title: Community-acquired, healthcare-associated and hospital-acquired bloodstream infection definitions in children: a systematic review demonstrating inconsistent criteria.
abstract: BACKGROUND
  Historically, bacterial infections were categorized as either community-acquired (CA) or hospital-acquired (HA). However, the CA/HA dichotomy no longer adequately reflects patterns of emerging healthcare-associated (HCA) infections in complex patients managed between hospital and the community. Studies trying to define this evolving epidemiology often excluded children.
  
  
  OBJECTIVE
  To identify what criteria have been used to distinguish between CA, HCA and HA bloodstream infections (BSIs) in children, and the proportional distribution of CA, HCA and HA among total BSIs and by organism.
  
  
  METHODS
  We systematically reviewed published literature from PubMed, UK Department of Health and US Centers for Disease Control and Prevention websites.
  
  
  RESULTS
  Results from 23 studies and the websites highlighted the use of inconsistent criteria. There were 13 and 15 criteria variations for CA and HA BSI respectively, although a 48h cut-off for cultures sampled post admission was most commonly reported. Five studies used variable clinical criteria to define HCA. The mean proportion of paediatric CA BSI in nine studies was 50%. Only four BSI organisms from five studies were predominantly CA (Streptococcus pneumoniae, Salmonella spp.) or HA (coagulase-negative staphylococci, Enterococcus spp.), whereas Pseudomonas spp., Klebsiella spp. and Enterobacter spp. did not clearly fit into either category.
  
  
  CONCLUSIONS
  Our study reveals inconsistent use of criteria, and a lack of evidence upon which to base them, to distinguish between CA, HCA and HA BSI in children. Criteria for CA, HCA and HA BSI need to be developed using population-based studies that consider patients' clinical characteristics, recent healthcare exposure as well as isolated organism species.
authors.affiliation: Department of Healthcare-Associated Infections and Antimicrobial Resistance, Public Health England, London, UK; Centre for Paediatric Epidemiology and Biostatistics, UCL Institute of Child Health, London, UK. Electronic address: Katherine.Henderson@phe.gov.uk.
authors.forename: K L
authors.initials: KL
authors.lastname: Henderson
authors.forename: B
authors.initials: B
authors.lastname: Müller-Pebody
authors.forename: A P
authors.initials: AP
authors.lastname: Johnson
authors.forename: A
authors.initials: A
authors.lastname: Wade
authors.forename: M
authors.initials: M
authors.lastname: Sharland
authors.forename: R
authors.initials: R
authors.lastname: Gilbert
mesh_terms: D000293:Adolescent; D016470:Bacteremia / Q000175:diagnosis* / Q000453:epidemiology* / Q000382:microbiology; D001419:Bacteria / Q000145:classification / Q000302:isolation & purification; D002648:Child; D002675:Child, Preschool; D017714:Community-Acquired Infections / Q000175:diagnosis* / Q000453:epidemiology* / Q000382:microbiology; D003428:Cross Infection / Q000175:diagnosis* / Q000453:epidemiology* / Q000382:microbiology; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D015995:Prevalence; D009626:Terminology as Topic
keywords: Bloodstream infection; Children; Community-acquired; Healthcare-associated; Hospital-acquired