Rabies PEP — DTM&H MCQ

Correct answer: D — Rabies vaccine plus RIG infiltrated around the wound

The correct answer is D, rabies vaccine plus RIG infiltrated around the wound. This child has a category III exposure: a transdermal bite from a stray dog in a rabies-endemic country (Cambodia), mandating combined active (vaccine) and passive (immunoglobulin) immunisation under UK Health Security Agency guidance. Wound washing alone is insufficient once skin has been broken by an animal likely to carry rabies. Rabies immunoglobulin (RIG) is infiltrated in and around the cleansed wound to neutralise virus at the inoculation site immediately, bridging the 7 to 10 day gap before vaccine-induced antibody develops. Hand wounds are high risk due to dense innervation, reinforcing full category III management rather than vaccine alone. Why the other options are wrong: A, rabies vaccine alone: vaccine alone suits category II exposures (scratches or abrasions without bleeding); a penetrating bite from an unvaccinated stray dog also requires passive immunisation with RIG. B, observation of the dog for 10 days first: this only applies to a healthy, owned, observable domestic dog in a low-risk setting; a stray dog in an endemic country cannot be observed reliably, and PEP must start immediately. C, rabies immunoglobulin alone: RIG without vaccine gives only short-lived passive protection with no durable active immunity, so it must never be given without concurrent vaccination. D, wound suturing and oral amoxicillin-clavulanate: antibiotics and closure address secondary bacterial infection, not rabies virus, and primary suturing of a deep bite wound is generally avoided to limit viral inoculation. Key point: any category III rabies exposure (transdermal bite from a high-risk animal in an endemic area) requires both vaccine and RIG, with RIG infiltrated locally at the wound site, never vaccine or RIG alone.

Reference: UKHSA, Guidelines on Managing Rabies Post-Exposure (January 2023, updated 2025), gov.uk: https://www.gov.uk/government/publications/rabies-post-exposure-prophylaxis-management-guidelines