Impact of COVID-19 related healthcare changes on antibiotic resistance in clinical Escherichia coli isolates: interrupted time series analyses in Scotland, UK.

ObjectivesThe SARS-CoV-2 pandemic has impacted healthcare use, with mixed reports about the impact on antimicrobial resistance. This work aimed to identify changes in healthcare utilisation and antibiotic prescribing in relation to the COVID-19 pandemic and quantify any subsequent impact on antibiotic resistance in clinical Escherichia coli isolates across a complete geographical population in Scotland. MethodsData including [~]490,000 people from January 2018 to March 2022 were accessed via the University of Dundee. Joinpoint regression analyses identified changes in trend for hospital encounters and antibiotic use in the community and hospital. Using identified joinpoints as the "intervention" time point, the impact of these changes on the proportions of E. coli blood and urine culture isolates that were antibiotic resistant and multidrug resistant (MDR) were examined using interrupted time series analysis (ITSA). ResultsJoinpoint regression analyses identified January 2020 as the intervention time point for ITSA. From 26% resistant (not MDR) and 35% MDR among urine E. coli isolates in the month immediately pre-intervention, there were upward changes in level of 2.5% (95%CI - 0.4% to 5.4%) and trend of 0.3% (95%CI 0.1% to 0.5%) per month for resistant (not MDR), and an upward change in level of 0.4% (95%CI - 2.0% to 2.8%) and a downwards change in trend of -0.3% (95% CI - 0.5% to -0.1%) per month for MDR. Increases in resistant (not MDR) and reductions in MDR proportions were found 9 months post-intervention compared to proportions predicted had the intervention not occurred. Similar changes were observed for blood culture isolates, but numbers were smaller, resulting in less certainty around estimates. ConclusionThere were small but significant reductions in the proportions of MDR E. coli isolates associated with COVID-19-related changes to healthcare utilisation and antibiotic prescribing. These results may inform future antimicrobial stewardship practices and their evaluation, including estimates of their impact on antibiotic resistance.