Legionnaires' disease gained national notoriety in 1976

What is Legionnaires' Disease? What is Pontiac Fever?

By Robert Herriman Robert Herriman Level: Platinum With over 20 years of microbiology and infectious disease experience, I will try to open up to you a microscopic world that causes much suffering ...

With the recent news where 3 former guests at a Miami hotel came down with Legionnaires ' disease, with one dying, I will go over the disease in a little more detail.

Legionnaires' disease gained national notoriety in 1976 when the Centers for Disease Control and Prevention (CDC) discovered it during an epidemic of pneumonia among American legion members at a convention in Philadelphia.

The causative organism is the bacteria, Legionella pneumophila. The legionella bacteria are found throughout nature, because of this most people become exposed to it but few develop symptoms.

The primary place in nature it's found is water sources particularly at warmer temperatures; lakes, rivers and moist soil.

It is also found in man-made facilities (frequently the source of outbreaks) such as air-conditioning ducts and cooling towers, humidifiers, whirlpools and hospital equipment.

People get exposed through inhaling infectious aerosols from these water sources. There is no transmission from person to person.

The infection can appear in two clinical forms: Legionnaires' disease and Pontiac fever.

Both conditions are typified by headache, fever, body aches and occasionally abdominal pain and diarrhea. Legionnaires' disease is the cause of pneumonia where a non productive cough is typical. Fatality rates of this form of the infection are around 15 % even with improvements in treatment.

Pontiac fever is a self limiting flu-like illness that does not progress to pneumonia or death. Diagnosis is usually made by typical symptoms in a outbreak setting.

Diagnosis of Legionnaires' disease depends on identifying the bacteria in microbiological culture, detecting the antigen in urine samples or a fourfold increase in antibody titer.

Certain health conditions make you more susceptible to infection to include increasing age, smoking, chronic lung disease, malignancy and diabetes mellitus.

Legionnaires' disease is treatable with antibiotics.

To following things can be done as preventive measures: cooling towers should be drained when not in use and cleaned to remove scale and sediment and biocides can be used to limit bacterial growth. Tap water should not be used in respiratory therapy devices.