Epidemiology of nontuberculous mycobacteria infection in Asia: A narrative review

Recent population-based studies conducted in Asia have revealed a notable increase in the overall incidence of nontuberculous mycobacteria (NTM) infection, coinciding with a decline in tuberculosis (TB) cases. The incidence of NTM infection has exceeded that of TB in Japan, with a prevalence rate showing a substantial increase over the years. Similarly, South Korea and Taiwan have witnessed an increase of NTM infection rates, particularly in pulmonary disease. The NTM species isolation rate has increased in the past years globally. The most common NTM species isolated in Asia was Mycobacterium avium complex (MAC) at 16.5%, followed by M. abscessus at 12.2%, and M. intracellulare at 11.1 %. Furthermore, the prevalence of co-infection of NTM and TB has been explored, highlighting a prevalence of 4.2% in patients diagnosed with TB infection and 7.6% in patients diagnosed with NTM infection. Extrapulmonary NTM infection manifests in diverse form, including pleuritis, peritonitis, ocular infections, central nervous system infections, skin and soft-tissue infections, lymphadenitis, genitourinary infections, and disseminated disease. The prevalence and manifestations of these extrapulmonary manifestations varies across countries, emphasizing the complex clinical spectrum of NTM infection. Increased awareness of NTM infection, their microbiological characteristics, and co-infection with TB in Asia provide valuable insights for effective diagnosis and management. This comprehensive review enhances the understanding of NTM infection in Asia, providing insights that may differ from Western countries and could contribute to the development of public health interventions.