Coccidioides precipitin is a blood test that looks for infections due to a fungus called Coccidioides immitis, which causes the disease coccidioidomycosis.
How the Test is Performed
A blood sample is drawn from a vein.
The sample is sent to a laboratory when it is examined for preciptin bands that form when Coccidiodes antibodies are present.
How to Prepare for the Test
There is no special preparation for the test.
How the Test will Feel
When the needle is inserted to draw blood, you may feel moderate pain, or only a prick or stinging sensation. Afterward, there may be some throbbing.
Why the Test is Performed
The precipitin test is one of several tests that can be done to determine if you are infected with the fungus Coccidioides immitis, which causes the disease coccidioidomycosis.
Antibodies defend the body against bacteria, viruses, and fungi. These and other foreign substances are called antigens. When you are exposed to antigens, your body produces antibodies.
The precipitin test helps check if the body has produced antibodies to a specific antigen, in this case, the Coccidioides immitis fungus.
The result of "no precipitins' is normal. This means the blood test did not detect the antibody to Coccidioidies immitis.
What Abnormal Results Mean
An abnormal (positive) result means the antibody to Coccidioides immitis has been detected.
In this case, another test is done to confirm that you have an infection. Your doctor can tell you more.
Veins and arteries vary in size from one patient to another, and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.
Other risks associated with having blood drawn are slight, but may include:
- Excessive bleeding
- Fainting or feeling light-headed
- Hematoma (blood accumulating under the skin)
- Infection (a slight risk any time the skin is broken)
During the early stage of an illness, few antibodies may be detected. Antibody production increases during the course of an infection. For this reason, this test may be repeated several weeks after the first test.
Coccidioidomycosis antibody test
Ampel NM. Coccidioidomycosis: a review of recent advances. Clin Chest Med.
Galgiani JN. Coccidioidomycosis. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine. 24th ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 341.
Update Date 5/19/2013
Updated by: Jatin M. Vyas, MD, PhD, Assistant Professor in Medicine, Harvard Medical School; Assistant in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Bethanne Black, and the A.D.A.M. Editorial Team.