Transmission

Until recently, genital herpes was mostly caused by HSV-2, but HSV-1 genital infection is increasing, most likely to due to oral sex. Shedding of genital HSV-1 is less common than with HSV-2, so HSV-1 is less likely to be transmitted, although transmission obviously still occurs, as evidenced by the rising prevalence of genital HSV-1. In fact, a person who carries both HSV-1 and HSV-2 poses a greater risk for sexually transmitting HSV-2 than a person who only carries HSV-2. A person who is infected only with HSV-1 has some protection against being infected by HSV-2.