Clostridium difficile Toxins A and B, EIA

Additional Information:

Epic order code: LAB5052

C difficile can produce two toxins, designated A and B, that have pathogenic effects in humans. Antibiotic-associated pseudomembranous colitis has been shown to result from the action of these two toxins. This disease has been associated with clindamycin use but it is now recognized that pseudomembranous colitis can follow administration of virtually any antibiotic. More than 70 percent of the cases in a large series were associated with cephalosporin therapy.1 The clinical spectrum of antibiotic-induced syndromes caused by C difficile includes patients with symptoms of acute abdomen with little or no diarrhea, as well as cases with fulminant life-threatening diarrhea. Nosocomial transmission and reinfection with different strains occurs as do spontaneous cases without prior antimicrobial therapy. In cases where cessation of antibiotic therapy does not produce a response, specific therapy with oral vancomycin, metronidazole, or oral bacitracin may be effective. Detection of the toxins produced by C difficile (rather than culture of the organism) is important in the determining therapy of this potentially fatal disease. The routine use of culture does not seem appropriate because of the costs and the high rate of recovery of strains which do not produce toxin.


  1. Talbot RW, Walker RC, Beart RW Jr, “Changing Epidemiology, Diagnosis and Treatment of Clostridium difficile Toxin-Associated Colitis,” Br J Surg, 1986, 73(6):457-60.PubMed 3719271


  • Bartlett JG, “Antibiotic-Associated Colitis,” Dis Mon, 1984, 30(15):1-54. PubMed 6391879
  • Gerding DN, “Disease Associated With Clostridium difficile Infection,” Ann Intern Med, 1989, 110(4):255-7. PubMed 2643913
  • Gerding DN, Olson MM, Peterson LR, et al, “Clostridium difficile-Associated Diarrhea and Colitis in Adults. A Prospective Case-Controlled Epidemiologic Study,” Arch Intern Med, 1986, 146(1):95-100. PubMed 3942469
  • Lyerly DM, Krivan HC, Wilkins TD, “Clostridium difficile: Its Disease and Toxins,” Clin Microbiol Rev, 1988, 1(1):1-18. PubMed 3144429
  • McFarland LV, Mulligan ME, Kwok RYY, et al, “Nosocomial Acquisition of Clostridium difficile Infection,” N Engl J Med, 1989, 320(4):204-10.PubMed 2911306

CPT Code(s):


Specimen Requirements:

Type: Stool

Container/Tube: Sterile screw-cap container or stool transport (Para-Pak® white clean vial); no preservative
  • Other container types often leak or even explode during transport and may be rejected by the laboratory.

Sample Volume: 5 g

Storage: Specimens should be kept at 4°C and transported to the laboratory within 24 hours of collection. If a longer period is required, the specimen should be frozen at -70°C on dry ice.
Rejection Criteria:

  • Inappropriate specimen transport conditions (e.g., room temperature) or transport device
  • Unlabeled specimen or name discrepancy between specimen and request label
  • Specimen received after prolonged delay (usually more than 72 hours)
  • Leaking specimen
  • Specimen received in an inappropriate container


This test is used to aid in the diagnosis of antibiotic-associated diarrheal disease and pseudomembranous colitis. It includes immunoassay for Clostridium difficile toxins A and B.


Detection of toxins A and B by enzyme immunoassay has a sensitivity approaching 90 percent, so multiple specimens may need to be tested.


Enzyme immunoassay (EIA) for Clostridium difficile toxins A and B