Acid Fast Bacilli (AFB) Culture
Acid fast bacilli cultures are used to grow, identify and isolate acid fast bacilli in the laboratory. AFB cultures are helpful in making a definitive diagnosis of AFB and testing their sensitivity to antibiotics.
Why the test is performed?
Acid Fast Bacilli Culture is helpful in diagnosing an active TB infection and monitoring the effectiveness of ongoing treatment. The cultures are also effective in determining the most effective antimicrobial agents to treat TB. They help in confirming the spread of TB to other organs and also in determining whether a person is still infected, even after undergoing the treatment.
When is the test ordered?
An AFB culture may be ordered if a patient with lung infection has these symptoms:
- Chronic cough producing sputum with streaks of blood
- Loss of appetite
- Unexplained weight loss
- Chest pain
An AFB culture is recommended after a positive TB screening test (X-ray, AFB smear), to evaluate the effectiveness of ongoing treatment and also to determine whether the person undergoing treatment is still infected or not. In addition, the test may also be recommended to individuals with TB outside the lungs.
How is the sample collected?
Sputum specimen is commonly collected. The sample may also be collected from body fluids.
How to prepare for the test?
No test preparation is required.