title: Systemic and localized extra-central nervous system bacterial infections and the risk of dementia among US veterans: A retrospective cohort study.
abstract: BACKGROUND
  Emerging evidence indicates associations between extra-central nervous system (CNS) bacterial infections and an increased risk for dementia; however, epidemiological evidence is still very limited.
  
  
  METHODS
  This study involved a retrospective cohort of a national sample of US veterans (N= 417,172) aged ≥56 years. Extended Cox proportional hazard models adjusted for demographic characteristics and medical and psychiatric comorbidities determined the associations between systemic and localized extra-CNS bacterial infections occurring >2 years before the initial dementia diagnosis and the risk for dementia.
  
  
  RESULTS
  Exposure to any extra-CNS bacterial infection was associated with a significantly increased risk for dementia (hazard ratio [HR] = 1.20 [95% confidence interval = 1.16-1.24]). Independently, septicemia (HR = 1.39 [1.16-1.66]), bacteremia (HR = 1.22 [1.00-1.49]), osteomyelitis (HR = 1.20 [1.06-1.37]), pneumonia (HR = 1.10 [1.02-1.19]), urinary tract infections (HR = 1.13 [1.08-1.18]), and cellulitis (HR = 1.14 [1.09-1.20]) were associated with a significantly increased risk for dementia.
  
  
  CONCLUSIONS
  Both systemic and localized extra-CNS bacterial infections are associated with an increased risk for developing dementia.
authors.affiliation: Department of Epidemiology, University of Iowa, Iowa City, IA, USA.
authors.forename: Francis
authors.initials: F
authors.lastname: Mawanda
authors.affiliation: Department of Epidemiology, University of Iowa, Iowa City, IA, USA; Department of Medicine, University of Iowa, Iowa City, IA, USA.
authors.forename: Robert B
authors.initials: RB
authors.lastname: Wallace
authors.affiliation: Center for Comprehensive Access & Delivery Research and Evaluation, Iowa City VA Health Care System, Iowa City, IA, USA.
authors.forename: Kimberly
authors.initials: K
authors.lastname: McCoy
authors.affiliation: Department of Epidemiology, University of Iowa, Iowa City, IA, USA; Department of Medicine, University of Iowa, Iowa City, IA, USA; Center for Comprehensive Access & Delivery Research and Evaluation, Iowa City VA Health Care System, Iowa City, IA, USA.
authors.forename: Thad E
authors.initials: TE
authors.lastname: Abrams
keywords: Bacteremia; Bacterial infections; Cellulitis; Dementia; Osteomyelitis; Pneumonia; Septicemia; Urinary tract infections; Veterans