Collection, transport, and processing of blood cultures.

Variables of particular importance to the detection of bacteremia and fungemia include the collection of at least two separate blood cultures per septic episode and the inoculation of a minimum of 20 mL of blood from adults into each set of blood cultures. Switching of needles between venipuncture and inoculation of blood culture systems has been shown not to be necessary to reduce contamination and should be avoided to obviate needle stick injuries. The selection of the most appropriate blood culture system for use in the laboratory depends on numerous factors, including costs, personnel qualifications, and patient demographics.