Legionella Bacteria Facts

In 1976, individuals frequenting the American Legion conference in Philadelphia, Pennsylvania began to become sick with an extraordinary type of pneumonia.Throughout the convention, 221 people became ill and 34 visitors died.Prior to the outbreak, the causative bacteria was undiagnosed.The outbreak was found to be caused from a gram negative bacterium that was dubbed Legionella pneumophila and the disorder become known as Legionnaires' disease.The bacteria existed prior to 1976, but was not as prevalent.After the outbreak, Legionnaires' disease began to become more common.The Centers for Disease Control and Prevention estimates that 8,000 and 18,000 people are infected annually in the United States.Legionnaires's diseases is more prevalent during the summer and early fall.The symptoms of the diseases mimic other types of pneumonia which makes it difficult to diagnose.The infected person usually exhibits a high fever, chills, and a cough.Muscle aches and headaches also occur.As the disease progresses, people may suffer from gastrointestinal disorders and problems with the nervous system.Symptoms usually begin to manifest in 2 to 14 days after exposure.The physician will usually order a series of chest X-rays and may perform a test on the patient's sputum, also known as phlegm.The bacteria can also be detected in the blood and urine.A urinary antigen test will detect Legionella bacteria from a urine specimen.Approximately 5 to 30 percent of the people who contract Legionnaires' disease will die.Antibiotics can successfully control the disease and most healthy people will ultimately recover.The Legionella bacteria also causes a milder form of the disease known as Pontiac fever.A patient suffering from Pontiac fever will usually only exhibit symptoms for 2 to 5 days and there will be no pneumonia.Most infected people only experience muscle aches and a headache.Pontiac fever does not usually require medication or any type of treatment.Legionella bacteria grows best in warm water.It can occur in hot tubs, air conditioning systems (especially large commercial units), hot water tanks, plumbing systems, excavation sites and cooling towers.It also occurs naturally in freshwater creeks, moist soil and ponds.To contract the disease, the person must breath in contaminated water vapor.The disease does not spread from person to person.In a hospital setting, the Legionella bacteria poses an increased risk because the patients often have a depressed immune system.A hospital's heating and cooling units can also be an ideal breeding ground for the bacteria.Outbreaks have occurred on cruise ships and at hotels.Older people -- those over the age of 50 -- are the most at risk for contracting the bacterial disease.Current smokers, past smokers or those suffering from a lung disease are also at an increased risk.People with a weakened immune system, cancer, diabetes or kidney failure are also vulnerable.Healthy people rarely suffer any danger from the bacteria.Because of the advanced age of its occupants, nursing homes and hospitals should remain vigilant and regularly have their heating and cooling systems checked.

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