What is being tested?This test detects the presence of
Clostridium difficile toxin A and/or B in a fresh or frozen stool sample.
C. difficile is a
bacterium that is present as part of the normal bacterial
flora in the gastrointestinal tract of up to 65% of healthy infants and 3% of healthy adults. Sometimes, when
broad-spectrum antibiotics are used to treat infections, the balance of the normal flora in the colon can be disrupted. Bacteria that are susceptible to the antibiotic will be eliminated from the GI tract and
C. difficile that are resistant to the antibiotic will remain or new strains of
C. difficile may be acquired. The
C. difficile may produce two toxins - toxin A and toxin B. The combination of overgrowth of
C. difficile and toxin production can damage the lining of the colon and lead to severe
inflammation of the colon and prolonged
diarrhea. Dead tissue, fibrin, and numerous white blood cells can form a pseudomembrane over the inflamed bowel, which is referred to as pseudomembranous colitis.
C. difficile is the most common cause of diarrhea in patients who present with diarrheal symptoms while hospitalized. C. difficile toxins are isolated from stools of 15-25% of patients with antibiotic-associated diarrhea and greater than 95% of patients with pseudomembranous colitis. While C. difficile is frequently carried by infants, it does not usually cause diarrhea in this population. The risk of being affected increases with age and increases in those who are immunocompromised, have acute or chronic colon conditions, have been previously affected by C. difficile, or who have had recent gastrointestinal surgery or chemotherapy. C. difficile-associated diarrhea usually occurs in patients who have been taking antibiotics for several days, but it can also occur several weeks after treatment is completed.
C. difficile-associated disease is a spectrum of illness ranging from mild diarrhea to a more severe colitis, or to toxic megacolon, which can result in sepsis and death. Symptoms may include frequent loose stools, abdominal pain and cramps, nausea, fever, dehydration, fatigue, and leukocytosis. Treatment typically consists of stopping the original antibiotic and administering specific oral antibiotic therapy to which the C. difficile is susceptible. Most patients improve as the normal flora re-establishes itself, but about 12-24% of patients may have a second episode within 2 months.
