Legionella Real-time PCR Panel
Legionella bacteria is increasingly recognized as an important pathogen causing both community acquired pneumonia and nosocomial pneumonia. The mortality rate can be lowered if the disease is diagnosed rapidly and appropriate antimicrobial therapy is instituted.
Laboratory diagnosis is important since pneumonia caused by Legionella is clinically indistinguishable from other pneumonias. It is estimated that in most Legionella infections, L. pneumophila is the causative agent 90% of the time; however, not all cases of Legionella infection are L. pneumophila. The non-Legionella pneumophila species have been documented to cause illness, but are difficult to culture and not detected by Urinary Antigen Testing. A molecular method such as PCR is a useful diagnostic tool since it is more rapid than culture and does not depend on growth of a fastidious organism. PCR is utilized for detection of Legionella species in respiratory specimens, providing early, definitive diagnosis of infection.
About Legionella
Legionella bacterium is often found in fresh water sources such as lakes or streams. It can grow, spread and be found in human-made water systems including indoor plumbing, hot tubs, water tanks, cooling towers and fountains. As Legionella grows, it contaminates the water source and is eventually released in droplets that can be inhaled or, less commonly, aspirated. Those with increased risk of infection due to Legionella include the immunocompromised, elderly, people with a history of smoking, and/or with chronic lung disease. Legionellosis can present as either Legionnaires’ disease or as Pontiac fever.
Diagnosis of Legionella infection can be confirmed through chest x-ray and PCR laboratory testing from sample types like sputum, blood, or urine. Legionella infection can often be treated using antibiotics. Possible complications include lung failure or death. The Center for Disease Control (CDC) states that about one of ten people that have Legionnaires’ disease will die from infection. Cases of Legionnaires’ disease have been on the rise since the year 2000, and reached around 6,000 cases in the United States in 2015. The CDC estimates many cases may go undiagnosed, which may underestimate the overall incidence of disease.
ProcedureExtraction of Legionella DNA from specimen followed by amplification and detection of Legionella species and L. pneumophila using real-time, qualitative PCR. An internal control is added to ensure the extraction was performed correctly and the PCR reaction was not inhibited. This test has not been cleared or approved for diagnostic use by the U.S. Food and Drug Administration.
SpecificityThe Legionella species assay design includes pathogen sequence information from 13 Legionella species described in the literature as causing human illness (Yu, 2002). L. pneumophila (serogroups 1-15), L. longbeachae, L. micdadei, L. jordanis. L. oakridgensis, L. gormanii, L. hackeliae, L. feeleii, L. ansia, L. dumoffii, L. wadsworthii, L. bozemanae and L. sainthelensi. The Legionella pneumophila specific assay does not cross react with any of the other Legionella species mentioned above.
The Legionella assays were tested for cross reactivity against Bordetella pertussis, Bordetella parapertussis, Bordetella bronchiseptica, all relevant species of Chlamydophila, all relevant strains of Mycoplasma pneumoniae, as well as Coxiella burnetii, Pneumocystis carinii, and common respiratory viruses with no cross reactivity noted.
Same day (within 12-18 hours from receipt of specimen), Monday through Saturday.
Specimen Type | Test Code | CPT Code | NY Approved | Volume | Assay Range | Special Instructions |
---|---|---|---|---|---|---|
BAL | 5409 | 87801, 87541 | Yes | 2 mL (min. 0.5mL) |
Detected/Not Detected |
|
pleural fluid | 5411 | 87801, 87541 | Yes | 2 mL (min. 0.5 mL) |
Detected/Not Detected |
|
nasal wash | 5413 | 87801, 87541 | Yes | 2 mL (min. 0.5 mL) |
Detected/Not Detected |
|
sputum | 5415 | 87801, 87541 | Yes | 2 mL (min. 0.5 mL) |
Detected/Not Detected |
|
trach asp | 5419 | 87801, 87541 | Yes | 2 mL (min. 0.5 mL) |
Detected/Not Detected |
|
throat gargle | 5423 | 87801, 87541 | Yes | 2 mL (min. 0.5 mL) |
Detected/Not Detected |
|
NP aspirate | 5424 | 87801, 87541 | Yes | 2 mL (min. 0.5 mL) |
Detected/Not Detected |
|
NP swab | 5425 | 87801, 87541 | Yes | 2 mL |
Detected/Not Detected |
|
bronch wash | 5426 | 87801, 87541 | Yes | 2 mL (min. 0.5 mL) |
Detected/Not Detected |
|
nasal swab | 5430 | 87801, 87541 | Yes | 2 mL |
Detected/Not Detected |
|
nasal asp | 5431 | 87801, 87541 | Yes | 2 mL (min. 0.5 mL) |
Detected/Not Detected |
|
NP wash | 5447 | 87801, 87541 | Yes | 2 mL (min. 0.5 mL) |
Detected/Not Detected |
|
trach wash | 5448 | 87801, 87541 | Yes | 2 mL (min. 0.5 mL) |
Detected/Not Detected |
|
Ship Monday through Friday. Friday shipments must be labeled for Saturday delivery. All specimens must be labeled with patient's name and collection date. A Eurofins Viracor test requisition form must accompany each specimen. Multiple tests can be run on one specimen. Ship specimens FedEx Priority Overnight® to: Eurofins Viracor, 18000 W 99th St. Ste, #10, Lenexa, KS 66219
Causes for RejectionRespiratory sample received in trap, specimen received outside stability, insufficient specimen volume, and specimen types other than those listed.
Specimens are approved for testing in New York only when indicated in the Specimen Information field above. The CPT codes provided are based on Eurofins Viracor interpretation of the American Medical Association's Current Procedural Terminology (CPT) codes and are provided for informational purposes only. CPT coding is the sole responsibility of the billing party. Questions regarding coding should be addressed to your local Medicare carrier. Eurofins Viracor assumes no responsibility for billing errors due to reliance on the CPT codes illustrated in this material.
ReferencesBenitez, A. (2013) Clinical application of a multiplex real-time PCR assay for simultaneous detection of Legionella species, Legionella pneumophila, and Legionella pneumophila serogroup 1. J Clin Microbiol, 51(1), 348-351. doi: 10.1128/JCM.02510-12
Benitez, A. (2016) Rapid Detection and typing of pathogenic nonpenumophila Legionella spp. isolates using a multiplex real-time PCR assay. Diagn Microbiol Infect Dis 84(4), 298-303. doi: 10.1016/j.diagmicrobio.2016.01.007
Joseph, S. (2016) Dynamics of genome change among Legionella species. Sci Rep, 6:33442. doi: 10.1038/srep33442
Muder, R. (2002) Infection Due to Legionella Species Other Than L. pneumophila. Clin Infect Dis 35(8):990-998. doi: 10.1086/342884
Yang, G. (2010) Duel detection of Legionella pneumophila and Legionella species by real-time PCR targeting this 23S-5S rRNA gene spacer region. Clin Microbiol Infect, 16(3), 255-261. doi: 10.1111/j.1469-0691.2009.02766.x
Yu, V. (2002). Distribution Of Legionella Species And Serogroups Isolated By Culture In Patients With Sporadic Community-Acquired Legionellosis: An International Collaborative Survey. Infectious Diseases in Clinical Practice, 11(4), 258. doi:10.1097/00019048-200205000-00039