Recurrent Clostridium difficile infection: a review of risk factors, treatments, and outcomes.

Episodes of recurrent Clostridium difficile infection (CDI) are difficult to treat for several reasons. Foremost, data are lacking to support any particular treatment strategy. In addition, treatment of recurrent episodes is not always successful, and repeated, prolonged treatment is often necessary. Identification of subgroups at risk for recurrent CDI may aid in diagnosing and treating these patients. Two likely mechanistic factors increasing the risk of recurrent CDI are an inadequate immune response to C. difficile toxins and persistent disruption of the normal colonic flora. Important epidemiologic risk factors include advanced age, continuation of other antibiotics, and prolonged hospital stays. Current guidelines recommend that the first recurrent episode be treated with the same agent (i.e., metronidazole or vancomycin) used for the index episode. However, if the first recurrence is characterized as severe, vancomycin should be used. A reasonable strategy for managing a subsequent episode involves tapering followed by pulsed doses of vancomycin. Other potentially effective strategies for recurrent CDI include vancomycin with adjunctive treatments, such as Saccharomyces boulardii, rifaximin "chaser" therapy after vancomycin, nitazoxanide, fecal transplantation, and intravenous immunoglobulin. New treatment agents that are active against C. difficile, but spare critical components of the normal flora, may decrease the incidence of recurrent CDI.