title: Clostridium difficile outbreak strain BI is highly endemic in Chicago area hospitals.
abstract: OBJECTIVE
  Describe the clinical and molecular epidemiology of incident Clostridium difficile infection (CDI) cases in Chicago area acute healthcare facilities (HCFs).
  
  
  METHODS
  Laboratory, clinical, and epidemiologic information was collected for patients with incident CDI who were admitted to acute HCFs in February 2009. Stool cultures and restriction endonuclease analysis typing of the recovered C. difficile isolates was performed.
  
  
  METHODS
  Two hundred sixty-three patients from 25 acute HCFs.
  
  
  RESULTS
  Acute HCF rates ranged from 2 to 7 patients with CDI per 10,000 patient-days. The crude mortality rate was 8%, with 20 deaths occurring in patients with CDI. Forty-two (16%) patients had complications from CDI, including 4 patients who required partial, subtotal, or total colectomy, 3 of whom died. C. difficile was isolated and typed from 129 of 178 available stool specimens. The BI strain was identified in 79 (61%) isolates. Of patients discharged to long-term care who had their isolate typed, 36 (67%) had BI-associated CDI.
  
  
  CONCLUSIONS
  Severe disease was common and crude mortality was substantial among patients with CDI in Chicago area acute HCFs in February 2009. The outbreak-associated BI strain was the predominant endemic strain identified, accounting for nearly two-thirds of cases. Focal HCF outbreaks were not reported, despite the presence of the BI strain. Transfer of patients between acute and long-term HCFs may have contributed to the high incidence of BI cases in this investigation.
authors.affiliation: Communicable Disease Program, Chicago Department of Public Health, Chicago, IL, USA. stephanie.black@cityofchicago.org
authors.forename: Stephanie R
authors.initials: SR
authors.lastname: Black
authors.forename: Kingsley N
authors.initials: KN
authors.lastname: Weaver
authors.forename: Roderick C
authors.initials: RC
authors.lastname: Jones
authors.forename: Kathleen A
authors.initials: KA
authors.lastname: Ritger
authors.forename: Laurica A
authors.initials: LA
authors.lastname: Petrella
authors.forename: Susan P
authors.initials: SP
authors.lastname: Sambol
authors.forename: Michael
authors.initials: M
authors.lastname: Vernon
authors.forename: Stephanie
authors.initials: S
authors.lastname: Burton
authors.forename: Sylvia
authors.initials: S
authors.lastname: Garcia-Houchins
authors.forename: Stephen G
authors.initials: SG
authors.lastname: Weber
authors.forename: Mary Alice
authors.initials: MA
authors.lastname: Lavin
authors.forename: Dale
authors.initials: D
authors.lastname: Gerding
authors.forename: Stuart
authors.initials: S
authors.lastname: Johnson
authors.forename: Susan I
authors.initials: SI
authors.lastname: Gerber
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002641:Chicago / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D016360:Clostridioides difficile / Q000302:isolation & purification*; D003015:Clostridium Infections / Q000453:epidemiology* / Q000401:mortality; D003428:Cross Infection / Q000453:epidemiology* / Q000401:mortality; D003967:Diarrhea / Q000453:epidemiology / Q000382:microbiology*; D005243:Feces / Q000382:microbiology; D005260:Female; D006761:Hospitals / Q000706:statistics & numerical data; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D008875:Middle Aged; D009735:Nursing Homes / Q000706:statistics & numerical data; D010360:Patient Transfer; D011159:Population Surveillance; D011446:Prospective Studies; D055815:Young Adult