Cases of severe Mycobacterium avium lung disease occurred in a married couple caused by identical strain.

Bacteria of the Mycobacterium avium complex, which are environmental organisms found in soil and water, have been found to cause human lung diseases. Although infection is reported to occur in cohabiting patients, the incidence of infection from the single clone remains rarely documented. Herein, we report a case of M. avium lung disease caused by specimens with the same clone strains in a married couple. The wife, a 67-year-old female, had severe M. avium lung disease despite receiving multidrug chemotherapy for eleven years. The husband, a 68-year-old male, died of acute lung injury complicated by M. avium pleurisy. The result of the variable-number tandem-repeat analysis of isolates from serial sputum specimens of both patients indicated that the severe M. avium lung disease in a married couple was caused by the isolates with identical pattern. This case were considered to have acquired clarithromycin resistance during each clinical course, revealing the possibility of infection with a strain that may induce severe pulmonary condition.