Contamination may occur during site preparation for venipuncture or catheter insertion, during collection set assembly, or when collection bottles are not properly disinfected. However, the most common source of contaminants are the organisms, existing as skin flora, that appear in blood culture specimens.
How do you get a blood culture sample?
After the draw, your nurse or technician covers the puncture site with some gauze and a bandage. The blood sample is then submitted to a laboratory where it's cultured: Each blood sample is added to a bottle containing a liquid known as broth. The broth encourages any microorganisms present in the blood sample to grow.
Can blood cultures become contaminated?
Blood culture contamination is common, constituting up to half of all positive blood cultures at some institutions. The identity of the organism isolated can help in determining if the culture is contaminated, as some organisms rarely cause BSIs.
How can a blood test get contaminated?
It has been suggested that during venipuncture the needle may pass through skin structures that still hold bacteria. As a result, these bacteria enter the needle and are then aspirated into the blood culture bottles, causing contamination.
What are common contaminants of blood cultures?
CNS, Micrococcus spp., viridans group streptococci, Propionibacterium acnes (Cutibacterium acnes), Corynebacterium spp., Clostridium perfringens and Bacillus spp. are the organisms most commonly described as contaminants [3,4].3 Apr 2018
What causes bacteria in blood culture?
, bacteria may periodically enter the bloodstream, causing bacteremia. Many common childhood bacterial infections cause bacteremia. Injecting recreational drugs can cause bacteremia because the needles used are usually contaminated with bacteria, and people may not properly cleanse their skin.