Reviewed by Jen Cihlar, DO, Vanderbilt University Medical Center
Bottom line:
A 4 year-long outbreak investigation of OXA-48-producing E. coli initially detected in a series of hospitalized patients was found to have likely community-based transmission with propagation from food premises in a high-income country.
An outbreak investigation was prompted when in August 2018 following a series of patients at a single public hospital serving the health district (Hutton Valley Hospital in New Zealand; HVH) were found with clinical infection or carriage of OXA-48–producing E. coli without any discernable risk factors, all of which were found to be multilocus ST 131. Over the span of the outbreak investigation (8/2018-12/2022), a total of 25 cases were identified, 7 from community-collected samples and 18 cases from hospital specimens. There was no significant intra-hospital transmission event or links were found in the 18 admitted cases or level of community reservoir via enhanced community screening. However, 18 patients identified a common “food premises A” in their exposure history, all of which had a visit to premises A and detection of their OXA-48-producing E. coli clinical specimen ranging from <1 month to >48 months: 50% within 2 months of visit and 7 of 18 of these having no hospital admission to HVH. Detailed investigation of premises A discovered multiple food safety concerns reports over the years since its 2017 opening. While no OXA-48-producing E. coli were identified from surface or food swabs, investigators did discover 4 food handlers colonized with OXA-48-producing E. coli with links to the case strains using whole genome sequencing. Sequencing analysis suggested the outbreak lineage likely originated abroad, possibly in Asia. Given the number of concerns for safe food handling at premise A, it was postulated that transmission and dissemination occurred via colonized food handlers.
This outbreak raises the possible role of community food premises as a source of carbapenemase producing Enterobacterales (CPE) transmission and demonstrates challenges with controlling community CPE spread such as time and resources required to identify epidemiological links, often incidental case detection with wide approximate exposure periods, delays in sampling, and linking retrospective events. That said, the authors felt it was important to recognize as CPE colonization is not a notifiable health condition in New Zealand, limiting public health action to investigate and control spread unlike the inpatient setting and would require development of comprehensive control strategies for the community setting.
Reference:
Thornley CN, Kelly M, Bloomfield M, et al. Community Outbreak of OXA-48–Producing Escherichia coli Linked to Food Premises, New Zealand, 2018–2022. Emerging Infectious Diseases. 2025;31(7):1300-1308. doi:10.3201/eid3107.250289.