Nontuberculous Mycobacterial Lung Disease Prevalence at Four Integrated Health Care Delivery Systems

Abstract

Rationale: Single-site clinic-based studies suggest an increasing prevalence of pulmonary nontuberculous mycobacteria (NTM) disease, but systematic data are lacking. Objectives: To describe prevalence and trends for NTM lung disease at four geographically diverse integrated heath care delivery systems in the United States. Methods: We abstracted mycobacterial culture results from electronic laboratory databases and linked to other datasets containing clinical and demographic information. Possible cases were defined as a single positive NTM pulmonary isolate, and definite cases were defined as two positive sputum cultures, or one positive culture from a bronchoalveolar lavage or lung biopsy. Annual prevalence was calculated using United States census data; average annual prevalence is presented for [2004][2005][2006]. Poisson regression models were used to estimate the annual percent change in prevalence. Measurements and Main Results: A total of 28,697 samples from 7,940 patients were included in the analysis. Of these, 3,988 (50%) were defined as possible cases, and 1,865 (47%) of these were defined as definite cases. Average annual (2004)(2005)(2006) site-specific prevalence ranged from 1.4 to 6.6 per 100,000. Prevalence was 1.l-to 1.6-fold higher among women relative to men across sites. The prevalence of NTM lung disease was increasing significantly at the two sites where trends were studied, by 2.6% per year among women and 2.9% per year among men. Among persons aged greater than or equal to 60 years, annual prevalence increased from 19.6 per 100,000 during 1994-1996 to 26.7 per 100,000 during [2004][2005][2006]. Conclusions: The epidemiology of nontuberculous mycobacterial lung disease is changing, with a predominance of women and increasing prevalence at the sites studied.

Clinical and Therapeutic Features of Pulmonary Nontuberculous Mycobacterial Disease, Rio de Janeiro, Brazil

“…One third of the NTM patients in this study population were infected with M. kansasii , a proportion substantially higher than that seen in the United States ( 5 , 19 )and in other areas of Brazil ( 10 , 14 ) and Australia ( 20 ). Global geographic variability in M. kansasii has been noted; a high prevalence of M. kansasii lung disease occurs in Western Europe, Switzerland, and the United Kingdom ( 17 , 21 – 23 ).…”

“…Although we were unable to determine the true prevalence of disease caused by these organisms in the state of Rio de Janeiro, the current study confirmed an increasing frequency of patients referred with NTM lung disease. In some industrialized countries, the prevalence of NTM has been found to be increasing ( 5 , 17 ), although it remains unclear whether this increase is related to increasing awareness of physicians that leads to more frequent diagnosis, to improved laboratory capacity, or to a combination of both factors.…”

“…NTM have historically been associated with disease in male smokers with COPD ( 27 ). However, over the last 20 years, the epidemiology has been changing in some industrialized countries, particularly the United States, with most patients identified without known risk factors or with bronchiectasis, all in the context of declining rates of TB ( 5 , 6 ). …”

“…Recent studies have documented the emergence of NTM lung diseases in industrialized countries, such as the United States ( 4 , 5 ). The current prevalence estimated for PNTM is ≈6 cases/100,000 population, with the highest prevalence in persons >50 years of age ( 4 – 6 ).…”

Microbiological criteria in non-tuberculous mycobacteria pulmonary disease: a tool for diagnosis and epidemiology

“…Still, PPV of stricter microbiologic criteria was considerably higher when compared to ATS/IDSA microbiologic criteria (93.3% vs. 59.8%). 4,17,18 Thus, to prevent unwarranted diagnoses and treatment of NTM disease, as well as unnecessary diagnostic delay, it could be helpful to use separate, more stringent criteria for species of low relevance, and less stringent criteria for species considered to be of high clinical relevance in the local setting. This aspect should be covered in the upcoming diagnostic criteria.…”