PARASITISM AND INFECTION WITH ‘ATYPICAL’ MYCOBACTERIA IN THE RESPIRATORY ORGAN

Abstract

Two patients, 57 year-old male and 72 year-old female, who were hospitalized as generallung fibrosis, excreted Mycobacterium nonchromogenicum and Mycobacterium intracellulare, respectively, 7 and 8 times during the periods of 3 years and 3 years and a half by monthly sputum examinations. The amounts of excretions were one to 10 colonies on each isolation. The patients finally showed fibro-caseous process in their lungs. The state before manifestation of the disease may be called as ‘parasitism’, as excretions of the organisms occurred without manifestation of the disease. Continuous excretions of ‘atypical’ mycobacteria are believed to be important as a preceding sign of manifestation of lung disease due to ‘atypical’ mycobacteria, even though their amounts were small. The present author (Tsukamura, M.: Kekkaku 49: 327-333, 1974) reported previously the importance of frequent excretions of M. intracellulare occurring not only as large amounts but also as small amounts for the diagnosis of lung disease due to this organism. The second case in the present study supports this previous observation,
The patients had shown obstructive ventilatory insufficiency. Decrease of clearance capacity in respiratory way seems to become a favorable condition for manifestation of the disease, as it provides a chance for multiplication of ‘atypical’ mycobacteria in a locus.
The present author also stated previously (Tsukamura, M.: Kekkaku 50: 17-30, 1975) that the characteristics of primary lung infection due to M. intracellulare tended to caseate which soon lead to cavity formation and lacking fibrotic process, but it has been shown from the obser vations in the present study that patients who have had general lung fibrosis before infection do not show significant cavity formation but fibrocaseous process. The fact may concern with immunologic state of the patients with lung fibrosis.