Keeping Up with Clostridium Difficile

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It is difficult to keep up with all of the relevant publications regarding Clostridium difficile–there are so many.  This likely reflects its emergence as a frequent and important pathogen.

Recent references:

  1. Sandberg KC et al. “Disproportionate Rise in Clostridium difficile Associated Hospitalizations Among US Youth with Inflammatory Bowel Disease, 19978-2011.” JPGN 2015; 60: 486-92 (editorial 421-22).
  2. Leffler DA, Lamont JT. NEJM 2015; 372: 1539-48.

In the first study, the researchers note that there has been a 5-fold increase in inflammatory bowel disease (IBD) hospitalizations with concomitant Clostridium difficile infection (CDI).  Whereas, the hospitalization without CDI increased 2-fold.  Associated with this 5-fold increase in hospitalizations, there were increased costs and longer length of stays.  Interestingly, IBD patients with CDI had a  lower likelihood (OR 0.31) of colectomy in this study. This epidemiology yields more questions than answers.  Certainly, a significant fraction of this increase is due to the use of more sensitive PCR-based assay. In addition, many of these patients may not be symptomatic due to CDI; it can be difficult to determine if IBD symptoms are due to IBD or due to CDI. Even treatment with antibiotics like vancomycin does not fully differentiate as the response could be nonspecific.

In the second review, severe useful points were made.

Risk factors:

  • Antibiotics –this remains most important risk factor
  • Older age (especially if >65 years)
  • Possible acid suppression -not confirmed in some studies when adjusting for coexisting conditions
  • Inflammatory bowel disease
  • Immunosuppression
  • Chronic kidney disease

Diagnosis:

  • Use of DNA assays has allowed for detection of “low levels of toxigenic organisms of uncertain clinical significance.”  Thus, these assays may detect clinically-insignificant infections.
  • Endoscopy is rarely needed, but sometimes helpful in ovelapping conditions like coexistent CDI from IBD
  • Negative PCR assay has a negative predictive value of “more than 95% in average-risk groups.”
  • Testing and treating persons with solid stools is not recommended

Prevention:

  • Probiotics “have an uncertain effect on the prevention of C difficile infection, and their routine use for the prevention or treatment of active infection is not recommended.”  The authors note that initial favorable studies of antibiotic-associated diarrhea were underpowered and that more recent studies have shown mixed results.  In studies of patients with unusually high rates of CDI, probiotics were shown to confer benefit.

Treatment:

  • Metronidazole and vancomycin remain 1st line treatments.
  • Fidaxomicin use has been limited due to expense, but has been shown to reduce recurrence of CDI in those who do not have the b1/NAP1/027 strain.
  • Alternative antimicrobials, including rifaximin, nitazoxanide and others, are “not recommended except in cases of unacceptable adverse effects.”
  • For recurrent infection, 1st line approach is retreatment with either metronidazole & vancomycin. Second recurrences are often treated with fidaxomicin or tapered vancomycin course.
  • Fecal microbial transplantation –noted to be highly effective and safe as salvage therapy. The precise components that are important are uncertain; however, “the phyla Bactteroidetes and Firmicutes are thought to comprise critical components.”  “More work is neede to understand the possible role for fecal microbial transplantation for primary CDI”

Bottomline: CDI remains an important pathogen and significantly complicates the management of IBD.

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