Clinics and Departments

Laboratory Services

Lab Dept:


Test Name:


General Information

Lab Order Codes:



Coccidioides Antibody; Coccidioides Aby; San Joaquin Valley Fever

CPT Codes:

86635 x3 - Antibody; Coccidiodes

Test Includes:

Coccidioides IgG by Complement Fixation and Coccidioides IgG and IgM by Immunodiffusion reported as negative or positive. Positive results will be titered.


Test Indications:

Useful for detection of antibodies in patients suspected of having coccidioidomycosis.

Serologic testing for coccidioidomycosis should be considered when patients exhibit symptoms of pulmonary or meningeal infection and have lived or traveled in areas where Coccidiodes immitis is endemic. Any history of exposure to the organism or travel cannot be overemphasized when a diagnosis of coccidioidomycosis is being considered.

Lab Testing Sections:

Serology - Sendouts

Referred to:

Mayo Medical Laboratories (MML Tes: 8295/SCOC)

Phone Numbers:

MIN Lab: 612-813-6280

STP Lab: 651-220-6550

Test Availability:

Daily, 24 hours

Turnaround Time:

4 – 7 days; test set up Monday - Friday

Special Instructions:



Specimen Type:



Red top tube

Draw Volume:

6 mL (Minimum: 3.6 mL) blood

Processed Volume:

2 mL (Minimum: 1.2 mL) serum


Routine venipuncture

Special Processing:

Lab Staff: Centrifuge serum, remove aliquot and store refrigerated in a screw-capped, round bottom vial. Ship refrigerated. Forward promptly.

Patient Preparation:


Sample Rejection:

Specimens other than serum, gross hemolysis, gross lipemia, mislabeled or unlabeled specimens


Reference Range:

Complement Fixation (CF):

If positive, results are titered

Titers of ≥1:2 may suggest active disease; however, titers may persist for months after infection has resolved. Increasing CF titers in serial specimens are diagnostic of active disease.

Immunodiffusion (ID):

Results are reported as positive, negative or equivocal.

The presence of IgM antibody may be detectable within 2 weeks after the onset of symptoms; however, antibody may be detected longer than 6 months after infection.

The presence of IgG antibody parallels the CF antibody and indicates an active or a recent asymptomatic infection with Coccidioides immitis; however, antibody may persist after the infection has resolved.

An equivocal result (a band of non-identity) cannot be interpreted as significant for a specific diagnosis. However, this may be an indication that a patient should be followed serologically.

Over 90% of primary symptomatic cases will be detected by combined ID and CF testing.

Critical Values:



Antibodies (both IgM and IgG) may be present after the infection has resolved.


Complement Fixation (CF) using Coccidiodin IgG
Immunodiffusion: IgG/IgM


Mayo Medical Laboratories Web Page July 2013

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