Trends in hospital acquired New Delhi metallo-beta-lactamase-producing Enterobacterales in Tuscany (Italy) from 2019 to 2021: impact of the COVID-19 pandemic

In Tuscany, Italy, New Delhi metallo-beta-lactamase-producing carbapenem-resistant Enterobacterales (NDM-CRE) in hospitalized patients has increasingly been observed since 2018, leading in 2019 to the implementation of enhanced control measures successfully reducing transmission. We describe the NDM-CRE epidemiology during the COVID-19 pandemic in Tuscany. Data on NDM-CRE patients hospitalized in five Tuscan hospitals were collected from January 2019 to December 2021. Weekly rates of NDM-CRE cases on hospital days in medical and critical-care wards were calculated. In March–December 2020, NDM-CRE rates were stratified by COVID-19 diagnosis. Multi-variate regression analysis was performed to assess outcomes' differences among two periods analysed and between COVID-19 populations. Since March 2020, an increase in NDM-CRE cases was observed, associated with COVID-19 admissions. COVID-19 patients differed significantly from non-COVID-19 ones by several variables, including patient features (age, Charlson index) and clinical history and outcomes (NDM-CRE infection/colonization, intensive care unit stay, length of stay, mortality). During the pandemic, we observed a higher rate of NDM-CRE cases per hospital day in both non-COVID-19 patients (273/100,000) and COVID-19 patients (370/100,00) when compared with pre-pandemic period cases (187/100,00). Our data suggest a resurgence in NDM-CRE spread among hospitalized patients in Tuscany during the COVID-19 pandemic, as well as a change in patients' case-mix. The observed increase in hospital transmission of NDM-CRE could be related to changes in infection prevention and control procedures, aimed mainly at COVID-19 management, leading to new challenges in hospital preparedness and crisis management planning.