The changing epidemiology of Clostridium difficile infections

Abstract

The epidemiology of Clostridium difficile infection (CDI) has changed dramatically during this millennium. Infection rates have increased markedly in most countries with detailed surveillance data. There have been clear changes in the clinical presentation, response to treatment, and outcome of CDI. These changes have been driven to a major degree by the emergence and epidemic spread of a novel strain, known as PCR ribotype 027 (sometimes referred to as BI/NAP1/027). We review the evidence for the changing epidemiology, clinical virulence and outcome of treatment of CDI, and the similarities and differences between data from various countries and continents. Community-acquired CDI has also emerged, although the evidence for this as a distinct new entity is less clear. There are new data on the etiology of and potential risk factors for CDI; controversial issues include specific antimicrobial agents, gastric acid suppressants, potential animal and food sources of C. difficile, and the effect of the use of alcohol-based hand hygiene agents.

FIG. 1.

Minimum-spanning-tree analysis of 59 C. difficile ribotype 027 isolates from 27 different regions of 14 countries typed by MLVA. Each circle (colored coded by country of origin [see key]) represents either a unique isolate or more isolates that are 100% homologous. The Dutch strains (green circles) (n = 17) are labeled by the submitting hospital plus a number. The other isolates are labeled by country and a number. The numbers between the circles represent the STRDs between MLVA types. The different-colored lines between the circles are indicative of one (green), two (red), three (blue), or four (gray) locus variants. Clindamycin-resistant isolates (n = 9) are IRE1, IRE5, IRE6, IRE8, IRE9, IRE10, FR1, BEL4, and BEL5. (Courtesy of National Reference Laboratory, Leiden, Netherlands; created by Celine Harmanus and used with permission.)