Herpes Simplex Virus Type 1 Remains the Principal Cause of Initial Anogenital Herpes in Edinburgh, Scotland

In Brief Goal: The goal of this study was to investigate the trends in the prevalence of anogenital herpes caused by herpes simplex virus (HSV) type-1 and HSV-2 among patients attending a sexually transmitted infections clinic. Methods: We conducted a retrospective study of virologically proven first-episode genital herpes diagnosed in the Department of Genitourinary Medicine in Edinburgh between 1989 and 2002. Results: First-episode anogenital herpes was associated with HSV-1 in 659 (62%) women and 294 (42%) men (P <0.0002). HSV-1 was recovered more often from women younger than 25 years than from older women (P <0.0005). For both HSV-1 and HSV-2 infections, the median ages of heterosexual men (26.0 and 28.0 years, respectively) were significantly higher than those of women (23.0 and 25.0 years, respectively)(P <0.05). The median age of men who have sex with men with HSV-1 (29.0 years) was significantly higher than that of heterosexual men (26.0 years)(P <0.01). Conclusion: HSV-1 remains the most common cause of symptomatic first-episode anogenital herpes, especially among young women in our clinic population. Classically, genital herpes is believed to be caused by herpes simplex virus type 2. Previous reports from our center, however, raised the possibility of type 1 of the virus becoming the predominant cause of genital herpes. We conducted a study to investigate the prevalence of different types of HSV responsible for initial genital herpes.