Postantibiotic colonization with Clostridium difficile in nursing home patients.

Clostridium difficile causes pseudomembranous colitis and is responsible for 20% to 25% of cases of postantibiotic diarrhea. In an earlier study, nursing-home patients with C. difficile infection were noted to have a high mortality rate. Because most of these infected patients had been treated with antibiotics, it was not clear whether this high mortality rate was associated with C. difficile infection or simply with antibiotic treatment. A prospective study was carried out to determine the rate of postantibiotic C. difficile colonization and risk factors for infection in patients in a 233-bed long-term care facility, as well as to determine whether C. difficile infection is associated with increased mortality. During a six-month period 150 courses of antibiotics were prescribed for 108 patients. Stool specimens were collected from 36 (33%) patients following the first course of antibiotic treatment, and 12 (33%) were infected with C. difficile. Risk factors for infection included ward location and stool incontinence. Age, body-mass index less than or equal to 18 kg/m2, and diagnoses of dementia and pressure scores tended to be associated with infection, but not significantly. Early mortality rates did not differ, but 12-month mortality for the infected patients was higher (83% vs 50%, P = .05). Therefore, we conclude that postantibiotic C. difficile infection serves as a marker of death in nursing-home patients, one that can be differentiated from the risk of antibiotic treatment alone. This increased death rate may be related in part to clinically unrecognized pseudomembranous colitis or, alternatively, to absorption of C. difficile toxins or even endotoxin from the gut lumen into the systemic circulation.