With respect to Clostridium Difficile (CD) colitis:
a) List 5 risk factors for infection.
Antimicrobial use, especially fluoroquinolones, clindamycin, broad spectrum penicillins and cephalosporins. (Specific antibiotics expected)
Increasing age use of PPI,
inflammatory bowel disease,
organ transplants, chemotherapy, chronic kidney disease, immune deficiency exposure to an infected individual, Nursing home/health care facility resident
b) What infection control measures would you take in a patient diagnosed with CD?
Strict contact precautions Isolation in single room
PPE: healthcare workers should wear gloves, gowns, 5 moments of hand hygiene should be observed
Use of soap and water more effective than alcohol based had wash (spores are resistant to killing by alcohol) in outbreak situations. Use of disposable equipment when possible
Post discharge disinfection of the room
c) Outline the approach to diagnosis and pharmacological management for severe CD colitis. Include the rationale for Faecal Microbial Transplantation and under what circumstances you would consider its use.
Diagnosis:
Diarrhoea
Radiographic evidence of ileus or megacolon
Positive stool testing - either ELISA or PCR
Presence of pseudomembranes on sigmoidoscopy
Pharmacological Management
Severe CD colitis – oral vancomycin (or fidaxamicin) and iv metronidazole.
Fidaxamicin may be an alternative if vancomycin is not available or not tolerated. Vancomycin can be given rectally if there is severe ileus
Faecal Microbial Transplantation (FMT)
The human colonic microbiota, which provides colonization resistance against bacterial pathogens, is a key determinant in the pathogenesis of C. difficile. After exposure to oral antibiotics, a decline in faecal microbial diversity is common and may last many months. FMT reconstitutes healthy microbiota.
Primarily indicated for recurrent disease that has not responded to antibiotic treatment
Examiners Comments:
Candidates need to read the question carefully; part c) specified severe infection which was not addressed in some answers.
This question falls into the growing group of SAQs which ask for a considerable amount of detail about this organism, known commonly as Clostridium difficile because of a post-Linnaean convention of binomial nomenclature where we do not capitalise the species name, even when it is based on an otherwise capitalised personal or place name. That nerdgasm notwithstanding, the question itself is fairly similar to all the others before it, and contains all the familiar elements (risk factors, infection control measures, diagnosis and management). The only novel curveball was the additional need to discuss a faecal microbiota transplant, which was also weirdly capitalised. It is unclear how much of the 60% mark was allocated to the discussion of this exotic therapy.
Risk factors for C.difficile colitis (from Deshpande et al, 2015, and Leffler et al, 2015, where paragraphs of the latter bear a striking resemblance to the college answer, suggesting its origin)
Infection control measures:
Diagnosis
Clinical suspicion
Radiological diagnosis:
Biochemical diagnosis: the current recommendations are:
Sigmoidoscopy (endoscopic diagnosis)
Pharmacological management
Mild-moderate C.difficile infection:
Severe and complicated C.difficile infection:
Recurrent C.difficile infection:
Faecal microbial transplant
Rationale:
Circumstances for use:
Parker C, Tindall B, Garrity G. " International Code of Nomenclature of Prokaryotes" November 2015, International Journal of Systematic and Evolutionary Microbiology
Deshpande, Abhishek, et al. "Risk factors for recurrent Clostridium difficile infection: a systematic review and meta-analysis." infection control & hospital epidemiology 36.4 (2015): 452-460.
Leffler, Daniel A., and J. Thomas Lamont. "Clostridium difficile infection." New England Journal of Medicine 372.16 (2015): 1539-1548.
McDonald, L. Clifford, et al. "Clinical practice guidelines for Clostridium difficile infection in adults and children: 2017 update by the Infectious Diseases Society of America (IDSA) and Society for Healthcare Epidemiology of America (SHEA)." Clinical infectious diseases 66.7 (2018): e1-e48.