Mycobacterial diseases are infectious diseases caused by bacteria. TB refers to the bacteria Mycobacterium tuberculosis. MAI refers to Mycobacterium avium-intracellulare (MAI), which is a term for two species of bacteria.

Overview and Symptoms

Overview and Symptoms

Symptoms of TB depend on where the infection is spreading. TB often occurs in the lungs. There are two types of TB infection: latent and active. With latent TB, your immune system has walled off the infection and you don’t show signs or symptoms of disease. You also can’t give it to others. However, because the bacteria is still inside your body, you can get active TB later if your immune system becomes weaker.

Active TB infection, does cause symptoms and can spread to other people if not treated. With active TB, treatment with antibiotics is essential.

Diagnosis is usually through a tuberculin skin test, which is administered by injection on your arm. After 48 to 72 hours, the test is read by checking whether your body reacted to the injection. If there is no reaction, infection is unlikely.

People who have received the bacille Calmette–Guérin (BCG) vaccine may need blood tests to check whether they have TB.


If you have active TB, it is very important to complete the full course of antibiotics. This can take six months or more of antibiotic therapy. Your physician will prescribe a combination of antibiotics.

TB also exists in multi-drug resistant forms. If you have multi-drug resistant TB, it will require an additional, longer treatment course.