TB Diagnosis

TB diagnosis is difficult

Tuberculosis of the lungs can be detected by a chest x-ray and sputum examination

TB of the lungs is usually detected in the chest radiograph (x-ray). The imaging procedure is safe. Pregnant women should tell the nurse or doctor about their condition before the chest x-ray is taken. Read more about TB diagnosis while pregnant here.

The patient will also have sputum samples collected for TB diagnosis. Sputum samples are always examined for the presence of mycobacteria using smear microscopy, culture and a nucleic acid hybridization test. Results of smear microscopy and nucleic acid hybridization test are available in a few working days.

The risk of transmission is high if acid-fast bacilli are seen in the sputum smear. The nucleic acid hybridization test also provides rapid information on susceptibility of the TB bacterium to rifampicin. TB culture is used to confirm that the bacterium detected is the type of bacterium that causes tuberculosis. The result of a TB culture usually comes back in about 2- 8 weeks. The TB strain is always tested for drug susceptibility and genotyped.