P131 Investigation of healthcare-associated links in transmission of nontuberculous mycobacteria (HALT NTM)

Nontuberculous mycobacterial (NTM) infections are a concern to people with cystic fibrosis (pwCF) due to the challenges in treatment and questions of infection acquisition. An evidence-based, standardized approach is used to investigate healthcare-associated NTM outbreaks. PwCF infected by clustered NTM may arise from healthcare sources. Respiratory NTM isolates were collected from US Centers and whole genome sequencing (WGS) analysis identified genetically similar clusters of isolates from pwCF cared for at a single Center. Epidemiological investigation, WGS comparison of respiratory and environmental isolates, and comparison of home residence watershed mapping was performed in 5 Care Centers. WGS analysis revealed NTM clusters (n = 11, 2, 7, 4, 1) at each Center. Epidemiologic investigation revealed opportunities for healthcare-associated transmission events in multiple clusters. One cluster, with no plausible healthcare-associated transmission, resided in the same watershed. Respiratory M. chimaera isolates revealed greater genetic similarity to a single hospital water biofilm environmental isolate than to each other. One subject had an M. abscessus respiratory isolate genetically similar to a healthcare environmental isolate. One additional Center outbreak investigation is ongoing. Center 1 demonstrated healthcare-associated patient-to-patient transmission of M. abscessus and M. avium. Center 2 demonstrated healthcare-associated acquisition of M. chimaera among 8/9 clustered subjects. Center 3 had no evidence of transmission or acquisition. Center 4 demonstrated acquisition of M. abscessus in one subject. Home of residence watershed analysis supports possible clustered M. abscessus acquisition outside the healthcare setting in Center 1. This study standardizes NTM outbreak investigation and supports investigation of all NTM known to infect pwCF to better understand healthcare-associated infection acquisition.