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Cat Bite Joint Infection Risk — SCE Infectious Diseases MCQ

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EasyInfection Prevention & ControlCat Bite Joint Infection RiskSCE Infectious Diseases

A 30-year-old man develops a severe bite wound on his hand from a domestic cat. The wound is deep, penetrating to the metacarpophalangeal joint. He presents 6 hours after the bite. What is the most important concern specific to cat bites?

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Correct answer: A — Cat bite wounds have a higher infection rate (~50%) than dog bites (~15%) because cat teeth are sharp and thin, creating deep narrow puncture wounds that inoculate bacteria (particularly Pasteurella multocida) deep into tissue planes and joints — wound exploration and prophylactic antibiotics (Co-amoxiclav) are essential

Cat bites have significantly higher infection rates than dog bites (50% vs 15%) because cat teeth create deep, narrow puncture wounds that: (1) inoculate bacteria into deep tissue planes (tendons, joints, bone), (2) are difficult to irrigate effectively, and (3) seed Pasteurella multocida (the most common cat bite pathogen — causes rapidly progressive cellulitis within 12–24 hours). A deep cat bite over a joint (MCP in this case) risks septic arthritis. Management: wound exploration (assess tendon/joint involvement), thorough irrigation, prophylactic Co-amoxiclav (covers Pasteurella, anaerobes, Staphylococci), tetanus review, and hand surgery/orthopaedic referral for joint involvement.

Reference: NICE NG149 2020 – Bite wounds; BNF 2024 – Co-amoxiclav