can contract Legionnaires’ disease when they accidently swallow water into the lungs or breathe in a mist containing the bacteria. The bacteria are not spread from one person to another person. Most healthy people exposed to Legionella do not become infected. People who have an increased risk of developing Legionnaires’ disease are those who are 50 years or older, current or former smokers, have a chronic lung disease, or weakened immune system from other underlying illnesses or medications. Individuals with any concerns about Legionnaires’ disease should consult their healthcare provider.

Legionella growth can occur in buildings or structures that have complex water systems, such as long-term care facilities, hospitals, hotels, and cruise ships, that are not managed adequately and where disinfectant levels are low, water is stagnant, or water temperatures are ideal for growth of Legionella. Proper maintenance and disinfection of the water systems in which Legionella grow, including hot tubs, hot water tanks, humidifiers, nebulizers, cooling towers, and decorative fountains, are the most effective measures in preventing Legionnaires’ disease. Cleaning, disinfecting, and maintenance should be done following manufacturer recommendations.

The Genesee County Health Department encourages high risk facilities to adopt water management plans to help prevent Legionnaires’ disease. The Center for Disease Control and Prevention has a toolkit that can help building managers develop a water management plan that can be accessed online at:

For more information on Legionnaires’ disease, visit or