Herpes Simplex Type 1 as the Predominant Cause of Genital Herpes in College Students

Background: Genital herpes etiology has been shifting to include a greater proportion of herpes simplex virus type 1 (HSV-1) infection in the last few decades. A prior study published in 2003 found that 48.9% of infections in a college health population were HSV-1. Methods: We evaluated the number of positive HSV polymerase chain reaction test results obtained from anogenital sites from undergraduate and graduate students from 2013 to 2022 in a college health clinic setting and analyzed the number caused by HSV-1 and HSV type 2 and compared by sex. This was then compared with the prior study from 1993 to 2001. Results: We received 691 (of 2685 samples) positive polymerase chain reaction results for HSV of both types in the period analyzed. Overall, 600 (86.8%) of these were HSV-1, and 520 (75.2%) were in female patients. The prior study in 1993 to 2001 found that 48.9% (244 of 675) of all positive test results were HSV-1; we observed an increase in the percentage of positive HSV-1 over all positive test results of 1.8 (chi(2) = 16.548; P < 0.001). Conclusions: Our study shows that 86.8% of the positive genital HSV test results from 2013 to 2022 were HSV-1. This shows that most positive HSV test results in this setting are now HSV-1, a substantial increase from the previous study in our clinic.