title: Incidence of polymerase chain reaction-diagnosed Clostridium difficile in a large high-risk cohort, 2011-2012.
abstract: OBJECTIVE
  To describe incidence rates (IRs) of polymerase chain reaction (PCR)-diagnosed Clostridium difficile infection (CDI) in a large high-risk cohort.
  
  
  METHODS
  Members of Kaiser Permanente Southern California 1 year or older who were admitted to any of 14 Kaiser Permanente hospitals from January 1, 2011, through December 31, 2012, were included in the study. The CDI cases were identified by PCR in the inpatient and outpatient settings. The CDI IRs per 10,000 inpatient-days are estimated by year, surveillance category, age, sex, race/ethnicity, and Charlson comorbidity index. Recurrence rates are presented by age, sex, and race/ethnicity. Death and colectomy in the 30 days after CDI diagnosis, white blood cell count, and serum creatinine level are assessed.
  
  
  RESULTS
  Among 268,655 patients, 4286 (1.6%) had CDI. Among these patients, 671 (15.7%) had recurrent infections. The IR was highest among community-onset, health care facility-associated infections (11.1 per 10,000 inpatient-days). The CDI IRs differed by age, sex, and race/ethnicity. Overall, 528 patients (12.3%) died within 30 days of a positive CDI test result. The CDI IRs increased 34% with implementation of PCR testing.
  
  
  CONCLUSIONS
  Increasingly, PCR is being used because of its higher diagnostic sensitivity. Reassessing the epidemic using PCR updates our understanding of CDI risk. Our capacity to identify patients presenting in the outpatient setting after discharge provides a more accurate picture of health care-associated CDI rates, particularly because the community appears to assume an increasing role in CDI onset and possibly transmission. The CDI burden differs by race, comorbidity, sex, and previous health care use. The detected increase in CDI incidence after transitioning to PCR diagnosis was modest compared with previous studies.
authors: Department of Research and Evaluation, Kaiser Permanente Southern California, Pasadena. Electronic address: sara.y.tartof@kp.org.
authors: Sara Y
authors: SY
authors: Tartof
authors: Department of Infectious Diseases, Southern California Permanente Medical Group, West Los Angeles.
authors: Kalvin C
authors: KC
authors: Yu
authors: Department of Research and Evaluation, Kaiser Permanente Southern California, Pasadena.
authors: Rong
authors: R
authors: Wei
authors: Department of Research and Evaluation, Kaiser Permanente Southern California, Pasadena.
authors: Hung Fu
authors: HF
authors: Tseng
authors: Department of Research and Evaluation, Kaiser Permanente Southern California, Pasadena.
authors: Steven J
authors: SJ
authors: Jacobsen
authors: Department of Infectious Diseases, Southern California Permanente Medical Group, Harbor City.
authors: Gunter K
authors: GK
authors: Rieg
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D002140:California / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D016360:Clostridioides difficile; D004761:Enterocolitis, Pseudomembranous / Q000175:diagnosis / Q000453:epidemiology*; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction / Q000379:methods / Q000706:statistics & numerical data; D012008:Recurrence; D012307:Risk Factors; D012720:Severity of Illness Index; D012737:Sex Factors; D055815:Young Adult