Knowledge of partners' genital herpes protects against herpes simplex virus type 2 acquisition.

Background: Prospective studies of herpes simplex virus type 2 (HSV-2) infection in discordant couples have shown a low rate of transmission. However, unlike partners with genital herpes in prospectively monitored couples, most persons who transmit genital herpes are not aware of having the infection.

Methods: Because HSV has a short incubation period and most persons who acquire genital herpes can identify the transmitting partner, a time-to-event design was used to assess risks of HSV acquisition among patients with newly acquired genital herpes.