title: Investigation of the case numbers of catheter-related bloodstream infection overestimated by the central line-associated bloodstream infection surveillance definition.
abstract: OBJECTIVE
  Diagnosis of catheter-related bloodstream infection (CRBSI) requires specific laboratory evidence. A simpler definition, central line-associated bloodstream infection (CLABSI), is recommended for surveillance purposes. Because exclusion of all other infection sources is difficult, CRBSI cases may be overestimated by using the CLABSI definition.
  
  
  METHODS
  A retrospective observational study was performed at a regional hospital in southern Taiwan from September 2012 to December 2013. All 106 reported CLABSI cases were assessed. Cases with catheter tip cultures were reviewed. CRBSI was defined as the identification of same organisms from the paired blood and catheter tip cultures (≥15 colony-forming units) without evidence of secondary bacteremia from other infection sources.
  
  
  RESULTS
  Overall, 64 cases were included and 31 (48.4%) were defined as CRBSI cases. In 30 (46.9%) cases, catheter tips were cultured after the corresponding blood cultures were performed. Later tip cultures were significantly more frequent in cases with other catheter types (18/22, 81.8%) than those with central lines (12/42, 28.6%; p < 0.0001). The same significant difference was also found among the CRBSI cases (central lines, 3/17, 17.6%; others, 13/14, 92.9%; p < 0.00005). Twelve bacterial species were identified from the CRBSI cases, with Staphylococcus aureus being the most frequent (13, 41.9%), followed by Pseudomonas aeruginosa (5, 16.1%).
  
  
  CONCLUSIONS
  The positive predictive value of the CLABSI definition for CRBSI cases was 48.4%. One should be aware of this discrepancy and should interpret the CLABSI surveillance definition with care.
authors.affiliation: Department of Critical Care Medicine, Tainan Municipal Hospital, Tainan, Taiwan; Department of Internal Medicine, Tainan Municipal Hospital, Tainan, Taiwan.
authors.forename: Xihn-Xuh
authors.initials: XX
authors.lastname: Chen
authors.affiliation: Committee of Infection Control, Tainan Municipal Hospital, Tainan, Taiwan.
authors.forename: Yi-Chu
authors.initials: YC
authors.lastname: Lo
authors.affiliation: Department of Laboratory Medicine, Chang Gung Memorial Hospital, Chang Gung University, College of Medicine, Kweishan, Taoyuan, Taiwan. Electronic address: sulinhui@gmail.com.
authors.forename: Lin-Hui
authors.initials: LH
authors.lastname: Su
authors.affiliation: Department of Internal Medicine, Tainan Municipal Hospital, Tainan, Taiwan; Committee of Infection Control, Tainan Municipal Hospital, Tainan, Taiwan. Electronic address: c2609926@yahoo.com.tw.
authors.forename: Chin-Lu
authors.initials: CL
authors.lastname: Chang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016470:Bacteremia / Q000453:epidemiology* / Q000382:microbiology; D055499:Catheter-Related Infections / Q000453:epidemiology*; D002405:Catheterization, Central Venous / Q000009:adverse effects*; D002408:Catheters, Indwelling / Q000382:microbiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011550:Pseudomonas aeruginosa / Q000302:isolation & purification / Q000472:pathogenicity; D012189:Retrospective Studies; D013211:Staphylococcus aureus / Q000302:isolation & purification / Q000472:pathogenicity; D013624:Taiwan
keywords: catheter tip cultures; catheter-related blood stream infection; central line-related blood stream infection