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Quick Facts

Infections Related to Tuberculosis (TB)

(Other Mycobacterial Infections)


The Manual's Editorial Staff

Last full review/revision Oct 2020| Content last modified Oct 2020
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Tuberculosis (TB) is a very common serious infection caused by bacteria called Mycobacterium tuberculosis. Less often, other kinds of mycobacteria cause diseases.

What is a MAC infection?

After TB, the most common mycobacterial disease is caused by a group of bacteria called Mycobacterium avium complex (MAC).

  • Healthy people rarely get MAC infections

  • MAC infections usually happen to frail elderly people, people with a weak immune system, and people with lung damage from emphysema or TB

  • MAC infections usually affect your lungs, but they can also involve your lymph nodes, bones, skin, and other tissues

  • MAC infections are hard to treat

  • You'll usually have to take antibiotics for 1 or 2 years

MAC infections of the lungs

MAC infections of the lungs start slowly. Symptoms are like those of TB in the lungs and include:

  • Cough

  • Spitting up blood or mucus

  • Tiredness

  • Weight loss

  • Fever

  • Trouble breathing

Doctors test your sputum (what you cough up from deep in your lungs). If you have a MAC infection, doctors treat it with antibiotics.

MAC infections of the lymph nodes

Lymph nodes are tiny bean-shaped organs that help fight off infection. Children can get a MAC infection in their lymph nodes by eating dirt or drinking water infected with mycobacteria.

Doctors treat these infections with surgery to take out the infected lymph nodes.

MAC infection throughout the body

People with AIDS or another health problem that weakens the immune system can get a whole body MAC infection.

Symptoms include:

  • Fever

  • Anemia (a low number of red blood cells)

  • Diarrhea

  • Belly pain

If they suspect a MAC infection throughout your body, doctors will take a sample of blood or tissue to test.

Doctors treat you with 2 or 3 antibiotics at the same time.

What other types of mycobacteria infection do people get?

Other types of mycobacteria cause:

  • Skin infections from swimming pools or aquariums—you get red bumps on your arms and legs which usually go away without treatment, though some people may need antibiotics

  • Buruli ulcer—swelling of the arms, legs, or face that turns into open sores—doctors treat you with antibiotics and often surgery

  • Infection of wounds, tattoos, and artificial body parts (such as breast implants)—doctors treat you with antibiotics and surgery

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