Understanding Herpes Tests: What They Detect & How They Work

Herpes tests can detect the herpes simplex virus (HSV) or the varicella-zoster virus (VZV). There are two types of HSV: HSV-1 and HSV-2. HSV-1 is the virus that usually causes oral herpes, also known as cold sores or fever blisters. HSV-2 is the virus that usually causes genital herpes. VZV is the virus that causes chickenpox and shingles.

Blood tests can look for antibodies to HSV-1, HSV-2, or VZV. These antibodies are proteins that the body produces in response to infection. A positive blood test means that the person has been infected with the virus at some point in their life, but it does not necessarily mean that they are currently sick with the virus.

Viral culture tests can detect the HSV or VZV virus in a sample of fluid from the affected area. This test can be used to diagnose both primary infections (the first time someone gets the virus) and recurrent infections (when someone who has already had the virus has another outbreak).

PCR (polymerase chain reaction) tests can detect the HSV or VZV virus in a sample of fluid or tissue from the affected area. PCR tests are very sensitive and can detect the virus even if it is present in very small amounts.