I had a similar experience as yours, except I got no positive cultures for 1 1/2 yrs before getting one positive for mai. My cts were worsening pretty steadily. I was also not underweight. I went to National Jewish last November after getting the first positive culture from an induced sputum specimen. Two bronchs had produced nothing except a collapsed lung. NJ had me send them another culture before I came out there, then they did more while I was there. They got 2 more positives from those. The guidelines are pretty specific regarding the labwork and other criteria in order to treat.
Just a word of encouragement…the first month on meds was kind of miserable. I had a lot of nausea, and didn’t feel well. I also developed pneumonia and a subsequent flare up about a month after starting meds. But, after the first month the nausea gradually subsided and now I feel wonderful after almost 5 months. I had no idea how much the fatigue had been keeping me down, even though I exercised regularly and ate well. The only nausea I have now is about an hour after I take my meds. I take ethambutol and Avelox daily, and azithromycin 3x a week. I exercise and eat healthy food and have a strong spiritual life. I am now officially overweight. My doctor at NJ said everyone is not so thin. I wasn’t heavy, but I looked that way next to some of the other patients. My diagnosis was mai infection along with mild bronchiectasis and all the other mumbo jumbo of lung problems (nodes, atel—something, etc.). I strongly encourage you to let the experts decide your course of treatment. They told me that I had done the right thing in continuing to seek treatment.