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Signs & Symptoms

Legionnaires' Disease

Chest x-ray

Legionnaires' disease can have symptoms like many other forms of pneumonia, so it can be hard to diagnose at first. Signs of Legionnaires' disease can include:

  • Cough
  • Shortness of breath
  • High fever
  • Muscle aches
  • Headaches

These symptoms usually begin 2 to 14 days after being exposed to the bacteria.

Pontiac Fever

A milder infection, also caused by Legionella bacteria, is called Pontiac fever. The symptoms of Pontiac fever are similar to those of Legionnaires’ disease and usually last for 2 to 5 days. Pontiac fever is different from Legionnaires' disease because the patient does not have pneumonia.

Symptoms go away on their own without treatment.