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

TY - JOUR

T1 - Impact of COVID-19 related healthcare changes on antibiotic resistance in clinical Escherichia coli isolates

T2 - interrupted time series analyses in Scotland, UK

AU - Ciaccio, Laura

AU - Donnan, Peter

AU - Parcell, Benjamin

AU - Marwick, Charis Ann

N1 - © The Author(s) 2026

PY - 2026/3

Y1 - 2026/3

N2 - Objectives: The COVID-19 pandemic impacted healthcare use, with mixed reports regarding impacts on antimicrobial resistance. The aim was to identify changes in healthcare utilisation and antibiotic prescribing related to the COVID-19 pandemic and quantify subsequent impacts on antibiotic resistance in clinical Escherichia coli (E. coli) isolates in Scotland. Methods: Data involving ~490,000 people from January 2018 to March 2022 were analysed. Joinpoint regression analyses identified trend changes in healthcare encounters, and antibiotic use in community and hospital settings. Using these joinpoints as an “intervention” timepoint, interrupted time series analysis (ITSA) quantified associated changes in proportions of E. coli blood and urine culture isolates that were antibiotic-resistant and multidrug-resistant (MDR). Results: January 2020 was identified as the intervention point. From 26% resistant (not MDR) and 35% MDR among urine E. coli isolates immediately pre-intervention, there were 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 level change of +0.4% (95%CI -2.0% to 2.8%) but trend change of -0.3% (95%CI -0.5% to -0.1%) per month for MDR. By nine months post-intervention, compared to predicted levels without intervention, resistant (not MDR) proportions increased while MDR proportions decreased. Similar changes occurred among blood culture isolates, but with less certainty around estimates. Conclusion: Small but significant reductions in MDR E. coli resulted from COVID-19-related changes in healthcare and antibiotic use. The findings are critical for antimicrobial stewardship and infection control interventions and evaluation.

AB - Objectives: The COVID-19 pandemic impacted healthcare use, with mixed reports regarding impacts on antimicrobial resistance. The aim was to identify changes in healthcare utilisation and antibiotic prescribing related to the COVID-19 pandemic and quantify subsequent impacts on antibiotic resistance in clinical Escherichia coli (E. coli) isolates in Scotland. Methods: Data involving ~490,000 people from January 2018 to March 2022 were analysed. Joinpoint regression analyses identified trend changes in healthcare encounters, and antibiotic use in community and hospital settings. Using these joinpoints as an “intervention” timepoint, interrupted time series analysis (ITSA) quantified associated changes in proportions of E. coli blood and urine culture isolates that were antibiotic-resistant and multidrug-resistant (MDR). Results: January 2020 was identified as the intervention point. From 26% resistant (not MDR) and 35% MDR among urine E. coli isolates immediately pre-intervention, there were 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 level change of +0.4% (95%CI -2.0% to 2.8%) but trend change of -0.3% (95%CI -0.5% to -0.1%) per month for MDR. By nine months post-intervention, compared to predicted levels without intervention, resistant (not MDR) proportions increased while MDR proportions decreased. Similar changes occurred among blood culture isolates, but with less certainty around estimates. Conclusion: Small but significant reductions in MDR E. coli resulted from COVID-19-related changes in healthcare and antibiotic use. The findings are critical for antimicrobial stewardship and infection control interventions and evaluation.

U2 - 10.1093/jac/dkag049

DO - 10.1093/jac/dkag049

M3 - Article

SN - 0305-7453

VL - 81

JO - Journal of Antimicrobial Chemotherapy

JF - Journal of Antimicrobial Chemotherapy

IS - 3

M1 - dkag049

ER -