Serologic (blood) tests can identify antibodies that are specific for either herpes virus simplex 1 (HSV-1) or herpes virus simplex 2 (HSV-2). When the herpes virus infects someone, their body’s immune system produces specific antibodies to fight off the infection. If a blood test detects antibodies to herpes, it’s evidence that you have been infected with the virus, even if the virus is in a non-active (dormant) state. The presence of antibodies to herpes also indicates that you are a carrier of the virus and might transmit it to others.
Newer “type-specific” assays test for antibodies to two different proteins that are associated with the herpes virus:
- Glycoprotein gG-1 is associated with HSV-1
- Glycoprotein gG-2 is associated with HSV-2
Although glycoprotein (gG) type-specific tests have been available since 1999, many of the older nontype-specific tests are still on the market. The CDC recommends only type-specific glycoprotein (gG) tests for herpes diagnosis.
Serologic tests are most accurate when performed 12 - 16 weeks after exposure to the virus. Recommended tests include:
- HerpeSelect. This includes two tests: ELISA (enzyme-linked immunosorbent assay) or Immunoblot. Both are highly accurate in detecting both types of herpes simplex virus. Samples need to be sent to a lab, so results take longer than the in-office Biokit test.
- Biokit HSV-2 (also marketed as SureVue HSV-2). This test detects HSV-2 only. Its major advantages are that it requires only a finger prick and results are provided in less than 10 minutes. It is very accurate, although slightly less so than the other tests. It is also less expensive.
- Western Blot Test. This is the gold standard for researchers with accuracy rates of 99%. It is costly and time consuming, however, and is not as widely available as the other tests.
False-negative (testing negative when herpes infection is actually present) results can occur if tests are done in the early stages of infection. False-positive results (testing positive when herpes infection is not actually present) can also occur, although less often than false-negative. Your doctor may recommend that you have the test repeated.
Doctors recommend serologic herpes tests especially for:
- People who have had recurrent genital symptoms but no positive herpes viral cultures
- People who have visible symptoms of genital herpes
- The partner of individuals diagnosed with genital herpes
- People who have multiple sex partners and who need to be tested for different types of STDs
At this time, doctors do not recommend screening for HSV-1 or HSV-2 in the general population.
Tests for Herpes Encephalitis
Review Date: 11/05/2010
Reviewed By: Harvey Simon, MD, Editor-in-Chief, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.