an update on the prevalence of nontuberculous in clinical samples in iran during 2000-2022: a retrospective systematic review and meta-analysis

Background and objectives: nontuberculous mycobacteria (ntm) are isolated from domestic and animal products as well as man-made systems such as medical devices, drinking water systems, water tanks, and shower streams. this study aimed to investigate the prevalence of ntm in clinical samples in iran during 2000-2022. methods: published studies addressing the prevalence of ntm in clinical samples in iran were reviewed according to the preferred reporting items for meta-analyses and systematic reviews protocol. original articles in persian and english published between january 2000 and 2022 in databases such as scopus, pubmed, web of science, google scholar, and iranian databases were included. the prevalence of ntm at 95% confidence interval (ci) was calculated by comprehensive meta-analysis. results: overall, 26 studies were included in the review. the combined prevalence of ntm in positive mycobacterial cultures was 4.5% (95% cl: 3.1-6.5). mycobacterium simiae [35.8% (95% ci 16.4-44.4)], mycobacterium intracellulare [19% (95% ci 8.7-28.3)], and mycobacterium kansasii [13.4% (95% ci 7.3-24.3)] were the most common slowly growing species, while mycobacterium fortuitum [24.6% (95% ci 12.9-46.7)], mycobacterium terrae [18.5 % (95% ci 11.5-29.2)], and mycobacterium gastri [15.9% (95% ci6.0-41.2)] were the most prevalent rapidly growing mycobacteria. conclusion: in summary, our findings indicate a relatively high combined prevalence of ntm in clinical samples in iran. some of these species such as m. simiae can have clinical and radiologic manifestations similar to those of tb and are resistant to anti-tb drugs. therefore, standardizing the use of molecular methods for the detection of ntm seems necessary