This may have been asked before, but I am new to all this. I’m aware I have oral herpes and recently took a blood test for herpes one and two because of a genital sore that appeared recently. If the test is positive for HSV-1 and HSV-2, is it conclusive that the genital sore is herpes or does there need to be a culture taken from the sore itself to be sure of diagnosis?
Good question. HSV-1 causes the majority of oral herpes and HSV-2 causes the majority of genital herpes. However, it is important to understand that both HSV-1 and HSV-2 can be contracted in either the oral or genital area. An individual’s genital area would have to be exposed to the herpes virus in order for her or him to be at risk of contracting genital herpes. The only way to know for sure whether the sore that appeared in the genital area is herpes is to have a swab test taken from that area, as you stated. Blood tests are helpful in finding out whether you are infected with the HSV-1 and/or HSV-2 but are unable to determine where the infection lies. However, the vast majority of people who test positive for HSV 2, whether they have symptoms or not, are infected genitally (per the CDC STD treatment guidelines). Also, please note that swab tests are most accurate if taken within 48 hours of the sore appearing. Negative swab tests may or may not be accurate whereas positive swab tests should be interpreted as infection in the symptomatic person. Lastly, when taking a blood test for herpes make sure it is a type-specific IgG blood test only. Do not rely on IgM antibody tests or a non-type specific antibody test.