Diagnosis and management of Clostridium difficile infection.

There have been dramatic changes in the epidemiology of Clostridium difficile infection (CDI), with increases in incidence and severity of disease, attributed to the emergence of a fluoroquinolone-resistant "hypervirulent" strain, ribotype 027. C. difficile is now the most common pathogen causing hospital-acquired infection in U.S. hospitals, and community-acquired infections are increasing. The diagnosis of CDI is based on a combination of signs and symptoms, confirmed by laboratory tests. Clinical manifestations of CDI can range from asymptomatic colonization to severe pseudomembranous colitis and death. Many aspects of laboratory diagnosis of CDI remain contentious. Toxin enzyme immunoassays are too insensitive to be used alone, while nucleic acid amplification tests have emerged as an option, either as a stand-alone test or as part of a multitest algorithm. Oral vancomycin and metronidazole have been the recommended antimicrobial therapy options, and fidaxomicin is an effective new alternative. There is ongoing concern regarding the potential inferiority of metronidazole, in particular for severe CDI. Management of severe CDI and recurrent CDI continue to represent major treatment challenges. Biological therapies for the restoration of the intestinal microbiota (e.g., fecal microbiota transplantation) and monoclonal antibody therapy are promising approaches for CDI management, in particular troublesome recurrent CDI. This review will concentrate on the diagnosis and management of CDI in adults.