Pulmonary versus Nonpulmonary Nontuberculous Mycobacteria, Ontario, Canada

Abstract

In Ontario, Canada, during 1998-2010, nontuberculous mycobacteria (NTM) from pulmonary sites comprised 96% of species/patient combinations isolated; annual rates of isolation and cases increased steadily. NTM isolates from nonpulmonary sites comprised 4% of species/patient combinations; annual rates and cases were temporally stable. NTM increases were driven exclusively by pulmonary isolates and disease.

Keywords: Canada; Mycobacterium avium complex; NTM; Ontario; bacteria; epidemiology; infection; nontuberculous mycobacteria; nontuberculous mycobacterium; tuberculosis and other mycobacteria.

Figure 1

Prevalence of pulmonary and nonpulmonary nontuberculous mycobacteria (NTM) isolation and pulmonary NTM disease in Ontario, Canada, 1998–2010. Annual increase and modeled annual change were 6.3% (3,4) and 1.04 (95% CI 0.696–1.38)/100,000 population (p<0.001) for pulmonary isolation and 8.0% (3) and 0.402 (95% CI 0.307–0.497)/100,000 population (p<0.001) for pulmonary disease. Significant increases occurred in Mycobacterium avium complex (annual change 0.291 [95% CI 0.236–0.346]/100,000 population; p<0.001); M. xenopi (annual change 0.059 [95% CI 0.015–0.103]/100,000 population; p = 0.002); and M. abscessus (annual change 0.019 [95% CI 0.015–0.024]/100,000 population; p<0.001). TB (all body sites) isolation decreased by an average of 2.2% annually (6.5 to 4.9/100,000 population) during the study period. TB, tuberculosis.

Figure 2

Isolation of nonpulmonary nontuberculous mycobacteria by body site, Ontario, Canada, 1998–2010. There was no significant temporal change by anatomic site except for a decrease in skin/soft tissue infections (modeled annual change −0.011 [95% CI −0.020 to −0.003]/100,000 population; p = 0.001). Mycobacterium marinum significantly decreased over time (modeled annual change −0.003 [95% CI −0.007 to 0.001]/100,000 population; p = 0.0480); isolation of other species from nonpulmonary sites was unchanged. Overall nonpulmonary isolation modeled annual change was −0.004 (95% CI −0.019 to 0.010)/100,000 population (p = 0.410). CNS, central nervous system; GI, gastrointestinal system; GU, genitourinary system, lymph, lymphatic system; MS, musculoskeletal system.