Herpes Blood Tests
If a person does not have visible symptoms of herpes, blood tests are often used to help make a diagnosis. While many blood tests are available, there are only two that are approved by the FDA for this purpose: the HerpeSelect ELISA Kits and the HerpeSelect Immunoblot Kit. Since there are so many different blood tests available, ask your healthcare provider if you are getting one of the newer, more accurate tests.
The standard testing procedure for herpes is to obtain a viral culture of a sore (lesion) within the first 48 hours after symptoms appear. Beyond 48 hours, there is a risk of the culture yielding a "false negative" result because the sore may have begun healing and there may not be live virus present. Blood tests can be used to confirm a negative viral culture result or to help determine herpes infection in a person with no visible symptoms.
(Click Diagnosing Genital Herpes to learn more about how herpes is diagnosed.)
There are currently two blood tests approved by the U.S. Food and Drug Administration (FDA) that accurately determine if a person is infected with HSV-1 or HSV-2: the HerpeSelect ELISA Kits and the HerpeSelect Immunoblot Kit.
Another blood test is the Western Blot. Although not 100 percent accurate, the Western Blot is considered the "gold standard" of blood tests and is used to determine the accuracy of other herpes blood tests that are developed.
Many older, FDA-cleared blood tests for herpes are still on the market, and many labs use these tests because they are widely available and inexpensive. Although they may be labeled type-specific (they can determine whether the infection is HSV-1 or HSV-2), they are not reliable.
It is difficult for people to make sure they are getting one of the newer, accurate tests. Doctors and even lab workers may not know what test they're using. You need to ask, but it's a very tall order. It will take a significant amount of work on your part and phone calls to the lab.