title: Epidemiology of community-associated Clostridium difficile infection, 2009 through 2011.
abstract: OBJECTIVE
  Clostridium difficile infection (CDI) has been increasingly reported among healthy individuals in the community. Recent data suggest that community-associated CDI represents one-third of all C difficile cases. The epidemiology and potential sources of C difficile in the community are not fully understood.
  
  
  OBJECTIVE
  To determine epidemiological and clinical characteristics of community-associated CDI and to explore potential sources of C difficile acquisition in the community.
  
  
  METHODS
  Active population-based and laboratory-based CDI surveillance in 8 US states.
  
  
  METHODS
  Medical records were reviewed and interviews performed to assess outpatient, household, and food exposures among patients with community-associated CDI (ie, toxin or molecular assay positive for C difficile and no overnight stay in a health care facility within 12 weeks). Molecular characterization of C difficile isolates was performed. Outpatient health care exposure in the prior 12 weeks among patients with community-associated CDI was a priori categorized into the following 3 levels: no exposure, low-level exposure (ie, outpatient visit with physician or dentist), or high-level exposure (ie, surgery, dialysis, emergency or urgent care visit, inpatient care with no overnight stay, or health care personnel with direct patient care).
  
  
  METHODS
  Prevalence of outpatient health care exposure among patients with community-associated CDI and identification of potential sources of C difficile by level of outpatient health care exposure.
  
  
  RESULTS
  Of 984 patients with community-associated CDI, 353 (35.9%) did not receive antibiotics, 177 (18.0%) had no outpatient health care exposure, and 400 (40.7%) had low-level outpatient health care exposure. Thirty-one percent of patients without antibiotic exposure received proton pump inhibitors. Patients having CDI with no or low-level outpatient health care exposure were more likely to be exposed to infants younger than 1 year (P = .04) and to household members with active CDI (P = .05) compared with those having high-level outpatient health care exposure. No association between food exposure or animal exposure and level of outpatient health care exposure was observed. North American pulsed-field gel electrophoresis (NAP) 1 was the most common (21.7%) strain isolated; NAP7 and NAP8 were uncommon (6.7%).
  
  
  CONCLUSIONS
  Most patients with community-associated CDI had recent outpatient health care exposure, and up to 36% would not be prevented by reduction of antibiotic use only. Our data support evaluation of additional strategies, including further examination of C difficile transmission in outpatient and household settings and reduction of proton pump inhibitor use.
authors.affiliation: Division of Healthcare Quality Promotion, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
authors.forename: Amit S
authors.initials: AS
authors.lastname: Chitnis
authors.forename: Stacy M
authors.initials: SM
authors.lastname: Holzbauer
authors.forename: Ruth M
authors.initials: RM
authors.lastname: Belflower
authors.forename: Lisa G
authors.initials: LG
authors.lastname: Winston
authors.forename: Wendy M
authors.initials: WM
authors.lastname: Bamberg
authors.forename: Carol
authors.initials: C
authors.lastname: Lyons
authors.forename: Monica M
authors.initials: MM
authors.lastname: Farley
authors.forename: Ghinwa K
authors.initials: GK
authors.lastname: Dumyati
authors.forename: Lucy E
authors.initials: LE
authors.lastname: Wilson
authors.forename: Zintars G
authors.initials: ZG
authors.lastname: Beldavs
authors.forename: John R
authors.initials: JR
authors.lastname: Dunn
authors.forename: L Hannah
authors.initials: LH
authors.lastname: Gould
authors.forename: Duncan R
authors.initials: DR
authors.lastname: MacCannell
authors.forename: Dale N
authors.initials: DN
authors.lastname: Gerding
authors.forename: L Clifford
authors.initials: LC
authors.lastname: McDonald
authors.forename: Fernanda C
authors.initials: FC
authors.lastname: Lessa
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000553:Ambulatory Care / Q000706:statistics & numerical data; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D016360:Clostridioides difficile / Q000145:classification / Q000302:isolation & purification*; D017714:Community-Acquired Infections / Q000453:epidemiology; D004363:Drug Utilization / Q000706:statistics & numerical data; D016521:Electrophoresis, Gel, Pulsed-Field / Q000706:statistics & numerical data; D004761:Enterocolitis, Pseudomembranous / Q000453:epidemiology* / Q000635:transmission; D005243:Feces / Q000382:microbiology; D005260:Female; D006635:Histamine H2 Antagonists / Q000627:therapeutic use; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D007223:Infant; D008297:Male; D008875:Middle Aged; D058889:Molecular Typing; D015999:Multivariate Analysis; D011159:Population Surveillance; D054328:Proton Pump Inhibitors / Q000627:therapeutic use; D014481:United States / Q000453:epidemiology; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents; D006635:Histamine H2 Antagonists; D007166:Immunosuppressive Agents; D054328:Proton Pump Inhibitors