Herpes Blood and Swab Tests Accuracy

Herpes swab test accuracy

A positive herpes swab test means we are 100% sure the current skin lesion is herpes. There is no false positive with the swab test.

But 25-70% of swab herpes tests can be false negatives. Why? The test was done on sores with low concentrations of the herpes virus (dry sores). Ideally, the test should be done right after the blister's roof comes off, when there is enough fluid, and the virus concentration is still high.

IgG herpes test.

A positive IgG herpes test means you are most likely herpes positive.

However, there is a 19% chance of a false positive result. This means that about 19% of people who test positive are negative. Why does this happen? Because the herpes virus (especially HSV-1) is cross-reactive with other viruses.

A negative IgG herpes test means you are considered herpes negative.

However, there is about a 38% chance that you got a false-negative test results [2] HSV-2 Tests for Genital Herpes Can Produce False Reactive Results - Letter to Clinical Laboratory Staff and Health Care Providers https://www.fda.gov/medical-devices/letters-health-care-providers/hsv-2-tests-genital-herpes-can-produce-false-reactive-results-letter-clinical-laboratory-staff-and . This mainly occurs when the test is done too early before antibodies are produced. The test is most accurate when it is done 3 months after exposure.