Test ID: CIMRP Coccidioides immitis/posadasii, Molecular Detection, PCR, Varies
Reporting Name
Coccidioides PCRUseful For
Rapid detection of Coccidioides DNA, preferred method
An aid in diagnosing coccidioidomycosis
Clinical Information
Coccidioidomycosis is caused by the dimorphic fungi, Coccidioides immitis and Coccidioides posadasii. These organisms are endemic to the southwestern regions of the United States, northern Mexico, and areas of Central and South America. The illness commonly manifests as a self-limited upper respiratory tract infection, but can also result in disseminated disease that may be refractory to treatment.(1) Clinical onset generally occurs 10 to 16 days following inhalation of coccidioidal spores (arthroconidia).(2) Disease progression may be rapid in previously healthy or immunosuppressed individuals.
At present, the gold standard for the diagnosis of coccidioidomycosis is culture of the organism from clinical specimens. Culture is highly sensitive and, with the implementation of DNA probe assays for confirmatory testing of culture isolates, yields excellent specificity.(3) However, growth in culture may take up to several weeks. This often delays the diagnosis and treatment of infected individuals. In addition, the propagation of Coccidioides species in the clinical laboratory is a significant safety hazard to laboratory personnel, serving as an important cause of laboratory-acquired infections if the organism is not quickly identified and handled appropriately (ie, in a Biosafety Level 3 facility). Serological tests including immunodiffusion and complement fixation are widely used for the detection of antibody against Coccidioides. Serology for Coccidioides can be limited by delays in antibody development or nonspecificity due to cross-reactions with other fungi. In addition, immunodiffusion and complement fixation tests are highly labor intensive and are generally limited to reference laboratories.
Molecular methods can identify Coccidioides species directly from clinical specimens, allowing for a more rapid diagnosis. Fungal culture should also be performed since the isolate may be needed for antifungal susceptibility testing.
Interpretation
A positive result indicates presence of Coccidioides DNA.
A negative result indicates absence of detectable Coccidioides DNA.
Testing Algorithm
See Meningitis/Encephalitis Panel Algorithm in Special Instructions.
Analytic Time
1 dayDay(s) and Time(s) Performed
Monday through Sunday
Clinical Reference
1. Chiller TM, Galgiani JN, Stevens DA: Coccidioidomycosis. Infect Dis Clin North Am 2003;17:41-57
2. Feldman BS, Snyder LS: Primary pulmonary coccidioidomycosis. Semin Respir Infect 2001;16:231-237
3. Padhye AA, Smith G, Standard PG, et al: Comparative evaluation of chemiluminescent DNA probe assays and exoantigen tests for rapid identification of Blastomyces dermatitis and Coccidioides immitis. J Clin Microbiol 1994;32:867-870
4. Inoue T, Nabeshima K, Kataoka H, Koono M: Feasibility of archival non-buffered formalin-fixed and paraffin-embedded tissues for PCR amplification: an analysis of resected gastric carcinoma. Pathol Int 1996;46:997-1004
5. Binnicker MH, Popa AS, Catania J, et al: Meningeal coccidioidomycosis diagnosed by real-time polymerase chain reaction analysis of cerebrospinal fluid. Mycopathologia 2011;171:285-289
6. Vucicevic D, Blair JE, Binnicker MJ, et al: The utility of Coccidioides polymerase chain reaction testing in the clinical setting. Mycopathologia 2010;170:345-351
Method Name
Real-Time Polymerase Chain Reaction (PCR)
Specimen Type
VariesShipping Instructions
Specimen must arrive within 7 days of collection; specimen >7 days will be rejected.
Necessary Information
Specimen Required
The high sensitivity of amplification by PCR requires the specimen to be processed in an environment in which contamination of the specimen by Coccidioides species DNA is unlikely.
Preferred Specimens: Body fluid, cerebrospinal fluid (CSF), ocular fluid, respiratory (eg, bronchoalveolar lavage [BAL], bronchial washing, sputum), fresh tissue, or bone
Acceptable Specimens: If no fresh specimen is available, digested respiratory specimens treated with N-acetyl-L-cysteine (NALC)/NaOH are acceptable (eg, bronchoalveolar lavage fluid, bronchial washing, respiratory fluid, sputum, or tracheal secretion)
Submit only 1 of the following specimens:
Specimen Type: Body fluid
Sources: Body, ocular, or CSF
Container/Tube: Sterile container
Specimen Volume: 1 mL
Additional Information: Only fresh, non-NALC/NaOH-digested body fluid is acceptable.
Specimen Type: Respiratory
Sources: BAL, bronchial washing, or sputum
Container/Tube: Sterile container
Specimen Volume: 1 mL if only PCR ordered or 3 mL if PCR ordered with smear and culture
Specimen Type: Tissue
Sources: Fresh tissue or bone
Container/Tube: Sterile container
Specimen Volume: 5-10 mm
Collection Instructions: Keep moist with sterile water or sterile saline
Additional Information: Only fresh, non-NALC/NaOH-digested tissue is acceptable.
Acceptable
Specimen Type: NALC/NaOH-digested respiratory specimens
Sources: Lavage fluid, bronchial washing, respiratory fluid, sputum, or tracheal secretion
Container/Tube: Sterile container
Specimen Volume: 2 mL
Collection Instructions:
1. Submit digested specimen treated with NALC/NaOH.
2. Clearly indicate on container and order form that specimen is a digested specimen.
Specimen Minimum Volume
Body fluid: 0.5 mL; Respiratory specimen nondigested: 0.5 mL; Fresh tissue or bone: 5 mm; NALC-NaOH-digested specimen: 1 mL
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Varies | Refrigerated (preferred) | 7 days | |
Frozen | 7 days |
Special Instructions
Reference Values
Not applicable
Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.CPT Code Information
87798
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
CIMRP | Coccidioides PCR | 48588-8 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
SRC64 | Coccidioides PCR, Specimen Source | 31208-2 |
88804 | Coccidioides PCR, Result | 48588-8 |
Forms
If not ordering electronically, complete, print, and send a Microbiology Test Request (T244) with the specimen.
mml-CNS-Infections, mml-Pediatric