ObjectiveTo investigate the diagnostic value of simultaneous culture of central venous catheter (CVC) blood and peripheral blood for catheter-related bloodstream infections (CRBSI). MethodsNon-septic patients who were treated with CVC for 1 to 7 days were enrolled from February 2011 to February 2015 in the First Hospital of Wuhan City. Blood were collected from both peripheral vein and CVC for bacterial culture once a day. The CVCs were removed from patients who got CRBSI from the first to sixth day and who did not by the end of the seventh day for semi-quantitative catheter culture, quantitative catheter culture, CVC culture and catheter exit-site pus culture. The diagnosis of CRBSI were based on 4 methods as follows:A, both peripheral and CVC blood were positive and the time of CVC blood positive were 2 hours earlier than peripheral blood; B, the colonies of semi-quantitative catheter cultures were ≥15 CFU and the microorganisms in both CVC and peripheral blood were the same; C, the colonies ratio of CVC and peripheral blood cultures were ≥5:1; D, the microorganisms in both the peripheral blood and catheter exit-site pus were the same. The diagnostic value of the four methods was compared. ResultsA total of 1 086 patients were finally included. From 1 to 7 days, 64 patients were peripheral blood positive, 79 were CVC blood positive. The patients diagnosed as CRBSI using A, B, C, and D methods were 58, 55, 51, and 36, respectively. Sixty patients were diagnosed as CRBSI based on the clinical and laboratory methods. For the number of patients diagnosed with CRBSI, there was no significant difference between A and B (P>0.05), as well as A and C (P>0.05), however, significant difference was found between A and D (P<0.05). In the diagnostic value of CRBSI, A is similar to B (sensitivity:93.33% vs. 91.67%, specificity:99.81% vs. 100%, Youden index:0.93 vs. 0.92). A, B and C had almost similar specificity (all >99%), however, A had higher sensitivity (93.33% vs. 76.67%, 58.33%) and Youden index (0.93 vs. 0.76, 0.58). ConclusionSimultaneous culture of CVC blood and peripheral blood has a good diagnostic value for CRBSI.