[A case of Mycobacterium scrofulaceum lung infection occurring in old lung tuberculosis lesion]

A 68-year-old man was admitted because of a persistent productive cough of 6 weeks' duration and detection of acid-fast bacilli from sputum. Based on chest roentgenograms and isolation of Mycobacterium scrofulaceum from sputum, on admission, a diagnosis of Mycobacterium scrofulaceum lung infection was made. Although the organisms were resistant to 0.1 microgram/ml of INH, 2.5 micrograms/ml of EB and 10 micrograms/ml of RFP, sputum converted to negative by the use of INH (0.4 g/day), EB (0.5 g/day) and RFP (0.3 g/day) for 2 months. The incidence rate of nontuberculous lung mycobacteriosis seems to be increasing recently. This is partially considered to be due to an increase of various strains of nontuberculous mycobacteria in the environment. A striking advance of clinical medicine and changes in the constitution of human society and environment surrounding us produce an increase in the number of compromised hosts. The lung disease due to Mycobacterium scrofulaceum, a kind of opportunistic pathogen, is considered to be increasing in a wide variety of compromised hosts in the future.