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Abstract

We appreciate the points raised by Hochman regarding challenges in laboratory diagnosis of Clostridium difficile infection (CDI). As discussed in our study, and pointed out by Hochman, distinguishing between true CDI and C difficile carriage is challenging. This is particularly true in children with inflammatory bowel disease who have a known higher rate of C difficile carriage and present with symptoms that could be due to either inflammatory bowel disease activity and/or CDI. The Infectious Disease Society of America and the Society for Healthcare Epidemiology of America recently reviewed the existing literature and published updated clinical practice guidelines for CDI.1McDonald L.C. Gerding D.N. Johnson S. Bakken J.S. Carroll K.C. Coffin S.E. 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).Clin Infect Dis. 2018; 66: 987-994Crossref PubMed Scopus (517) Google Scholar They acknowledge that the optimum method for the diagnosis of CDI remains elusive, but point out that several studies have demonstrated that polymerase chain reaction tests are more sensitive than toxin-based assays. Accordingly, they recommend a test strategy based on pretest probability, using more sensitive polymerase chain reaction-based assays in clinical scenarios in patients with appropriate clinical symptoms. This strategy was used in our study; we defined CDI as “a positive fecal Clostridium difficile PCR test in combination with characteristic symptoms of diarrhea, hematochezia, or crampy abdominal pain.”2Brumbaugh D.E. De Zoeten E.F. Pyo-Twist A. Fidanza S. Hughes S. Dolan S.A. et al.An Intragastric Fecal Microbiota Transplantation Program for Treatment of Recurrent Clostridium difficile in Children is Efficacious, Safe, and Inexpensive.J Pediatr. 2018; 194: 123-127Abstract Full Text Full Text PDF PubMed Scopus (26) Google Scholar We acknowledge that this approach has the potential to overestimate the incidence of CDI and correspondingly underestimate the success rate of fecal microbiota transplantation in our study, but opted for this approach as to not misrepresent the potential benefits of fecal microbiota transplantation. Although the quoted study by Polage et al, is an important contribution to our understanding of the diagnostics of CDI, it is limited by being a single-center study, differences in empiric treatment choices between groups, enrollment of only adults, and not focused on patients with inflammatory bowel disease.3Polage C.R. Gyorke C.E. Kennedy M.A. Leslie J.L. Chin D.L. Wang S. et al.Overdiagnosis of Clostridium difficile Infection in the Molecular Test Era.JAMA Intern Med. 2015; 175: 1792-1801Crossref PubMed Scopus (383) Google Scholar We fully agree that more research is needed to both develop and validate diagnostic assays and/or clinical algorithms that can better distinguish between CDI and C difficile colonization in children. Immunoassay helps limit overdiagnosis of Clostridium difficile infectionThe Journal of PediatricsVol. 199PreviewThe recently published study by Brumbaugh et al1 summarized their retrospective experience with intragastric fecal microbiota transplantation (FMT) for recurrent Clostridium difficile infection (CDI) in 42 children (47 FMTs). The authors noted a much lower response rate of FMT in children with inflammatory bowel disease (IBD), 54% (7/13), compared with 94% (16//17) success in otherwise-healthy children. Full-Text PDF