Where is this study I keep hearing about with the 10% transmission rate per year?

[Ishmael]

In a lot of herpes information outlets, including articles written about herpes online in places like the Huff Post and Washing post, I keep seeing this statistic that, over a year of sexual intercourse, a HSV+ male has 10% chance to infect a HSV- female. I see this so frequently that it seems to be taken as a matter of fact, yet I never see the actual study or source cited, ever. When I try to find anything conclusive on Google scholar, I can't find it. Does anyone know what this is from and where I can access it? Also, can anyone link to studies on transmission rates per sexual act using different methods (like, transmission rates when using antivirals and condoms versus not)? Thanks. 

[Ubikwity]

Yes, I'm curious too. Once something is written it seems to become an oft-repeated fact, no one really follows up to see if the statistic is actually TRUE.