Sputum For AFB

The Sputum for Acid-Fast Bacilli (AFB) Test is a laboratory examination used to detect acid-fast bacteria in a sputum sample. It is commonly requested when investigating suspected pulmonary tuberculosis (TB) and other mycobacterial infections.

The test helps healthcare professionals assess whether acid-fast bacilli are present in respiratory secretions.

What Does This Test Check?

The test examines sputum for the presence of acid-fast bacilli (AFB), which may include bacteria belonging to the Mycobacterium group.

Depending on the laboratory method, the examination may involve:

• AFB Smear Microscopy: Examines a stained sputum sample under a microscope.

• AFB Culture: Attempts to grow mycobacteria for further identification, if specifically requested.

A positive smear indicates the presence of acid-fast organisms but does not independently confirm tuberculosis.

Sample Requirements

• Sample Type: Sputum Sample

• Sample Quantity: To be confirmed by the laboratory.

• Collection Container: Sterile, wide-mouth, leak-proof sputum container.

• Collection Instructions: Collect sputum from the lungs rather than saliva. Avoid contamination with food, water, or other substances.

Patient Preparation

• A deep-cough sputum sample, often collected early in the morning, may be preferred.

• Rinse the mouth with plain water before collection.

• Take a deep breath and cough deeply to bring up sputum from the chest.

• Follow the laboratory's instructions regarding the number of samples and transportation.

Important Information

• A negative AFB smear does not completely exclude tuberculosis.

• A positive AFB smear does not identify the exact mycobacterial species.

• Molecular testing, such as GeneXpert MTB/RIF, or culture may be required for further investigation.

• Smear, culture, and molecular testing are different investigations and should not be considered interchangeable.

Reporting Time: To be confirmed by the laboratory.

Please confirm test availability and sample collection requirements with the laboratory before booking.