Population-based Incidence of Pulmonary Nontuberculous Mycobacterial Disease in Oregon 2007 to 2012

Abstract

Pulmonary nontuberculous mycobacteria (NTM) disease is a chronic, nonreportable illness, making it difficult to monitor. Although recent studies suggest an increasing prevalence of NTM disease in the United States, the incidence and temporal trends are unknown. To describe incident cases and calculate the incidence and temporal trends of pulmonary NTM disease in Oregon. We contacted all laboratories performing mycobacterial cultures on Oregon residents and collected demographic and specimen information for patients with NTM isolated during 2007 to 2012. We defined a case of pulmonary NTM disease using the 2007 American Thoracic Society/Infectious Disease Society of America microbiologic criteria. We used similar state-wide mycobacterial laboratory data from 2005 to 2006 to exclude prevalent cases from our calculations. We calculated annual pulmonary NTM disease incidence within Oregon during 2007 to 2012, described cases demographically and microbiologically, and evaluated incidence trends over time using a Poisson model. We identified 1,146 incident pulmonary NTM cases in Oregon residents from 2007 to 2012. The median age was 69 years (range, 0.9-97 yr). Cases were more likely female (56%), but among patients less than 60 years old, disease was more common in male subjects (54%). Most (86%) were Mycobacterium avium/intracellulare cases; 68 (6%) were Mycobacterium abscessus/chelonae cases. Although not statistically significant, incidence increased from 4.8/100,000 in 2007 to 5.6/100,000 in 2012 (P for trend, 0.21). Incidence increased with age, to more than 25/100,000 in patients 80 years of age or older. This is the first population-based estimate of pulmonary NTM disease incidence in a region within the United States. In Oregon, disease incidence rose slightly during 2007 to 2012, and although more common in female individuals overall, disease was more common among male individuals less than 60 years of age.