tetano
Editor, Senior Moderator
NEJM Evid
. 2025 Oct;4(10):EVIDoa2400108.
doi: 10.1056/EVIDoa2400108. Epub 2025 Sep 23. Peri-Covid-19 Antibiotic Use and Antimicrobial Resistance in Older Adults
Derek R MacFadden[SUP] 1 2 [/SUP], Colleen Maxwell[SUP] 2 3 [/SUP], Dawn Bowdish[SUP] 4 [/SUP], Susan Bronskill[SUP] 2 [/SUP], James Brooks[SUP] 5 [/SUP], Kevin Brown[SUP] 6 7 [/SUP], Lori L Burrows[SUP] 4 [/SUP], Anna E Clarke[SUP] 1 2 [/SUP], Bradley J Langford[SUP] 6 7 [/SUP], Elizabeth Leung[SUP] 8 9 [/SUP], Valerie Leung[SUP] 7 10 [/SUP], Doug Manuel[SUP] 1 2 [/SUP], Allison McGeer[SUP] 6 11 [/SUP], Sharmistha Mishra[SUP] 2 8 12 13 14 [/SUP], Andrew M Morris[SUP] 11 [/SUP], Caroline Nott[SUP] 5 [/SUP], Sumit Raybardhan[SUP] 6 15 [/SUP], Mia E Sapin[SUP] 16 [/SUP], Kevin L Schwartz[SUP] 2 6 7 8 [/SUP], Miranda So[SUP] 9 17 18 [/SUP], Jean-Paul R Soucy[SUP] 6 [/SUP], Nick Daneman[SUP] 2 7 19 20 [/SUP]
Affiliations
Background: Antibiotic use during the coronavirus disease 2019 (Covid-19) pandemic was common in the outpatient setting, but was not supported by guidelines. We sought to evaluate the role of this antibiotic use on downstream antibiotic resistance.
Methods: We performed a population-wide cohort study of all nonhospitalized adults 66 years of age or older in Ontario, Canada, from January 1, 2020, to June 30, 2021, with a first identification of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We evaluated the relationship between outpatient peri-Covid-19 antibiotic exposure (within a period of 7 days before or after index SARS-CoV-2 reporting) and downstream isolation of an antibiotic-resistant organism from clinical culture within 6 months. We calculated adjusted odds ratios of the association between peri-Covid-19 prescribing and antibiotic-resistant organism detection, as well as the adjusted attributable fractions of downstream antibiotic-resistant organisms.
Results: Of the 53,533 eligible individuals included, 8228 (15%) were prescribed a peri-Covid-19 antibiotic, and 1477 (3%) had a downstream antibiotic-resistant organism identified. The adjusted odds ratio for the presence of any antibiotic-resistant organism with peri-Covid-19 antibiotic use was 1.24 (95% confidence interval [CI], 1.09 to 1.41), while the adjusted odds ratio for the presence of gram-negative antibiotic-resistant organisms was 1.27 (95% CI, 1.11 to 1.46) and for gram-positive antibiotic-resistant organisms it was 1.02 (95% CI, 0.70 to 1.48). Among all individuals who received an antibiotic within 7 days of SARS-CoV-2 diagnosis, the attributable fraction of downstream antimicrobial resistance related to peri-Covid-19 antibiotic use was 17% (95% CI, 7 to 26%). Among all individuals with a SARS-CoV-2 diagnosis, the population-attributable fraction of downstream antimicrobial resistance related to peri-Covid-19 antibiotic use was 4% (95% CI, 2 to 7%).
Conclusions: Peri-Covid-19 antibiotic use was associated with downstream antimicrobial resistance, and particularly the presence of gram-negative antibiotic-resistant organisms. (Funded by the Canadian Institutes of Health Research Operating Grant [grant number 179461] and others).
. 2025 Oct;4(10):EVIDoa2400108.
doi: 10.1056/EVIDoa2400108. Epub 2025 Sep 23. Peri-Covid-19 Antibiotic Use and Antimicrobial Resistance in Older Adults
Derek R MacFadden[SUP] 1 2 [/SUP], Colleen Maxwell[SUP] 2 3 [/SUP], Dawn Bowdish[SUP] 4 [/SUP], Susan Bronskill[SUP] 2 [/SUP], James Brooks[SUP] 5 [/SUP], Kevin Brown[SUP] 6 7 [/SUP], Lori L Burrows[SUP] 4 [/SUP], Anna E Clarke[SUP] 1 2 [/SUP], Bradley J Langford[SUP] 6 7 [/SUP], Elizabeth Leung[SUP] 8 9 [/SUP], Valerie Leung[SUP] 7 10 [/SUP], Doug Manuel[SUP] 1 2 [/SUP], Allison McGeer[SUP] 6 11 [/SUP], Sharmistha Mishra[SUP] 2 8 12 13 14 [/SUP], Andrew M Morris[SUP] 11 [/SUP], Caroline Nott[SUP] 5 [/SUP], Sumit Raybardhan[SUP] 6 15 [/SUP], Mia E Sapin[SUP] 16 [/SUP], Kevin L Schwartz[SUP] 2 6 7 8 [/SUP], Miranda So[SUP] 9 17 18 [/SUP], Jean-Paul R Soucy[SUP] 6 [/SUP], Nick Daneman[SUP] 2 7 19 20 [/SUP]
Affiliations
- PMID: 40985783
- DOI: 10.1056/EVIDoa2400108
Background: Antibiotic use during the coronavirus disease 2019 (Covid-19) pandemic was common in the outpatient setting, but was not supported by guidelines. We sought to evaluate the role of this antibiotic use on downstream antibiotic resistance.
Methods: We performed a population-wide cohort study of all nonhospitalized adults 66 years of age or older in Ontario, Canada, from January 1, 2020, to June 30, 2021, with a first identification of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We evaluated the relationship between outpatient peri-Covid-19 antibiotic exposure (within a period of 7 days before or after index SARS-CoV-2 reporting) and downstream isolation of an antibiotic-resistant organism from clinical culture within 6 months. We calculated adjusted odds ratios of the association between peri-Covid-19 prescribing and antibiotic-resistant organism detection, as well as the adjusted attributable fractions of downstream antibiotic-resistant organisms.
Results: Of the 53,533 eligible individuals included, 8228 (15%) were prescribed a peri-Covid-19 antibiotic, and 1477 (3%) had a downstream antibiotic-resistant organism identified. The adjusted odds ratio for the presence of any antibiotic-resistant organism with peri-Covid-19 antibiotic use was 1.24 (95% confidence interval [CI], 1.09 to 1.41), while the adjusted odds ratio for the presence of gram-negative antibiotic-resistant organisms was 1.27 (95% CI, 1.11 to 1.46) and for gram-positive antibiotic-resistant organisms it was 1.02 (95% CI, 0.70 to 1.48). Among all individuals who received an antibiotic within 7 days of SARS-CoV-2 diagnosis, the attributable fraction of downstream antimicrobial resistance related to peri-Covid-19 antibiotic use was 17% (95% CI, 7 to 26%). Among all individuals with a SARS-CoV-2 diagnosis, the population-attributable fraction of downstream antimicrobial resistance related to peri-Covid-19 antibiotic use was 4% (95% CI, 2 to 7%).
Conclusions: Peri-Covid-19 antibiotic use was associated with downstream antimicrobial resistance, and particularly the presence of gram-negative antibiotic-resistant organisms. (Funded by the Canadian Institutes of Health Research Operating Grant [grant number 179461] and others).