Originally published in MedPage Today
by Charles Bankhead, MedPage Today Staff Writer
Clostridium difficile infection has spread from the hospital to the community but has proved manageable thus far.
From 1991 to 2005, the incidence of community-acquired C. difficile in Olmsted County, Minn., quadrupled but still remained less common than the hospital-acquired gastrointestinal infection, Sahil Khanna, MD, of the Mayo Clinic in Rochester, Minn., said at the American College of Gastroenterology meeting.
“Patients with community-acquired C. difficile infection were younger, more likely to be female, and less likely to have severe infections,” Khanna observed.
Epidemiologic studies have shown an increasing incidence of both nosocomial and community-acquired infections. However, few studies have looked at the incidence of community-acquired C. difficile, said Khanna.
Moreover, no population-based studies have included comparisons of nosocomial and community-acquired infection.
To examine recent trends in C. difficile infection, researchers examined computer-linked records of patients in Olmsted County, which includes the Mayo Clinic, and identified all cases of C. difficile documented from 1991 to 2005. Diagnosis was based on a positive stool assay and appearance of pseudomembranous colitis.
Investigators defined severe disease as infection associated with a white blood cell count >15,000/mm3 and a rise in serum creatinine of more than 50% from baseline.
Severely complicated infection included the same criteria plus hypotension, ileus, toxic megacolon, perforation, ICU admission, surgery, or death.
The review uncovered 385 cases of C. difficile infection. Nosocomial infection accounted for 192 cases, nursing homes for 35, and community-acquired infection for 158 cases. Patients with nosocomial infections had a median age of 72 compared with 50 for patients with community-acquired infection (P<0.001). Additionally, women accounted for 60% of hospital-acquired versus 75% of community-acquired cases (P<0.001).
Overall, the infection rate increased from fewer than 10 cases per 100,000 person-years during 1991 to 1993 to about 45 cases per 100,000 person-years during 2003 to 2005.
The rate among women exceeded 50 cases per 100,000 person years and was significantly higher than the rate in men (P<0.001).
Broken down by source, the rate of nosocomial C. difficile infection increased from fewer than five cases per 100 hospital bed-years to about 16 cases during the period reviewed and was similar among men and women.
The overall rate of community-acquired infection increased from about three cases per 100,000 person-years to more than 12 cases per 100,000 person-years.
The rate in women exceeded 20 cases per 100,000 person-years during 2000 to 2002 before decreasing to 17 to 18 cases per 100,000 person-years during 2003 to 2005 (P<0.001).
Infection was associated with antibiotic use within the previous 90 days in 94% of the hospital-acquired cases and 78% of the community-acquired infections.
About 20% of community-acquired infections met criteria for severe illness, compared with about 35% of nosocomial infections (P<0.01).
Metronidazole was the choice for initial therapy in 84% of community cases and 91% of nosocomial cases. Metronidazole failure occurred in about 20% of cases in both groups, and the rate of recurrent infection was about 30% in both groups.
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