My view is that Clostridium difficile infection (CDI) in children with inflammatory bowel disease is often overdiagnosed due to detection of a carrier state in many when tested by PCR assays and the overlapping clinical features. This is particularly important when considering fecal microbiota transplantation (FMT) due to the potential risks of this treatment.
Recently, I had a letter to the editor (J Pediatr 2018; 199: 283) on this topic that was accepted:
- Immunoassay helps limit the overdiagnosis of Clostridium difficile infection (Journal of Pediatrics)
- Link: Authors’s reply
The author’s reply suggested that their approach followed IDSA guidelines by checking CDI with PCR in those who were clinically-symptomatic. Yet, the IDSA guidelines (link here: IDSA C diff guidelines) do not focus on the issue of IBD flare-ups which cause identical symptoms. Expert IBD specialists have recommended the following for identifying CDI in patients with IBD:
“Start with enzyme immunoassay-based tests with a reflex to PCR test for discordant enzyme immunoassay results.” Rationale: “PCR is quite sensitive for the presence of toxigenic C difficile, it may increase the detection of asymptomatic colonization and shedding.” (K Rao, PDR Higgins. Inflamm Bowel Dis 2016; 22: 1744-54.)
Related blog posts:
- Clostridium difficile guidelines
- 4 Points for C diff in Inflammatory Bowel Disease
- Overdiagnosis of C difficile with PCR Assays
- C diff Risk factors in children
- Clostridium difficile/Fecal Microbiota Transplantation Video …
- Clostridium difficile: Colonization vs. Symptomatic Infection …
- Clostridium difficile Epidemiology | gutsandgrowth
- Precise Identification of C difficile Transmission …
- Clostridium difficile in IBD | gutsandgrowth
- A C difficile two-fer | gutsandgrowth
- Keeping Up with Clostridium Difficile | gutsandgrowth
- How Common are Clostridium difficile infections …
- Predicting Severe Clostridium Difficile | gutsandgrowth
- Consensus Guidelines on FMT | gutsandgrowth
gutsandgrowth 
Is there any concern or thought process that even if PCR positive in a active or flaring IBD patient you should treat? ….because the inflamed gut is still at higher risk of having that C. Diff present turn into active infection?
We really don’t know. That being said, if a patient is PCR+ for C diff but immmunoassay negative, they probably will not benefit from C diff therapy.