Colonization versus carriage of Clostridium difficile.

Asymptomatic carriage of toxigenic strains of Clostridium difficile is common in health care facilities and the community. However, infection control efforts have traditionally focused almost entirely on symptomatic patients. There is now growing concern that asymptomatic carriers may be an underappreciated source of transmission. This article provides an overview of the pathogenesis and epidemiology of C difficile colonization, reviews the evidence that asymptomatic carriers shed spores and contribute to transmission, and examines practical issues related to prevention of transmission from carriers.