Rabies post-exposure prophylaxis — DTM&H MCQ

Correct answer: B — Immediate wound washing, rabies vaccine and rabies immunoglobulin

The correct answer is B, immediate wound washing, rabies vaccine and rabies immunoglobulin. This child has sustained deep, bleeding transdermal bites from an unvaccinated dog that fled and cannot be observed or tested, which is a WHO category III exposure. Category III exposures mandate immediate and thorough wound washing plus a full course of rabies vaccine and rabies immunoglobulin (RIG) infiltrated around the wound, as vaccine alone is insufficient to guarantee protection against this near-universally fatal infection once symptoms start. Wound washing mechanically reduces viral load at the inoculation site, while RIG provides immediate passive neutralising antibody until active immunity from vaccination develops. UKHSA guidance mirrors WHO recommendations, confirming that category III bites (multiple or deep transdermal wounds) require both vaccine and immunoglobulin, not vaccine alone. Why the other options are wrong: C. Rabies vaccine after symptoms develop: once clinical rabies manifests, the disease is essentially always fatal; prophylaxis only works if given before symptom onset, making this option clinically futile. E. Oral amoxicillin without vaccine: antibiotics address secondary bacterial wound infection only and have no activity against rabies virus, so they do nothing to prevent the fatal viral illness. A. Tetanus vaccine as the sole intervention: tetanus prophylaxis is a legitimate adjunct for any deep, contaminated bite wound but does not confer any protection against rabies, which is the life-threatening risk here. D. Observation without prophylaxis because the dog escaped: category III exposures require immediate treatment regardless of whether the animal is available for observation; waiting risks missing the window before symptoms (and death) occur, since the biting dog cannot be assessed. Key point: Deep or multiple bleeding bites from an unvaccinated, unobservable animal are category III exposures and always need wound washing, vaccine, and immunoglobulin together, not vaccine alone.

Reference: UKHSA, Guidelines on managing rabies post-exposure (January 2023), gov.uk; WHO Rabies vaccinations and immunization guidance, category III exposure criteria