A Rapid Enzyme Immunoassay for the Detection of Clostridium difficile Toxins A and B in Stool Specimens

AND EXPLANATION OF THE TEST Toxigenic Clostridium difficile is the leading cause of nosocomial infectious diarrhea in developed countries. An estimated 300,000 cases of C. difficile associated disease (CDAD) are seen per year in U.S. hospitals alone. 2 Clostridium difficile is the etiologic agent in approximately 25% of all cases of antibiotic-associated diarrhea. Virtually any antibiotic can predispose a patient to CDAD. The clinical presentation for CDAD ranges from asymptomatic colonization to life-threatening pseudomembranous colitis and toxic megacolon. Most pathogenic strains of C. difficile produce two biologically and immunologically distinct toxins: toxin A (enterotoxin) and toxin B (cytotoxin). Toxin A was once thought to be responsible for most of the pathology seen in human CDAD until reports of clinically relevant disease caused by strains of C. difficile that produce only toxin B began to appear in the late 1990’s. The most accurate assay overall for the detection of C. difficile is the cytotoxin assay, however the method requires tissue culture facilities, 48-72 hour incubation and is not standardized. The use of a rapid test such as ImmunoCard Toxins A & B enables the physician to verify infection quickly, begin proper treatment and to initiate enteric isolation precautions in a hospital setting.