Blood cultures: towards zero false positives

The culture of micro-organisms from blood is an essential laboratory test for the diagnosis of bacteraemia. Early positive results provide valuable diagnostic information on which appropriate antimicrobial therapy can be initiated. Like any tests, however, false-positive blood culture results can limit the utility of this important tool. These false-positive results arise due to contamination. Reports from NHS trusts and equipment suppliers suggest these contamination rates could be as high as 10% (Department of Health (DH), 2007). A variety of strategies have been investigated and employed to decrease contamination rates. This article describes the utility of a variety of approaches to reduce the number of false-positive percutaneous blood cultures specifically in the adult population.