Clostridium difficile Infection, Colorado and the Northwestern United States, 2007¹

Jennifer L. Kuntz, Eric S. Johnson, Marsha A. Raebel, Amanda F. Petrik, Xiuhai Yang, Micah L. Thorp, Steven J. Spindel, Nancy Neil, and David H. Smith

Author affiliations: Kaiser Permanente Northwest, Portland, Oregon, USA (J.L. Kuntz, E.S. Johnson, A.F. Petrik, X. Yang, M.L. Thorp, S.J. Spindel, D.H. Smith); Kaiser Permanente Colorado Institute for Health Research, Denver, Colorado, USA (M.A. Raebel); University of Colorado School of Pharmacy, Denver (M.A. Raebel); Decision Research, Eugene, Oregon, USA (N. Neil)

Abstract

To determine the incidence of Clostridium difficile infection during 2007, we examined infection in adult inpatient and outpatient members of a managed-care organization. Incidence was 14.9 C. difficile infections per 10,000 patient-years. Extrapolating this rate to US adults, we estimate that 284,875 C. difficile infections occurred during 2007.

Clostridium difficile infection is a major source of illness in the United States (1). Population-based estimates of its incidence tend to include only subsets of infections defined by the setting of C. difficile acquisition (2–4) or are from patient populations outside the United States (5–9). These studies (2–9) offer useful data for control measures but do not help clinicians and policy makers understand the population-based incidence of C. difficile infection. To determine the incidence of C. difficile infection during 2007, we estimated the incidence of C. difficile infection among members of 2 Kaiser Permanente health plans and extrapolated our incidence estimate to the US adult population.