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Coccidioides complement fixation
Coccidioides antibody test
Coccidioides complement fixation is a blood test that looks for antibodies to the fungus Coccidioides immitis. This fungus causes the disease coccidioidomycosis.
How the Test is Performed
Blood sample is needed
Venipuncture is the collection of blood from a vein. It is most often done for laboratory testing.
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, some people feel moderate pain, while others feel only a prick or stinging. Afterward, there may be some throbbing.
Why the Test is Performed
This test is used to detect infection with the fungus that causes coccidioidomycosis or valley fever. This condition can cause lung or widespread (disseminated) infection.
Coccidioidomycosis
Valley fever is an infection that occurs when the spores of the fungus Coccidioides immitis enter your body through the lungs.
Normal Results
A normal result means no Coccidioides immitis antibodies are detected in the blood sample.
Antibodies
An antibody is a protein produced by the body's immune system when it detects harmful substances, called antigens. Examples of antigens include micr...
Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your doctor about the meaning of your specific test results.
What Abnormal Results Mean
Abnormal results mean that Coccidioides immitis antibodies are present. This can mean that you have a current or recent infection.
The test may be repeated after several weeks to detect a rise in titer (antibody concentration), which confirms an active infection.
Titer
A titer is a measurement of the amount or concentration of a substance in a solution. It usually refers to the amount of antibodies found in a perso...
In general, the worse the infection, the higher is the titer, except in people with a weakened immune system.
There can be false positive tests in people with other fungal diseases such as histoplasmosis and blastomycosis , and false negative tests in people with single lung masses from coccidioidomycosis.
Histoplasmosis
Histoplasmosis is an infection that occurs from breathing in the spores of the fungus Histoplasma capsulatum.
Blastomycosis
Blastomycosis is an infection caused by breathing in the Blastomyces dermatitidis fungus. The fungus is found in decaying wood and soil.
Risks
Veins and arteries vary in size from one person 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 lightheaded
- Hematoma (blood accumulating under the skin)
- Infection (a slight risk any time the skin is broken)
References
Galgiani JN. Coccidioidomycosis ( Coccidioides species ). In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases . 8th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 267.
Iwen PC. Mycotic diseases. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods . 22nd ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 61.
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Blood test - illustration
Blood is drawn from a vein (venipuncture), usually from the inside of the elbow or the back of the hand. A needle is inserted into the vein, and the blood is collected in an air-tight vial or a syringe. Preparation may vary depending on the specific test.
Blood test
illustration
-
Blood test - illustration
Blood is drawn from a vein (venipuncture), usually from the inside of the elbow or the back of the hand. A needle is inserted into the vein, and the blood is collected in an air-tight vial or a syringe. Preparation may vary depending on the specific test.
Blood test
illustration
Review Date: 9/10/2015
Reviewed 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, Boston, MA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.
