Genital herpes infections usually start out as a suspicious, mildly itchy rash around the genitals. Then they blossom into small, fluid-filled blisters on the penis, scrotum or inner thighs (in men) or on the inner or outer lips ofthe vagina, inside the vagina or around the rectum (in women). The blisters eventually burst open, evolve into burning, itching, ulcerated sores and finally scab over and heal without leaving scars. Infections usually show up about a week after contact with an infected person (although sometimes they don't show up for months) and generally last for one to three weeks.

For some people, these outbreaks can be extremely unpleasant. A particu¬larly hellish episode can make it painful to urinate or even to walk and leave you feeling tired, feverish and without appetite. For others, though, the symp¬toms are so mild they're never even reported to a doctor. There may not even be any symptoms at all- which is why nobody really knows how widespread the disease is.

"Herpes has a wide range of manifestations- many people don't even know they have it, although they may still be able to transmit it," explains Dr. Ross. "The natural history of the disease is that a person becomes infected, the lesions go away, but the virus persists. But everybody who's infected will have an antibody to it-that's how we tell ifa person has ever been infected."
And when doctors measure the prevalence of herpes antibodies in the population-the "footprints" of the disease-the numbers are truly astounding. By some estimates, over 40 percent ofthe population has been exposed to herpes.