Herpes is tested mainly in two ways depending on whether symptoms, such as sores or blisters, are present:
- Swab Test (if sores/blisters are present): A healthcare provider collects fluid or cells from a herpes sore using a swab. This sample can be tested by:
- Viral culture, where the cells are grown in a lab to check for HSV.
- Polymerase Chain Reaction (PCR) test, which looks for herpes virus genetic material. PCR is faster and more accurate than viral culture.
- Blood Test (if no sores are present): A blood sample is taken to look for antibodies to the herpes simplex virus (HSV-1 or HSV-2). These antibodies indicate whether a person has been exposed to the virus in the past.
Other testing methods include examination of cerebrospinal fluid if infection in the brain or spine is suspected. At-home tests are also available, usually involving blood samples mailed to a lab. The swab test is most effective when sores are new (a few days old), while blood tests detect past or asymptomatic infections by measuring immune response proteins (antibodies). The blood test cannot detect an active outbreak, just exposure to the virus. In summary, herpes testing involves swabs from sores for direct virus detection or blood samples for antibody detection, with PCR being the most accurate for swab samples and IgG antibody testing preferred in blood samples.
