Blood Culture
About blood culture test
A blood culture test is a routine test that checks a blood sample for the presence of disease-causing germs such as bacteria, yeast, and other microbes that can seriously damage the body's immune system and internal organs. This test is used to identify blood infections (known as septicemia) which can lead to sepsis, a life-threatening and chronic condition.
Functions of blood
Blood is a body fluid that has four main components like plasma, red blood cells, white blood cells, and platelets. Blood plays vital roles, including:
·      Transports nutrients, oxygen to the lungs and tissues
·      Forms blood clots which prevent blood loss
·      Carries cells and antibodies to fight off infection
·      Carries waste products to liver and kidneys
·      Maintains body temperature
Blood culture testing is commonly used to diagnose infections and determine if any bacteria has entered the bloodstream. This test is recommended for identifying the specific germ causing an infection and enables further testing to determine the type of most effective treatment.
How is the blood culture test performed?
The site where blood will be drawn for the blood sample is cleaned with an antiseptic like chlorhexidine. This reduces the chance of bacteria on the skin getting into (contaminating) the blood sample and causing a false-positive result, which means you do not have a true infection.
The sample is then sent to a laboratory. A laboratory technician puts a portion of the blood sample onto a dish containing material (culture) that encourages germs to grow. The culture is then observed to check whether any bacteria or other disease-causing germs grow. A gram stain may also be performed; it is a method of identifying bacteria under a microscope using a special series of stains (colours). In some cases, bacteria can be found in the blood only at intervals so a series of three or more blood cultures may be done to increase the chances of finding an infection
Who should get a blood culture test?
Symptoms of sepsis (infection in blood) that requires a blood culture test includes:
Fever
Chills
Fast heartbeat
Rapid breathing
Low blood pressure
Confusion
Decreased urination
Inflammation throughout the body
Infections (affecting heart valves, bones, spinal cord or brain)
Organ failure
What is blood culture test used for?
In testing for infections, a blood culture test has varied roles such as:
Testing for a bacteria, fungi or virus in the blood to confirm that an infection is the cause of an individual’s symptoms
Determining the specific type of bacteria causing an infection
Assessing the severity of the infection
Planning the treatment to check which antibiotic works best against the bacteria
Monitoring how well the infection is responding to the treatment
Preparation for test
No special preparation is required for this test. Some antibiotics can affect the test results, so make sure your doctor is aware of any antibiotics that you have taken before the test.
Interpretation of the Test Results
Positive test result
If you have a positive result for blood culture test, it means that bacteria or other germs were seen in your blood sample. This may be caused due to sepsis, it is a medical emergency and you will be admitted to a hospital for treatment. Sometimes, an abnormal result may be caused due to contamination of the blood sample. This means that bacteria identified may have come from your skin or from the lab equipment instead of your blood, giving a false-positive result.
Negative test result
If you have a negative result for blood culture test, it means that no bacteria or other germs were seen in your blood sample.
FAQs
What are the risks involved in a blood culture test?
This test involves negligible risk. There might be slight pain or tenderness around the site where the needle went in. Rarely, the site can become infected
Can children get tested for blood culture test?
Blood culture tests can be performed on both adults and children. The number of times blood drawn, the amount of blood in each sample, and the preparation of the samples for testing may be different in the case of children. Blood culture testing may also be done in children up to 3 years of age who have a fever with no apparent cause and no other symptoms of infection
What should you do if you have a positive blood culture test result?
A positive blood culture test result could mean that you have a bacterial or yeast infection in your blood. If you are suspected of having a blood infection, you will begin treatment right away with intravenous antibiotics. Depending on the kind of organism discovered in your blood, another test called a sensitivity or susceptibility test is performed to help determine which specific medication will work best against that organism
Are the test results always accurate?
Test results are not always accurate and the results of a blood culture test can be affected by certain factors such as:
Organisms that do not grow in lab cultures: Some types of bacteria, fungi, and viruses are difficult to grow in the laboratory. When a person is infected with one of these germs, they can get a negative test result even in the case of an infection.
Contamination of sample: Sometimes germs from the skin enter the blood during the blood draw, or germs from lab equipment get into the culture dish. In such cases, the test result may be positive even though the germs are not actually present in the individual’s blood.
Antibiotics use: Taking any antimicrobial drug can limit the accuracy of a blood culture test. Therefore, samples for a blood culture test are taken before beginning treatment for an infection
When do I need follow-up blood culture tests?
Depending on your symptoms and the results of your blood culture test, you may require follow-up testing if your blood culture tests are negative but you have symptoms of an infection. Since a blood culture test cannot detect all germs, other types of tests or repeat blood culturing test may be ordered to look for the cause or spread of an infection. After treatment has started, you may need follow-up blood culture tests to see if the treatment is working against the germs and your infection is getting better
Related tests
Sputum Examination, Routine
₹ 120-
Includes
1 Test Parameter(s)
-
A Sputum examination test is done to identify bacterial or fungal infections in the respiratory tract. The sputum of an individual is collected by asking them to cough deeply and spit phlegm from their lungs into a sterile container. Sputum examination includes parameters such as color, Consistency, Epithelial Cells, Microscopic and Physical Examination., and Pus Cells, Quantity which indicates the presence of harmful pathogens. This test is prescribed for patients suffering from acute and chronic respiratory diseases such as pneumonia, bronchial asthma, pulmonary fungal infection (infections affecting lungs), and tuberculosis.
CSF Examination, Routine
₹ 700-
Includes
1 Test Parameter(s)
-
Cerebrospinal fluid (CSF) is a clear liquid around the brain and spinal cord, which acts as a protective cushion for the brain and spinal cord from sudden impact or injury.CSF testing is performed to evaluate the concentration of different substances and cells in CSF to diagnose conditions affecting the brain and spinal cord, such as meningitis (inflammation of the protective membranes covering the brain and spinal cord), encephalitis (inflammation of the brain), bleeding around the brain, cancer, or autoimmune disorder
Culture Fungus
₹ 950-
Includes
1 Test Parameter(s)
-
A fungus culture test is a traditional method for identifying fungal infections and their causative organism. Fungal infections can occur when exposed to different types of fungi like Candida and ringworm. Fungal infections usually affect externally - such as on the skin or genitalia, however, fungal infections may also affect internal organs like the lungs, lungs, eyes, liver, and brain. Health care providers advise fungal culture tests for symptomatic fungal infections. The fungus culture test also helps to select appropriate medication for fungal infections and check the effectiveness of treatment.
Tests At Lupin Diagnostics
Culture Automated Bone Marrow (Blood culture bottle), Aerobic- VITEK
₹ 1,200-
Includes
1 Test Parameter(s)
Culture Automated Bone Marrow (Blood culture bottle), Anaerobic- VITEK
₹ 1,200-
Includes
1 Test Parameter(s)
-
Culture-automated bone marrow (blood culture bottle) is used to detect the presence of anaerobes (bacteria that do not require oxygen to grow) in the bone marrow. This test is performed to confirm bone marrow infection. This test helps to verify the disease affecting bone marrow or blood, as changes in blood cells are often detected in marrow samples before they appear in blood samples. Osteomyelitis is a bone marrow infection caused by Bacteroides spp, Fusobacterium spp, Clostridium spp, Peptostreptococcus, Bacillus, and Corynebacterium spp. A bone marrow culture test is done throughout the treatment process of bone marrow infection.
Blood Culture bottle 1 and 2 ( Aerobic & anaerobic)- VITEK
₹ 1,500-
Includes
1 Test Parameter(s)