Environmental intervention for two cases of non-tuberculous mycobacterial disease

Non-tuberculous Mycobacterium avium complex (MAC) disease is caused by inhalation of water or soil dust containing MAC bacteria. Treatment of MAC disease should include not only drug treatment, usually a three-drug regimen consisting of a macrolide, ethambutol, and a rifamycin, but also environmental intervention. However, there is no standardized approach to environmental evaluation or remediation of potentially harmful exposures from potting soils in home or workplace environments for patients with non-tuberculous mycobacterial infection. We present two patients with MAC disease who were positive for anti-MAC antibodies but had no culturable mycobacteria in sputum. One patient discontinued gardening, and the other patient moved her many indoor plants outside. Both patients subsequently had decreased sputum, and subsequent chest computed tomography showed decreased ground-glass opacities, consolidation, and small nodules. Environmental intervention may therefore be sufficient treatment for mild MAC disease.