Epidemiology of Healthcare Facility-Associated Nontuberculous Mycobacteria From 2012 Through 2020 in a 10-Hospital Network in the United States

Background Data on the epidemiology of healthcare facility-associated (HCFA) nontuberculous mycobacteria (NTM) are sparse. We performed a multicenter longitudinal cohort study of HCFA NTM epidemiology. Methods We retrospectively analyzed positive cultures for NTM performed from 2012 through 2020 within a network of 10 US academic hospitals and associated clinics. A unique NTM episode was defined as a patient's first positive culture for a particular NTM species and specimen source category (pulmonary vs extrapulmonary). Episodes linked to specimens obtained on day 3 or later of hospitalization were classified as hospital-onset (HO). Seven hospitals contributed at least 12 months of data prior to January 2014. Within this closed cohort, incidence rate ratios (IRRs) and trends in incidence from 2014 through 2020 were estimated, assuming the number of episodes followed the Poisson distribution. Results A total of 12 855 unique NTM episodes occurred from 2012 through 2020 during 19 248 137 patient-days of surveillance. Of these episodes, 3045 (24%) were HO. HO incidence rates were highly variable among hospitals, with a median hospital rate of 1.06 episodes per 10 000 patient-days (range, 0.35–5.48). Within the 7-hospital closed cohort from 2014 through 2020, the incidence rate of HO episodes decreased from 2.29 to 1.42 episodes per 10 000 patient-days (IRR, 0.62; 95% confidence interval,.53–.73; P <.0001). Conclusions Incidence rates of HO NTM episodes decreased from 2014 through 2020, but rates varied substantially among hospitals. These results provide comprehensive data on HO NTM isolation, including benchmark rates that can be used to improve hospital-based NTM surveillance.