title: Increased Age-Dependent Risk of Death Associated WithlukF-PV-PositiveStaphylococcus aureusBacteremia.
abstract: BACKGROUND
  Panton-Valentine leucocidin is aStaphylococcus aureusvirulence factor encoded bylukF-PVandlukS-PVthat is infrequent inS aureusbacteremia (SAB), and, therefore, little is known about risk factors and outcome oflukF-PV/lukS-PV-positive SAB.
  
  
  METHODS
  This report is a register-based nationwide observational cohort study.lukF-PVwas detected by polymerase chain reaction. Factors associated with the presence oflukF-PVwere assessed by logistic regression analysis. Adjusted 30-day hazard ratios of mortality associated withlukF-PVstatus were computed by Cox proportional hazards regression analysis.
  
  
  RESULTS
  Of 9490 SAB cases, 129 werelukF-PV-positive (1.4%), representing 14 different clonal complexes.lukF-PVwas associated with younger age, absence of comorbidity, and methicillin-resistantS aureus. In unadjusted analysis, mortality associated withlukF-PV-positive SAB was comparable to SAB. However,lukF-PV-positive SAB nonsurvivors were significantly older and had more comorbidity. Consequently, by adjusted analysis, the risk of 30-day mortality was increased by 70% forlukF-PV-positive SAB compared with SAB (hazard ratio, 1.70; 95% confidence interval, 1.20-2.42;P= .003).
  
  
  CONCLUSIONS
  lukF-PV-positive SAB is rare in Denmark but associated with a significantly increased risk of mortality. Although the risk oflukF-PV-positive SAB was highest in the younger age groups, >80% of deaths associated withlukF-PV-positive SAB occurred in individuals older than 55 years.
authors.affiliation: Department of Infectious Diseases and; Department of Hematology, Roskilde Hospital, Denmark.
authors.forename: Trine A
authors.initials: TA
authors.lastname: Knudsen
authors.affiliation: Reference Laboratory for Antimicrobial Resistance and Staphylococci, Statens Serum Institut , Copenhagen , Denmark.
authors.forename: Robert
authors.initials: R
authors.lastname: Skov
authors.affiliation: Reference Laboratory for Antimicrobial Resistance and Staphylococci, Statens Serum Institut , Copenhagen , Denmark.
authors.forename: Andreas
authors.initials: A
authors.lastname: Petersen
authors.affiliation: Reference Laboratory for Antimicrobial Resistance and Staphylococci, Statens Serum Institut , Copenhagen , Denmark.
authors.forename: Anders R
authors.initials: AR
authors.lastname: Larsen
authors.affiliation: Department of Infectious Diseases and; Clinical Research Centre, Copenhagen University Hospital, Hvidovre, Denmark;; Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark.
authors.forename: Thomas
authors.initials: T
authors.lastname: Benfield
keywords: Panton-Valentine leucocidin; Staphylococcus aureus.; bacteremia; lukF/S-PV; mortality