Testing for Herpes: What You Need to Know
By Barb Dehn, NP
If you or someone you care about is concerned that they may have genital herpes, then you know that it can be a very worrisome time with a long list of questions. What makes it even more difficult is that you might be hearing conflicting and confusing information.
Testing for herpes when symptoms are present
If there are visible or active symptoms, such as sores, small bumps, crusted lesions or small skin tears, then a health care provider can swab the area and send it out for a PCR (polymerase chain reaction) evaluation. This is the most accurate way to test because it looks for the viral DNA, which is present even after a few days of symptoms. We don't use cultures anymore because they are not as reliable.
When symptoms are not present
If a person does not have any symptoms and wants to know if they have been exposed to the virus and become infected, then the best test to ask for is a HerpeSelect blood test. This is a type specific glycoprotein (g) test that is highly accurate. We do not test IgG or IgM anymore without the type specific testing because there are too many false positives.
Learn more about How to Deal With Your Partner's Herpes.
Can a person find out when they were infected?
This question comes up frequently, but because of the time it takes to develop symptoms and to get a definitive diagnosis, it can be difficult to pinpoint the time of infection.
The time it takes to develop symptoms of a herpes infection after contact: Symptoms typically start within 3 to 7 days of being exposed.
The time it takes for the body to develop blood antibodies to the herpes virus: Antibody formation takes 6 to 12 weeks after infection.
That means that with a new infection:
The PCR test will be positive; the HerpeSelect will be negative.
When someone has had the virus for longer than 12 weeks:
The PCR test will be positive and the HerpeSelect will be positive.
This blog originally appeared on Nurse Barb's Daily Dose. Barb Dehn is a women's health nurse practitioner, award-winning author and nationally recognized health expert. She practices with Women Physicians in the Silicon Valley of California.