Genital herpes is a more common infection than is widely appreciated. It is estimated that between two and four out of ten Americans carry one of the viruses responsible for genital herpetic infection. Women tend to have higher rates of infection than men. The reason for this is not known, though it is suspected that men may secrete more virus than women and thus are more likely to transmit it to their female sexual partners. Also, the nature of the female genital tract may increase the probability of a woman becoming infected. The approximate risk of a susceptible woman contracting one of the viruses responsible for genital herpes after a single contact with an infected male partner is 80%.
The etiological agent most often responsible for genital herpes is Herpes Simplex Virus-2 (HSV-2). Herpes Simplex Virus-1 (HSV-1) has also been shown to be responsible for a small percentage of genital herpes infection. However, genital infection caused by HSV-1 Infection is acquired through sexual contact with an infected person, with the susceptible person usually having an abraded site where the virus will be contracted. The primary infection is the most severe. It is marked by macules and papules, followed by vesicles, pustules, and ulcers which appear at the abraded site of infection. The lesions typically last three weeks. In women, the primary lesions usually appear bilaterally on the vulva and the cervix. Lesions can also appear on the buttocks, perineum and/or vagina. Such lesions are invariably painful and are associated with inguinal adenopathy and dysuria. As many as 25% of infected women develop aseptic meningitis with primary infection.
In men, the lesions primarily appear on the glans penis and the penile shaft. Lesions also may appear on the thigh, buttocks, and perineum. Such lesions are typically vesicular in nature and are superimposed on an erythematous base. The number of lesions varies significantly from six to many more. Primary anal and perianal HSV-2 infection have become common among male homosexuals. Aseptic meningitis can also develop in males as a result of primary HSV-2 infection. Nonetheless, it should be noted that many primary HSV-2 infections are subclinical.
Non-primary but initial infection tends to be less severe than primary infection. Non-primary infection in this case refers to infection appearing in an individual with preexisting antibodies to HSV-2. This would describe a person who had an asymptomatic primary infection. Non-primary infection is marked by a shorter duration, fewer lesions, less pain, and a decreased likelihood of complications. Preexisting antibodies to HSV-1 also tend to decrease the severity of HSV-2 infection.
The frequency of recurrent infection varies among individuals and is correlated with the severity of the primary infection. A third of patients have recurrences more than eight times a year while one third have only four to seven per year and the final third have roughly two to three recurrences per year. The more severe the primary infection, the more common the recurrences. Complications with recurrent disease are rare, though paresthesias and dysathesias do occur. Recurrent infection is heralded by localized irritation. During recurrent asymptomatic or symptomatic infection, the infected individual can transmit the infection to sexual partners.