Role of time to positivity of blood culture in differentiating bloodstream infection from contamination during blood withdrawal
10.3969/j.issn.1671-9638.2015.12.003
- VernacularTitle:血培养报阳时间在鉴别血流感染和采血污染中的应用
- Author:
Huina LIU
;
Xianhai JIANG
;
Qiang LI
- Publication Type:Journal Article
- Keywords:
blood culture;
bloodstream infection;
time to positivity;
contaminated bacteria;
pathogenic bacteria
- From:
Chinese Journal of Infection Control
2015;(12):803-806
- CountryChina
- Language:Chinese
-
Abstract:
Objective To analyze the significance of time to positivity(TTP)of blood culture in differentiating bloodstream infection(BSI)from contamination during blood withdrawal.Methods Clinical data and TTP of blood culture in patients hospitalized in different departments from November 2013 to November 2014 were compared retrospectively,role of TTP in differential diagnosis of BSI was evaluated.Results Of 2 605 blood culture specimens,137 were positive for blood culture,78 (56.93%)of which were pathogenic bacteria and 59(43.07%) were contaminated bacteria,coagulase negative staphylococcus had the highest contamination rate(75.76%),while Escherichia coli had the lowest contamination rate(12.50%).TTP of pathogenic bacteria was shorter than that of contaminated bacteria ([13.86 ±8.19]h vs [40.72 ±20.96]h,P <0.05 ).Of pathogenic bacteria,Enterococcus had the earliest TTP ([10.20±8.00]h),followed by Escherichia coli ([11 .12 ±3.91 ]h),Staphylococcus aureus ([12.22±5.08]h),Klebsiella pneumoniae ([14.72±10.45]h),the other gram-negative bacteria([16.11 ±12.97] h),and coagulase negative staphylococci([16.42±5.74]h),fungi had the latest TTP ([29.04±3.67]h ).TTP of gram-negative bacteria was ≤16.59 h,sensitivity and specificity of BSI were 84.09% and 100.00% respectively;TTP of gram-positive bacteria was ≤20.96 h,sensitivity and specificity of BSI were 96.77% and 94.44% respec-tively.Conclusion Combination of TTP of blood culture and other clinical indications can provide reference for early differentiating isolated pathogenic bacteria from contaminated bacteria.
