Pulmonary Infection with Nontuberculous Mycobacteria

Nontuberculous mycobacterial infections (NTM) are being increasingly recognized as a cause of chronic pulmonary disease. We recently reviewed the clinical, radiologic, and bacteriologic presentation of 89 adult patients ill enough to have been hospitalized between 1981 and 1985 with the diagnosis of NTM. Preexisting lung disease was present in 82% and alcohol abuse in 40%. Although M. avium complex was identified in 51% of the patients, M. xenopi, which is usually reported to occur infrequently, accounted for 38% of our cases and M. kansasii for only 9%. Treatment was limited by a high incidence of associated disease, in vitro drug resistance, drug toxicity, and a mortality rate of 32% within 18 months of admission. Nevertheless, bacteriologic conversion occurred in 29% of those treated. M. xenopi appears to be an important pathogen in southern Ontario. It differs from the other NTM by having a different pattern of in vitro drug resistance but not by its clinical or radiologic presentation.