Clostridium difficile, 2013

Clostridium difficile is an anaerobic, spore-forming, Gram-positive bacillus that produces two pathogenic toxins: A and B. C. difficile infections (CDI) range in severity from mild diarrhea to fulminant colitis and death. Transmission of C. difficile occurs primarily in health care facilities, where environmental contamination by C. difficile spores and exposure to antimicrobial drugs are common. The primary risk factor for development of CDI in health care settings is recent use of antimicrobials, particularly clindamycin, cephalosporins, and fluoroquinolones. Other risk factors for CDI acquisition in these settings are age >65 years, severe underlying illness, intensive care unit admission, nasogastric intubation, and longer duration of hospital stay.

A marked increase in the number of CDI cases and mortality due to CDI has been noted across the United States, Canada, and England. Most notable was a series of large-scale protracted outbreaks in Quebec first reported in March 2003. During this period, Quebec hospitals reported a 5-fold increase in health care-acquired CDI. These and other health care facility (e.g., long-term care facilities) outbreaks have been associated with the emergence of a new more virulent strain of C. difficile, designated North American PFGE type 1 (NAP1), toxinotype III.

Community-associated (CA) CDI is also receiving increased attention. Several cases of serious CDI have been reported in what have historically been considered low-risk populations, including healthy persons living in the community and peripartum women. At least 25% of these cases had no history of recent health care or antimicrobial exposure.

In 2009, as part of the EIP, we initiated population-based, sentinel surveillance for CDI at clinical laboratories serving Stearns, Benton, Morrison, and Todd Counties; in 2012 Olmsted County was added. A CDI case is defined as a positive C. difficile toxin assay on an incident stool specimen from a resident (≥1 year of age) of one of the as health care facility-onset (HCFO) if the initial specimen was collected greater than 3 days after admission to a health care facility. Community-onset (CO) cases who had an overnight stay at a health care facility in the 12 weeks prior the initial specimen are classified as CO-HCFA, whereas CO cases without documented overnight stay in a health care facility in the 12 weeks prior the initial specimen result are classified as CA. A more detailed set of case definitions is available upon request.

In 2013, 691 incident cases of CDI were reported in the five sentinel counties (175 per 100,000 population). Fifty-seven percent of these cases were classified as CA, 25% as COHCFA, and 18% as HCFO. The median ages for CA, CO-HCFA, and HCFO cases were 48 years, 63 years, and 73 years, respectively. Fifty-eight percent of CA cases were prescribed antibiotics in the 12 weeks prior to stool specimen collection compared to 79% of HCFO cases and 85% of CO-HCFA cases. Of the 391 putative CA cases eligible for interview, 267 were interviewed and confirmed as CA cases. Sixty percent of CA cases reported antibiotic use in the 12 weeks prior to illness onset date. Most common uses of antibiotics included treatment of ear, sinus, or upper respiratory infections (32%); dental procedures (18%); skin infections (13%); and urinary tract infections (9%).

• For up to date information see>> Clostridium Difficile
• Full issue>> Annual Summary of Communicable Diseases Reported to the Minnesota Department of Health, 2013