Non-tuberculosis Mycrobacterial lung infection (MAC lung disease)
There are many bacteria that are in the same family as tuberculosis (called Mycobacteria( that can cause lung disease, but are different from tuberculosis (TB). These are called Non-tuberculous Mycobacteria (NTM) and are often also called "atypical TB".
The commonest NTM in Australia is Mycobacterium intracellulare, also called Mycobacterium avium complex, or MAC for short. This is still quite uncommon, but the number of people affected by it is increasing for unclear reasons. Disease caused by MAC is now more common than TB.
MAC most often causes lung disease in middle-aged to elderly people, more commonly females. It is not caught from someone else, and, unlike TB, is not contagious. The germ is breathed in from the environment, and why it causes disease in some and not others is not clear. Most people with MAC disease do not have a problem with their immune system.
The infection can cause damaged airways and scarring on the lungs, and lead to bronchiectasis. Symptoms include cough, phlegm production, night sweats, weight loss and lethargy. These usually develop very slowly, and sometimes the disease can develop over years before being diagnosed.
Treatment is with specialized antibiotics, which are given over a prolonged period. This can be difficult for the patient, and requires the expertise of a doctor specializing in the disease. However, the treatment is often effective in stopping symptoms and any further damage to the lungs.