Pulmonary nontuberculous mycobacterial disease prevalence and clinical features: an emerging public health disease.

RATIONALE: Respiratory specimens with nontuberculous mycobacteria (NTM) are increasingly common; however, pulmonary disease prevalence is unknown. OBJECTIVES: To determine the disease prevalence, clinical features, and risk factors for NTM disease, and to examine the predictive value of the microbiologic criteria of the American Thoracic Society (ATS)/Infectious Diseases Society of America (IDSA) pulmonary NTM case definition for true NTM disease. METHODS: We identified all Oregon residents during 2005-2006 with at least one respiratory mycobacterial isolate. From a population-based subset of these patients, we collected clinical and radiologic information and used the ATS/IDSA pulmonary NTM disease criteria to define disease. MEASUREMENTS AND MAIN RESULTS: In the 2-year time period, 807 Oregonians had one or more respiratory NTM isolates. Four hundred and seven (50%) resided within the Portland metropolitan region, among which 283 (70%) had evaluable clinical records. For those with records, 134 (47%) met ATS/IDSA pulmonary NTM disease criteria for a minimum overall 2-year period prevalence of 8.6/100,000 persons, and 20.4/100,000 in those at least 50 years of age within the Portland region. Case subjects were 66 years of age (median; range, 12-92 yr), frequently female (59%), and most with disease caused by Mycobacterium avium complex (88%). Cavitation (24.5%), bronchiectasis (16%), chronic obstructive pulmonary disease (28%), and immunosuppressive therapy (25.5%) were common. Eighty-six percent of patients meeting the ATS/IDSA microbiologic criteria for disease also met the full ATS/IDSA disease criteria. CONCLUSIONS: Respiratory NTM isolates frequently represent disease. Pulmonary NTM disease is not uncommon, particularly among elderly females. The ATS/IDSA microbiologic criteria are highly predictive of disease and could be useful for laboratory-based NTM disease surveillance.

Nontuberculous mycobacterial disease prevalence and risk factors: a changing epidemiology.

BACKGROUND: Nontuberculous mycobacteria (NTM) are important human pathogens, yet little is known about disease prevalence in the United States. Reports suggest prevalence has increased, particularly in women, but population-based data to substantiate this are lacking. We sought to estimate NTM disease prevalence in Oregon, and describe disease by site, species, and patient demographic characteristics. METHODS: We contacted laboratories that performed mycobacterial cultures on Oregon residents in 2005-2006. For each isolate, we obtained source, collection date, species, and patient demographics. We used the microbiologic component of the American Thoracic Society/Infectious Diseases Society of America's pulmonary NTM disease criteria to define cases of pulmonary NTM, and patients with isolates from a normally sterile site were classified as having extrapulmonary disease. RESULTS: We identified 933 patients with > or =1 NTM isolate. Of these, 527 (56%) met the case definition (annualized prevalence, 7.2 cases per 100,000 persons). Pulmonary cases predominated (5.6 cases per 100,000 persons), followed by skin/soft-tissue cases (0.9 cases per 100,000 persons). Mycobacterium avium complex was the most common species identified in pulmonary cases (4.7 cases per 100,000 persons). Pulmonary disease prevalence was significantly higher in women (6.4 cases per 100,000 persons) than men (4.7 cases per 100,000 persons) and was highest in persons aged >50 years (15.5 cases per 100,000 persons). CONCLUSIONS: NTM are frequently isolated from Oregon residents; more than one-half of all isolates likely represent true disease. Pulmonary NTM is most common among elderly women, and M. avium causes most disease. Future efforts to monitor disease trends should be undertaken, and efforts made to validate the use of the ATS/IDSA microbiologic criteria alone to predict pulmonary NTM disease.