Clostridium Difficile, Colitis, and Colonoscopy: Pediatric Perspective.

PURPOSE OF THE REVIEW: Review tests available for detection of Clostridium difficile (C. Diff) induced disease, including when such tests should be done in children and how they should be interpreted.

RECENT FINDINGS: Multiple tests are available for detecting disease due to C. diff. These include colonoscopy and stool analysis. Colonoscopy with biopsy is the most sensitive test for detecting the presence of colitis. The toxins produced by the C. diff. (toxin A, toxin B, and binary toxin) are the agents that cause injury and disease. Only toxin producing C. diff. Strains will cause disease. Binary toxin by itself is not thought to produce disease. Binary toxin causes disease in humans when present with toxin A and B producing bacteria, and has been implicated with fulminant life threatening disease. Stool analyses vary in sensitivity and specificity depending on the assay used. The presence of toxin producing strains of C diff. in the stool does not equate with disease. The presence of a toxin-producing bacteria or toxins (A or B) only equates with disease if diarrhea or a diseased colon (toxic megacolon, ileus, and sepsis) is present. Nucleic acid amplification testing (NAAT), when used in the stool from patients with diarrhea, appears to be the most efficient study to detect the gene that encodes for toxin A and B and thus to diagnose C. diff.-induced disease. Infants have a high carriage rate of C. diff. and are believed not to develop disease from it or its toxins. Infants should not be tested for C. difficile. The NAAT is most specific when done on patients with diarrhea with liquid stools. Testing for C. difficile should only be done on patients with diarrhea. One can assume that a patient who has no diarrhea and is not ill does not have C. diff.-induced disease. Treatment should be limited to patients with diarrhea who test positive for C. diff. toxin (A or B) or toxin-producing bacteria. Direct testing for binary toxin is not commercially available. Binary toxin is only thought to cause disease in humans when C. diff. toxin (A and B)-producing bacteria are present.