An accurate determination of the risk of STDs in child sexual abuse victims has been hindered by several factors. The prevalence of sexually transmitted infections may vary regionally and among different populations within the same region; few studies have attempted to differentiate between infections existing prior to abuse; and the presence of pre-existing infections may be related to prolonged colonization after perinatal acquisition, inadvertent nonsexual spread, prior consensual peer sexual activity, or prior sexual abuse. Incubation periods for STDs range from a few days for Neisseria gonorrhoeae to several months for human papilloma virus. Incubation periods and the timing of an examination after abuse are critically important in detecting infections. Multiple episodes of abuse have been found to increase the risk of infection, probably by increasing the number of contacts with an infected individual. In most cases, the site of infection is consistent with the child's history of assault. Rates of infection also vary with respect to assault type; vaginal or rectal penetration is more likely to lead to detectable infection than fondling. The transmissibility of STDs in children is specifically discussed for gonorrhea, Chlamydia trachomatis, human papillomavirus, syphilis, bacterial vaginosis, Trichomonas vaginalis, herpes simplex virus, and HIV. 60 references