Diagnosis of Legionnaires disease
Test Id | Reporting Name | Available Separately | Always Performed |
---|---|---|---|
RMALD | Ident by MALDI-TOF mass spec | No, (Bill Only) | No |
ISAE | Aerobe Ident by Sequencing | No, (Bill Only) | No |
TISSR | Tissue Processing | No, (Bill Only) | No |
When this test is ordered, the reflex tests may be performed at an additional charge.
Conventional Culture
50008-LEGI
When this test is ordered, the reflex tests may be performed at an additional charge.
Varies
Because examination by rapid polymerase-chain reaction (PCR) increases sensitivity and provides faster results, it is strongly recommended to also order LEGRP / Legionella species, Molecular Detection, PCR, Varies.
Specimen source is required.
Question ID | Description | Answers |
---|---|---|
Q00M0033 | Specimen Source |
Specimen Type: Lower respiratory
Sources: Bronchoalveolar lavage, bronchial aspirate/brushing/lavage/washing, tracheal/endotracheal secretions/aspirate, sputum
Container/Tube: Sterile container
Specimen Volume: Entire collection
Specimen type: Fresh tissue or biopsy
Sources: Lung, pleura, heart valve, pericardium
Container/Tube: Sterile container
Specimen Volume: 5 mm(3)
Collection Instructions: Aseptically collect a 1 to 2 cm(3) piece of tissue whenever possible
Specimen type: Fluid
Sources: Pericardial, pleural, chest, chest tube drainage, thoracentesis, empyema
Container/Tube: Sterile container
Specimen Volume: 2 mL
If not ordering electronically, complete, print, and send a Microbiology Test Request (T244) with the specimen.
See Specimen Required
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Varies | Refrigerated | 48 hours |
Diagnosis of Legionnaires disease
When this test is ordered, the reflex tests may be performed at an additional charge.
The Legionellaceae are ubiquitous in natural freshwater habitats, allowing them to colonize artificial water supplies (eg, reservoirs), which may then serve as the source for human infections.
Legionella pneumophila and the related species, Legionella bozemanii, Legionella dumoffii, Legionella gormanii, Legionella micdadei, Legionella longbeachae, and Legionella jordanis have been isolated from patients with pneumonia (Legionnaires disease). The organism has been isolated from lung tissue, bronchoalveolar lavage, pleural fluid, and sputum. The signs, symptoms, and radiographic findings of Legionnaires disease are generally nonspecific.
No growth of Legionella species after 7 days of incubation
Identification of Legionella species from respiratory specimens provides a definitive diagnosis of Legionnaires disease.
Organisms isolated are identified as Legionella species via matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry and/or 16S ribosomal RNA (rRNA) gene sequencing.
Although semi-selective media is utilized, recovery of Legionella in specimens heavily contaminated with indigenous microbiota (ie, sputum) may be difficult.
1. Edelstein PH. Legionella In: Carroll KC, Pfaller MA, eds. Manual of Clinical Microbiology. 12th ed. ASM Press; 2019:905-920
2. Clinical and Laboratory Standards Institute. Interpretive Criteria for Identification of Bacteria and Fungi by Targeted DNA Sequencing. 2nd ed. CLSI Guideline MM18. CLSI; 2018
3. Rucinski SL, Murphy MP, Kies KD, Cunningham SA, Schuetz AN, Patel R. Eight years of clinical Legionella PCR testing illustrates a seasonal pattern. J Infect Dis. 2018;218(4):669-670. doi:10.1093/infdis/jiy201
Specimens are cultured on buffered charcoal-yeast extract-based media. Colonies may appear within a few days; however, cultures are incubated for 7 days before issuing a negative report. Positive specimens will be identified via matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry and/or 16S ribosomal RNA (rRNA) gene sequencing.(Edelstein PH. Improved semi-selective medium for isolation of Legionella pneumophila from contaminated clinical and environmental specimens. J Clin Microbiol. 1981;14:298-303; CLSI. Interpretive Criteria for Identification of Bacteria and Fungi by Targeted DNA Sequencing. 2nd ed. CLSI Guideline MM18. Clinical and Laboratory Standards Institute; 2018)
Monday through Sunday
This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.
87081
87077-Ident by MALDI-TOF mass spec
Test Id | Test Order Name | Order LOINC Value |
---|---|---|
LEGI | Legionella Culture | 593-4 |
Result Id | Test Result Name |
Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
|
---|---|---|
LEGI | Legionella Culture | 593-4 |