OBJECTIVES:Strategies to improve antibiotic use may exacerbate health inequities if they do not consider existing barriers to healthcare access. We examined associations between social determinants of healthcare access (SDOH) and antibiotic prescribing and variations in these associations pre- and post-COVID-19 emergence. METHODS:We conducted a retrospective cohort study of community-dwelling adults aged ≥66 years in Ontario, Canada, between March 2018 and March 2020 (pre-pandemic period) and March 2020 and March 2022 (pandemic period). Multivariable Fine-Gray subdistribution hazard models were used to examine associations between three SDOH variables (neighbourhood-level income and proportion racialized, and individual-level recent immigration) and incident antibiotic prescriptions, accounting for mortality as a competing risk. We assessed for potential effect modification by the pandemic period. RESULTS:The pre-pandemic (n = 2 567 382) and pandemic (n = 2 744 337) cohorts were similar in average age (75 years). Antibiotic prescribing was slightly higher among residents in the highest income neighbourhoods in pre-pandemic (subdistribution hazard ratio [sHR], 1.03 [95% CI, 1.02-1.04], compared with lowest income) and pandemic (sHR, 1.02 [1.01-1.03]) periods. Prescribing was higher among recent immigrants (vs. long-term residents) in both periods, with a more pronounced difference observed during the pandemic (sHR, 1.21 [1.18-1.25]) than pre-pandemic (sHR, 1.12 [1.09-1.16]) period. Prescribing was lower among residents living in the most diverse neighbourhoods (vs. least diverse) in both periods, with a more pronounced difference during the pandemic (sHR, 0.81 [0.80-0.82]) than pre-pandemic (sHR, 0.92 [0.91-0.93]) period. DISCUSSION:SDOH variables are associated with antibiotic prescribing patterns over time among older outpatients, and the COVID-19 pandemic further modified some of these associations.

Pneumocystis jirovecii is a ubiquitous opportunistic fungus that can cause life-threatening pneumonia. People with HIV (PWH) who have low CD4 counts are one of the populations at the greatest risk of Pneumocystis jirovecii pneumonia (PCP). While guidelines have approached the diagnosis, prophylaxis, and management of PCP, the numerous studies of PCP in PWH are dominated by the 1980s and 1990s. As such, most studies have included younger male populations, despite PCP affecting both sexes and a broad age range. Many studies have been small and observational in nature, with an overall lack of randomized controlled trials. In many jurisdictions, and especially in low- and middle-income countries, the diagnosis can be challenging due to lack of access to advanced and/or invasive diagnostics. Worldwide, most patients will be treated with 21 days of high-dose trimethoprim sulfamethoxazole, although both the dose and the duration are primarily based on historical practice. Whether treatment with a lower dose is as effective and less toxic is gaining interest based on observational studies. Similarly, a 21-day tapering regimen of prednisone is used for patients with more severe disease, yet other doses, other steroids, or shorter durations of treatment with corticosteroids have not been evaluated. Now with the widespread availability of antiretroviral therapy, improved and less invasive PCP diagnostic techniques, and interest in novel treatment strategies, this review consolidates the scientific body of literature on the diagnosis and management of PCP in PWH, as well as identifies areas in need of more study and thoughtfully designed clinical trials.

PURPOSE:Antimicrobial misuse contributes to antimicrobial resistance in thoracic transplant (TTx) and mechanical circulatory support (MCS) recipients. This study uses a modified Delphi method to define the expected appropriate antimicrobial prescribing for the common clinical scenarios encountered in TTx and MCS recipients.METHODS:An online questionnaire on managing 10 common infectious disease syndromes was submitted to a multidisciplinary Delphi panel of 25 experts from various disciplines. Consensus was predefined as 80% agreement for each question. Questions where consensus was not achieved were discussed during live virtual live sessions adapted by an independent process expert.RESULTS:An online survey of 62 questions related to 10 infectious disease syndromes was submitted to the Delphi panel. In the first round of the online questionnaire, consensus on antimicrobial management was reached by 6.5% (4/62). In Round 2 online live discussion, the remaining 58 questions were discussed among the Delphi Panel members using a virtual meeting platform. Consensus was reached among 62% (36/58) of questions. Agreement was not reached regarding the antimicrobial management of the following six clinical syndromes: (1) Burkholderia cepacia pneumonia (duration of therapy); (2) Mycobacterium abscessus (intra-operative antimicrobials); (3) invasive aspergillosis (treatment of culture-negative but positive BAL galactomannan) (duration of therapy); (4) respiratory syncytial virus (duration of antiviral therapy); (5) left ventricular assist device deep infection (initial empirical antimicrobial coverage) and (6) CMV (duration of secondary prophylaxis).CONCLUSION:This Delphi panel developed consensus-based recommendations for 10 infectious clinical syndromes seen in TTx and MCS recipients.

Background: Post-transplant infections remain a leading cause of morbidity and mortality in solid organ transplant recipients (SOTRs) and local standardized antimicrobial treatment guidelines may contribute to improved clinical outcomes. Our study assessed the rate of therapeutic compliance with local standard guidelines in the treatment of common infections in SOTR, and their associated outcomes.Methods: Consecutive adult SOTRs admitted to the transplant floor from January-September 2020 and were treated for an infectious syndrome were followed until discharge or for 30 days following the date of diagnosis, whichever was shorter. Data was extracted from electronic medical records. Guideline compliance was characterized as either appropriate, effective but unnecessary, undertreatment, or inappropriate.Results: Nine hundred and thirty-six SOTR were admitted to the transplant ward, of which 328 patients (35%) received treatment for infectious syndromes. Guidelines were applicable to 252 patients, constituting 275 syndromes: 86 pneumonias; 82 urinary tract infections; 40 intra-abdominal infections; 38 bloodstream infections; and 29 C. difficile infections. 200/246 (81%) of infectious syndromes received appropriate or effective but unnecessary empiric treatment. In addition, appropriate tailoring of antimicrobials resulted in a significant difference in 30-day all-cause mortality (adjusted OR of 0.07, 95% CI 0.01-0.38; P = .002). Lastly, we found that guideline-compliant empiric therapy was found to prevent the development of multi-drug resistance in a time-dependent analysis (adjusted HR of 0.21, 95% CI 0.08-0.52; P = .001).Conclusion: Our data show that adherence to locally developed guidelines was associated with reduced mortality and resistant-organism development in our cohort of SOTR.

The epidemiology of invasive aspergillosis (IA) is evolving. To define the patient groups who will most likely benefit from primary or secondary Aspergillus prophylaxis, particularly those whose medical conditions and IA risk change over time, it is helpful to depict patient populations and their risk periods in a temporal visual model. The Sankey approach provides a dynamic figure to understand the risk of IA for various patient populations. While the figure depicted within this article is static, an internet-based version could provide pop-up highlights of any given flow's origin and destination nodes. A future version could highlight links to publications that support the color-coded incidence rates or other actionable items, such as bundles of applicable pharmacologic or non-pharmacologic interventions. The figure, as part of the upcoming Infectious Diseases Society of America's aspergillosis clinical practice guidelines, can guide decision-making in clinical settings.

Solid organ transplant and hematopoietic cell transplant patients face an increased risk of infectious diseases, greater exposure to antibiotics, and heightened risk of multidrug-resistant organisms (MDROs) due to their immunosuppressed state. Antimicrobial stewardship programs (ASP) are essential in reducing the incidence of MDRO by conserving antimicrobial use, minimizing treatment durations, and improving the appropriate use of diagnostic testing. However, the role of ASP in transplant infectious diseases (TID) is still evolving, necessitating greater collaboration between ASP and transplant programs. This collaboration will mitigate infection risks, reduce infection-associated costs, and improve outcomes. This article reviews the key components for implementing ASP in TID, especially for those that are establishing or growing their ASP to include TID, including specific goals, structure and funding, ASP initiatives (including antibiotic allergy delabeling, diagnostic stewardship, and antiviral/antifungal stewardship), metrics, and educational opportunities.

Advancement in solid organ transplantation and hematopoietic stem cell transplant continues to improve the health outcomes of patients and widens the number of eligible patients who can benefit from the medical progress. Preserving the effectiveness of antimicrobials remains crucial, as otherwise transplant surgeries would be unsafe due to surgical site infections, and the risk of sepsis with neutropenia would preclude stem cell transplant. In this review, we provide updates on three previously discussed stewardship challenges: febrile neutropenia, Clostridioides difficile infection, and asymptomatic bacteriuria. We also offer insight into four new stewardship challenges: the applicability of the “shorter is better” paradigm shift to antimicrobial duration; antibiotic allergy delabeling and desensitization; colonization with multidrug-resistant gram-negative organisms; and management of cytomegalovirus infections. Specifically, data are accumulating for “shorter is better” and antibiotic allergy delabeling in transplant patients, following successes in the general population. Unique to transplant patients are the impact of multidrug-resistant organism colonization on clinical decision-making of antibiotic prophylaxis in transplant procedure and the need for antiviral stewardship in cytomegalovirus. We highlighted the expansion of antimicrobial stewardship interventions as potential solutions for these challenges, as well as gaps in knowledge and opportunities for further research.

Background: Antimicrobial resistance (AMR) is a threat to effective treatment of bacterial infections. Gastrointestinal colonization with an antimicrobial resistant organism (ARO) is a risk factor for subsequent systemic infection, and increasing resistance is associated with increased infection recurrence. Patient-level interventions to decrease or minimize antimicrobial harms and reduce gastrointestinal colonization and translocation without worsening selection for AMR have tremendous potential for clinical impact. Despite the prevalence and mortality associated with bloodstream infections, there are no effective therapies for decolonization of the gut microbiome in attempts to potentially decrease the risk of recurrence. Reconstituting the perturbed microbiome is a novel therapeutic modality with the potential to decrease ARO colonization and subsequent infection and combat AMR without additional selection pressure for further AMR. No clinical trial has yet assessed the potential of a therapeutic microbial consortium for ARO decolonization and infection prevention after antibiotic treatment. Methods: Antimicrobial Resistant Organism Decolonization After Microbiome Perturbation (ARO-DECAMP) is a multi-centre, placebo-controlled, pilot randomized controlled feasibility trial using the microbial consortium Microbial Ecosystem Therapeutic-2. Non-intensive care unit hospitalized patients >18 years of age receiving antibiotic treatment for a bloodstream infection caused by an ARO will be included. Participants will be randomized in a 1:1 ratio to receive either MET-2 or placebo for 10 days, with treatment initiation 2-3 days after completion of antibiotics. Participants will be followed for 180 days, and biological samples will be collected periodically for clinical, ecological, and biomarker outcomes. Recruitment rate and study intervention adherence will be evaluated for feasibility. Discussion: This study is designed to determine if a trial of administration of microbial consortia after antibiotic treatment for bloodstream infections is feasible. Results of this pilot study will inform the design and sample size of a definitive trial powered to assess the effectiveness of the intervention as a therapeutic strategy for augmenting the microbiome and improving clinical outcomes. Trial registration: ClinicalTrials.gov, NCT06214403. Registered 19 January 2024, https://clinicaltrials.gov/study/NCT06214403

Patient case simulation software are described in pharmacy education literature as useful tools to improve skills in patient assessment (including medication history-taking and physical assessment), clinical reasoning and communication, and are typically well-received by students and instructors. The virtual interactive case (VIC) system is a web-based software developed to deliver deliberate practice opportunities in simulated patient encounters across a spectrum of clinical topics. This article describes the implementation and utilization of VIC in the undergraduate curriculum at one Canadian pharmacy school. Methods: At our facility, the use of VIC was integrated across the training spectrum in the curriculum, including core and elective didactic courses and practice labs, experiential learning, interprofessional education, and continuing education. Its use was evaluated through student and instructor surveys and qualitative student interviews). VIC is easy to navigate and created a positive and realistic learning environment. Students identified that it enhanced their ability to identify relevant patient information, accurately simulated hospital pharmacy practice and thereby helped them to prepare for their upcoming experiential courses. The use of VIC has expanded beyond its original intended purpose for individual student practice to become a valuable addition to pharmacy undergraduate education. Future plans include ongoing development of cases and exploration of further uses of VIC within the didactic curriculum, for remediation in experiential courses, and for pharmacist continuing education.

Sara M. Karaba, MD, PhD, MHS; Sara E. Cosgrove, MD, MS; Jae Hyoung Lee, MD, MPH; Suiyini Fiawoo, MD, MPH; Emily L. Heil, PharmD, MS; Katelyn S. Quartuccio, PharmD, BCIDP, BCPS; Katherine C. Shihadeh, PharmD; Pranita D. Tamma, MD, MHS

Abstract Background Prospective audit-and-feedback (PAF) for hospitalized leukemia patients is resource-intensive, while data on stadardized assessment of the quality, i.e. appropriateness, of antimicrobial prescribing are scarce. We implemented a multifaceted program combining patient-level PAF with unit-level appropriateness reports generated by serial point-prevalence surveys using the web-based Canadian National Antimicrobial Prescribing Survey (NAPSTM) platform. Quality of prescribing was assessed based on local guidelines and clinical justification using published definitions (Fig. 1). The objective of the study was to evaluate the impact of PAF+NAPS interventions on antibiotic use (AU) in acute leukemia patients at an academic cancer center, compared to PAF-only. Methods In this retrospective cohort study, during the PAF-only period (Jun 1 2017-May 31 2019), the AMS team led 30-minute PAF rounds with prescribers 2x/week. After implementating PAF+NAPS (Jun 1 2019-Mar 31 2020), we met 2x/month for 30 minutes. At each meeting we presented an automated NAPS dashboard report (Fig. 2) of aggregate appropriateness adjudication of antibiotic prescriptions, followed by targeted PAF on select patients with complex antimicrobial needs. We analyzed the impact of the two-step approach on the primary outcome of AU (defined daily dose [DDD]/100 patient-days [PD]) using interrupted time series models. Secondary outcomes were appropriateness of AU during PAF+NAPS, lenght of stay and in-hospital mortality. Target appropriatenesss was at least 90%. Categorical variables were compared using chi-square test and continuous variable using Mann Whitney U test.Fig. 2Sample Canadian NAPS Dashboard Report From a Point-Prevalence Survey Results Patient characteristics and outcomes were presented in Table 1. AU data were presented in Table 2. AU of piperacillin-tazobactam and vancomycin decreased significantly after implementation of 2x/month PAF+NAPS, compared to 2x/week PAF-only interventions (Fig. 3). Overall appropriateness was 91.4% (1757/1921 prescriptions). Conclusion Despite reducing frequency of interventions from 2x/week to 2x/month, PAF+NAPS was an efficient and sustainable AMS model that promoted appropriate and judicious antimicrobial use in hematology-oncology patients (Fig. 4), allowing the AMS team to expand to other specialized areas. Disclosures Shahid Husain, MD, Astellas: Grant/Research Support|Avir: Grant/Research Support|F2G: Grant/Research Support|Gilead: Grant/Research Support|Merck: Grant/Research Support|Pfizer: Grant/Research Support|Pulmocide: Grant/Research Support|Synexis: Grant/Research Support|Takeda: Honoraria

Background Frequent use of antibiotics in patients with COVID-19 threatens to exacerbate antimicrobial resistance. We aimed to establish the prevalence and predictors of bacterial infections and antimicrobial resistance in patients with COVID-19. Methods We did a systematic review and meta-analysis of studies of bacterial co-infections (identified within <= 48 h of presentation) and secondary infections (>48 h after presentation) in outpatients or hospitalised patients with COVID-19. We searched the WHO COVID-19 Research Database to identify cohort studies, case series, case-control trials, and randomised controlled trials with populations of at least 50 patients published in any language between Jan 1, 2019, and Dec 1, 2021. Reviews, editorials, letters, pre-prints, and conference proceedings were excluded, as were studies in which bacterial infection was not microbiologically confirmed (or confirmed via nasopharyngeal swab only). We screened titles and abstracts of papers identified by our search, and then assessed the full text of potentially relevant articles. We reported the pooled prevalence of bacterial infections and antimicrobial resistance by doing a randomeffects meta-analysis and meta-regression. Our primary outcomes were the prevalence of bacterial co-infection and secondary infection, and the prevalence of antibiotic-resistant pathogens among patients with laboratory-confirmed COVID-19 and bacterial infections. The study protocol was registered with PROSPERO (CRD42021297344). Findings We included 148 studies of 362 976 patients, which were done between December, 2019, and May, 2021. The prevalence of bacterial co-infection was 5 center dot 3% (95% CI 3 center dot 8-7 center dot 4), whereas the prevalence of secondary bacterial infection was 18 center dot 4% (14 center dot 0-23 center dot 7). 42 (28%) studies included comprehensive data for the prevalence of antimicrobial resistance among bacterial infections. Among people with bacterial infections, the proportion of infections that were resistant to antimicrobials was 60 center dot 8% (95% CI 38 center dot 6-79 center dot 3), and the proportion of isolates that were resistant was 37 center dot 5% (26 center dot 9-49 center dot 5). Heterogeneity in the reported prevalence of antimicrobial resistance in organisms was substantial (I-2=95%). Interpretation Although infrequently assessed, antimicrobial resistance is highly prevalent in patients with COVID-19 and bacterial infections. Future research and surveillance assessing the effect of COVID-19 on antimicrobial resistance at the patient and population level are urgently needed.

Armin Rashidi, MD, PhD; Fei Gao, PhD; David N. Fredricks, MD; Steven A. Pergam, MD, MPH; Marco Mielcarek, MD; Filippo Milano, MD, PhD; Brenda M. Sandmaier, MD; Stephanie J. Lee, MD, MPH

Abstract Background: Febrile neutropenia (FN) is a medical emergency with significant morbidity and mortality for oncology patients, requiring comprehensive workup and timely antibiotic administration. We evaluated concordance with locally developed FN guidelines and outcomes of cancer patients admitted to general internal medicine at an academic teaching hospital. Methods: We conducted a retrospective observational cohort study of patients admitted between July 1, 2016, and June 30, 2017, for FN. Patients were classified as having low-risk or high-risk FN according to their malignancy and chemotherapy. Primary outcome was the proportion of patients receiving guideline-concordant antibiotics within 48 hours of admission to general internal medicine. Secondary outcomes were the proportion of patients in whom empirical antibiotics were active against pathogens isolated, rate of antibiotic-associated adverse events, and in-hospital mortality. We used logistic regression to model relationship between FN risk and guideline-concordant antibiotics. Results: Among 100 patients included, 34 (34%) were low-risk FN and 66 (66%) were high-risk. Proportion of guideline-concordant empirical antibiotics was significantly lower among low-risk FN patients than high-risk patients: 12 (35%) of 34 versus 47 (71%) of 66 (P = .001). Empirical antibiotics were active against 17 (94%) of 18 isolated pathogens. The mortality rate was 3%, and 16% of patients experienced antibiotic-associated adverse events. Hematological malignancy and infectious diseases–trained physician involvement were associated with guideline-concordant prescribing, with adjusted odds ratios of 3.76 (95% CI, 1.46–9.70; P = .006) and 3.71 (95% CI, 1.49–9.23; P = .005), respectively. Conclusions: Guideline concordance was low compared to published reports. Factors influencing appropriate antimicrobial prescribing in patients with FN warrant further exploration.

Abstract Background Antibiotics are frequently prescribed unnecessarily in outpatients with coronavirus disease 2019 (COVID-19). We sought to evaluate factors associated with antibiotic prescribing in outpatients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Methods We performed a population-wide cohort study of outpatients aged ≥66 years with polymerase chain reaction–confirmed SARS-CoV-2 from 1 January 2020 to 31 December 2021 in Ontario, Canada. We determined rates of antibiotic prescribing within 1 week before (prediagnosis) and 1 week after (postdiagnosis) reporting of the positive SARS-CoV-2 result, compared to a self-controlled period (baseline). We evaluated predictors of prescribing, including a primary-series COVID-19 vaccination, in univariate and multivariable analyses. Results We identified 13 529 eligible nursing home residents and 50 885 eligible community-dwelling adults with SARS-CoV-2 infection. Of the nursing home and community residents, 3020 (22%) and 6372 (13%), respectively, received at least 1 antibiotic prescription within 1 week of a SARS-CoV-2 positive result. Antibiotic prescribing in nursing home and community residents occurred, respectively, at 15.0 and 10.5 prescriptions per 1000 person-days prediagnosis and 20.9 and 9.8 per 1000 person-days postdiagnosis, higher than the baseline rates of 4.3 and 2.5 prescriptions per 1000 person-days. COVID-19 vaccination was associated with reduced prescribing in nursing home and community residents, with adjusted postdiagnosis incidence rate ratios (95% confidence interval) of 0.7 (0.4–1) and 0.3 (0.3–0.4), respectively. Conclusions Antibiotic prescribing was high and with little or no decline following SARS-CoV-2 diagnosis but was reduced in COVID-19–vaccinated individuals, highlighting the importance of vaccination and antibiotic stewardship in older adults with COVID-19.

Background: Little is known about the current landscape of vancomycin therapeutic drug monitoring (TDM) in Canadian hospitals, which operate within publicly funded health care systems. Objectives: To determine current TDM practices for vancomycin and associated challenges and to gather perceptions about TDM based on area under the concentration-time curve (AUC) in Canadian hospitals. Methods: An electronic survey was distributed to hospital pharmacists in spring 2021 through multiple national and provincial antimicrobial stewardship, public health, and pharmacy organizations. The survey gathered data about hospital characteristics, TDM methods, inclusion criteria for patient selection, pharmacokinetic and pharmacodynamic targets, vancomycin susceptibility testing and reporting, and perceived barriers and challenges. Results: In total, 120 pharmacists from 10 of the 13 provincial and territorial jurisdictions in Canada, representing 12.5% of Canadian acute care hospitals (n = 962), completed at least 90% of survey questions. The predominant TDM method was trough-based (107/119, 89.9%); another 10.1% of respondents (12/119) reported performing AUC-based TDM (with or without trough-based TDM), and 17.9% (19/106) of those not already using AUC-based TDM were considering implementing it within 1 to 2 years. Among hospitals performing trough-based TDM, 60.5% (66/109) targeted trough levels between 15 and 20 mg/L for serious infections with methicillin-resistant Staphylococcus aureus. One quarter of the respondents using this method (27/109, 24.8%) agreed that trough-based TDM was of uncertain benefit, and about one-third (33/109, 30.3%) were neutral on this question. Multiple challenges were identified for trough-based TDM, including sub-or supra-therapeutic concentrations and collection of specimens at inappropriate times. Overall, 40.5% (47/116) of respondents agreed that AUC-based TDM was likely safer than trough-based TDM, whereas 23.3% (27/116) agreed that AUC-based TDM was likely more effective. Conclusions: This survey represents a first step in developing evidence based, standardized best practices for vancomycin TDM that are uniquely suited to the Canadian health care system.

Objective: To describe the current landscape of antimicrobial stewardship (AMS) instruction in Canadian entry-to-practice pharmacy programs and the perceived barriers and facilitators to optimizing teaching and learning.Design: Electronic survey.Participants: Faculty representatives from the 10 Canadian entry-to-practice pharmacy programs, including content experts and faculty leadership.Methods: A review of international literature pertaining to AMS in pharmacy curricula informed a 24-item survey, which was open for completion from March to May of 2021. Curriculum content questions were developed using AMS topics recommended by pharmacy educators in the United States, and professional roles described by the Association of Faculties of Pharmacy of Canada.Results: All 10 Canadian faculties returned a completed survey. All programs reported teaching AMS principles in their core curricula. Content coverage varied, with programs teaching, on average, 68% of the recommended AMS topics from the United States. Potential gaps were identified within the professional roles of "communicator" and "collaborator." Didactic methods of content delivery and student assessment, such as lectures and multiple-choice questions, were most frequently used. Three programs offered additional AMS content in their elective curricula. Experiential rotations in AMS were commonly offered, though teaching AMS in formalized interprofessional settings was rare. Curricular time constraints were identified by all programs as a barrier to enhancing AMS instruction. A course to teach AMS, a curriculum framework, and prioritization by the faculty's curriculum committee were perceived as facilitators.Conclusions: Our findings highlight potential gaps and areas of opportunity within Canadian pharmacy AMS instruction.

BACKGROUND Empirical antibiotics are not recommended for coronavirus disease 2019 (COVID-19). METHODS In this retrospective study, patients admitted to Toronto General Hospital's general internal medicine from the emergency department for COVID-19 between March 1 and August 31, 2020 were compared with those admitted for community-acquired pneumonia (CAP) in 2020 and 2019 in the same months. The primary outcome was antibiotics use pattern: prevalence and concordance with COVID-19 or CAP guidelines. The secondary outcome was antibiotic consumption in days of therapy (DOT)/100 patient-days. We extracted data from electronic medical records. We used logistic regression to model the association between disease and receipt of antibiotics, linear regression to compare DOT. RESULTS The COVID-19, CAP 2020, and CAP 2019 groups had 67, 73, and 120 patients, respectively. Median age was 71 years; 58.5% were male. Prevalence of antibiotic use was 70.2%, 97.3%, and 90.8% for COVID-19, CAP 2020, and CAP 2019, respectively. Compared with CAP 2019, the adjusted odds ratio (aOR) for receiving antibiotics was 0.23 (95% CI 0.10 to 0.53, p = 0.001) and 3.42 (95% CI 0.73 to 15.95, p = 0.117) for COVID-19 and CAP 2020, respectively. Among patients receiving antibiotics within 48 hours of admission, compared with CAP 2019, the aOR for guideline-concordant combination regimens was 2.28 (95% CI 1.08 to 4.83, p = 0.031) for COVID-19, and 1.06 (95% CI 0.55 to 2.05, p = 0.856) for CAP 2020. Difference in mean DOT/100 patient-days was -24.29 (p = 0.009) comparing COVID-19 with CAP 2019, and +28.56 (p = 0.003) comparing CAP 2020 with CAP 2019. CONCLUSIONS There are opportunities for antimicrobial stewardship to address unnecessary antibiotic use.