Legionnaires’ Disease Symptoms and Diagnosis

What are the Symptoms of Legionnaires' Disease?

Legionnaires’ disease usually begins with the following symptoms that are similar to other types of pneumonia within 2-14 days after you are exposed: 

• Headache
• Muscle aches
• Joint aches
• Low-grade fever
• Shortness of breath
• Cough
• Fatigue
• Appetite loss

You may experience worsening symptoms, such as a high fever of up to 104 degrees, more severe cough, difficulty breathing, chest pain, nausea, diarrhea, chills and confusion.

How is Legionnaires’ Disease Diagnosed?

Based on your signs and symptoms, if your healthcare provider suspects pneumonia, they will order a chest x-ray. If you have portions of your lung where the air sacs have filled with fluid or pus, it will look cloudy in an x-ray. 

To diagnose Legionnaires’ disease among other types of pneumonia, your doctor will order a urine test, followed by a sputum culture and/or lung fluid or tissue tests to determine the presence of the Legionella bacteria in your lungs.

Legionnaires' disease is a reportable disease, meaning that if a healthcare provider diagnoses a case, they are required to report it to the health department. Health departments then determine if an investigation is required and if more people should be tested based on possible exposure.