Sputum Test For Tuberculosis
6,500 Kshs | Home Collection Available
Synonyms
Mycobacteria Culture
Purpose
This Sputum Test For Tuberculosis involves examining a sputum sample under a microscope or using molecular techniques (like GeneXpert) to identify TB bacteria. It is especially important for people who exhibit TB symptoms such as persistent cough, chest pain, coughing up blood, and unexplained weight loss.
Sputum testing is one of the most reliable methods for confirming active pulmonary TB, particularly in infectious cases. Early detection enables the initiation of treatment promptly and reduces the risk of transmission to others.
The test can be done alongside GeneXpert MTB/RIF Test, Chest X-ray, Tuberculin Skin Test (Mantoux Test), Culture Test, and ZN Stain (Ziehl-Neelsen).
Patient Preparation
The patient must remove dentures, rinse the mouth, and gargle with water.
Samples
2ml of expectorated sputum collected in a sterile screw-capped vial. The first morning specimen is preferred. The patient must not collect saliva. Refrigerate.
Reference Range
Negative/Normal
Results Turnaround
4 – 8 days after receipt of samples
Diseases / Diagnostic indicators
Some possible outcomes of the test include;
Positive Result:
A positive sputum test confirms the presence of Mycobacterium tuberculosis in the lungs or airways.
This indicates active pulmonary tuberculosis, meaning the individual can potentially spread the infection to others through coughing or sneezing.
A positive culture also allows for drug susceptibility testing to determine if the TB strain is resistant to common antibiotics.
Negative Result:
A negative result may suggest:
- No active TB infection
- Low bacterial load, especially in early-stage TB or in patients with weakened immune systems.
Doctors may recommend additional tests like GeneXpert, chest X-ray, or bronchoscopy to confirm TB if they still suspect the infection.
If the sample is contaminated or improperly collected, the results may be inconclusive, requiring a repeat test.
For more on Sputum for TB testing, read this study.