@sews MAC is Mycobacterium Avium Complex - Mycobacteria are a slow growing class of bacteria that include TB, and several strains are widespread in air, water and soil. For most people, they are not problematic., but for those with some lung conditions, like bronchiectasis or cystic fibrosis, who have trouble clearing mucus, and therefore contaminants from their lungs, there is risk of infection. Being warm,dark & moist, the lung provides an ideal breeding ground for opportunistic infection to set in. I believe the research is now showing some people with COPD are also at elevated risk for developing MAC infections, but have not researched it thoroughly.

Some symptoms of MAC infection include fatigue, weight loss, increased shortness of breath, worsening cough with increased green/yellow sputum, fever and night sweats. Not every person has all the symptoms, and they usually come on gradually. MAC is diagnosed through a sputum culture, which must be sent to a specialized lab and takes up to 6 weeks to grow out.

Treatment is generally with a long course of multiple antibiotics, though mild cases may just be monitored and treated with airway clearance techniques.
Sue