Shah, Aditya

Abstract Background The incidence of end-stage heart failure necessitating advanced cardiac therapy continues to increase in the United states. Implantable left ventricular assist devices (LVADs) represent an important modality that is utilized both as a bridge to heart transplant or as destination therapy. LVAD-associated infections, ranging from driveline exit site or pocket infections to endovascular infections, are a major complication with high mortality. Antibiotic prophylaxis at time of LVAD implantation is therefore an important strategy to mitigate infections. However, a clear surgical infection prophylaxis regimen and associated outcomes have not been reported. Methods We performed a single center, retrospective cohort study evaluating the impact of antimicrobial prophylaxis on risk of infection in patients who underwent LVAD implantation between February 2007 and June 2019 at Mayo Clinic. LVAD-specific and related infections were defined according to the International Society of Heart Lung Transplantation criteria. Single drug prophylaxis (SDP) included cefazolin only, vancomycin only, or cefazolin and vancomycin; multidrug (MDP) regimen includes either of the SDP regimens plus another antibiotic. We compared incidence of infection within 90-day and within one-year of implantation, as well as risk of C. difficile infections between the SDP and MDP cohorts. Results We reviewed 403 patients who received LVAD implantation (Table 1), 402 of had information on surgical prophylaxis. 307 (76%) patients received SDP and 95 patients (24%) received MDP. 14 patients developed an infection within 1 year of implantation (Table 2). There was no difference in the incidence of infections between SDP and MDP arms both at 90 days and 1-year post-implantation (p=0.11). The median time of infection since LVAD implantation was similar between SDP and MDP (p=0.37) arms. Incidence of C. difficile infection was not different between groups (p=0.10) (Table 3). Conclusion There was no significant difference in incidence or time to first infection, within 90-day and 1-year of implantation, between single- and multidrug antibiotic surgical prophylaxis regimens administered at the time of LVAD implantation. Future prospective trials are needed to develop a clear LVAD antibiotic prophylaxis protocol. Disclosures John C. O'Horo, Sr., MD, MPH, Bates college: Advisor/Consultant|MITRE corporation: Grant/Research Support|nferenec, Inc: Grant/Research Support.

Abstract In a cohort of 483 high-risk patients treated with nirmatrelvir/ritonavir for COVID-19, 2 patients (0.4%) required hospitalization by day 30. Four patients (0.8%) experienced rebound of symptoms, which were generally mild, at a median of 9 days after treatment, and all resolved without additional COVID-19–directed therapy.

Elizabethkingia species are Gram-negative bacilli that were most recently linked to a cluster of infections in the Midwestern United States from 2016 to 2017. Inappropriate empirical and directed antibiotic selection for this organism is common among providers and is an independent risk factor for mortality.

Abstract Social media has emerged as a tool to facilitate communication and dissemination of information for both patients and healthcare professionals. We describe 3 social media engagement strategies used to reach a broad and diverse audience on the topics of infectious diseases and antimicrobial stewardship, including the use of memes, a clue-based knowledge assessment quiz, and a personality quiz. We describe a novel acronym “VIRAL” to guide engaging social media strategies in healthcare, including eye catching Visuals, Interactive content, showing Respect and empathy for the audience, Adapting to new technology, and making Learning fun.

Abstract Background Elizabethkingia spp. are non-enteric, gram-negative bacilli that are ubiquitous in environment. It has recently been identified as a causative pathogen in hospital outbreaks of life-threatening bloodstream infections in the Midwestern United States. Methods Retrospective electronic medical record review was performed for patients with Elizabethkingia spp. isolated from any site between November 2011 and September 2020 at our tertiary academic medical center. Antimicrobial susceptibilities are performed using Wadsworth agar dilution method. Results Fifteen cases with Elizabethkingia spp. were included. Ten patients (66.7%) were male and fourteen (93.3%) were Caucasian. The median age was 58 years (IQR 42-67). Four patients had diabetes mellitus, with two of these having end-organ damage (nephropathy, neuropathy, or retinopathy). Five patients had a tracheostomy, two patients had a history of lung transplantation, and four patients had active malignancy at the time of diagnosis (table 1). The most common clinical syndrome was respiratory infection (n=6), followed by catheter-related bloodstream infection (CRBSI) (n=4). Three patients were considered to be asymptomatically colonized. Five patients (33.3%) died, one of which was attributable to Elizabethkingia infection. A total of 55 isolates from all sites were available from the fifteen patients. The most common site of isolation was respiratory tract (23/55, 41.8%). In total, 33 of 55 isolates had polymicrobial growth, with the highest rate occurring in respiratory tract specimens (Table 2). A total of 23 clinical isolates were included in tabulation of antimicrobial susceptibility profiles; except for aztreonam (n=13). 95.7% of Elizabethkingia isolates were susceptible to trimethoprim-sulfamethoxazole, followed by levofloxacin and piperacillin-tazobactam (87% and 73.9%, respectively). All isolates were uniformly resistant to amikacin, aztreonam, and tobramycin (Table 3). Conclusion Elizabethkingia spp. can result in respiratory, bloodstream, and sinus infections especially in patients with active malignancy and tracheostomy. Amongst tested antimicrobials, trimethoprim-sulfamethoxazole showed the most favorable susceptibility profile (Figure 1). Figure 1. AN, amikacin; ATM, aztreonam; CAZ, ceftazidime; CIP, ciprofloxacin; FEP, cefepime; GM, gentamicin; LVX, levofloxacin; MEM, meropenem; NN, tobramycin; SXT, sulfamethoxazole/trimethoprim; TZP, piperacillin/tazobactam. Disclosures All Authors: No reported disclosures

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.