Diagnosis & Treatment

TB infection is most commonly diagnosed through the Mantoux Skin Test. In this test, a small amount of tuberculin is injected into the top layer of the skin

a negative reaction indicates no infection. A positive reaction with a skin rash diameter more than 10mm within 48-72 hours after injection most likely indicates the person is infected the person is infected with the TB germs.

There is a difference between being infected with TB and having TB disease. Someone infected with TB has the TB germs in their body. The body's defenses are protecting them from the germs, and they are not sick. Someone with TB disease is sick and may spread the disease to other people.

A person with a significant skin test needs to see a doctor to determine what further test and treatment may be necessary. Chest x-rays, sputum tests, tissue and urine exam and other tests are used to determine whether the positive reaction is associated with TB disease.

A sputum specimen is obtained from patients suspected of having pulmonary TB disease. The specimen is examined under a microscope for the presence of acid-fast bacilli (AFB). When AFB are seen, they are counted.

Patients with positive smears are considered infectious. The specimen is then cultured. Or grown, to determine whether it contains M. tuberculosis. A positive cultured for M. tuberculosis confirms the diagnosis of TB disease.

After the specimen has been cultured, it is tested for drug susceptibility. The results of drugs susceptibility test can help clinicians the appropriate drugs for use in treatment.