Genital herpes is a sexually transmitted disease (STD) that is caused by the herpes simplex virus. There are two types of herpes simplex: Type 1 (HSV-1) and Type 2 (HSV-2). Most genital herpes is caused by HSV-2. <B>The HSV Type I and II IgG test is appropriate for exposure at least 4 weeks prior to testing.</b> Positive results may require further evaluation by your physician.