LEGIONELLA DIRECT ANTIGEN

Mnemonic

LEGDFA

Synonym

Legionella DFA

Guidelines

Use for Pericardial fluid, respiratory, or tissue specimens.
Tests available for other specimen types: Legionella Pneumophila Antigen, Urine, Legionella Species by PCR, and Legionella Species, Culture. PCR is the test of choice for diagnosing Legionella.

Specimen Collection Requirements

Collect

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.

Handling

Must specify source on order or requisition. Do not leave tubing attached to cap of collection device.

Preferred Volume

1.0 mL fluid

Minimum Volume

1.0 mL fluid

Transport

Frozen

Rejection Criteria

Non-respiratory specimens. Specimens in preservatives or viral transport medium.

Stability

Fluid or Tissue: Ambient: 12 hours; Refrigerated: 48 hours; Frozen: 1 week
Slides: Ambient: 1 week; Refrigerated: 1 week, Frozen: 1 week

Testing Information

Performed

Sun - Sat

Reported

1-3 days

Method

Direct Fluorescent Antibody Stain

Referral Lab

ARUP (2004598)

Reference Values

Reference Values

Interpretation provided.

Comments

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 organism in the specimen.

DFA is not recommended for diagnosing Legionella pneumophila-caused infections. For diagnosing Legionella pneumophila-caused infections, refer to Culture, Legionella or Legionella PCR testing, or Legionella pneumophila antigen test in Urine for urine specimens.

CPT Codes

87278

Last Updated: Thursday, January 5, 2017 03:42:19 AM