Legionellosis (Legonella Infection)

The causal agent of the infectious disease known as Legionellosis is the bacterium Legionella pneumophila. Legionellosis is distinguished in two forms: Legionnaires’ Disease and Ponatiac Fever. Pontiac Fever is the milder version while Legionnaires’ Disease is a very severe infection that includes pneumonia. Legionnaires’ Disease took its name from an outbreak in 1976 during which pneumonia spread amongst attendees of the American Legion convention in Philadelphia.

Legionnaires’ Disease hospitalizes approximately 8,000 to 18,000 individuals each year in America. Scientists suggest that the actual numbers must be higher since many infections go undiagnosed or unreported. Most instances occur during early autumn and summer.

The clinical features of Legionnaires’ Disease are very similar to those of other types of pneumonia, making diagnosis difficult at times. Symptoms include coughing, chills, and a high fever, with the possibility of headaches and aching muscles. Symptoms may manifest in just a couple of days up to a couple of weeks after initial exposure to the bacteria.

The milder version of Legionellosis known, Pontiac Fever, has symptoms that only last about five days at most. The symptoms include headaches, fever, and aching muscles without any indication of pneumonia. The clinical features of Pontiac Fever typically go away on their own without any complications.

Legionnaires’ Disease is far more dangerous and requires proper diagnosis quickly. Diagnosis entails chest x-rays in order to verify bacterial pneumonia. Phlegm, urine, and blood may be examined as well for signs of bacteria. It is estimated that five to thirty percent of cases result in death though most instances treated properly with antibiotics are resolved successfully.

Legionella bacteria are naturally occurring, especially in warm water. They may be found in cooling towers, hot tubs, plumbing systems, large scale air conditioning systems, or hot water tanks. Humans contract Legionnaires’ Disease when contaminated particles are breathed in from vapor or mist. Bacteria cannot be spread from one individual to another, but outbreaks occur when groups of people are breathing in contaminated vapors from a shared water system. Cruise ships, hotels, and hospitals are examples of places that can be at risk without proper sanitation and hygienic practices.

Anyone can get Legionnaires’ Disease but people aged over 65 are at high risk. Chain smokers, people with weakened immune systems or kidney failure, and patients with chronic lung conditions are also at greater risk. If you suspect that you have had exposure to Legionella bacteria, contact your doctor for advice. If you are infected, you are not contagious.