Although victims of sexual assault are overwhelmingly adult women, the problem is encountered among persons of diverse age and gender. In 1995–1996, a national survey of 8,000 women and 8,000 men found that 1 in 6 women and 1 in 33 men had experienced an attempted or completed rape at some time in their lives [1]. One-half of the female victims reported they had been assaulted before their 18th birthday. Most rape victims indicated the assailant was someone they knew, and only 1 in 5 reported the assault to the police. Based on these data, the lifetime incidence of sexual assault in the United States was estimated to be 18% for women and 3% for men. Given the complexity of the problem and the limited methodology of reported studies, most of which were survey-based, the actual incidence is greater than indicated by these data [2].

Sexual violence disproportionately affects some groups. Women and racial/ethnic minority groups experience higher rates of sexual violence. According to CDC surveillance, more than 2 in 5 non-Hispanic American Indian or Alaska Native and non-Hispanic multiracial women have reported being raped in their lifetime [47]. Most victims of sexual assault are young, and population groups at increased risk include mistreated children and adolescents, college students, the mentally disabled, the homeless, and persons who are gay, lesbian, bisexual, or transgender [3,4]. Victimization of college students, often perpetrated by an acquaintance and frequently associated with the heavy use of alcohol by both victim and assailant, has become a national problem and public health concern [5].

Victims of sexual assault are most likely to present to hospital emergency departments (EDs), public health and gynecology clinics, college infirmaries, and primary care offices. Published clinical series from urban EDs have helped define the scope and character of sexual assault injury [7,8,9]. Based on these clinical reports, it may be seen that victims of sexual assault presenting to an ED are predominantly female, relatively young, often know their assailant, and are likely to have been threatened with violence and to show physical signs of trauma.

In one such study of 1,076 cases seen between 1992 and 1995, the age of victims ranged from 1 to 86 years (half were younger than 26 years of age) and 96% were women [7]. In 60% of cases, the assailant was someone known to the victim. Force was used in 80% and a weapon was present in 27% of incidents. Vaginal penetration was documented in 83% of cases, oral assault in 25%, and anal penetration in 17%. Signs of genital trauma were evident in 53% of cases, and extra-genital trauma was noted in 67% of victims. Similar results were found in an ED study of 1,100 patients published in 2009. In this study, 92% of victims were female, and the median age was 27 years. Most victims (57%) knew their assailant. Threat of force was used in 72% of cases, and physical trauma was evident in 52% of victims [8]. Alcohol consumption or drug use was involved in 54% of these assaults.

The evaluation and treatment of sexual assault victims should incorporate the following components [11,12]:

Non-genital bodily injury is seen in more than half of all rape victims presenting to EDs [7,8]. In one study of 162 women examined between 2002 and 2006, signs of bodily injury were found in 61% of patients, with genital injury present in 39% [13]. Most common were bruises (56%) and abrasions (41%), followed by lacerations, penetrating injury, and bites. Evidence of injury was higher in the 137 cases examined within 72 hours of assault (66% vs. 33%) and in cases in which the assaults occurred outdoors (79% vs. 52%).

Signs of genital traumatic injury are not always found after sexual assault, and in such cases should not be taken as evidence that sexual assault did not occur [13]. When routine inspection is combined with additional examination techniques, such as colposcopy and toluidine blue staining, the rate for identifying genital injury approaches 70% [9]. Observed rates of genital injury are highest in women examined within 72 hours (40% vs. 7%), in those of virginal state (60% vs. 33%), and in cases involving assault by strangers or multiple assailants [14].

The first step in preserving evidence is identifying the precise nature of the assault, circumstances, and scope of injury to the victim. This helps to determine the direction of the investigation and the type of forensic evidence to be obtained during the clinical and forensic evaluation. The time of the assault and the sequence of events following should be ascertained, as the quality of evidence often deteriorates over time. For example, DNA in saliva deteriorates especially rapidly, often in less than 48 hours. It is recommended that a sexual assault forensic exam be administered within 96 hours of an attack for the collection of trace evidence; however, bruises, bite marks, and other injuries are often still evident beyond this time frame [16,17].

Photo-documentation will typically proceed along with the physical examination and the collection of evidence. When an injury or other evidence (e.g., fluids, fibers) is found, it should be photographed. It is considered good practice to capture four images of each finding [15]. One should be an overall shot of the body that includes a clear anatomical reference (e.g., arm, hand, leg, foot), another should be a medium shot, and there should be two detailed shots of the finding. The wide and medium shots can be used to document multiple findings. Detailed, close-up images of each injury should be taken before evidence collection, during manipulation, and after the evidence is swabbed or removed. If a lifesaving measure may disturb evidence, it is ideal to photograph the site/finding beforehand, if possible.

The patient should be seen in follow-up within one to two weeks. The purpose of this encounter is to assess clinical progress and compliance with medication, to check the adequacy of the patient's support system, and to offer counseling. A diagnostic evaluation for STIs may be performed as well, if this was deferred at the time of the initial evaluation.