A case-control study of community-associated Clostridium difficile infection: no role for proton pump inhibitors.

BACKGROUND: The epidemiology of community-associated Clostridium difficile infection is not well known. We performed a multicenter, case-control study to further describe community-associated C. difficile infection and assess novel risk factors.
METHODS: We conducted this study at 5 sites from October 2006 through November 2007. Community-associated C. difficile infection included individuals with diarrhea, a positive C. difficile toxin, and no recent (12 weeks) discharge from a health care facility. We selected controls from the same clinics attended by cases. We collected clinical and exposure data at the time of illness and cultured residual stool samples and performed ribotyping.
RESULTS: Of 1041 adult C. difficile infections, 162 (15.5%) met criteria for community-associated: 66 case and 114 control patients were enrolled. Case patients were relatively young (median 64 years), female (56%), and frequently required hospitalization (38%). Antimicrobials, malignancy, exposure to high-risk persons, and remote health care exposure were independently associated with community-associated C. difficile infection. In 40% of cases, we could not confirm recent antibiotic exposure. Stomach-acid suppressants were not associated with community-associated infection, and 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors appeared protective. Prevalence of the hypervirulent NAP-1/027 strain was infrequent (17%).
CONCLUSIONS: Community-associated C. difficile infection resulted in a substantial health care burden. Antimicrobials are a significant risk factor for community-associated infection. However, other unique factors also may contribute, including person-to-person transmission, remote health care exposures, and 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors. A role for stomach-acid suppressants in community-associated C. difficile infection is not supported.