title: NAP1 strain type predicts outcomes from Clostridium difficile infection.
abstract: BACKGROUND
  Studies are conflicting regarding the importance of the fluoroquinolone-resistant North American pulsed-field gel electrophoresis type 1 (NAP1) strain in Clostridium difficile infection (CDI) outcome. We describe strain types causing CDI and evaluate their association with patient outcomes.
  
  
  METHODS
  CDI cases were identified from population-based surveillance. Multivariate regression models were used to evaluate the associations of strain type with severe disease (ileus, toxic megacolon, or pseudomembranous colitis within 5 days; or white blood cell count ≥15 000 cells/µL within 1 day of positive test), severe outcome (intensive care unit admission after positive test, colectomy for C. difficile infection, or death within 30 days of positive test), and death within 14 days of positive test.
  
  
  RESULTS
  Strain typing results were available for 2057 cases. Severe disease occurred in 363 (17.7%) cases, severe outcome in 100 (4.9%), and death within 14 days in 56 (2.7%). The most common strain types were NAP1 (28.4%), NAP4 (10.2%), and NAP11 (9.1%). In unadjusted analysis, NAP1 was associated with greater odds of severe disease than other strains. After controlling for patient risk factors, healthcare exposure, and antibiotic use, NAP1 was associated with severe disease (adjusted odds ratio [AOR], 1.74; 95% confidence interval [CI], 1.36-2.22), severe outcome (AOR, 1.66; 95% CI, 1.09-2.54), and death within 14 days (AOR, 2.12; 95% CI, 1.22-3.68).
  
  
  CONCLUSIONS
  NAP1 was the most prevalent strain and a predictor of severe disease, severe outcome, and death. Strategies to reduce NAP1 prevalence, such as antibiotic stewardship to reduce fluoroquinolone use, might reduce CDI morbidity.
authors.affiliation: Division of Healthcare Quality Promotion.
authors.forename: Isaac
authors.initials: I
authors.lastname: See
authors.forename: Yi
authors.initials: Y
authors.lastname: Mu
authors.forename: Jessica
authors.initials: J
authors.lastname: Cohen
authors.forename: Zintars G
authors.initials: ZG
authors.lastname: Beldavs
authors.forename: Lisa G
authors.initials: LG
authors.lastname: Winston
authors.forename: Ghinwa
authors.initials: G
authors.lastname: Dumyati
authors.forename: Stacy
authors.initials: S
authors.lastname: Holzbauer
authors.forename: John
authors.initials: J
authors.lastname: Dunn
authors.forename: Monica M
authors.initials: MM
authors.lastname: Farley
authors.forename: Carol
authors.initials: C
authors.lastname: Lyons
authors.forename: Helen
authors.initials: H
authors.lastname: Johnston
authors.forename: Erin
authors.initials: E
authors.lastname: Phipps
authors.forename: Rebecca
authors.initials: R
authors.lastname: Perlmutter
authors.forename: Lydia
authors.initials: L
authors.lastname: Anderson
authors.forename: Dale N
authors.initials: DN
authors.lastname: Gerding
authors.forename: Fernanda C
authors.initials: FC
authors.lastname: Lessa
mesh_terms: D000368:Aged; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D015373:Bacterial Typing Techniques; D016360:Clostridioides difficile / Q000145:classification* / Q000187:drug effects / Q000472:pathogenicity*; D003015:Clostridium Infections / Q000453:epidemiology* / Q000382:microbiology* / Q000401:mortality; D024881:Drug Resistance, Bacterial; D016521:Electrophoresis, Gel, Pulsed-Field; D004761:Enterocolitis, Pseudomembranous / Q000382:microbiology; D005260:Female; D024841:Fluoroquinolones / Q000494:pharmacology; D006760:Hospitalization; D006801:Humans; D008532:Megacolon, Toxic / Q000382:microbiology; D008875:Middle Aged; D011159:Population Surveillance; D015995:Prevalence; D012307:Risk Factors; D016896:Treatment Outcome
chemical_list: D000900:Anti-Bacterial Agents; D024841:Fluoroquinolones
keywords: Clostridium difficile; clinical outcomes; epidemiology; strain typing