i agree with tanya. i cultured MAC a few months ago and didn't have ANY odd symptoms. i was in for an exacerbation so they just did the 5 weeks of abx until my FEV1 went back up and then stopped treating me.
as far as i know, i'm not running fevers or anything cause of MAC and my docs said they do not treat MAC unless it is for sure the culprit and nothing else works to treat symptoms. they said its VERY hard to tell if its CF-infection (i.e. pseudo,staph,etc.) or MAC causing problems, so if you get better on the "usual" abx, it was probably not MAC.
i have since had MAC-free cultures without even treating it (knock wood)... but, they too told me it would always be there.
i'd been taken off azithro every M,W, and F, back when i cultured it cause apparently that is one of the only meds that works against MAC, however, since i've now had 2 MAC-free cultures, I asked at my last clinic if I could please go back on the maintenance azithro as I really think it helped my FEV1 stabalize. they reluctantly said it was my choice, as there isn't much research at all about how to treat MAC with regard to CF, whereas there are guidelines to treat it in HIV patients, etc.
my doc even said he wrote to the NIH suggesting far more studies on MAC and medications to treat it and HOW to treat it. its showing up more and more in the older poplulation, which generally means we "older" cfers get the "firsts" of things and treatment options. they're just really not sure how to go about treating MAC AND CF at the same time according to my doc. i mean they have some things that work (such as the months and months of abx as mentioned above), but also things they're just "speculating" such as taking patients off azithro. there just haven't been many MAC studies done.
anyway, this is my two cents. i too was taken back when MAC was first diagnosed, but my docs kinda said its very very common with CF and sometimes causes problems and sometimes not, just like many funguses, etc. that we culture at any given point in time.
best of luck to you! sorry if i rambled.