Epidemiology of Nontuberculous Mycobacteriosis

Abstract

Annual prevalence estimates for pulmonary nontuberculous mycobacterial (PNTM) disease in the contiguous United States range from 1.4 to 13.9 per 100,000 persons, while one study found an annual prevalence of up to 44 per 100,000 persons in Hawaii. PNTM prevalence varies by region, sex, and race/ethnicity, with higher prevalence among women and persons of Asian ancestry, as well as in the Southern United States and Hawaii. Studies consistently indicate that PNTM prevalence is increasing, with estimates ranging from 2.5 to 8% per year. Most PNTM disease is associated with complex (MAC), although the proportion of disease attributed to MAC varies by region. Host factors identified as influencing disease risk include structural lung disease, immunomodulatory medication, as well as variants in connective tissue, mucociliary clearance, and immune genes. Environmental variables including measures of atmospheric moisture and concentrations of certain soil factors have also been shown to correlate with higher PNTM prevalence. Prevalence of extrapulmonary NTM disease is lower, stable, and associated with different risk factors, including primary immune deficiencies or HIV infection.

Mycobacterial Testing Trends, United States, 2009–20151

“…Further, many identified predictors of receiving a mycobacterial culture test are consistent with predictors of positivity, as identified in this and previous studies. This finding suggests that tests are being successfully focused toward groups such as older women and Asians that are at high risk for culture positivity (1).…”

“…Nontuberculous mycobacteria (NTM) are opportunistic environmental pathogens that can cause chronic lung disease ( 1 , 2 ). NTM are identified through laboratory testing for acid-fast bacilli, which test for all mycobacteria, including Mycobacterium tuberculosis .…”

“…NTM are identified through laboratory testing for acid-fast bacilli, which test for all mycobacteria, including Mycobacterium tuberculosis . Multiple studies have described increasing NTM pulmonary disease (NTM PD) prevalence in the United States ( 1 , 3 – 6 ), a phenomenon that might be caused by true increase in disease rates, new efficient testing technologies, increased mycobacterial testing, or any combination of those. We assessed trends in mycobacterial testing rates and NTM PD prevalence from 2009 through 2015.…”

Looking beyond Typical Treatments for Atypical Mycobacteria

“…Although some mycobacterial species may cause other forms of disease, such as cutaneous infections, in this review, we will focus mainly on pulmonary disease. The exact numbers are difficult to find, as in most countries, the reporting of infections by NTM is not mandatory [5][6][7]. According to the available data, the incidence of disease varies considerably with NTM species, geographic distribution, sex, race/ethnicity, age, and risk factors (e.g., concomitant debilitating diseases).…”

“…Women are at higher risk of infection, alongside people with Asian ancestry and from the Southern United States, such as Hawaii [8,9]. Species of the M. avium complex (MAC) are the most common causes of NTM infections and are mainly responsible for the observed increase in disease incidence [3,5,6,10]. Their resistance to antibiotics is growing; therefore, the treatment used today is a multidrug therapy comprising at least three antibiotics, with treatments taking from six months to years.…”