(547) Healthcare-Associated Links in Transmission of Nontuberculous mycobacteria in People with Cystic Fibrosis (HALT NTM): A Multi-Center Study

Thursday, November 3, 2022

12:45 PM – 1:25 PM ET

Presenting Author(s)

Jane E. Gross, MD PhD

Assistant Professor
National Jewish Health
Denver, Colorado, United States

Co-Author(s)

Charlotte C. Teneback, MD

Associate Professor
University of Vermont Larner College of Medicine
Burlington, Vermont, United States
JS

Julie Sweet

United States
Silvia M. Caceres

Research Coordinator
National Jewish Health
Denver, Colorado, United States
NH

Nabeeh A. Hasan, PhD

Bioinformatics Analyst III
National Jewish Health
Denver, Colorado, United States
Fan Jia, PhD

Bioinformatics analyst II
National Jewish Health, United States
LE

L. Elaine Epperson, PhD

Research Associate
National Jewish Health, Colorado, United States
EL

Ettie Lipner, PhD

United States
CV

Charmie K. Vang

Research Associate
National Jewish Health, United States
Jennifer R. Honda, PhD

Assistant Professor
National Jewish Health, United States
MS

Matthew Strand, PhD

Associate Professor
National Jewish Health, United States
Vinicius Calado Nogueira de Moura

Senior Lab Researcher
National Jewish Health
Denver, Colorado, United States
CD

Charles L. Daley, MD

Professor
National Jewish Health, United States
MS

Michael Strong, PhD

Associate Professor
National Jewish Health, United States
RD

Rebecca M. Davidson, PhD

Associate Professor
National Jewish Health, United States
JN

Jerry A. Nick, MD

United States

Background: Nontuberculous mycobacterial infections pose an increasing concern to individuals with CF, due to the challenges in treatment and open questions pertinent to infection acquisition. An evidence-based, standardized approach was developed to investigate healthcare-associated nontuberculous mycobacteria (NTM) transmission. Hypothesis: Clusters of highly similar strains of NTM in people cared for at the same cystic fibrosis (CF) Care Center may arise from healthcare sources including patient-to-patient transmission and/or acquisition from environmental sources.

Methods: Respiratory NTM isolates were collected from Centers nationwide and whole genome sequencing (WGS) analysis identified genetically similar clusters of NTM isolates from people who are 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 4 Care Centers.

Results: In Center A, WGS analysis revealed 11 clusters of NTM (6 Mycobacterium abscessus subspecies (ssp.) abscessus (MAB), 1 M. abscessus ssp. massiliense, 2 M. avium, and 2 M. intracellulare). Epidemiologic investigation revealed potential healthcare-associated transmission events in 2 (33%) MAB clusters and 2 (100%) M. avium clusters. Respiratory and healthcare environmental isolate comparisons revealed no genetic similarity. One cluster, with no plausible healthcare-associated transmission, resided in the same watershed. In Center B, WGS analysis revealed 2 clusters of NTM (M. avium and M. chimaera). Epidemiologic investigation demonstrated multiple opportunities for healthcare-associated transmission in both clusters. Respiratory and healthcare environmental M. avium isolate comparisons revealed no genetic similarity. Respiratory M. chimaera isolates revealed greater genetic similarity to a single hospital water biofilm environmental isolate than to each other. Neither cluster had all subjects residing in the same watershed. Two additional Center outbreak investigations are ongoing.

Conclusions: Each healthcare-associated NTM investigation has unique findings. Center A eliminated healthcare-associated transmission for nearly all subjects, with possible healthcare-associated transmission of MAB and M. avium and Center B demonstrates possible healthcare-associated acquisition of M. chimaera. Home of residence watershed analysis supports possible clustered MAB acquisition in Center A but not in Center B. NTM was identified in the healthcare environment in both Centers, and was genetically similar with clustered respiratory isolates only in Center B. The presence of genetically similar isolates is insufficient to definitively demonstrate healthcare-associated NTM transmission. Use of a standardized epidemiological investigation, coupled with environmental sampling and watershed analysis, will improve our understanding of the frequency and nature of healthcare-associated NTM acquisition and transmission.

Acknowledgements: This work was supported by the CFF (GROSS19Q0, NICK20Y2SVC, NICK20Y2OUT & NICK15RO).

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