While some people realize that they have genital herpes, many do not. It is estimated that one in five persons in the United States has genital herpes; however, as many as 90 percent are unaware that they have the virus. This is because many people have very mild symptoms that go unrecognized or are mistaken for another condition or no symptoms at all.

Cullins explains that the first, or initial, outbreak is usually the worst, and “over time when you have recurrent episodes, you may not have systemic symptoms” or frequent symptoms. But everyone’s body and immune system reacts to the virus differently; while some people may never have many outbreaks, other people may be more chronically symptomatic. The National Institutes of Health indicate that infrequent outbreaks, around one or two per year, are not uncommon.
Herpes is contracted through direct contact with an active lesion or body fluid of an infected person.[31] Herpes transmission occurs between discordant partners; a person with a history of infection (HSV seropositive) can pass the virus to an HSV seronegative person. Herpes simplex virus 2 is typically contracted through direct skin-to-skin contact with an infected individual, but can also be contracted by exposure to infected saliva, semen, vaginal fluid, or the fluid from herpetic blisters.[32] To infect a new individual, HSV travels through tiny breaks in the skin or mucous membranes in the mouth or genital areas. Even microscopic abrasions on mucous membranes are sufficient to allow viral entry.

As with almost all sexually transmitted infections, women are more susceptible to acquiring genital HSV-2 than men.[41] On an annual basis, without the use of antivirals or condoms, the transmission risk of HSV-2 from infected male to female is about 8–11%.[37][42] This is believed to be due to the increased exposure of mucosal tissue to potential infection sites. Transmission risk from infected female to male is around 4–5% annually.[42] Suppressive antiviral therapy reduces these risks by 50%.[43] Antivirals also help prevent the development of symptomatic HSV in infection scenarios, meaning the infected partner will be seropositive but symptom-free by about 50%. Condom use also reduces the transmission risk significantly.[44][45] Condom use is much more effective at preventing male-to-female transmission than vice versa.[44] Previous HSV-1 infection may reduce the risk for acquisition of HSV-2 infection among women by a factor of three, although the one study that states this has a small sample size of 14 transmissions out of 214 couples.[46]
Herpes sores usually appear as one or more blisters on or around the genitals, rectum or mouth. The blisters break and leave painful sores that may take a week or more to heal. These symptoms are sometimes called “having an outbreak.” The first time someone has an outbreak they may also have flu-like symptoms such as fever, body aches, or swollen glands.
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.