Even though Legionnaires' disease is a johnny-come-lately to the known disease party (the first recognized case was in 1976), it is not uncommon by any means. In fact, it represents over 4 percent of all community-acquired pneumonias.

You have probably hear of Legionnaires' disease more than other recently-discovered diseases due to the media frenzy surrounding various “outbreaks.” However, the disease most often occurs in single, isolated cases.

The disease is a sever form of pneumonia caused by a bacterium known as legionella. The legionella bacterium also causes Pontiac fever, a milder illness resembling the flu. Separately or together, the two illnesses are sometimes called legionellosis.

Legionnaires' disease cannot be transmitted via person-to-person contact, but rather through inhalation of the bacterium. Older adults, smokers and people with weakened immune systems are particularly susceptible to Legionnaires' disease.

Most people become infected when they inhale microscopic water droplets containing the legionella bacterium. This might be the spray from a shower, faucet or whirlpool, or water dispersed through the ventilation system in a large building. Outbreaks have been linked to a range of sources, including:

·         Hot tubs and whirlpools on cruise ships

·         Cooling towers in air conditioning systems

·         Decorative fountains

·         Swimming pools

·         Physical therapy equipment

·         Water systems in hotels, hospitals and nursing homes

Although legionella bacteria primarily spread through aerosolized water droplets, the infection can be transmitted in other ways, including from contaminated potting soil

The symptoms of Legionnaires' disease include:

·         Headache

·         Muscle pain

·         Chills

·         Fever that may be 104 degrees F. or higher

·         Cough, which may bring up mucus and sometimes blood

·         Shortness of breath

·         Chest pain

·         Gastrointestinal symptoms, such as nausea, vomiting and diarrhea

·         Confusion or other mental changes

See your doctor as soon as possible if you believe you have been exposed to the bacterium, as an early treatment can help shorten the recovery period and prevent serious complications. For people at high risk –  older adults, smokers and people with weakened immune systems –  prompt treatment is critical.

Your doctor can diagnose Legionnaires' disease by way of a blood test or urinalysis. It can be treated handily with antibiotics, provided it is caught soon enough.