A-Z Index × Submit A-Z Index × Submit A-Z Index Search Dropdown × Submit Facebook Twitter LinkedIn Syndicate Emerging Infectious Disease journal ISSN: 1080-6059 Disclaimer: Early release articles are not considered as final versions. Any changes will be reflected in the online version in the month the article is officially released.
Mycobacterium abscessus infections are frequently drug resistant and can cause severe disease, particularly among vulnerable populations in healthcare settings. In June 2024, a cluster of M. abscessus infection cases was reported at a hospital in Maryland, USA. An investigation involving hospital infection prevention staff, the Maryland Department of Health, the Centers for Disease Control and Prevention, and the Wadsworth Laboratory of the New York State Department of Health included initiation of mitigation efforts such as tap water use restrictions, point-of-use water filters, hospitalwide water flushing, and staff education regarding sink safety. Whole-genome sequencing of patient and environmental isolates, coupled with epidemiologic data, revealed a strong association (0–24 single-nucleotide polymorphism differences) between environmental and patient samples, indicating that infections were likely a result of patient exposure to M. abscessus . Ensuring initiation of mitigation initiatives likely prevented additional patient infections. Although effective in this investigation, not all mitigation strategies are equal or sustainable.
Nontuberculous mycobacteria (NTM) are a group of bacteria found naturally in soil, dust, and water; infections caused by NTMs are increasing globally ( 1 – 3 ). The NTM Mycobacterium abscessus and its subspecies are classified as rapid growers and are responsible for skin and soft tissue infections, bacteremia, and pulmonary infections, among other conditions ( 4 ). M. abscessus infections are difficult to treat because of intrinsic drug resistance that limits treatment options ( 2 ). The environmental persistence of M. abscessus and the often treatment-resistant infections it can cause make it an emerging bacterium of concern. M. abscessus outbreaks have been reported in healthcare settings, often involving exposure to contaminated water sources ( 5 – 8 ).
In June 2024, hospital infection prevention (IP) staff at a hospital in Maryland, USA, notified the Maryland Department of Health (MDH) of 10 patients with cultures positive for M. abscessus . The ensuing investigation involved the IP staff, MDH, the Centers for Disease Control and Prevention (CDC), and the Wadsworth Laboratory of the New York State Department of Health. This activity was reviewed by the CDC Public Health Infrastructure Center’s human subjects review staff, was deemed not research, and was conducted consistent with applicable federal law and CDC policy (e.g., 45 C.F.R. part 46, 21 C.F.R. part 56; 42 U.S.C. §241(d); 5 U.S.C. §552a; 44 U.S.C. §3501 et seq.).
After they identified an initial case of M. abscessus infection in May 2024, hospital IP staff initiated retroactive case finding. The hospital had a previous cluster of 3 cases of M. abscessus (2 positive CSF cultures, 1 positive sputum culture) in 2021, shortly after occupancy of a newly constructed building. Preoccupancy water quality testing was within acceptable ranges but did not include specific testing for M. abscessus . With guidance from MDH and CDC, water samples from the 2021 outbreak were tested at CDC, where NTM was identified, but not…