Most commenters in the various herpes forums say that if a person already has HSV 1 oral herpes they can't catch HSV 1 in the genital area. But I just read a few research papers (some on this site) that, by deduction, would imply it must be happening. Think of the statistical implications of several studies that say that HSV 1 genital herpes is skyrocketing -- for example this article -- http://journals.lww.com/stdjournal/pages/default.aspx
-- says 78% of new genital herpes cases at the colleges tested in 2001 were HSV 1 (up from just 31% 9 years earlier), yet numerous studies since the early 1980s show that 50% of the population tests positive for oral HSV 1 by the age or 20 and that percentage has remained constant for decades. Further, the number of new genital herpes cases has remained steady (or even slightly declined) as a percentage of the population. Studies from the UK and Isreal show similar trends. Thus, either you can catch HSV 1 genitally despite having it orally, or else virtually all the increase in HSV 1 genital cases is coming only from the half of the population that doesn't test positive for oral HSV 1, while the half that does test positive for oral HSV 1 had a parallel offsetting decline in genital herpes HSV 2 cases. The odds of that are not only miniscule, there could be no reason for it. Anyone have another explanation, or aware of a research study that directly measures HSV 1 genital after HSV 1 oral?