Natural history of genital herpes simplex virus type 1 infection

Background: Herpes simplex virus type 1 (HSV-1) has been increasingly reported as a cause of genital herpes, yet there have been few studies on the long-term natural history of this infection. Goal: The goal was to examine the clinical course of genital HSV-1 infection. Study Design: This was a cohort study of patients presenting with culture-proven primary genital HSV-1 infection. Results: The median follow-up of the 77 patients was 736 days. The overall rate of recurrences was 1.3/year in the first year of infection, decreasing to 0.7/year in the second year. In the first year of infection, 43% of study patients did not have a recurrence. In the second year of infection, 67% of study patients did not have a recurrence. Conclusion: Genital HSV-1 recurs infrequently in most patients, and the rate decreases further in the subsequent years of infection. Because the prognoses of genital HSV-1 and HSV-2 infections differ, determination of the viral type is important for patient counseling.