Useful as an adjunct to culture for the presumptive diagnosis of past or current Legionnaires disease (Legionella pneumophila serogroup 1)
Specimen Type
Random Urine
Specimen Requirements
Urine Cup
Specimen Collection / Processing Instructions
Collect a random urine specimen
No preservative
Excessively bloody or very turbid specimens containing protein, cells, or particulates are not acceptable
Do not centrifuge
Specimens with any dyes or unnatural color are not acceptable
Minimum Sample Volume
0.25 mL
Stability
Refrigerated (preferred): 7 days
Frozen: 14 days
Ambient: 24 hours
Unacceptable Specimen Conditions
Gross hemolysis
Turbidity
Colored
Limitations
This assay has been verified using urine specimens only. For serum specimens, order SLEG / Legionella pneumophila (Legionnaires Disease), Antibody, Serum
Other specimen types (eg, plasma or body fluids) that may contain Legionella antigen have not been verified for testing.
The diagnosis of Legionnaires disease cannot be based on clinical or radiological evidence alone. There is no single satisfactory laboratory test for Legionnaires disease. Culture results, serology, and antigen detection methods should all be used in conjunction with clinical findings for diagnosis
The Legionella pneumophila serogroup 1 will not detect infections caused by other serogroups, Legionella micdadei or Legionella longbeachae. Culture is recommended for suspected pneumonia to detect causative agents other than L pneumophila serogroup 1, and to confirm infection
Excretion of Legionella antigen in urine may vary among patients, depending on their underlying illness or treatment. Some individuals have been shown to excrete antigen for extended periods of time (up to 1 year after acute infection) and positivity may, therefore, indicate previous infection rather than current infection. Early treatment with appropriate antibiotics may decrease antigen excretion in some individuals, and the use of diuretics may affect the ability of the test to detect antigen. Consequently, patient history (eg, a history of a recent respiratory illness compatible with Legionnaires disease) must be considered when evaluating results.
