Urinalysis says no histoplasmosis-could it be wrong?

My husband is continually diagnosed with Emphysema.  He has never been a smoker.  Whatever is getting his lungs came on him suddenly a year ago.  Since that time he has had continually diminishing lung capacity.  He lately has so little lung capacity that he can't even breathe in his rescue inhaler.  Cat scans show alot of scarring but they say he doesn' have pulmonary fibrosis.  He has all the symptoms of histoplasmosis.  I asked his doctor to test him for it and he did a urinalysis.  That came back negative but I've read that false negatives are a problem with this testing.  We live on a farm in the Mississippi river region and this is common in this area.  My husband had chemo and radiation on his throat in 2003 and now some doctors are saying it's from that.  He went in a hyperbaric chamber for this 3 days last week. He started spitting up bloo after the treatment the last 2 times.  I'm so scared he has interstitial lung disease because they are never supposed to get the treatments if that's what this is.  My husband is not going to last much longer if somebody doesn't get things right for him.  Please answer quick or you'll probably be wasting your time later.  Thanks, purelight52