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HelpTest Code CBSRP Coxiella burnetii (Q Fever), Molecular Detection, PCR, Serum
Reporting Name
Coxiella burnetii (Q fever) PCR, SUseful For
Aiding in the diagnosis of Coxiella burnetii infection (ie, Q fever) using serum specimens
Method Name
Real-Time Polymerase Chain Reaction (PCR)
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Specimen Type
SerumSpecimen Required
The high sensitivity of amplification by polymerase chain reaction requires the specimen to be processed in an environment in which contamination of the specimen by Coxiella burnetii DNA is unlikely.
Collection Container/Tube:
Preferred: Red top
Acceptable: Serum gel
Submission Container/Tube: Sterile vial
Specimen Volume: 1 mL
Collection Instructions: Centrifuge and aliquot serum into a sterile vial within 2 hours of collection.
Specimen Minimum Volume
0.5 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Serum | Frozen (preferred) | 7 days | |
| Refrigerated | 7 days |
Reject Due To
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.Reference Values
Not applicable
Day(s) Performed
Monday through Friday
CPT Code Information
87798
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| CBSRP | Coxiella burnetii (Q fever) PCR, S | 90443-3 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 35189 | Specimen Source | 31208-2 |
| 35190 | Coxiella burnetii PCR | 90443-3 |
Clinical Information
Coxiella burnetii, the causative agent of Q fever, is a small obligately intracellular bacterium associated with animals. Acquired through aerosol exposure, it generally causes mild respiratory disease. A small number of acute cases advance to a chronic infection, which typically manifests as endocarditis. Left untreated, Q fever endocarditis may be fatal. Serologic and histopathologic studies may be nonspecific and subjective, respectively, limiting usefulness for patient diagnosis.
Evaluation of infected tissue, blood, or serum using polymerase chain reaction (PCR) may be a useful tool for diagnosing some cases of Coxiella burnetii infection. Mayo Clinic Laboratories has developed a real-time PCR test that rapidly detects Coxiella burnetii DNA in clinical specimens by targeting a sequence of the shikimate dehydrogenase gene (aroE) unique to Coxiella burnetii.
Interpretation
A positive result indicates the presence of Coxiella burnetii DNA.
A negative result indicates the absence of detectable C burnetii DNA but does not negate the presence of the organism and may occur due to inhibition of PCR, sequence variability underlying primers or probes, or the presence of C burnetii DNA in quantities less than the limit of detection of the assay.
Cautions
Test results should be used as an aid in diagnosis and not be considered diagnostic in themselves. A single assay should not be used as the only criteria to form a clinical conclusion, but results should be correlated with patient symptoms and clinical presentation. A negative result does not negate the presence of the organism or active disease.
Method Description
Bacterial nucleic acid is extracted from the specimen using the automated MagNA Pure instrument. The purified DNA is placed on the LightCycler instrument, which amplifies and monitors by fluorescence the development of target nucleic sequences after each PCR cycle. A specific target sequence from Coxiella burnetii is amplified and the resulting segment is detected using specific hybridization probes. Detection of the Coxiella burnetii target is performed through melting curve analysis using the LightCycler software.(Cockerill FR, Uhl FR: Applications and challenges of real-time PCR for the clinical microbiology laboratory. In: Reischl U, Wittwer C, Cockerill F, eds. Rapid Cycle Real-Time PCR, 2002:3-27; Kersh GJ, Bleeker-Rovers CP: Coxiella. In: Carroll K, Pfaller M, eds. Manual of Clinical Microbiology. 12th ed. ASM Press; 2019:1180-1188)