How Do You Get Tested For Legionnaires Disease?

Legionnaires disease refers to a severe type of pneumonia or lung inflammation caused often because of infection from a common type of bacteria i.e. legionella. This type of pneumonia disease does not take place because of physical contact. Rather, a majority of people suffer from Legionnaires disease because of the inhalation of the respective bacterium. Smokers, old people and people possessing relatively weak immune system are often susceptible to the problem.

Symptoms of Legionnaires Disease

Legionnaires disease often develops from minimum 2 days to 10 days after you expose to legionella bacterium. Initially, the problem starts with following common signs and symptoms-

  • Chills
  • Muscular/body pain
  • Headache
  • High fever of about 104 F or 40 C

After 2 or 3 days of your problem, you may develop various other signs and symptoms, like-

Even though the mentioned pneumatic type of problem affects one’s lungs primarily, it may even cause infections in different parts of the body, in existing wounds and in the heart.

How Do You Get Tested For Legionnaires Disease?

Since Legionnaires disease is a type of pneumonia, doctors recommend for following important tests to identify the presence of respective harmful bacteria within less time as possible.

Culture Test

Isolation of the Legionella bacterium on media supporting its growth from the tissues of one’s lungs, lower part of the respiratory secretions, pleural fluid or any other regular sterile site acts as a confirmatory and the most important method to diagnose the problem. By comparing both environmental and clinical isolates based on molecular and serologic techniques, one can identify the prime source related to outbreak investigation of the Legionnaire disease. Since Legionella problem takes place often in the environment, clinical isolates are helpful in the interpretation of findings related to environmental investigations.

Urinary Antigen Test

Another common type of laboratory test to diagnose Legionnaires disease is urinary antigen test. Accordingly, doctors detect Legionella bacterium in the form of molecules present in the patients’ urine. In case an individual is already suffering from pneumonia and the test displays positive result, you should consider that the person has Legionnaires problem. Result of this test continues to remain positive for about a few weeks of post infection even when the patient undergoes with antibiotic treatment.

Other Tests for Legionnaires disease

Along with the ones mentioned here, doctors often recommend a few other tests to pneumonia patients to detect Legionella bacterium. These include-

  • Blood tests
  • Sample test performed on a particular sample collected from lungs’ tissues or sputum
  • Chest X-ray to indicate the extent of Legionnaires disease infection in the lungs, but the test is unable to confirm about the disease in any way.
  • Doctors perform MRI or CT scan of the brain or lumbar puncture known as spinal tap in patients in case they suffer from neurological symptoms, like difficulty in concentration or confusion.

Indications for Patients to Go with Legionnaires Diagnose Test

Doctors recommend the following categories of pneumatic patients to undergo with Legionnaires disease diagnose Test-

  • Patients failed to undergo with outpatient-based antibiotic type of treatment associated with community-acquired pneumonia problems
  • Severe pneumatic patients requiring special and intensive care
  • Pneumonia patients with relatively weak immune system
  • Patients often have travel history within 10 days before their disease/illness
  • Almost every patient suffering from pneumonia in the setting consisting of Legionnaires disease/problem outbreak


To conclude we should say that Legionnaires disease patients have to undergo with different tests to detect Legionnaires problem, while the types of tests depend primarily on underlying condition/conditions.

Also Read:

Pramod Kerkar, M.D., FFARCSI, DA
Pramod Kerkar, M.D., FFARCSI, DA
Written, Edited or Reviewed By: Pramod Kerkar, M.D., FFARCSI, DA Pain Assist Inc. This article does not provide medical advice. See disclaimer
Last Modified On:August 30, 2018

Recent Posts

Related Posts