Don’t routinely collect or process specimens for Clostridium difficile testing when stool is not diarrhea (i.e., does not take the shape of the specimen container), the patient has had a prior nucleic acid amplification test result within the past seven days (e.g., polymerase chain reaction) or as a test of cure. A positive test in the absence of diarrhea likely represents C. difficile colonization. Repeated C. difficile testing within seven days of a negative test generally adds little diagnostic value. A test of cure in patients with recent C. difficile infection is also not recommended, as colonization may continue indefinitely. Contact precautions are required until symptoms (i.e., diarrhea) resolve.
Sources:
Aichinger E, et al. Nonutility of repeat laboratory testing for detection of Clostridium difficile by use of PCR or enzyme immunoassay. J Clin Microbiol. 2008 Nov;46(11):3795-7. PMID: 18784320.
Choosing Wisely Canada. Association of Medical Microbiology and Infectious Diseases Canada: Five things physicians and patients should questions [Internet]. 2017 Jun [cited 2017 Sep 25].
Luo RF, et al. Is repeat PCR needed for diagnosis of Clostridium difficile infection? J Clin Microbiol. 2010 Oct;48(10):3738-41. PMID: 20686078.
Luo RF, et al. Alerting physicians during electronic order entry effectively reduces unnecessary repeat PCR testing for Clostridium difficile. J Clin Microbiol. 2013 Nov;51(11):3872-4. PMID: 23985918.
Public Health Agency of Canada. Clostridium Difficile Infection: Infection Prevention and Control Guidance for Management in Acute Care Settings [Internet]. 2013 Jan 11 [cited 2017 Sep 25].