title: Blood collection procedures influence contamination rates in blood culture: a prospective study.
abstract: BACKGROUND
  Blood culture contamination is a significant adverse event. The aim of this project was to evaluate the efficacy of a strict blood collection procedure in reducing the blood culture contamination rate.
  
  
  METHODS
  A prospectively controlled study was performed in two different medical areas in Peking Union Medical College Hospital (PUMCH) for 16 months (from May 2006 to September 2007). In test group, a strict blood collection procedure was carried out by trained nurses with the veinpuncture sites were scrupulously disinfected with 2.5% tincture of iodine plus 70% alcohol. In control group, commonly used procedure in PUMCH was performed with 0.45% chlorhexidine acetate plus 0.2% iodine. Blood culture positive results for 4 target organisms (Coagulase-negative staphylococci, Propionibacterium acnes, Corynebacterium species and Bacillus species) were further assessed by physicians from infectious department to determine whether a sample was true positive (pathogen) or false positive (contamination).
  
  
  RESULTS
  Total 9321 blood culture collections were analyzed. The blood culture contamination rate in test group was significantly lower than that in control group (5/3177 (0.16%) vs. 77/6144 (1.25%); χ(2) = 13.382, P < 0.001). The most common contaminant was Coagulase-negative staphylococcus (76.83%). The average cultural time during which contaminated samples became positive was longer than that for true pathogen samples (42.0 hours vs. 13.9 hours, P = 0.041).
  
  
  CONCLUSIONS
  Using a strict blood collection procedure can significantly reduce blood culture contamination rate.
authors.affiliation: Department of Infectious Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100730, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Ge
authors.forename: Xiao-Qing
authors.initials: XQ
authors.lastname: Liu
authors.forename: Ying-Chun
authors.initials: YC
authors.lastname: Xu
authors.forename: Shan
authors.initials: S
authors.lastname: Xu
authors.forename: Min-Hong
authors.initials: MH
authors.lastname: Yu
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.forename: Guo-Hua
authors.initials: GH
authors.lastname: Deng
mesh_terms: D000891:Anti-Infective Agents, Local / Q000494:pharmacology; D001407:Bacillus / Q000187:drug effects; D001769:Blood / Q000382:microbiology*; D001800:Blood Specimen Collection / Q000009:adverse effects* / Q000379:methods*; D002710:Chlorhexidine / Q000493:pharmacokinetics; D003352:Corynebacterium / Q000187:drug effects; D004203:Disinfection / Q000379:methods*; D006801:Humans; D007455:Iodine / Q000494:pharmacology; D011424:Propionibacterium / Q000187:drug effects; D011446:Prospective Studies; D013210:Staphylococcus / Q000187:drug effects
chemical_list: D000891:Anti-Infective Agents, Local; D007455:Iodine; D002710:Chlorhexidine