Ordering Recommendation

Aids in diagnosis of coccidioidal meningitis (Valley fever).




Semi-Quantitative Complement Fixation/Qualitative Immunodiffusion




2-6 days

New York DOH Approval Status

Specimens from New York clients will be sent out to a New York DOH approved laboratory, if possible.

Specimen Required

Patient Preparation


Specimen Preparation

Transfer 2.5 mL CSF to an ARUP Standard Transport Tube. (Min: 1 mL) Parallel testing is preferred and convalescent specimens must be received within 30 days from receipt of the acute specimens.

Storage/Transport Temperature


Unacceptable Conditions

Other body fluids. Contaminated, hemolyzed, xanthochromic, or severely lipemic specimens.


Mark specimens plainly as "acute" or "convalescent."


Ambient: 48 hours; Refrigerated: 2 weeks; Frozen: 1 year (avoid repeated freeze/thaw cycles)

Reference Interval

Test Number Components Reference Interval
3000064 Coccidioides by Immunodiffusion, CSF None detected.
0050711 Coccidioides Ab by CF, CSF Less than 1:2

Interpretive Data

Refer to report. 

This test was developed and its performance characteristics determined by ARUP Laboratories. It has not been cleared or approved by the US Food and Drug Administration. This test was performed in a CLIA certified laboratory and is intended for clinical purposes.

Compliance Category

Modified FDA


For Coccidioides, immunodiffusion (ID) measures IgM antibody, while complement fixation (CF) measures both IgG and IgM. ELISA tests can be used to detect both coccidioidal IgG and IgM antibodies. While elevated single antibody titers may be diagnostic, paired specimens are preferred. Acute and convalescent specimens (drawn at least 21 days apart) showing a fourfold or greater rise in titer are diagnostic.

Negative fungal serology does not rule out the possibility of current infection.

Hotline History


CPT Codes

86635 x2


Component Test Code* Component Chart Name LOINC
0050711 Coccidioides Ab by CF, CSF 13917-0
3000064 Coccidioides by Immunodiffusion, CSF 21209-2
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.


Coccidioides Ab by CF & ID, CSF