Legionella DNA, Qualitative, Real-Time PCR

Legionella species, Molecular Detection, PCR, Varies

Test Codes

Epic: LAB1232097, Beaker: LegionPCR, Quest: 15062

Department

Send Outs

Specimen Collection Criteria

Collection varies (see below).
1.0 mL bronchoalveolar lavage (BAL) or bronchial wash collected in a sterile plastic leak-proof container or 1.0 mL sputum collected in a sputum collection kit or a sterile plastic leak-proof container. 

Alternate Specimens: Throat or nasopharyngeal swab collected in 3.0 mL M4 media or VCM medium (green-cap) or equivalent (UTM) tube.

Throat, nasopharyngeal (NP) swabs: Use sterile vials containing 3.0 mL of sterile VCM, M4, or equivalent (UTM) media. If using swabs, use only sterile dacron or rayon swabs. Do not use calcium alginate swabs, as they may contain substances that inhibit PCR testing. Break applicator sticks off near the tip to permit tightening of the cap.

Physician Office/Draw Specimen Preparation

Maintain specimen in sterile screw top container refrigerated (2-8°C or 36-46°F) prior to transport.

Preparation for Courier Transport

Transport:  Specimen in sterile screw top container, refrigerated (2-8°C or 36-46°F). (Minimum 0.3 mL)

Rejection Criteria

• Calcium alginate swabs.
• Specimens not collected and processed as indicated.

In-Lab Processing

Maintain specimen in sterile screw top container at refrigerated (2-8°C or 36-46°F) prior to transport.

Transport: Specimen in sterile screw top container, refrigerated (2-8°C or 36-46°F). (Minimum 0.3 mL)

Storage

Specimen Stability for Testing:

Room Temperature (20-26°C or 68-78.8°F): 48 hours
Refrigerated (2-8°C or 36-46°F): 14 days
Frozen (-20°C/-4°F or below): 30 days

Specimen Storage in Department Prior to Disposal:  7 days

Specimen retention time is determined by the policy of the reference laboratory. Contact the Send Outs Laboratory with any questions.

Laboratory

Sent to Quest Diagnostics, Wood Dale, IL.

Performed

Monday – Sunday
Results available in 3-5 days.

Reference Range

Legionella species	Not detected
Legionella pneumophila	Not detected

Test Methodology

Fluorescent resonance energy (FRET) hybridization.

Interpretation

By report.

Clinical Utility

Legionella DNA, Qualitative, Real-Time PCR - This test is intended for the qualitative detection of DNA from Legionella pneumophila and other pathogenic Legionella species in patients at risk for legionellosis.

Most species of the bacteria Legionella are pathogenic and can cause respiratory infections that present as either Legionnaires? disease or Pontiac fever, which are collectively referred to as legionellosis. Transmission most commonly occurs via inhalation of aerosolized water containing the bacteria. Risk factors include age ≥50, smoking, chronic lung disease, immune system disorders due to illness or medication, a recent stay outside the home, systemic malignancy, underlying illnesses such as diabetes or renal failure, and exposure to hot tubs (1).

A detected Legionella pneumophila result is consistent with the presence of DNA from any serotype of L. pneumophila, while the presence of DNA above the limit of detection from most species of clinically relevant Legionella species, including but not limited to L. pneumophila, L. longbeachae, L. micdadei, L. dumoffii, L. feeleii and L. bozemanii, will cause a detected Legionella species result.

This test is faster and generally more sensitive than culture-based tests, and it allows for the detection of a wider range of targets as compared to urine antigen tests, which typically only detect specific serotypes of L. pneumophila. It does not, however, detect all species of Legionella and may not detect L. jordanis and L. oakridgensis.

CPT Codes

87541, 87798

Contacts

Last Updated

12/18/2025