Community-associated Clostridium difficile Infections, Monroe County, New York, USA

Ghinwa Dumyati

, Vanessa Stevens, George E. Hannett, Angela D. Thompson, Cherie Long, Duncan MacCannell, and Brandi Limbago

Author affiliations: University of Rochester, Rochester, New York, USA (G. Dumyati, V. Stevens); State University of New York at Buffalo, Buffalo, New York, USA (V. Stevens); New York State Department of Health, Albany, New York, USA (G.E. Hannett); Centers for Disease Control and Prevention, Atlanta, Georgia, USA (A.D. Thompson, C. Long, D. MacCannell, B. Limbago)

Abstract

We conducted active sentinel surveillance in Monroe County, New York, USA, to compare incidence of community-associated Clostridium difficile infections (CA-CDIs) with that of health care–associated infections (HA-CDIs) and identify exposure and strain type differences between CA and HA cases. Patients positive for C. difficile toxin and with no documented health care exposure in the previous 12 weeks were defined as possible CA case-patients. Patients with onset in a health care setting or recent health care exposure were defined as HA case-patients. Eighteen percent of CDIs were CA; 76% were in persons who reported antimicrobial drug use in the 12 weeks before CDI diagnosis. Strain type distribution was similar between CA and HA cases; North American pulsed-field 1 was the primary strain (31% CA, 42% HA; p = 0.34). CA-CDI is an emergent disease affecting patients recently exposed to antimicrobial drugs. Community strains are similar to those found in health care settings.

Clostridium difficile is an anaerobic, spore-forming, gram-positive bacillus that produces 2 major toxins (TcdA and TcdB). Illness caused by toxigenic C. difficile varies from mild diarrhea to fulminant disease and death. Infection occurs commonly in the health care setting because of concomitant exposure to the organism and antimicrobial drugs in patients with severe illnesses and concurrent conditions. Over the past several years, the incidence (1), severity and mortality rate (especially in elderly persons) (2), and treatment failure rate of C. difficile infection (CDI) (3) have increased. In addition, CDI has been more commonly observed in healthy persons often without known CDI risk factors (4).
The changing pattern of disease is in part being caused by the emergence of a new epidemic hypervirulent C. difficile strain identified as North American pulsed-field 1 (NAP1) by pulsed-field gel electrophoresis (PFGE), BI by restriction endonuclease analysis, and 027 by PCR ribotyping (5). NAP1 strains often demonstrate resistance to quinolones, and increased use of these drugs may provide a positive selection pressure for NAP1 relative to other strains (6). The incidence, risk factors, and mode of transmission of CDI in hospital-associated (HA) disease are well described. However, few studies have examined the role of the hypervirulent NAP1 strain, antimicrobial drugs, proton pump inhibitors (PPI), and foodborne transmission on the emergence of CDI (7–19).
To define the magnitude of CDI across the continuum of care (hospital, long-term care, and the community) and assess the relative incidence and possible risk factors for community-associated disease, a 6-month surveillance program for laboratory-diagnosed CDI cases was initiated in Monroe County, New York, USA, in 2008. This program was undertaken in 2 sentinel laboratories in preparation for population-based surveillance of CDI in several US states through the Emerging Infections Program of the Centers for Disease Control and Prevention (CDC). A secondary goal of this study was to compare C. difficile recovery rates between refrigerated fecal swab and frozen fecal specimens.