Herpes serology; HSV blood test
Serum herpes simplex antibodies is a blood test that looks for antibodies to the herpes simplex virus (HSV), including HSV-1 and HSV-2. HSV-1 most often causes cold sores (oral herpes). HSV-2 causes genital herpes.
How to Prepare for the Test
No special steps are needed to prepare for this test.
How the Test will Feel
When the needle is inserted to draw blood, some people feel a little pain. Others feel only a prick or stinging sensation. Afterward, there may be some throbbing.
Why the Test is Performed
The test is done to find out whether a person has ever been infected with oral or genital herpes. It looks for antibodies to herpes simplex virus 1 (HSV-1) and herpes simplex virus 2 (HSV-2). An antibody is a substance made by the body's immune system when it detects harmful substances such as the herpes virus. This test does not detect the virus itself.
A negative (normal) test most often means you have not been infected with HSV-1 or HSV-2.
If the infection occurred very recently (within a few weeks to 3 months), the test may be negative, but you may still be infected. This is called a false negative. It can take up to 3 months after a possible herpes exposure for this test to be positive.
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
A positive test means you have been infected with HSV recently or at some point in the past.
Tests can be done to help determine if you have a recent infection.
About 70% of adults have been infected by HSV-1 and have antibodies against the virus. About 20 to 50% of adults will have antibodies against the HSV-2 virus, which causes genital herpes.
HSV stays in your system once you have been infected. It may be "asleep" (dormant), and cause no symptoms, or it may flare up and cause symptoms. This test cannot tell whether you are having a flare-up.
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)
Even when you do not have sores, you can pass (shed) the virus to someone during sexual or other close contact. To protect others:
- Let any sexual partner know that you have herpes before having sex. Allow him or her to decide what to do. If you both agree to have sex, use latex or polyurethane condoms.
- DO NOT have vaginal, anal, or oral sex when you have sores on or near the genitals, anus, or mouth.
- DO NOT kiss or have oral sex when you have a sore on the lips or inside the mouth.
- DO NOT share your towels, toothbrush, or lipstick. Make sure dishes and utensils you use are washed well with detergent before others use them.
- Wash your hands well with soap and water after touching a sore.
Palmore TN, Henderson DK. Nosocomial herpesvirus infections. In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases, Updated Edition. 8th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 308.
Whitley RJ. Herpes simplex virus infections. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 25th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 374.
Workowski KA, Bolan GA; Centers for Disease Control and Prevention. Sexually transmitted diseases treatment guidelines, 2015. MMWR Recomm Rep. 2015;64(RR-03):1-137. PMID: 26042815 www.ncbi.nlm.nih.gov/pubmed/26042815.