Suspected child sexual abuse with a positive STI — forensic evaluation, prophylaxis and safety planning OSCE

Station objectives

1. Grade an STI as evidence of sexual contact while excluding non-sexual routes, especially perinatal acquisition. [1] [6]
2. Run a trauma-informed, safety-first evaluation with consent, chaperone and forensic documentation discipline. [1] [2]
3. Decide on HIV post-exposure prophylaxis, STI prophylaxis and emergency contraception by risk and timing. [5] [3]
4. Frame conditional confidentiality and complete the mandated-reporting and multidisciplinary safety plan. [2] [8]

Candidate brief

You are the paediatric doctor in the emergency department. You have 10 minutes for Station A (a four-year-old with an incidental positive gonococcal NAAT and her mother) and 12 minutes for Station B (an adolescent disclosing an acute assault within the forensic window). Examiners score safety reasoning, forensic discipline, communication and the safeguarding plan. [1]

Station A — Incidental positive gonococcal NAAT

Setup: A four-year-old girl had a swab taken for vaginal discharge that returned positive for Neisseria gonorrhoeae. Her mother is present and anxious; there is no disclosure of contact. [1] [6]

Expected actions:

• Confirm the child is safe now and address the mother's distress with a clear, non-blaming explanation of what the result means. [1]
• Grade gonococcal infection at a non-conjunctival site in a prepubertal child as a strong marker of sexual contact, while explicitly excluding perinatal acquisition (rare to persist to this age, unlike chlamydia). [1] [6]
• Plan a trauma-informed history and a targeted examination in a trained setting with consent, chaperone and photo-documentation, noting that a non-specific examination is common and does not exclude abuse. [2]
• Make the child-protection notification your jurisdiction requires and arrange multidisciplinary follow-up; do not discharge the child into danger. [2]

Station B — Acute adolescent assault

Setup: A 14-year-old discloses a single episode of vaginal rape eight hours ago by a contact whose HIV status is unknown. She is distressed but physiologically stable. [7]

Expected actions:

• Confirm safety, address acute distress and suicidality, and preserve evidence: advise against washing, bathing or changing clothes, and retain clothing. [7]
• Collect forensic samples within the evidence window, because forensic yield concentrates in the early hours after assault, and maintain chain of custody. [7] [4]
• Offer HIV post-exposure prophylaxis by source status, exposure type and time since contact; provide STI prophylaxis per the CDC STI Treatment Guidelines; update hepatitis B vaccination; and offer emergency contraception. Confirm exact regimens from local protocol. [5] [3]
• Frame conditional confidentiality, complete the mandated report, and arrange window-period re-testing and trauma-informed psychological follow-up with a named contact. [2] [8]

Marking anchors

Clear pass: grades the STI correctly, excludes perinatal and non-sexual routes explicitly, runs a trauma-informed safety-first evaluation with consent and chaperone, decides prophylaxis by risk and timing, and delivers a mandated-reporting and multidisciplinary safety plan with named follow-up. [1] [5] [2] Borderline: identifies the STI as concerning but cannot grade it or exclude perinatal acquisition, or offers prophylaxis without a clear risk-and-timing rationale. Fail: treats the result as a routine infection only, interrogates the child, collects forensic samples without consent or chain of custody, promises absolute secrecy, or discharges the child into danger. [2] [7]

Debrief pearls

• The infection is treatable; the interpretation is forensic. [1]
• A normal examination never overrides a credible disclosure or a strong-marker STI. [2]
• The forensic window is short — preserve evidence and collect early. [7]
• Perinatal chlamydia can persist for years; perinatal gonorrhoea rarely does. [6]