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Mycobacterium avium complex (MAC)

Mycobacterium avium (MEYE-koh-bak-TEER-ee-uhm AY-vee-uhm) complex, or MAC, affects adults with HIV usually when their T-cells drop below 50. Children can get MAC even when their T-cells are higher. MAC disease is less common in people with HIV/AIDS than it used to be before today's HIV drugs were available. Although MAC usually infects people through their lungs or intestines, it spreads quickly through the body. At this point, MAC infection means that you have AIDS. MAC disease can cause:

  • Fever
  • Night sweats
  • Weight loss
  • Stomach pain
  • Tiredness
  • Diarrhea
  • Blood infections
  • Hepatitis
  • Pneumonia

People with AIDS probably get MAC disease through normal contact with air, food, and water. MAC germs can be found in most sources of drinking water, like treated water systems, in dirt, and in household dust. MAC disease does not seem to be spread from one person to another.

Because MAC germs are found in food, water, and soil, there is no easy way to avoid them. However, there are drugs that can prevent MAC germs from causing disease. Because MAC disease occurs in people with very low T-cell counts, you should not get treatment to prevent MAC disease unless your T-cell count is below 50. Ask your doctor whether you should take drugs to lower your chances of getting MAC. If you get MAC, you will probably need antibiotics, and you will have to take them for life to keep MAC from returning.

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Content last updated: July 01, 2011.

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