When found early, most STDs are treatable or quickly treatable. HIV (human immunodeficiency infection) is an infection that attacks the body's body immune system, destroying the CD4 cells (also called T cells). It is mainly spread out by having genital or anal sex or sharing injection drug equipment with someone that has HIV. In time, HIV compromises the body's capability to eliminate off infections and disease. Herpes is a common viral infection that is brought on by the herpes simplex infection (HSV).