Although there are very few cases of tuberculosis in Belgium, this disease continues to be a significant public health problem that requires continual vigilance.
How do you test for a Mycobacterium tuberculosis infection?
Testing for infection does not distinguish latent tuberculosis from active tuberculosis.
The intradermal test consists of injecting tuberculin (a mixture of proteins derived from the Koch Bacillus and acting as antigens) into the forearm of the person tested. If a local inflammatory reaction occurs within three to five days after injection, this means that there is probably an infection.
For a few years now, blood tests have also been used to detect infection. The detection of infection in people at risk and the follow-up of infected persons make it possible to diagnose the development of tuberculosis in time, begin treatment quicker and limit the contagion.
How is tuberculosis diagnosed?
Diagnostic tests distinguish latent tuberculosis from active tuberculosis.
- A rapid diagnosis is essential, as it allows treatment to start early in the disease and thus limits the spread of infection.
- If pulmonary tuberculosis is suspected, an X-ray of the lungs can be used to make an initial diagnosis.
- Finally, microbiological analysis of a sample (e.g. sputum) can confirm the diagnosis. Bacteria present in sputum are examined under a microscope and cultured.
- If the culture is positive, an antibiogram is routinely performed to verify that the bacteria are sensitive to conventional anti-tuberculosis antibiotics.