We measured the prevalence and temporal trends of pulmonary nontuberculous mycobacterial disease among residents of Ontario, Canada, during 1998-2010. Five-year prevalence increased from 29.3 cases/100,000 persons in 1998-2002 to 41.3/100,000 in 2006-2010 (p<0.0001). Improved laboratory methods did not explain this increase, suggesting a surge in disease prevalence.
Keywords: Canada; Mycobacterium avium-intracellulare; Mycobacterium avium-intracellulare complex; Ontario; atypical Mycobacterium; atypical mycobacteria; bacteria; epidemiology; mycobacterium intracellulare; nontuberculous Mycobacterium; tuberculosis and other mycobacteria.