Abstract
For decades, the incidence of pulmonary nontuberculous mycobacteria (NTM) has been
reported to be increasing, yet formal epidemiological evaluation of this notion has
been lacking until recently. Defining the epidemiology of NTM has been more challenging
than with Mycobacterium tuberculosis (MTB). Unlike MTB, NTM are soil and water organisms, and infection is thought to be acquired from the
environment rather than transmitted from person-to-person, with very rare exceptions.
Due to their nearly ubiquitous presence in municipal water supplies, exposure to NTM
is common. Further, NTM can colonize the respiratory tract without causing disease.
NTM disease is not reportable to public health authorities; therefore, epidemiological
and surveillance data are not readily available. Nonetheless, the prevalence of pulmonary
NTM disease has increased dramatically in the United States and globally over the
past 3 decades. Mycobacterium avium complex (MAC) accounts for the majority of NTM infections worldwide, but there is
significant regional variability of various species. Additionally, novel species have
been implicated in several countries in NTM pulmonary disease.
Keywords
nontuberculous mycobacteria - epidemiology -
Mycobacterium avium
-
Mycobacterium tuberculosis
