Legionella urine antigen
What is this test?
This test detects the antigen to a species of bacteria called Legionella in urine . It is used to help diagnose an infection caused by this bacteria.
What are other names for this test?
- Legionella antigen assay, urine
What are related tests?
Why do I need this test?
Laboratory tests may be done for many reasons. Tests are performed for routine health screenings or if a disease or toxicity is suspected. Lab tests may be used to determine if a medical condition is improving or worsening. Lab tests may also be used to measure the success or failure of a medication or treatment plan. Lab tests may be ordered for professional or legal reasons. You may need this test if you have:
- Legionella infection
When and how often should I have this test?
When and how often laboratory tests are done may depend on many factors. The timing of laboratory tests may rely on the results or completion of other tests, procedures, or treatments. Lab tests may be performed immediately in an emergency, or tests may be delayed as a condition is treated or monitored. A test may be suggested or become necessary when certain signs or symptoms appear.
Due to changes in the way your body naturally functions through the course of a day, lab tests may need to be performed at a certain time of day. If you have prepared for a test by changing your food or fluid intake, lab tests may be timed in accordance with those changes. Timing of tests may be based on increased and decreased levels of medications, drugs or other substances in the body.
The age or gender of the person being tested may affect when and how often a lab test is required. Chronic or progressive conditions may need ongoing monitoring through the use of lab tests. Conditions that worsen and improve may also need frequent monitoring. Certain tests may be repeated to obtain a series of results, or tests may need to be repeated to confirm or disprove results. Timing and frequency of lab tests may vary if they are performed for professional or legal reasons.
How should I get ready for the test?
To prepare for giving a urine sample, be sure to drink enough fluids before the test, unless you have been given other instructions. Try not to empty your bladder before the test.
How is the test done?
To provide a sample of urine, you will be asked to urinate into a container. Fill the container as much as you can, but do not overfill it. Urine samples may also be taken from a catheter.
How will the test feel?
The amount of discomfort you feel will depend on many factors, including your sensitivity to pain. Communicate how you are feeling with the person doing the test. Inform the person doing the test if you feel that you cannot continue with the test.
This test usually causes no discomfort.
What should I do after the test?
After collecting a urine sample, close the container if it has a lid. Place the container where the healthcare worker asked you to put it. Clean your hands with soap and water.
What are the risks?
Urine: A urine test is generally considered safe. Talk to your healthcare worker if you have questions or concerns about this test.
What are normal results for this test?
Laboratory test results may vary depending on your age, gender, health history, the method used for the test, and many other factors. If your results are different from the results suggested below, this may not mean that you have a disease. Contact your healthcare worker if you have any questions. The following is considered to be a normal result for this test:
- Negative 
What follow up should I do after this test?
Ask your healthcare worker how you will be informed of the test results. You may be asked to call for results, schedule an appointment to discuss results, or notified of results by mail. Follow up care varies depending on many factors related to your test. Sometimes there is no follow up after you have been notified of test results. At other times follow up may be suggested or necessary. Some examples of follow up care include changes to medication or treatment plans, referral to a specialist, more or less frequent monitoring, and additional tests or procedures. Talk with your healthcare worker about any concerns or questions you have regarding follow up care or instructions.
Where can I get more information?
- Centers for Disease Control and Prevention (CDC) - http://www.cdc.gov/
 Waterer GW, Baselski VS, & Wunderink RG: Legionella and community-acquired pneumonia: a review of current diagnostic tests from a clinician's viewpoint. Am J Med 2001; 110:41-48.
 Lindsay DS, Abraham WH, Findlay W, et al: Laboratory diagnosis of legionnaires' disease due to Legionella pneumophila serogroup 1: comparison of phenotypic and genotypic methods. J Med Microbiol 2004; 53(Pt 3):183-187.
 Murdoch DR: Diagnosis of Legionella infection.. Clin Infect Dis 2003; 36:64-69.
 Helbig JH, Uldum SA, Bernander S, et al: Clinical utility of urinary antigen detection for diagnosis of community-acquired pneumonia, travel-associated, and nosocomial legionnaires' disease.. J Clin Microbiol 2003; 41:37-43.
 Dominguez JA, Gali N, Pedroso P, et al: Comparison of the Binax Legionella urinary antigen enzyme immunoassay (EIA) with the Biotest Legionella Urin antigen EIA for detection of Legionella antigen in both concentrated and nonconcentrated urine samples. J Clin Microbiol 1998; 36(9):2718-22.
 Aguero-Rosenfeld ME & Edelstein PH: Retrospective evaluation of the Du Pont radioimmunoassay kit for detection of Legionella pneumophila serogroup 1 antigenuria in humans. J Clin Microbiol 1988; 26(9):1775-8.
 Sathapatayavongs B, Kohler RB, Wheat LJ, et al: Rapid diagnosis of Legionnaires' disease by urinary antigen detection. Comparison of ELISA and radioimmunoassay. Am J Med 1982; 72(4):576-582.
 Kohler RB, Zimmerman SE, Wilson E, et al: Rapid radioimmunoassay diagnosis of Legionnaires' disease: detection and partial characterization of urinary antigen. Ann Intern Med 1981; 94(5):601-605 .
Last Updated: 5/4/2018