Worse yet, the research shows that HSV-1 has become a significant cause of genital herpes, likely thanks to oral sex. In fact, as many as 140 million people -- mostly in the Americas, Europe, and Western Pacific -- are now infected with genital HSV-1. Earlier this year, the WHO estimated that more than 400 million people of the ages 15-49 have the HSV-2 infection, or genital herpes, which means that well over half a billion people have a genital infection between HSV-1 and HSV-2.
As of 2012, there were 178 million women (49%) and 142 million men (39%) 49 years old or younger infected with HSV-1 in the Americas. Additionally, the Americas saw 6 million new HSV-1 infections among women, and 5 million new HSV-1 infections among men that year alone. Those numbers were even higher in other parts of the world like Africa, where 17 million women and 18 million men became infected with HSV-1 in 2012, bringing the total to 350 million women (87%), 355 million men (87%), according to the WHO.