A blood culture is done when a person has symptoms of a blood infection, also called bacteremia. Blood is drawn from the person one or more times and is tested in a laboratory to find and identify any microorganism present and growing in the blood. If a microorganism is found, more testing is done to determine the antibiotics that will be effective in treating the infection.
Bacteremia is a serious clinical condition and can lead to death. To give the best chance for effective treatment and survival, a blood culture is done as soon as an infection is suspected.
Symptoms of bacteremia are fever, chills, mental confusion, anxiety, rapid heart beat, hyperventilation, blood clotting problems, and shock. These symptoms are especially significant in a person who already has another illness or infection, is hospitalized, or has trouble fighting infections because of a weak immune system. Often, the blood infection results from an infection somewhere else in the body that has now spread.
Additionally, blood cultures are done to find the causes of other infections. These include bacterial pneumonia (an infection of the lung), and infectious endocarditis (an infection of the inner layer of the heart). Both of these infections leak bacteria into the blood.
After a blood infection has been diagnosed, confirmed by culture, and treated, an additional blood culture may be done to make sure the infection is gone.
Nancy J. Nordenson, The Gale Group Inc., Gale, Detroit,