Use for the rapid identification of L. pneumophila; sensitivity is dependent on patient population and specimen type. Molecular testing is generally preferred; refer to Legionella Species by Qualitative PCR (2010125).
Direct Fluorescent Antibody Stain
Within 24 hours
Pericardial fluid, respiratory, or tissue specimens.
Fluid: Prepare two duplicate slides. OR transfer 1 mL fluid to a sterile container.
Tissue: Transfer tissue to a sterile container and place on gauze moistened with sterile non-bacteriostatic saline to prevent drying.
Refrigerated. OR frozen if transport occurs more than 48 hours after collection.
Non-respiratory specimens. Specimens in preservatives or viral transport medium.
Specimen source preferred.
Fluid or Tissue: Ambient: 12 hours; Refrigerated: 48 hours; Frozen: 1 week
Slides: Ambient: 1 week; Refrigerated: 1 week; Frozen: 1 week
A negative stain result does not exclude the possibility of infection. False-negative results may occur due to sampling errors or a low number of organisms in the specimen. DFA is not recommended for diagnosing Legionella pneumophila-caused infections. For diagnosing Legionella pneumophila-caused infections, refer to Legionella Species, Culture (ARUP test code 0060113), Legionella Species by Qualitative PCR (ARUP test code 2010125) for amplified DNA testing of respiratory specimens, or Legionella pneumophila Antigen, Urine (ARUP test code 0070322) for urine specimens.
|Component Test Code*||Component Chart Name||LOINC|
|2004599||Legionella pneumophila DFA Source||31208-2|
|2004600||Legionella pneumophila DFA Result||588-4|
- L. pneumophilia DFA
- Legionella Smear, DFA