Years ago The Helper ran an article "Good Virus, Bad Virus." The title played off the perception that HSV-1 is “good” because it more often relates to oral herpes whereas HSV-2 gets the “bad” moniker due to its association with the nether regions.
The article pointed out the truth of the matter, though: the HSV strains are remarkably similar and either can be experienced as oral or genital infections (although oral HSV-2 infections are uncommon). The traditional associations of HSV-1 as oral herpes and HSV-2 as genital, then, were always generalizations. A number of studies, including a recent paper published in the journal Clinical Infectious Diseases, adds to the evidence that HSV-1 is responsible for an increasing number of genital infections.
With the research published in CID, more than 3,400 young women with negative HSV blood tests were followed for 20 months to see how many acquired primary HSV infections. The subjects were all part of the HERPEVAC Trial for Women that evaluated a candidate HSV vaccine that ultimately proved ineffective. Over the course of follow-up 127 HSV-1 infections were detected, as were 56 cases of HSV-2. The higher rate of HSV-1 is not surprising, perhaps, but consider this: among subjects with symptomatic genital herpes, there were actually more cases attributed to HSV-1 (28) than HSV-2 (24).
The researchers also noted racial and age differences: black subjects were more likely to have HSV-2 detected compared to whites and Hispanics, and younger women were more likely to acquire HSV-1 (and were also less likely to develop obvious symptoms).
For more on oral and genital herpes, visit the Herpes Resource Center.
Bernstein D, Bellamy A, Hook E, Levin M, Wald, A, et al. Epidemiology, Clinical Presentation, and Antibody Response to Primary Infection with Herpes Simplex Virus Type 1 and Type 2 in Young Women. CID, 2012. 56(3):344-351.