Tests and diagnosis

By Mayo Clinic Staff

Legionnaires' disease is similar to other types of pneumonia. To help identify the presence of legionella bacteria quickly, your doctor may use a test that checks your urine for legionella antigens — foreign substances that trigger an immune system response. You may also have one or more of the following:

  • Blood tests
  • Chest X-ray, which doesn't confirm Legionnaires' disease but can show the extent of infection in your lungs
  • Tests on a sample of your sputum or lung tissue
  • A CT scan of your brain or a spinal tap (lumbar puncture) if you have neurological symptoms such as confusion or trouble concentrating
Jan. 02, 2014