Abstract
HSV-1 is associated with oral lesions and non-sexual transmission; HSV-2 is primarily transmitted through sexual contact and causes genital infections. Understanding the epidemiological dynamics of both viruses is essential for guiding targeted public-health responses. We conducted a retrospective analysis of 177,599 clinical specimens collected between September 2018 and December 2022 from patients with symptoms suggestive of sexually transmitted infections (STIs) at healthcare institutions across South Korea. HSV-1 and HSV-2 were identified using a real-time PCR assay; positivity rates were stratified by age, sex, specimen type, and year of testing. The overall positivity rate was 0.26% for HSV-1 and 1.60% for HSV-2. HSV-1 was most prevalent among individuals aged <19 years; HSV-2 showed the highest positivity in females aged 20-29 years, declining with age thereafter. HSV-2 positivity was significantly higher in females than in males. A significant decline in HSV-2 positivity was observed over the 5-year study period, while HSV-1 positivity remained stable. This nationwide PCR-based study reveals distinct age- and sex-related epidemiological patterns of HSV-1 and HSV-2. The findings support the need for age-specific and gender-specific STI screening strategies and health education programs. The declining trend in HSV-2 infection may reflect the impact of recent public-health initiatives.