Incidence and prevalence of herpes simplex virus infections in adolescent women

Objectives: We conducted this study to examine the incidence, prevalence, and risk factors for herpes simplex virus (HSV) 1 and HSV 2 infection in a cohort of young women who were closely followed for acquisition of sexually transmitted infections. Study Design: Women between the ages of 14 and 18 years had blood and genital specimens obtained quarterly to test for incident sexually transmitted infections. Subjects also had 2 12-week periods each year when they kept a detailed behavioral diary and performed weekly vaginal swabs. Serum specimens were tested for HSV 1 and HSV 2 antibody, and genital specimens were tested for HSV DNA by PCR. Results: A total of 100 subjects enrolled and had at least 2 sera that could be analyzed for seroconversion. The mean age of the subjects was 15.8 years at entry. The HSV 1 and HSV 2 seroprevalence at entry was 59.6% and 13.5%, respectively. During the study, 4 subjects acquired HSV 1 antibody and 7 acquired HSV 2 antibody, but there were no cases of symptomatic HSV infection identified. The annualized incidence among susceptible individuals was 8.9% for HSV 1 and 7.4% for HSV 2. Three of the 7 HSV 2 seroconverters had HSV 2 DNA detected in vaginal swabs. Age, duration of sexual activity, and the presence of other sexually transmitted infections were predictors of HSV 2 antibody positivity. Conclusions: Acquisition of HSV 1 and HSV 2 is relatively common in adolescent women, although symptomatic infection is uncommon. HSV 2 is shed in the genital tract despite the lack of symptoms.