Hello Irene! It's been awhile..... You bring up a very good subject: One thinking they are well, when, in fact, they are not. I have been going to Mayo Clinic since 2013, and tested negative for MAC since 2014. All chest x-rays and CT's showed little change over the years and then Blam! I am told that I have two colonies of MAI MAC and aspergillus, and....need a lung transplant soon! Up until Dec 2021; I thought I was holding my own and staying steady. Actually, my lung function was steadily deteriorating. I don't know if there is any correlation, but I was taken off of my Tobramycin in Dec 2021, but kept on the cipro every other month..(and now have tested pos for MAI) A dr recently told me that since I had been on cipro for 9 years; I am most likely resistant to it by now. So, I have been unprotected by prophylactic antibiotics for six months now. I have a Zoom meeting with my I.D. this Tues, so I will see what she recommends.