Pathology Associates Of Lexington, P.A.
Pathology Associates Of Lexington, P.A.
Pathology Associates Of Lexington, P.A.
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        C. difficile testing

The gold standard test for this spore-forming bacteria is culture (a 24 to 48 hour process). The cytotoxic assay (CTA...a 24 to 48 hour process) is triggered positive by all cytotoxins. EIA testing is rapid but witha wide vendor/kit sensitivity & specificity variation, with sensitivity as low as 53% and specificity as low as 75%. So, our clinical doctors must use history and physical findings, to include colonoscopy in conjunction with tests. In general, a negative test does not rule out CDAD (C. diff. associated diarrhea); a positive test can "confirm" a high index of clinical suspicion. See 2003 discussion.

Newly available on the market is a rapid "common antigen" (glutamate dehydrogenase) detection kit with 100% sensitivity and 100% negative predictive value.

As of 6/06, we use the "Wampole C. Difficile TOX A/B II" toxin-detection kit with a manufacturer's sensitivity rate of 83-96% and specificity of 100%. The negative predictive value is 90-99%. And, most of the tests are on inpatients or nursing home patients.

This is a dramatic case which had variable test results: pseudomembraneous colitis [a dramatic case with pneumoperitoneum, L12-9760].

See May 2006 write-up in CAP Today.

    (posted 28 May 2006; a case added 16 April 2013)

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