Mycobacteroides abscessus Outbreak and Mitigation in a Cardiothoracic Transplant Population: The Problem with Tap Water

• Published in: The Journal of hospital infection
• Main Authors: Rathod, Shardul N., Weber, Rachel T., Salim, Asra A., Tanna, Sajal D., Stosor, Valentina, Malczynski, Michael, O’Boye, Anne, Hoke, Kathleen, Landon, Jennifer, McCarthy, Stephanie, Qi, Chao, Angarone, Michael P., Ison, Michael G., Williams, Janna L., Zembower, Teresa R., Bolon, Maureen K.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 06-11-2024
• Subjects: cardiothoracic transplant; heart transplant; lung transplant; Mycobacteroides abscessus; Nontuberculous mycobacteria; outbreak; tap water; cardiothoracic transplant; lung transplant; Nontuberculous mycobacteria; Mycobacteroides abscessus; outbreak; heart transplant; tap water
• ISSN: 0195-6701; 1532-2939; 1532-2939
• DOI: 10.1016/j.jhin.2024.10.016

Hospital outbreaks caused by Mycobacteroides abscessus complex are a major cause for concern in vulnerable patients such as the cardiothoracic transplant population.
To describe the outbreak investigation and mitigation steps undertaken to address an increase in healthcare-associated Mycobacteroides abscessus (M. abscessus) complex cases in an inpatient cardiothoracic transplant population.
We extracted clinical characteristics from patients with M. abscessus pre-outbreak (March 2018 – December 2020) and during the outbreak (January 2021 – June 2022) from the electronic medical record. A multidisciplinary team conducted the outbreak investigation and devised a mitigation strategy to implement at our institution.
The baseline incidence of healthcare-associated M. abscessus was 0.11 cases per 10,000 patient-days; this increased to 0.24 cases per 10,000 patient-days during the outbreak. There were 1/9 (11%) cardiothoracic transplant patients in the pre-outbreak group compared to 7/12 (58%) during the outbreak, and respiratory specimen types compromised 6/9 (67%) of M. abscessus results in the pre-outbreak group compared to 10/12 (83%) during the outbreak. Among the clinical care activities involving water, a variety of water sources were utilized, including filtered and tap water. The incidence of healthcare-associated M. abscessus subsequently decreased to 0.06 cases per 10,000 patient-days after implementing an outbreak mitigation strategy of sterile water precautions.
Robust educational efforts from a multidisciplinary team on eliminating exposure to tap water were effective measures to reduce healthcare-associated M. abscessus incidence at our institution. NTM infection surveillance, targeted education, and water mitigation strategies may be beneficial preventative strategies for other lung transplant centres facing similar issues.