'''''Mycobacterium avium ''complex''' is a group of [[mycobacteria]] comprising '''''Mycobacterium intracellulare''''' and '''''Mycobacterium avium''''' that are commonly grouped because they infect humans together; this group, in turn, is part of the group of [[nontuberculous mycobacteria]]. These bacteria cause disease in humans called [[Mycobacterium avium-intracellulare infection|''Mycobacterium avium-intracellulare'' infectioninfections]] or ''Mycobacterium avium'' complex infectioninfections in humans.<ref>{{cite web|title=Mycobacterium Avium Complex. MAI; MAC Information|url=https://patient.info/doctor/mycobacterium-avium-complex|publisher=Patient Info|date=29 August 2014}}</ref> These bacteria are common and are found in fresh and salt water, in household [[dust]] and in soil.<ref name=":0">{{Cite web|url=https://rarediseases.info.nih.gov/diseases/7123/mycobacterium-avium-complex-infections|title=Mycobacterium Avium Complex infections {{!}} Genetic and Rare Diseases Information Center (GARD) – an NCATS Program|website=rarediseases.info.nih.gov|language=en|access-date=2020-03-29}}</ref> MAC bacteria usually cause infection in those who are [[immunocompromised]] or those with severe [[lung disease]].
