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.

Results: Among 199 persons with laboratory-documented newly acquired genital herpes, the median duration of the sexual relationship with the transmitting partner was 3.5 months, and the median number of sex acts before transmission was 40. The median time to HSV-2 acquisition was greater among participants whose partners disclosed that they had genital herpes, compared with participants whose partners did not disclose their status (270 vs. 60 days; P = .03). In multivariate models, having a partner who disclosed that he or she had genital herpes remained a strong protective factor against genital HSV-2 acquisition (hazard ratio, 0.48 [95% confidence interval, 0.25-0.91]).

Conclusions: These findings suggest that testing persons with HSV type-specific serologic assays and encouraging disclosure may result in a decreased risk of HSV-2 transmission to sex partners.