Epidemiology of Genital Herpes Simplex Virus Type 1 and 2 Infections in Southwestern Finland During a 10-Year Period (2003–2012)

Abstract

The objective of this study was to analyze the proportion of herpes simplex virus types 1 and 2 (HSV-1 and HSV-2) in genital infections during a 10-year period (2003-2012) among outpatients of a clinic of sexually transmitted disease in Southwestern Finland. We analyzed prospectively the proportion of HSV-1- or HSV-2-positive culture samples from our sexually transmitted disease clinic outpatients with genital herpes infection during the years 2003 to 2012 and compared the proportions of positive HSV-1 and HSV-2 findings with the age and sex of the patients. Herpes simplex virus type 2 was typed in 66.4% (557/839) and HSV-1 in 33.6% (282/839) of the patients during the entire study period. The mean age of male patients (26.3 years) with a laboratory-confirmed HSV-1 infection was significantly lower than that in male patients with an HSV-2 infection in 2003 to 2007 (26.3 vs. 32.9 years), with P < 0.0001, and (28.6 vs. 34.0) P < 0.0019 in 2008 to 2012, respectively. More female than male patients had HSV-1 infection; in the first study period (2003-2007), 58% were female, and in 2008 to 2012, it was again 63.6%. There was no significant difference between the age of female patients with HSV-1 and those with HSV-2. Herpes simplex virus type 2 was still the most common causative agent of genital herpes in Southwestern Finland, but the proportion of HSV-1 was increasingly high. The age difference between male patients with HSV-1 and HSV-2 narrowed during the years studied.