Two types of herpes simplex virus infections can cause genital herpes: 1  HSV-1. 2  This is the type that usually causes cold sores or fever blisters around your mouth, though it can be spread to your genital area during oral sex. 3  Recurrences are much less frequent than they are with HSV-2 infection. This is the type that usually causes cold sores or fever blisters around your mouth, though it can be spread to your genital area during oral sex. 2  Recurrences are much less frequent than they are with HSV-2 infection. 3  HSV-2. 4  This is the type that commonly causes genital herpes.