What is a blood culture?
A blood culture is a test to see what kind of bacteria or fungi are infecting your blood.
Usually, a blood infection occurs with other serious infections. These include infections in your lungs, kidneys, bowels, gallbladder, or heart valves.
You may also get a blood infection if your immune system is weak.
Why is a blood culture done?
Ablood cultureis done to:
- Find abacterial infectionthat has spread into the blood. These includemeningitisandosteomyelitis. They also includepneumonia,kidney infections, and sepsis.
- Find afungal infectionin the blood. One common type is a yeast infection.
- Check forendocarditis. This is abacterial infection on the heart valves.
- Find the bestmedicinesto kill the bacteria or fungi.
- Find the cause of an unexplained fever,shock, or other very serious illness.
How is a blood culture done?
A health professional uses a needle to take a blood sample, usually from the arm.
Blood is often collected from two or three different body sites. Or it may be collected at two different times a few hours apart.
Some people may have long-term catheters placed in a major vein because they are receiving chemotherapy or nutrition supplements for weeks or months at a time. For these people, blood for a blood culture will be collected from their catheters for this test.
How do you prepare for your child's blood culture?
- You don't need to do anything at home to prepare for the test.
- Tell the doctor or nurse if your child took antibiotics recently.
What do the results of a blood culture mean?
Most bacteria can be seen in the culture in 2 to 3 days. But some types can take 10 days or longer to show up. Fungus can take up to 30 days to show up in the culture.
Normal:
- No bacteria or fungus is found. Normal culture results are called negative.
Abnormal:
- Bacteria or fungus grows in the culture. Abnormal culture results are called positive.
If bacteria are found in the culture, another test is often done to find the best antibiotic that will kill the bacteria. This is called sensitivity or susceptibility testing. Sensitivity testing is important so the blood infection is treated correctly. This also helps prevent bacteria from becoming resistant to antibiotics.
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