Incidence of Mycobacterium avium-intracellulare complex bacteremia in human immunodeficiency virus-positive patients.

The product-limit incidence of Mycobacterium avium-intracellulare complex (MAC) bacteremia in 1006 human immunodeficiency virus (HIV)-positive patients followed at one institution over a 3-year period from the day of AIDS diagnosis with monthly lysis-centrifugation blood cultures was 21% +/- 2% SE at 1 year and 43% +/- 3% at 2 years. The product-limit incidence of MAC bacteremia at 1 year after the patients' first CD4 cell count was related to both the CD4 cell count and to whether they had an AIDS diagnosis (both P less than .0001) but not to age, sex, or race. This incidence was 39% +/- 6% for CD4 cell counts of less than 10/mm3, 30% +/- 5% for 10-19/mm3, 20% +/- 4% for 20-39/mm3, 15% +/- 4% for 40-59/mm3, 8% +/- 3% for 60-99/mm3, and 3% +/- 1% for 100-199/mm3. MAC may eventually infect most if not all HIV-positive patients who do not die from another HIV-related event.