What is this test?
This laboratory test is performed on an ascitic fluid sample to detect Acid-fast bacilli such as Mycobacterium species causing infection. It involves staining and microscopic examination of the sample.
Why is this test performed?
This test is performed to detect the presence of Acid-fast bacilli such as mycobacterium tuberculosis that causes extra-pulmonary tuberculosis. Tuberculosis can cause ascites when there is hematogenous spread of M.tuberculosis or from direct contact or ingestion of primary active focus.
- Which mycobacteria might be detected in AFB testing?
- Mycobacterium tuberculosis
- Mycobacterium marinum
- Mycobacterium bovis
- Mycobacterium avium-intracellulare complex
- Mycobacterium abscessus.
- What are the symptoms of abdominal tuberculosis?
Abdominal tuberculosis is a very common form of extrapulmonary tuberculosis. It presents the following symptoms:
- Ascites
- Abdominal pain
- Loss of weight
- Recurrent diarrhea
- Anorexia
- Lump in the abdomen
- What are the risks of this test?
- Bleeding
- Infection
- Damage to vessels and bladder from needle
- Shock
- Low blood pressure.
- How to prepare for the test?
Your doctor might ask you to empty your bladder before the test. Inform your doctor about your complete medical history especially of pregnancy, allergy, and bleeding problems.
- Is the procedure painful?
No, a numbing medicine is used to make it a painless procedure. However, pressure is felt from the needle.
- What are the risk factors of developing abdominal Tb?
- HIV
- Liver cirrhosis
- Diabetes
- Malignancy
- Anti-tumor necrosis factor agents.
Positive or negative
Interpretation of test results:
- Positive: A positive test result means that Acid-fast bacilli are detected in the ascitic fluid which is causing the infection.
- Negative: A negative test result means that Acid-fast bacilli are not detected in the ascitic fluid and the infection might be due to other microorganisms.
