Herpesblood tests are highly accurate.

Herpes blood testing is a two-step process in which an initialpositive resultis followed by a second confirmatory test.

A positive result from both tests can be considered a definitive diagnosis of herpes.

An illustration with information about the accuracy of a herpes blood test

Illustration by Paige McLaughlin for Verywell Health

Sensitivityis how often a test correctly identifies someone with a disease.

A test that is 90% sensitive will correctly identify 90 people out of 100 who have the disease.

Ten people will have afalse-negativeresult.

The higher the sensitivity and specificity, the lower the chances of a false (incorrect) result.

The first test is the enzyme-linked immunosorbent assay (ELISA).

HSV antibodies are present even when there are no symptoms.

If the ELISA result is positive, your healthcare provider may administer a Western blot assay.

HSV antibodies produced in response to these antigens help the immune system target its attack.

With that said, the accuracy of the tests can be affected by the timing of the tests.

Can You Still Have Herpes if the Result is Normal (Negative)?

But, other tests may be more useful and/or reliable in certain situations.

These tests rely on the direct detection of HSV using fluids obtained from a swab of a herpes sore.

Compared to all other methods of HSV detection, viral culture is considered the gold standard of testing.

Delays in transport or improper refrigeration can also weaken the accuracy of the test.

Can a regular blood test detect herpes?

Routine blood tests do not look for herpes.

Limitations of Testing

As accurate as herpes tests are, they are not used for routine screening.

This doesn’t mean that you shouldn’t get tested under certain circumstances.

Summary

Herpes can be diagnosed with blood tests.

This includes the ELISA test that detects herpes antibodies and a Western blot test used to confirm the results.

Herpes testing is generally recommended for people with herpes symptoms only.

Both rely on a swab of fluid from a herpes sore.

US Preventive Services Task Force.Serologic screening for genital herpes infection: US Preventive Services Task Force recommendation statement.JAMA.

2019;5(2):e14216 doi:10.2196/14216

University of California, San Francisco.Serum herpes simplex antibodies.

U.S. Preventive Services Task Force.Genital herpes infection: Serologic screening.

Centers for Disease Control and Prevention.Genital herpes CDC fact sheet (detailed).

2024;11(5):ofae230.

doi:10.1093/ofid/ofae230

Centers for Disease Control and Prevention.Screening for genital herpes.