Ann Clin Microbiol 2024;27:3-10. Laboratory diagnosis of Clostridioides difficile infection: guidelines and status of practice in Korea

Table 1. Comparison of guidelines for diagnosis of C. difficile infection
References [12] [15] [16]
Organizations European Society of Clinical Microbiology and Infectious Diseases (ESCMID) Infectious Diseases Society of America (IDSA), Society for Healthcare Epidemiology of America (SHEA) American College of G astroenterology (ACG)
Diagnosis of CDI Clinical signs and symptoms in combination with laboratory tests The presence of symptoms and either a laboratory test positive, or colonoscopic or histopathologic findings revealing pseudomembranous colitis No single test can replace clinical acumen Diagnosis and decision to treat are clinical issues
Indications for CDI testing Age ≥ 3 years Unformed stool samples Formed stool samples should not be tested (except in the case of paralytic ileus) In patients suspected of ileus, a rectal swab can be used. Patients with unexplained and newonset, with three or more unformed stools in 24 hours Refuse a specimen from a patient receiving laxatives. Individuals with symptoms suggestive of active CDI (three or more unformed stools in 24 hours) Exception: formed stool may be tested for infection control purposes, documentation of colonization, etc. Rectal swabs for PCR may be useful for patients with an ileus
Recommendations for stand-alone testing Not recommended NAAT alone can be tested if there are pre-agreed institutional criteria for patient stool submission No single test is suitable to be used as a stand-alone test
Recommendations for multistep algorithm 2-step algorithm NAAT or GDH → Toxin AB → TC or NAAT (Optional) GDH and Toxin AB → TC or NAAT (Optional) Stool toxin test as part of multistep algorithm GDH plus toxin GDH plus toxin, arbitrated by NAAT NAAT plus toxin Algorithms should include both a highly sensitive and a highly specific testing modality 2-step algorithm GDH or NAAT → Toxin A/B