Nontuberculous Mycobacteria–Associated Lung Disease, United States in Hospitalized Persons, 1998–2005

Megan E. Billinger; Kenneth N. Olivier; Cecile Viboud; Ruben Montes de Oca; Claudia Steiner; Steven M. Holland; D. Rebecca Prevots


Emerging Infectious Diseases. 2009;15(10) 

In This Article

Abstract and Introduction


The prevalence and trends of pulmonary nontuberculous mycobacteria (NTM)–associated hospitalizations in the United States were estimated using national hospital discharge data. Records were extracted for all persons with a pulmonary NTM International Classification of Diseases code (031.0) hospitalized in the 11 states with continuous data available from 1998 through 2005. Prevalence was calculated using US census data. Pulmonary NTM hospitalizations (031.0) increased significantly with age among both sexes: relative prevalence for persons 70–79 years of age compared with those 40–49 years of age was 15/100,000 for women (9.4 vs. 0.6) and 9/100,000 for men (7.6 vs. 0.83). Annual prevalence increased significantly among men and women in Florida (3.2%/year and 6.5%/year, respectively) and among women in New York (4.6%/year) with no significant changes in California. The prevalence of pulmonary NTM–associated hospitalizations is increasing in selected geographic areas of the United States.


Clinic- and laboratory-based studies since the 1980s have shown an increased prevalence of persons with nontuberculous mycobacterial (NTM) pulmonary disease[1,2] with a predominance of women >60 years of age who have no underlying risk factors.[3–5] NTM comprise a multispecies group of environmental organisms living in soil as well as in treated and untreated water sources. These mycobacteria were first identified as human pathogens in the 1950s when 1%–2% of patients in tuberculosis (TB) sanitaria did not respond to traditional TB treatment. Their illnesses were caused by organisms that were not Mycobacterium tuberculosis. These patients tended to be older than those having TB, were more likely to be white, and to have underlying lung disease.[6,7]

The success of TB elimination efforts has resulted in a continued decline in the incidence and prevalence of tuberculosis in the United States. In 2007, the incidence of TB in the United States was 4.4/100,000 population, and 2.1/100,000 among US-born persons, the lowest rates since reporting began in 1953.[8] The apparent increase in NTM disease has occurred during the same period that TB has been declining. Although NTM are not transmissible, the diseases they cause may greatly affect public health and medical care resources. In some state health departments, findings of an acid-fast bacilli, indicative of mycobacteria, are reportable,[9] and may trigger a public health investigation with substantial expenditure of resources until species identification is confirmed.

Population-based surveys conducted during 1981–1983 estimated the prevalence of pulmonary NTM disease at 1–2 cases/100,000 persons in the United States.[10] A more recent retrospective analysis from Ontario, Canada found an average annual increase of 8.4% for the isolation prevalence of NTM at the Ministry of Health Mycobacterial Laboratory between 1997 and 2003.[11] Similar trends have been noted in other areas of the world.[12–16] However, no current US nationally representative data exist regarding the prevalence of pulmonary disease associated with NTM. Furthermore, information is limited regarding risk factors associated with the disease. Our study describes the prevalence, demographic characteristics, and trends of pulmonary NTM–associated hospitalizations during 1998–2005.


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