Herpes 2 is a reference to herpes simplex 2, one of two strains of the herpes simplex virus. Herpes simplex 2 is thought to infect roughly twenty percent of adults. Herpes simplex 2 typically causes genital herpes, an STD. When a herpes simplex 2 infection presents symptoms, the symptoms are typically an outbreak of blisters in the genital area. A herpes simplex 2 genital herpes infection usually goes unrecognized: roughly eighty percent of people with genital herpes are unaware of their status. A herpes 2 infection is not a threat to one's overall health.