A sample of urine is required. It does not have to be midstream.
This test will detect only infections caused by L. pneumophila serogroup 1 and not other Legionella species.
A negative antigen result may not exclude infection with L. pneumophila serogroup 1 if the antigen level in the urine is below detection levels.
The diagnosis of Legionnaires’ Disease cannot be based on clinical or radiological evidence alone. There is no single satisfactory laboratory test for Legionnaires’ Disease. Therefore, culture results, serology and antigen detection methods should be used in conjunction with clinical findings to make an accurate diagnosis.
Excretion of Legionella antigen in urine may vary depending on the individual patient. Antigen excretion may begin as early as 3 days after onset of symptoms and persist for up to 1 year afterwards.