Legionnaires' disease is a type of pneumonia caused by Legionella, a bacterium found in fresh water environments such as lakes and streams. It becomes a health concern when the bacteria make its way into human-made water systems such as water tanks, hot tubs, plumbing systems, and showerheads and faucets. It thrives in water temperatures between 95 to 115 degrees Fahrenheit.

Unlike most water borne diseases, Legionnaires’ disease isn’t transmitted by direct human contact, but through tiny water droplets in the air, or mist. A person becomes infected when the water droplets are breathed in and enter the lungs.

Legionella derived its name from its first outbreak in 1976, when 129 out of 2000 people who attended an American Legion convention became infected. Among those infected, 29 died. In the US, there are between 8,000 are 18,000 reported cases of Legionnaire’s disease every year. About 10% of those who contract the disease die.

Many people who are exposed to the bacteria may not even develop the disease. However, there are risk factors that increase the likelihood of infection such as old age, chronic lung disease, smoking, and a poor immune system. Symptoms of the disease include cough, fever, muscle pains, shortness of breath, vomiting, and occasionally, diarrhea.

There is no known vaccine to immunize from the disease. Taking clean water precautions, especially with drinking water, is a one way to prevent exposure. If infected, antibiotics and hospitalization will be required (CDC, 2018).