What is this test?
This test detects a bacteria called Brucella. It is used when brucella arthritis  or an infection called brucellosis are suspected. A sample of blood, bone marrow, body fluid (including synovial fluid) or another tissue type may be collected for this test.
What are related tests?
Indirect Coombs test
- Agglutination assay
- Enzyme-linked immunosorbent assay
- Fluorescent immunoassay
- Western blot assay
Why do I need this test?
Laboratory tests may be done for many reasons. Tests are performed for routine health screenings or if a disease or toxicity is suspected. Lab tests may be used to determine if a medical condition is improving or worsening. Lab tests may also be used to measure the success or failure of a medication or treatment plan. Lab tests may be ordered for professional or legal reasons. You may need this test if you have:
- Brucella arthritis
When and how often should I have this test?
When and how often laboratory tests are done may depend on many factors. The timing of laboratory tests may rely on the results or completion of other tests, procedures, or treatments. Lab tests may be performed immediately in an emergency, or tests may be delayed as a condition is treated or monitored. A test may be suggested or become necessary when certain signs or symptoms appear.
Due to changes in the way your body naturally functions through the course of a day, lab tests may need to be performed at a certain time of day. If you have prepared for a test by changing your food or fluid intake, lab tests may be timed in accordance with those changes. Timing of tests may be based on increased and decreased levels of medications, drugs or other substances in the body.
The age or gender of the person being tested may affect when and how often a lab test is required. Chronic or progressive conditions may need ongoing monitoring through the use of lab tests. Conditions that worsen and improve may also need frequent monitoring. Certain tests may be repeated to obtain a series of results, or tests may need to be repeated to confirm or disprove results. Timing and frequency of lab tests may vary if they are performed for professional or legal reasons.
How should I get ready for the test?
Before having blood collected, tell the person drawing your blood if you are allergic to latex. Tell the healthcare worker if you have a medical condition or are using a medication or supplement that causes excessive bleeding. Also tell the healthcare worker if you have felt nauseated, lightheaded, or have fainted while having blood drawn in the past.
A bone marrow biopsy is a procedure that requires written consent. Review the consent form with the healthcare worker and ask any questions that you have before signing the consent form.
Tell the healthcare worker if you have a medical condition or are using a medication or supplement that causes excessive bleeding. You should also report if you have a history of allergic or other reactions to local anesthetics. Inform the healthcare worker of any past or present bone diseases. You may need to have other tests done before a bone marrow biopsy.
To prepare for a bone marrow biopsy, you may be offered a mild sedative prior to the procedure to help you relax. To decrease pain, you will also receive a topical or local anesthetic injection at the biopsy site.
An arthrocentesis is a procedure that requires written consent. Review the consent form with the healthcare worker and ask any questions that you have before signing the consent form.
Tell the healthcare worker if you have a medical condition or are using a medication or supplement that causes excessive bleeding. You should also report if you have a history of allergic or other reactions to local anesthetics. Blood tests may need to be done before an arthrocentesis.
Other body fluid or tissue sample:
A different sample other than the samples listed above may be used for this test. Ask your healthcare worker for information about how to prepare for this test. If you have questions or concerns about the preparation for this test, talk to the healthcare worker.
How is the test done?
A sample of blood, bone marrow, synovial fluid, or another body fluid or tissue may be collected for this test.
When a blood sample from a vein is needed, a vein in your arm is usually selected. A tourniquet (large rubber strap) may be secured above the vein. The skin over the vein will be cleaned, and a needle will be inserted. You will be asked to hold very still while your blood is collected. Blood will be collected into one or more tubes, and the tourniquet will be removed. When enough blood has been collected, the healthcare worker will take the needle out.
Bone marrow is the tissue inside certain bones where new blood cells are made. A bone marrow sample is collected by biopsy. Local anesthesia may be used for a bone marrow biopsy. Your skin will be shaved and cleaned, and a sterile area will be prepared for the procedure. A needle will be inserted through the skin and into the bone using a twisting motion. A sample of marrow will be removed with a syringe, and another needle will be used to remove a piece of tissue. When the samples are collected, the needle will be removed.
Synovial fluid is the fluid around the joints. A synovial fluid sample is obtained by a procedure called an arthrocentesis. The skin over the joint will be cleaned, and a local anesthetic will be used to numb the tissue at the insertion site. A needle will be inserted into the space around the joint, and fluid collected into a syringe. After enough synovial fluid has been collected, the needle will be removed.
Other body fluid or tissue sample:
A different sample other than the samples listed above may be used for this test. Methods used to collect other body fluids or tissue samples may vary. Ask the healthcare worker to explain how this sample may be collected. If you have questions or concerns about this test, talk to the healthcare worker.
How will the test feel?
The amount of discomfort you feel will depend on many factors, including your sensitivity to pain. Communicate how you are feeling with the person doing the test. Inform the person doing the test if you feel that you cannot continue with the test.
During a blood draw, you may feel mild discomfort at the location where the blood sample is being collected.
Before a bone marrow biopsy, you may receive medication to help you relax. When the numbing medicine is injected, you may feel mild discomfort or stinging. The local anesthetic is used to minimize pain, but as the procedure needle is inserted, you may feel some pressure and discomfort. You may feel brief pain as the bone marrow is removed. You may feel discomfort at the procedure site for several days.
During an arthrocentesis, a local anesthetic is given to numb the procedure area. You may feel mild discomfort or stinging when the numbing medicine is injected. You may feel pressure or discomfort during the procedure. Brief pain may be felt as the needle passes through the joint membrane. Your procedure site may be sore for several days.
Other body fluid or tissue sample:
A different sample other than the samples listed above may be used for this test. This test may feel different depending on many factors, including the sample needed and how it is collected. Ask the healthcare worker what to expect during this test.
What should I do after the test?
After a blood sample is collected from your vein, a bandage, cotton ball, or gauze may be placed on the area where the needle was inserted. You may be asked to apply pressure to the area. Avoid strenuous exercise immediately after your blood draw. Contact your healthcare worker if you feel pain or see redness, swelling, or discharge from the puncture site.
After the sample of bone marrow is collected, pressure may be applied and a bandage will be placed over the biopsy site. You will be given instructions for when to remove the bandage, and the signs and symptoms of infection to watch for. Contact your healthcare worker if you experience a fever or increased pain, and if you see increasing redness, swelling, or pus at the procedure site.
After an arthrocentesis is completed, pressure may be held to the site, and a bandage secured over the puncture site. If a large amount of fluid is removed, an elastic wrap may be used to support your joint. To treat swelling and pain, you may place cold packs over the joint. Avoid heavy use of the joint for a few days. If you have difficulty using the affected arm or leg after the procedure, contact your healthcare worker.
You will be given instructions for how to care for your bandage and the signs and symptoms of infection to watch for. Contact your healthcare worker if you have a fever or increased pain, and if you see increasing redness, swelling, or pus at the procedure site.
Other body fluid or tissue sample:
A different sample other than the samples listed above may be used for this test. Instructions for what to do after a collection of other body fluid or tissue samples may vary. Ask the healthcare worker to instruct you on what to expect after this test is completed. If you have questions or concerns about what to expect after the test is completed, talk to the healthcare worker.
What are the risks?
Blood: During a blood draw, a hematoma (blood-filled bump under the skin) or slight bleeding from the puncture site may occur. After a blood draw, a bruise or infection may occur at the puncture site. The person doing this test may need to perform it more than once. Talk to your healthcare worker if you have any concerns about the risks of this test.
Bone marrow: Bone marrow is collected by a procedure called aspiration and biopsy. The sample may be taken from multiple sites, but the most common site for biopsy is the pelvis. Risks of a bone marrow biopsy vary depending on the biopsy method used and the site selected for the biopsy. General risks of this procedure are infection and bleeding from the biopsy site. If you have a medical condition, or are using a medication or supplement that causes excessive bleeding, you are at a higher risk of bleeding from the procedure site.
Bone marrow biopsies performed on the sternum (breastbone) have the most risk. This area is only tested on adults, and only certain types of biopsies are done on the sternum. Due to the location and thickness of the sternum, it is rare but possible to damage the heart, major blood vessels, and the mediastinum (space of the chest that holds essential organs). A puncture to these areas could lead to severe bleeding, infection, or trapped air in the chest cavity. The person doing this procedure may need to perform it more than once. Talk to your healthcare worker if you have any concerns about the risks of having a bone marrow aspiration and biopsy.
Synovial fluid: An arthrocentesis is the procedure used to get a sample of synovial fluid for testing. Risks of an arthrocentesis include bleeding into the joint and joint infection. If you have a medical condition, or are using a medication or supplement that causes excessive bleeding, you are at a higher risk of bleeding from the puncture site. The person doing this procedure may need to perform it more than once. Talk to your healthcare worker if you have any concerns about the risks of having an arthrocentesis.
Other body fluid or tissue samples: A different sample other than the samples listed above may be used for this test. Ask your healthcare worker to explain the risks of this test to you. If you have questions or concerns about this test, talk to the healthcare worker.
What are normal results for this test?
Laboratory test results may vary depending on your age, gender, health history, the method used for the test, and many other factors. If your results are different from the results suggested below, this may not mean that you have a disease. Contact your healthcare worker if you have any questions. The following is considered to be a normal result for this test:
What follow up should I do after this test?
Ask your healthcare worker how you will be informed of the test results. You may be asked to call for results, schedule an appointment to discuss results, or notified of results by mail. Follow up care varies depending on many factors related to your test. Sometimes there is no follow up after you have been notified of test results. At other times follow up may be suggested or necessary. Some examples of follow up care include changes to medication or treatment plans, referral to a specialist, more or less frequent monitoring, and additional tests or procedures. Talk with your healthcare worker about any concerns or questions you have regarding follow up care or instructions.
Where can I get more information?
- Centers for Disease Control and Prevention - http://www.cdc.gov
 Yagupsky P, Peled N, & Press J: Use of BACTEC 9240 blood culture system for detection of Brucella melitensis in synovial fluid. J Clin Microbiol 2001; 39:738-739.
 Doern GV: Detection of selected fastidious bacteria. Clin Infect Dis 2000; 30:166-173.
 Araj G: Human brucellosis: a classical infectious disease with persistent diagnostic challenges. Clinical Laboratory Science 1999; 12(4):207-212.
 Yagupsky P, Peled N, Press J, et al: Rapid detection of Brucella melitensis from blood cultures by a commercial system. Eur J Clin Microbiol Infect Dis 1997; 16:605-607.
 Tietz NW (Ed): Clinical Guide to Laboratory Tests, 3rd ed. W. B. Saunders, Philadelphia, PA, 1995.
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