a blood culture is a test on a sample of blood to check for bacteria, a fungus, or sometimes viruses in the bloodstream. the test may be done if a doctor suspects a blood infection. a blood culture may help determine the specific organism causing an infection and select the appropriate antibiotic to treat it.
usually a blood culture is needed only if a person is severely ill. blood cultures are commonly done when a person has a high fever or shaking chills that mean there may be an infection of the blood.
it usually takes between 1 and 3 days to get the results of a blood culture. but a blood culture to look for a fungus or virus can take weeks.