OK, so the majority of people have it. Just this year, the World Health Organization released a study that estimates two thirds of people in the world (67%) have the HSV-1 strain of the herpes simplex virus — that’s approximately 3.7 billion people worldwide. While HSV-1 typically refers to oral herpes infections, it also includes some genital infections. The new report estimates that half of the HSV-1 infections in people between the ages of 15–49 are actually genital infections transmitted via oral-to-genital contact. The Center For Disease Control (CDC) estimates that 1 in 6 people have genital herpes.
A scary finding is that more cases of genital herpes than ever before are now being caused by HSV-1 (the type most people assume only causes mouth sores), and about 85 percent of people with genital herpes don’t even know it. (7) Studies show that about 50 percent of the new genital herpes infections in young adults are due to HSV-1 and about 40 percent in older adults. The fact that most people don’t ever find out they’re infected is one of the reasons that transmission rates are steadily climbing.
A 2004 study in the New England Journal of Medicine found that suppressive therapy decreases the risk of HSV-2 transmission from symptomatic, infected partners to uninfected partners by 48%. So “the risk of transmission is significantly reduced, but cannot be eliminated even with suppressive therapy,” Johnston explains, and she stresses that the virus can be passed along even without signs or symptoms.