An Update on Prevalence of Slow-Growing Mycobacteria and Rapid-Growing Mycobacteria Retrieved from Hospital Water Sources in Iran—A Systematic Review

Introduction: This study aimed to assess the prevalence of slow growing mycobacteria (SGM) and rapid-growing mycobacteria (RGM) retrieved from hospital water sources in Iran from 2016 to 2020. Methods: The review was conducted to get eligible published studies from 1^st January 2016 to 25^th March 2020 based on PRISMA protocol. A combination of related words from the Medical Subject Heading Terms (MeSH), with (AND, OR) were used to search for published studies reporting the prevalence of nontuberculous mycobacteria (NTM) in Scopus, MEDLINE, Web of Sciences, Google Scholar, and Iranian databases. Then data from the studies were extracted and reported. Results: Our study showed that different water sources of hospitals were contaminated with NTMs. The prevalence of RGM isolates in hospital water samples varied between 42.2%-67.5%, and the prevalence of SGM varied between 32.5%-57.7%, respectively. M. lentiflavum (84.7%), M. avium complex (2.8%-56.4%) and M. gordonae (2.8%-56.2%) were the most prevalent NTM species amongst SGM, whereas M. fortuitum (2.9%-44.2%), M. chelonae (8%-36.8%), M. mucogenicum (8%-25.6%) were the most leading NTM isolates among RGM. Conclusions: A high prevalence of NTM was reported from hospital environments particularly hospital water sources which can colonize medical devices, solutions, and water used for patients and cause nosocomial infection. Therefore, the hospitals should check the microbiological quality of the water used.