This is a common problem and a worldwide epidemic. Twenty percent of the sexually active adults in North America are infected with HSV-2 and up to 40% are infected in parts of Africa. It is the most common sexually transmitted disease. Almost 50 million American adults and adolescents have genital herpes and there are about 500,000 new cases a year making it one of the most contagious diseases. It is more common in women than in men.