What is this test?
This laboratory test is performed on a sputum sample to detect Acid fast bacilli such as Mycobacterium species causing infection. It involves staining and microscopic examination of the sample. It is commonly performed with a sputum culture to confirm a diagnosis.
Why is this test performed?
This test is performed if the patient has symptoms of infection from mycobacteria, such as Tuberculosis. Symptoms include:
- Chronic cough
- Chest pain
- Fatigue
- Fever and chills
- Weakness.
- What is sputum?
Sputum is a thick mucus and saliva produced by the respiratory tract in reaction to an infection. It should not be confused with saliva.
- What is tuberculosis?
TB is a serious bacterial infection caused by mycobacterium tuberculosis. It majorly affects the lungs.
- What happens if I can’t cough up enough sputum for the sample?
Other methods of collecting sample include:
- Inducing sputum by inhaling saline aerosol
- With the help of a bronchoscope.
- How much sputum is required for sample?
Minimum of 2mL sputum is acceptable for the sample.
- What are the risk factors for TB?
Risk factors of TB include:
- Close contact with an active TB patient
- Immune suppressing diseases
- TB endemic areas.
- Are there any risks of bronchoscopy?
You don’t necessarily need bronchoscopy. If you have undergone bronchoscopy, your throat may feel sore and hoarse for some time.
Positive or negative
- Interpretation of test results:
Positive: A positive result means that mycobacterial infection is present. It is further confirmed by a Sputum culture.
Negative: A negative result in the presence of infection means that the infection is due to non-mycobacterial species.