Is repeat PCR needed for diagnosis of Clostridium difficile infection?

Abstract

Patients with diarrhea, defined as loose or watery stool, and two or more Clostridium difficile tcdB PCR tests within 14 days of each other were investigated. Repeat PCR for 293 patients with a prior negative result yielded negative results in 396 (97.5%) of 406 tests. Ten new positives were detected, including one false positive. Repeat PCR within 7 days appears rarely useful, except for patients with evidence of a new infection.

FIG. 1.

Results for repeat PCR tests following a negative result. The PCR results per day for all patients who underwent repeat testing 1 to 14 days following a prior negative result are shown.