Acute sexual assault in the emergency department

(i) Governing principles and consent. The encounter is governed by trauma-informed, patient-centred care. The premise is that the patient, having had her autonomy overridden by the assault, must regain control through every decision that follows. I would offer privacy, a same-sex chaperone and clinician where possible and where she wishes, a support person of her choosing, and the explicit statement that she may stop, decline, or pause at any point. The five principles — safety, trustworthiness, choice, collaboration, empowerment — frame the encounter.^[4] Consent is sought at every step and is specific to each component: she may consent to prophylaxis but decline the forensic examination, consent to the examination but decline police involvement, or consent to a report but decline to give a statement. Each decision is honoured without persuasion and documented with the reasoning. I would assess her capacity — she is alert and coherent, so she has capacity — and the acute medical treatment and forensic options all proceed on her consent.^[4]

(ii) Forensic examination and chain of custody. The forensic medical examination yields the most evidence within 72 hours of the assault; she is at 6 hours, well within the window. The examination is performed by a trained examiner — a forensic medical officer, a sexual assault nurse examiner, or a clinician from the local sexual-assault service — using the standardised sexual assault kit, with her explicit consent for each component. Swabs are taken from each site of contact, her clothing is collected and sealed, body-map documentation and photographs of injury are taken, and reference samples are obtained. She cannot recall whether ejaculation occurred, so the swabs are taken on the worst-case assumption. The chain of custody governs every specimen: each item is placed in a labelled, sealed container, the seal and label signed and dated by the collector, and every subsequent transfer — to a nurse, a police officer, or a laboratory — recorded on a chain-of-custody form signed by both parties. A single unexplained break can render the evidence inadmissible. If she declines the examination, I would offer to defer it, document the offer and the decline, and reassure her that all medical care and prophylaxis remain available to her.^[4]

(iii) Post-exposure prophylaxis. I would first do a pregnancy test (her last menstrual period was two weeks ago, so she is at the fertile window) and confirm it is negative before emergency contraception. I would offer the full prophylactic regimen. Emergency contraception: ulipristal 30 mg orally is preferred over levonorgestrel 1.5 mg orally because she is near ovulation and ulipristal is effective within 120 hours and more effective near ovulation; the copper intrauterine device is the most effective method and may be offered within 5 days.^[5] STI prophylaxis: ceftriaxone 500 mg intramuscularly single dose (1 g if 150 kg or more), doxycycline 100 mg twice daily and metronidazole 500 mg twice daily for 7 days, with hepatitis B vaccine at the initial examination if she is non-immune (plus immunoglobulin only if the assailant is known HBsAg-positive).^[1] HIV post-exposure prophylaxis: because she cannot recall whether ejaculation occurred and the act was vaginal penetration, I would assess the source risk — if the source is known HIV-positive, from a high-prevalence group, or the act carried significant risk, I would start a 28-day three-drug regimen of bictegravir/emtricitabine/tenofovir alafenamide or dolutegravir-based triple therapy, within 72 hours (ideally within 24) and never delayed for laboratory results, after counselling on adherence, side effects and the need for completion.^[2] I would take baseline HIV, syphilis, hepatitis B and hepatitis C serology, and arrange repeat serology at the follow-up interval.

(iv) Safety assessment and mandatory reporting. The assailant is an acquaintance, so intimate partner violence screening and a danger assessment apply. I would screen her alone — she has presented alone, which is ideal — and ask directly about prior violence, threats, strangulation, coercive control, stalking, firearms, and the risk of escalation. A non-fatal strangulation event carries over seven-fold odds of completed homicide, so I would examine the airway, the nervous system and the carotid vessels for any sign of injury. I would conduct a structured danger assessment and a safety plan in collaboration with her: an identified safe place, a packed bag, the domestic-violence helpline, and a bridge to the specialist service. The mandatory-reporting considerations divide by age: she is a competent adult, so the default is confidentiality and patient autonomy, and the decision to report to police is hers. I would not report without her consent unless a specific statutory duty applies — there is no FGM, no weapon injury, and she is not a vulnerable adult or a child — and I would offer the forensic examination that preserves the option to report later.^[3][1][6][7]

(v) Discharge and follow-up. I would not discharge her until the forensic examination is complete or declined, the prophylaxis is given or declined, the safety assessment and plan are documented, and a contact for the specialist sexual-assault and domestic-violence service is in her hand. I would arrange follow-up at the sexual-health or sexual-assault service for repeat HIV, syphilis, hepatitis B and C serology at the recommended intervals, for completion of the hepatitis B vaccination and the HIV PEP course, and for psychological support and counselling. I would give her written information, the crisis-line numbers, and the safety-net advice to return if she develops symptoms of infection, if she reconsiders the report, or if her safety situation changes.^[1]