Non-tuberculous mycobacteria (NTM) are a large family of
acid-fast bacteria, widespread in the environment. In children, NTM cause
lymphadenitis, skin and
soft tissue infections, and occasionally also
lung disease and disseminated
infections. These manifestations can be indistinguishable from
tuberculosis on the basis of clinical and radiological findings and
tuberculin skin testing. A diagnostic and therapeutic problem for respiratory physicians and other clinicians is therefore evident, particularly in settings where childhood
tuberculosis is common, and bacteriological confirmation of any mycobacterial disease is difficult because of low availability of laboratory services in low-resource settings and the inherent paucibacillary nature of mycobacterial disease in childhood. The epidemiology of NTM varies by world region, and attempts to understand the burden of NTM disease and to identify risk factors in the paediatric population are hampered by inadequate mandatory NTM reporting and the overlap of clinical presentation with
tuberculosis. The immune response to both NTM and Mycobacterium tuberculosis is based on cellular immunity and relies on the type-1
cytokine pathway. The disruption of this immune response by genetic or acquired mechanisms, such as mendelian susceptibility to mycobacterial disease or HIV, might result in predisposition to mycobacterial
infections. Published diagnostic and management guidelines do not provide specific advice for diagnosis of NTM in children, from whom the quantity and quality of diagnostic samples are often suboptimum. Treatment of NTM
infections is very different from the treatment of
tuberculosis, depends on the strain and anatomical site of
infection, and often involves
antibiotic combinations, surgery, or both. In this Review, we summarise the epidemiological and clinical features of NTM
infection in children, with a specific focus on the implications for public health in settings with a high endemic burden of childhood
tuberculosis.