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C. difficile — SCE Infectious Diseases MCQ

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ModerateHealthcare-Associated InfectionsC. difficileSCE Infectious Diseases

A 72-year-old woman develops profuse watery diarrhoea 10 days after completing a course of Co-amoxiclav for a chest infection. She has a white cell count of 22 × 10⁹/L, creatinine 180 µmol/L (baseline 85), temperature 38.5°C, and albumin 22 g/L. Clostridioides difficile toxin is positive. This is her first episode. What is the most appropriate treatment?

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Correct answer: E — Oral Vancomycin 125 mg four times daily for 10 days

This is confirmed Clostridioides difficile infection: diarrhoea with a positive C. difficile toxin test after recent broad-spectrum antibiotic exposure. It is a first episode and is severe because the WCC is >15 × 10⁹/L and creatinine has risen by >50% from baseline. Under current NICE UK guidance, the first-line antibiotic for a first episode of mild, moderate or severe C. difficile infection is oral vancomycin 125 mg four times daily for 10 days. Higher-dose oral vancomycin 500 mg QDS plus IV metronidazole is reserved for life-threatening disease or specialist-directed treatment failure, not uncomplicated severe first-episode disease. Fidaxomicin is used if vancomycin is ineffective or in specified further episodes; metronidazole is no longer first-line. Therefore the most appropriate treatment is oral vancomycin 125 mg four times daily for 10 days.

Reference: NICE Guideline NG199: Clostridioides difficile infection: antimicrobial prescribing. Published 2021. https://www.nice.org.uk/guidance/ng199/chapter/Recommendations