Coccidioides antibody, serum/plasma (qualitative/quantitative immunoassay)

What Does This Test Measure?

The test checks for the presence of antibodies against *Coccidioides* antigens, which your body makes after exposure to the fungus. Antibodies are proteins that help fight infections. This test is often used to confirm a diagnosis of coccidioidomycosis (Valley Fever) or to track how your infection is progressing.

Why Might You Need This Test?

Your healthcare provider may recommend this test if you have symptoms like fever, cough, chest pain, or fatigue—especially if you live or traveled to areas where *Coccidioides* is common (e.g., parts of the southwestern U.S., parts of Latin America, or Australia). It may also be used if you have a weakened immune system or if you’ve been exposed to the fungus.

How Is the Test Done?

A blood sample is drawn from a vein in your arm. The sample is sent to a lab, where it’s tested using an immunoassay method to detect specific antibodies. Results are reported as either positive (antibodies present) or negative (no detectable antibodies).

What Are Possible Results?

A positive result means your body has produced antibodies to *Coccidioides*, suggesting past or current infection. A negative result means no detectable antibodies were found. False positives or negatives can occur, so results are often reviewed by a healthcare provider.