Stevens, Ryan W

Abstract Objectives To compare the efficacy and safety of antibiotic lock therapy (ALT) versus catheter removal in managing central vascular catheter–associated bloodstream infection (CVC-BSI). Methods We conducted a single-centre, retrospective cohort study of adult patients treated with ALT or catheter removal for management of CVC-BSI between 2018 and 2022. The primary outcome was a composite of 90 day microbiological relapse or recurrent BSI. Secondary outcomes included 30 day mortality, CVC-associated complications and Clostridioides difficile infection (CDI). Logistic regression with propensity score-adjustment was used to evaluate differences in outcomes and identify predictors of relapse. Results During the study period, 106 participants received ALT and 181 underwent catheter removal. Patients treated with ALT received shorter courses of systemic antimicrobials (11 versus 14 days; P < 0.001) and had shorter hospital stays (4 versus 10 days; P < 0.001). Median duration of catheter salvage in patients receiving ALT was 28 days (IQR 7–80). Primary composite outcome was similar between both groups, but ALT was associated with a significantly higher risk of microbiological relapse within 90 days (20% versus 7%; adjusted odds ratio 3.93, 95% CI 1.64–9.40; P = 0.002). No significant difference in 30 day mortality, CVC-related complications or CDI was observed. CoNS BSI was an independent predictor of microbiological relapse in patients treated with ALT (OR 2.28; P = 0.05). Conclusions Although ALT offers a non-invasive catheter salvage strategy, its association with higher relapse rates, particularly in CoNS BSI, suggests catheter removal should remain the preferred approach when feasible. ALT could be considered a short-term catheter salvage strategy for pathogens with low virulence when used with close surveillance.

Abstract Objective: Patients with Opioid Use Disorder (OUD) are prone to Multidrug-Resistant Organism (MDRO) colonization and infections, thus at risk for worse outcomes during critical illness. Understanding the prevalence and predictors of MDRO infections is essential to optimize interventions and treatments. Design: Retrospective cohort study. Methods: The study evaluated the prevalence of MDRO isolation among adults with OUD admitted to an intensive care unit (ICU) between January 1, 2018, and July 31, 2023. It included adults admitted to an ICU with bacterial infections and positive cultures obtained within 48 hours of admission. Demographics, clinical traits, and MDRO isolation rates were analyzed using descriptive statistics, univariate methods, and Least Absolute Shrinkage and Selection Operator (LASSO) regression. Results: MDRO isolation occurred in 178 of 790 patients (22.5%), with methicillin-resistant Staphylococcus aureus as the most frequently isolated organism. LASSO regression identified housing insecurity (OR: 1.79, 95% CI 1.09–2.93, P = .022), no receipt of medications for OUD treatment (OR: 1.56, 95% CI 1.06–2.29, P = .023), positive hepatitis C virus (HCV) status (OR: 2.19, 95% CI 1.19–4.03, P = .012), and intravenous antibiotic use in the prior 90 days (OR: 1.04 per 24 h, 95% CI 1.01–1.07, P = .007) as significant predictors of MDRO isolation. Conclusions: The study highlights a high prevalence of MDRO isolation in critically ill OUD patients admitted for infection-related issues with positive cultures obtained within 48 hours of admission, influenced by factors like housing insecurity, no receipt of medications for OUD treatment, HCV status, and prior antibiotic use.

Abstract Objective: To retrospectively observe procalcitonin (PCT) and antibiotic ordering practices in patients hospitalized with community-acquired pneumonia (CAP). Design: Retrospective, exact matched, multicenter cohort study from October 1, 2018 – March 31, 2023. Setting: All hospitals across the Mayo Clinic Enterprise. Participants: Adult patients with CAP, identified using pneumonia diagnosis codes and receipt of systemic antibiotics with an indication of “respiratory tract infection” within 48 hours of hospitalization. Methods: PCT testing within the first 7 days of hospitalization was compared to non-PCT care (nPCT). The primary outcomes were treatment duration, antibiotic days of therapy (DOT), and length of stay (LOS). Results: 15364 patients met inclusion criteria. PCT testing occurred in 42.4% (6515/15364) of encounters, totaling 8214 PCT results. 12880 unique patient encounters were matched 1:1, 6440 in each group. Treatment duration was longer in the PCT group compared to the nPCT group (5.1 vs 4.6 days, respectively, P < 0.001). Patients in the PCT group also received more DOT (8.6 vs 7.6 DOT, P < 0.001) and had a longer LOS (6.8 vs 5.9 days, P < 0.001), respectively. There was no difference in 30-day all-cause mortality or C. difficile infection between groups. In a sensitivity analysis of nPCT patients compared to those with a peak value <0.25 ng/mL (i.e. normal result) there was no difference in treatment duration (4.6 days nPCT vs 4.7 days normal PCT, P = 0.104) or LOS (5.9 days nPCT vs 6.0 days normal PCT, P = 0.134). Conclusion: PCT testing in patients hospitalized with CAP was not associated with reduced antimicrobial utilization, LOS, or 30-day all-cause mortality.

Abstract Reducing antimicrobial exposure by limiting the duration of therapy is an effective antimicrobial stewardship strategy. In this article, we describe the impact of modification of the electronic health record to remove default durations of therapy on ambulatory antibiotic prescriptions issued from emergency departments in a large, multicenter health system.

ABSTRACT Campylobacter fetus is known to cause human disease, particularly in elderly and immunocompromised hosts. There are limited published data for antimicrobial susceptibility patterns with this organism, and no interpretive criteria are available. We reviewed antimicrobial susceptibilities of C. fetus isolates tested at a tertiary care center and reference laboratory over an 11-year period. C. fetus isolates from patients treated at Mayo Clinic and those sent as referrals for identification and susceptibility were included. Antimicrobial susceptibility testing was performed using agar dilution for ciprofloxacin, doxycycline, erythromycin, gentamicin, meropenem, and tetracycline. Geographic distribution, culture source, organism minimal inhibitory concentration (MIC) distributions, and MIC 50 and MIC 90 were examined. Excluding duplicates, 105 unique isolates were identified from 110 positive cultures. Blood cultures represented the most common source, followed by body fluids, skin and soft tissue, and central nervous system. Gentamicin and meropenem had favorable MIC 50 and MIC 90 of 1 µg/mL. Ciprofloxacin demonstrated an MIC 50 of 1 µg/mL; however, the MIC 90 was >2 µg/mL. Erythromycin demonstrated MIC 50 and MIC 90 of 2 µg/mL. Tetracycline and doxycycline were tested on a limited number of isolates and showed a wide range of MICs. Gentamicin and meropenem demonstrated favorable MICs in C. fetus isolates. These may represent therapeutic options for consideration in serious C. fetus infections, pending susceptibility results. Ciprofloxacin, which showed variable results, may be more appropriate for use only after susceptibility testing. C. fetus interpretive criteria are needed to aid clinicians in selection of both empiric and definitive therapies. IMPORTANCE Our findings contribute to the scant literature on Campylobacter fetus antimicrobial susceptibility test results. We used a reference test method of agar dilution and provide MICs for a large number of organisms and antimicrobial agents.

Abstract Background The aim of this study was to evaluate the frequency of unnecessary antibiotic prescribing for Tier 3 upper respiratory infection (URI) syndromes across the Mayo Clinic Enterprise before and after a multifaceted antimicrobial stewardship intervention, and to determine ongoing factors associated with antibiotic prescribing and repeat respiratory healthcare contact in the postintervention period. Methods This was a quasi-experimental, pre/post, retrospective cohort study from 1 January 2019 through 31 December 2022, with 12-month washout during implementation from 1 July 2020 through 30 June 2021. All outpatient encounters, adult and pediatric, from primary care, urgent care, and emergency medicine specialties with a Tier 3 URI diagnosis were included. The intervention was a multifaceted outpatient antibiotic stewardship bundle. The primary outcome was the rate of antibiotic prescribing in Tier 3 encounters. Secondary outcomes included 14-day repeat healthcare contact for respiratory indications and factors associated with persistent unnecessary prescribing. Results A total of 165 658 Tier 3 encounters, 96 125 in the preintervention and 69 533 in the postintervention period, were included. Following intervention, the prescribing rate for Tier 3 encounters decreased from 21.7% to 11.2% (P &lt; .001). Repeat 14-day respiratory healthcare contact in the no antibiotic group was lower postintervention (9.9.% vs 9.4%; P = .004). Multivariable models indicated that increasing patient age, Charlson comorbidity index, and primary diagnosis selected were the most important factors associated with persistent unnecessary antibiotic prescribing. Conclusions Outpatient antibiotic stewardship initiatives can reduce unnecessary antibiotic prescribing for Tier 3 URIs without increasing repeat respiratory healthcare contact. Advancing age and number of comorbidities remain risk factors for persistent unnecessary antibiotic prescribing.

Genotypic testing for mecA / mecC is heavily relied upon for rapid optimization of antimicrobial therapy in infections due to Staphylococcus aureus . Little is known regarding optimal reporting and/or therapy for patients demonstrating lack of genotypic evidence of mecA or mecC but phenotypic oxacillin resistance.

AbstractBackgroundItraconazole is the recommended first‐line treatment for mild‐to‐moderate blastomycosis and consolidation treatment of moderate‐to‐severe disease. Itraconazole is metabolised into three metabolites, including an active metabolite hydroxy‐itraconazole. Literature provides little evidence indicating whether therapeutic drug monitoring targets should be based on itraconazole parent compound alone or a sum of itraconazole and hydroxy‐itraconazole serum concentrations.ObjectivesThis study aims to compare clinical outcomes and adverse drug events (ADEs) of combined itraconazole and hydroxy‐itraconazole concentrations versus itraconazole parent compound alone in patients with blastomycosis.Patients/MethodsThis study was a retrospective cohort review of patients ≥18 years with probable or proven Blastomyces infection who received itraconazole with at least one documented serum itraconazole concentration. The primary outcome was rate of partial or complete treatment response across three patient groups: (1) Itraconazole parent compound >1.0 mcg/ml (parent), (2) parent compound <1.0 mcg/ml, but a combined itraconazole and hydroxy‐itraconazole >1.0 mcg/ml (combined) and (3) failure to achieve a combined or parent concentration >1.0 mcg/ml (subtherapeutic) for >75% of the duration of itraconazole therapy.ResultsA total of 80 patients were included (parent = 32, combined = 36, subtherapeutic = 12). No statistically significant difference was observed for rate of partial or complete treatment response (97% parent vs 94% combined, p = .99). Significantly higher mortality due to blastomycosis was observed in patients in the subtherapeutic group (0% parent vs 3% combined vs 25% subtherapeutic, p = .01).ConclusionsThis study supports an itraconazole therapeutic target combining itraconazole and hydroxy‐itraconazole >1.0 mcg/ml for blastomycosis treatment.

Abstract Objectives Despite low rates of bacterial coinfection in patients admitted with COVID-19, antimicrobials are frequently prescribed. Our primary objective was to evaluate antimicrobial prescribing over time in patients admitted with COVID-19. The secondary objectives were to evaluate the role of ID providers in antimicrobial utilization, describe the rate of confirmed bacterial infection and determine factors associated with empirical antimicrobial prescribing in COVID-19. Materials and methods Retrospective review was performed for adult patients admitted to a tertiary care centre with COVID-19 between 1 March 2020 and 30 November 2020. Patient demographics, disease severity, risk factors for severe disease, clinical outcomes, antimicrobial prescribing and respiratory microbiological testing were collected and analysed. Prescribing trends were evaluated by month, and factors contributing to prescribing were established using univariate and multivariable analysis. Results Antibiotics were prescribed during admission in 37.9% of the study cohort, with 85.1% of patients who received antibiotics having therapy initiated within 48 h of admission. Antibiotic prescribing incidence increased with disease. Over the study period, antimicrobial prescribing rates decreased by 8.7% per month. Multivariable analysis found ICU admission, obtainment of procalcitonin values, intubation, heart failure, haemodialysis and nursing home residence were associated with empirical antimicrobial prescribing. Conclusions Unnecessary antimicrobial prescribing in patients with viral syndromes like COVID-19 continues to represent an area of concern. Antimicrobial stewardship efforts during COVID-19 should consider patient-specific factors associated with antibiotic prescribing. Recognition of such factors, in combination with application of well-established antimicrobial stewardship tactics, may serve to impact antimicrobial prescribing trends, even as patient volumes rise.