what means mac infection of the lungs
1 MAC is not contagious. 2  MAC lung disease seen in HIV negative (non-AIDS) patients is a chronic lung infection and early-on is often misdiagnosed as chronic bronchitis or recurrent pneumonia. 3  MAC Lung Disease is acquired from the environment (soil, air, natural waters, tap water, etc.). The average age of patients with MAC lung disease in men is 55 years and 67 years in women. 2  Men are more likely to have cavitary MAC (holes in their lungs). 3  Women are more likely to have non-cavitary, nodular MAC. 4  Diagnosis of MAC lung disease usually requires: