You should stop having sexual contact as soon as you feel warning signs of an outbreak. Warning signs may include a burning, itching, or tingling feeling on the genitals or around the mouth. Do not have vaginal, anal, or oral sex — even with a condom — until seven days after the warning signs stop or the sore heals. The virus can spread from sores not covered by the condom. It can also spread in sweat or vaginal fluids to places the condom doesn't cover.
However, asymptomatic carriers of the HSV-2 virus are still contagious. In many infections, the first symptom people will have of their own infections is the horizontal transmission to a sexual partner or the vertical transmission of neonatal herpes to a newborn at term. Since most asymptomatic individuals are unaware of their infection, they are considered at high risk for spreading HSV.
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.
A person may show symptoms within days after contracting genital herpes, or it may take weeks, months, or years. Some people may have a severe outbreak within days after contracting the virus while others may have a first outbreak so mild that they do not notice it. Because of these possibilities, it can be difficult for people to know when and from whom they may have contracted the virus.