Definition

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 most often causes genital herpes.

Alternative Names

Herpes serology; HSV blood test

How the Test is Performed

A blood sample is needed.

The sample is taken to the lab and tested for the presence and amount of antibodies.

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.

Normal Results

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

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)

Considerations

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.

References

Centers for Disease Control and Prevention website. Sexually transmitted infections treatment guidelines, 2021. www.cdc.gov/std/treatment-guidelines/default.htm. Updated June 13, 2023. Accessed September 1, 2023.

Khan R. Women. In: Glynn M, Drake WM, eds. Hutchison's Clinical Methods. 25th ed. Philadelphia, PA: Elsevier; 2023:chap 5.

Schiffer JT, Corey L. Herpes simplex virus. In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 9th ed. Philadelphia, PA: Elsevier; 2020:chap 135.

Whitley RJ, Gnann JW. Herpes simplex virus infections. In: Goldman L, Cooney KA, eds. Goldman-Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 345.