• To calculate the half-life of detectable HSV-2 DNA in genital mucosa during a clinical recurrence of genital herpes, after treatment with acyclovir has begun. [ Time Frame: 5 days ] [ Designated as safety issue: No ]
  

• To describe the time course, diurnal variation, and pattern of resolution of HSV-2 shedding during both acyclovir-treated and untreated clinical recurrences of genital herpes. [ Time Frame: 5 days ] [ Designated as safety issue: No ]
  

The purpose of the study is to evaluate the pattern of viral shedding after beginning treatment with acyclovir for a clinical recurrence of genital herpes and to compare it with the pattern of viral shedding during an untreated clinical recurrence of genital herpes.

Participants are asked to visit the University of Washington Virology Research Clinic for an initial screening appointment in which the clinician will ensure eligibility and informed consent will be obtained.

Participants who experience an outbreak during the next year will be asked to call the clinic at the beginning of their next outbreak. The clinician will arrange to admit the participant to the UW General Clinical Research Center (GCRC) for a 5-day hospitalization stay. During hospitalization, participants will take acyclovir (400mg 3 times daily) and genital swabs will be collected every 2 hours during the day and every 4 hours at night for 5 days. After the last swab has been taken, the study nurse at the GCRC will do a final genital exam and the participant will be discharged. Some participants will also be asked to enroll in a control arm during which the same procedures will be followed except they will not take acyclovir during the recurrence.