Opportunities For Stewardship Research Articles

Limited utility of Epstein-Barr virus (EBV) surveillance for predicting post-transplant lymphoproliferative disorders in adult EBV seropositive lung transplant recipients.

EBV DNAemia surveillance, with reduction of immunosuppression at certain viral load (VL) thresholds, is a common practice for mitigating progression from EBV DNAemia to post-transplant lymphoproliferative disorder (PTLD) in lung transplant recipients (LTRs). The utility of EBV surveillance in adult EBV seropositive LTRs is unknown. We performed a retrospective cohort study of EBV seropositive adult LTRs who underwent lung transplant between 1/1/19 and 12/31/20 and received whole blood (WB) EBV PCR surveillance. We compared peak WB EBV VLs among 3 groups: 1) asymptomatic LTRs who developed PTLD, before PTLD was clinically suspected, 2) LTRs who developed PTLD, after PTLD was clinically suspected, and 3) LTRs who did not develop PTLD. We calculated the positive predictive value (PPV) of moderate-grade DNAemia (2840 to 11,360 IU/mL) and high-grade DNAemia (≥ 11,360 IU/mL) for identifying active or future PTLD. Six (2.6 %) of 229 LTRs developed PTLD. Among LTRs who developed PTLD, median peak EBV VL was significantly higher after PTLD was suspected than before clinical signs of PTLD were present (16,004 IU/mL vs. ≤568 IU/mL, p = 0.016). Median peak EBV VLs were similar between asymptomatic LTRs who later developed PTLD and LTRs who did not develop PTLD (median peak EBV VL ≤568 IU/mL vs. ≤568 IU/mL, p = 0.62). The PPVs for moderate- and high-grade DNAemia were 14.7 % and 33.3 %, respectively. EBV surveillance did not accurately identify EBV seropositive LTRs at risk for progressing to PTLD. EBV PCR testing in asymptomatic EBV seropositive transplant recipients may represent an opportunity for diagnostic stewardship.

P-304. Vancomycin Resistant Enterococcus faecium Minimum Inhibitory Concentration Trends from 2019-2024: Have We Killed Daptomycin?

Abstract Background Vancomycin resistant Enterococcus faecium (VRE) has been categorized as a bacterium with serious antibiotic resistance threats in the United States, where daptomycin (DAP) has been a drug of choice. In 2019, the Clinical and Laboratory Standard Institute M100S 29th edition revised DAP breakpoints for VRE to susceptible dose dependent with a minimum inhibitory concentration (MIC) of ≤ 4 mcg/mL. Higher MICs are associated with resistant mechanisms and increased microbiological failure is seen with MICs of 3-4 mcg/L. Linezolid (LZD) is an VRE treatment option that has favorable clinical outcomes and microbiological eradication with less emerging resistance, but LZD use can be controversial due to outdated dogma of using a bacteriostatic agent. The purpose of this study was to evaluate MIC trends for DAP and LZD in patients with VRE bloodstream infections (BSI) at a large academic medical center. Bloodstream Infection VRE Comment within the Electronic Health Record: Current and Proposed Methods IRB-exempt, cross-sectional study of adult patients with VRE BSI and a healthcare encounter from 2019-2024 at a 5-hospital health-system in southeast Michigan. Patients were identified using Microsoft SQL Server queries based on microbiology results. The primary outcome was the proportion of patients with a DAP MIC > 1 mcg/mL with corresponding LZD MICs. Our health-system currently recommends DAP or LZD for VRE BSI until susceptibilities are available via blood culture comment (Figure 1). Measured MICs of daptomycin and linezolid, 2019-2024 *Daptomycin MIC Breakpoints: Susceptible Dose Dependent = ≤ 4 mcg/mL, Resistant = ≥8 mcg/mL. Linezolid MIC Breakpoints: Susceptible = ≤4 mcg/mL, Intermediate = 4 mcg/L, Resistant ≥8 mcg/L Results 555 LZD and 491 DAP unique MICs from VRE BSI were evaluated. Figure 2 represents the average MICs by month and year for DAP and LZD from 2019-2024. The majority of DAP MICs were measured at 2 (30%), 3 (56%), and 4 (18%) mcg/mL. DAP MIC50 and MIC90 values were calculated at 3 mcg/mL and 4 mcg/mL, respectively. 98.7% of LZD MICs were measured at ≤2 mcg/mL (Table 1). LZD MIC50 and MIC90 values were calculated at 2 mcg/mL. Average daptomycin and linezolid MIC per month and year, 2019-2024 Conclusion While the VRE MICs for DAP are increasing, LZD has remained stable over the past 5 years. A possible stewardship opportunity is to modify the health-system's current blood culture comment could suggest LZD as the VRE drug of choice and high-dose DAP as an alternative in patients until susceptibilities are available (Figure 1). Disclosures Rachel M. Kenney, PharmD, BCIDP, Medtronic Inc: Spouse is an employee, stockholder

P-1130. Association Between Procalcitonin, CRP Values and Antibiotic Use in Children with Community-Acquired Pneumonia

Abstract Background Procalcitonin (PCT) and C-reactive protein (CRP) are biomarkers used to help identify bacterial etiologies of community-acquired pneumonia (CAP) as it is often challenging to differentiate between viral and bacterial causes. This study evaluated the association between PCT, CRP values, and antibiotic initiation in children with CAP. Methods This single-center, retrospective study evaluated patients aged 6 weeks to 19 years who presented with acute signs or symptoms of lower respiratory tract illness from December 1 2022 to December 31, 2023. Enrolled were patients with PCT and CRP values obtained within the first 24 hours of their hospital visit. The primary outcome was the initiation of antibiotics within the first 36 hours of the encounter. Patients with tracheostomy, prior antibiotic use, aspiration, or hospital-acquired pneumonia were excluded. PCT and CRP were categorized into 4 groups correlating to values suggesting very unlikely, unlikely, likely, and very likely bacterial infection. Bivariate and logistic regression analyses were conducted. Patients outcomes (admission to PICU, pleural effusion and need for intubation) by Procalcitonin levels No association was seen between patient outcomes and procalcitonin levels. Results The study included 193 patients, 83% of whom received antibiotics. Among these, 11% had a PCT < 0.1 ng/ml and 8% had a CRP < 0.3 mg/dl. Third-generation cephalosporins (3GC) were the most commonly used antibiotic (n=139, 72%). PCT and CRP values were strongly associated with initiation of antibiotics (p< 0.0001). CRP >10 mg/dl had a 14.8% increase in odds of receiving antibiotics (95% confidence interval [CI]: 2.8, 78.2), and PCT >0.5 ng/mL had a 6.9% increase in odds (95%CI: 2.3, 21.2) compared to the reference category (PCT < 0.3 ng/mL and CRP < 0.3 mg/dL respectively). A CRP of ≥10mg/dL and PCT of >0.5 ng/mL were associated with using 3GC and methicillin-resistant Staphylococcus aureus (MRSA) coverage. Days of hospitalization, pleural effusion, intubation, and PICU admission were not associated with PCT and CRP values. Conclusion Most subjects received antibiotics including those with normal PCT and CRP levels, suggesting a possible overuse of antibiotics. Higher levels of PCT and CRP were associated with antibiotic initiation and usage of broad-spectrum antibiotics, identifying opportunities for antibiotic stewardship. Disclosures All Authors: No reported disclosures

P-1711. Evaluation of Microbiology and Antibiotic Prescribing Behavior of Foot Puncture Wound Infection: An Opportunity for Antimicrobial Stewardship

Abstract Background The primary pathogen(s) of soft tissue infections, including those of the foot, are β-hemolytic Streptococci and Staphylococcus aureus (SA). Pseudomonas aeruginosa (PsA) has been implicated as a cause of foot infections after sustaining a nail puncture wound through a sneaker, historically leading to recommendations for prescribing empiric anti-PsA antibiotics (abx). At Olive View-UCLA Medical Center (Sylmar, CA), we evaluated the microbiology and empiric abx prescribing behavior of foot puncture wound infections. Methods Retrospective chart review on adults (≥ 18 years) admitted with an ICD-10 code for puncture wound from January 1, 2017 to December 31, 2023. Inclusion criteria included foot infection after sustaining nail, screw, staple, thumbtack, or razorblade puncture. Non-foot puncture wound and puncture from an object other than those listed in the inclusion criteria were excluded. Anti-PsA abx was defined as either piperacillin-tazobactam, cefepime, ceftazidime, or ciprofloxacin. Results 58 cases were reviewed and 45 met inclusion criteria. The majority of puncture wound was due to nail (n=34, 76%) followed by screw (n=6, 13%) [Table 1]. Empiric anti-PsA abx was prescribed in the emergency department in 41/45 (91%); empiric anti-PsA abx was prescribed or continued by the admitting physician in 19/45 (42%). Anti-PsA abx average days of therapy (DOT) was 2 days [IQR 2-3]. Wound culture was obtained in 44 cases, with no isolation of PsA. The majority of pathogens consisted of methicillin-susceptible SA (26/44 cases, 59%) and Streptococcus agalactiae (19/44, 43%) [Figure 1]. Infection involving both SA and Streptococcus spp. was seen in 15 cases (34%). Subsequent foot infection with PsA within 30 days of puncture wound infection did not occur in any cases. Conclusion PsA was not isolated in any cases of foot puncture wound infections, although the majority were started on an empiric anti-PsA abx, per historical recommendations. The primary pathogen(s) were SA and/or Streptococcus spp. Therefore, current evidence shows that PsA is not a significant pathogen of foot puncture wound infections, and this represents an opportunity for antimicrobial stewardship services to prioritize empiric abx against SA and Streptococcus spp., and not against PsA, for this infection type. Disclosures All Authors: No reported disclosures

P-1697. Antibiotic prescribing patterns among outpatients with acute sinusitis in Michigan

Abstract Background Acute sinusitis is a common presenting illness in the outpatient setting. While antibiotics are often prescribed, they are infrequently indicated in adults. Limited data are available assessing prescribing practices. This study aimed to describe statewide antibiotic prescribing for sinusitis among outpatients in Michigan to identify opportunities for antimicrobial stewardship (AMS) interventions for clinical and public health partners.Figure 1:Outpatient antibiotic prescribing practices for sinusitis in Michigan, 2019-2021 Methods The Michigan Department of Health and Human Services received medical and pharmacy claims data from IQVIA from 2019 – 2021. Outpatients with medical claims data with a diagnosis code (J01) for acute sinusitis were included, while those with concomitant upper respiratory tract, urinary tract, or skin and soft tissue infectious diagnoses codes were excluded. Patients with a J01 diagnosis in their medical claims were linked to their corresponding antibiotic prescriptions from pharmacy claims based on patient identifier, prescription date, ordering provider, and antibiotic utilized. Prescribing patterns of antibiotics (frequency of prescription, agent selection, and duration of therapy) were analyzed for the overall cohort and stratified by place of service, provider specialty, year of service, patient zip code, age, and gender.Figure 2:Frequency of acute sinusitis encounters with an antibiotic prescription by 3-digit zip code Results From 2019 - 2021 there were 560,255 unique encounters from 424,684 patients for acute sinusitis in Michigan within the IQVIA medical claims database. Antibiotics were prescribed in 66% of these cases. Amoxicillin-clavulanic acid (33%), azithromycin (25%), and amoxicillin (20%) were the most prescribed antibiotics, with median durations of 10 days, 5 days, and 10 days, respectively. The prescription patterns among different groups are shown in Figures 1 and 2. Prescription rates, agent selection, and durations were remarkably consistent across calendar year, age group, sex, place of service, provider specialty, and patient zip code. Conclusion The study revealed a concerning pattern of high antibiotic prescription rates, inappropriate antibiotic selection, and prolonged durations of therapy in the outpatient management of acute sinusitis in Michigan. These findings were consistent in all subgroups analyzed and emphasize the need to prioritize outpatient AMS practices for sinusitis. Disclosures jason M. Pogue, PharmD, Entasis: Advisor/Consultant|GSK: Advisor/Consultant|Melinta: Advisor/Consultant|Melinta: Grant/Research Support|Merck: Advisor/Consultant|Merck: Grant/Research Support|Shionogi: Advisor/Consultant|Shionogi: Grant/Research Support|Venatorx: Advisor/Consultant

P-1602. Urinalysis with Reflex Urine Culture to Screen for Asymptomatic Bacteriuria in Kidney Transplant Recipients: Opportunities for Diagnostic and Antimicrobial Stewardship

Abstract Background Routine screening and treatment of asymptomatic bacteriuria (ASB) in kidney transplant recipients (KTRs) beyond 1 month post-transplant are no longer recommended due to potential harm. Evidence from clinical trials demonstrated that screening and treatment of ASB does not reduce the risk of pyelonephritis, acute rejection or long-term graft impairment. However, ASB screening post-transplant remains a common practice. This study characterizes our institution’s current practice with associated testing costs regarding screening and treatment for ASB for the first 3 months post-transplant. Estimated annual cost of urinalysis and urine culture in kidney transplant recipients at University of Washington Medical Center The estimated annual cost of urinalysis and urine culture was calculated based on the testing cost in 50 patients for the first three months post-transplant, assuming a total of 200 patients receive kidney transplant annually at our institution. The average cost of urinalysis and urine culture per person for the first three months after transplant was $1511.47. This estimate does not take into account urinalyses and urine cultures beyond three months. The estimated cost savings assume that urinalysis with reflex urine cultures is de-implemented and urine cultures are ordered only for symptomatic patients. This estimate does not consider the potential reduction in the number of urine cultures based on negative urinalysis in symptomatic patients. Methods We conducted a retrospective review of electronic records for 50 consecutive adult KTRs at University of Washington Medical Center between January and April 2023. Data collected included demographics, laboratory results, microbiological findings, antibiotic usage for 3 months post-transplant, and rejection within 1 year post-transplant. A chart review by 2 independent reviewers was performed to determine whether each positive urine culture (UCx) represents ASB or urinary tract infection (UTI). Results Among 50 KTRs, a total of 709 urinalyses (UA, mean 14.2 per person) and 263 UCx (mean 5.2 per person) were performed within 3 months post-transplant. Reflex from UA accounted for 95.4% of UCxs (251 out of 263), and 35.4% of UA were reflexed to UCx (251 out of 709). Of 40 positive urine cultures, 6 were considered symptomatic UTI and 34 as ASB. The mean cost of routine screening with UA with reflex UCx for the first 3 months after transplant was $1511.47. The estimated annual cost based on 200 KTRs per year exceeds $300,000 (Figure 1). All 6 UTI episodes and 5 of 34 ASB episodes (14.7%) were treated with antibiotics. Acute rejection by 1 year post-transplant occurred in 2 out of 50 patients (4%), but neither had ASB nor UTI within 3 months of transplant. Conclusion Routine UA with reflex UCx during post-transplant clinic visits accounted for the majority of cases of ASB within the first 3 months post-transplant. Decreasing the ordering of UA-guided reflexive UCx has the potential to reduce the identification of ASB and associated costs. Disclosures Ajit P. Limaye, MD, GSK: Advisor/Consultant|Memo: Advisor/Consultant|merck: Advisor/Consultant|merck: Grant/Research Support|Moderna: Advisor/Consultant|NobelPharma: DSMB member|Novartis: DSMB member|syneos: DSMB member

P-1630. Retrospective Evaluation of Urinalysis to Urine Culture Reflex Frequency and Criteria

Abstract Background Patients with asymptomatic bacteriuria (ASB) often receive inappropriate treatment despite IDSA guidelines recommendation against antimicrobial treatment of ASB in the majority of adults. Emphasis on laboratory results rather than symptoms often triggers ASB treatment. At our institution, a urinalysis (UA) positive for ≥ 1 criteria ( > 10 WBC / HPF, leukocyte esterase (LE), or nitrites) results in a reflex to urine culture (UC). The objective of this study was to assess the frequency of UC reflex orders and the specific criteria driving reflex to identify opportunities for diagnostic stewardship and treatment guidance. Methods Retrospective data were provided by the Best Practices Integrated Informatics Core for hospitalized adults with an ICD-10 diagnosis of urinary tract infection (UTI) or related condition and a UA +/- UC order within 72 hours between 11/1/2022 and 4/30/2023 at a large academic medical center. Number and frequency of UA to UC reflex and UA criteria driving UC reflex were assessed. LE results were considered positive if “moderate” or “large” and negative if “small”, “trace”, or “negative”. RStudio (version 2023.06.0) was utilized to perform logistic regression analyses with univariable and multivariable models to calculate odds ratios for reflex to UC. Results This cohort comprised 2007 unique patients with a total of 3193 UA orders. Of 3193 UA orders, 1016 (31.8%) reflexed to UC. The highest frequency of UC reflex was with 2 of 3 UA criteria positive (43.2%), followed by 1 of 3 criteria positive (39.0%), then 3 of 3 criteria positive (9.5%), and lastly, the remaining 8.3% of patients had UC reflexed for unknown reasons that need to be further investigated (Table 1). All 3 criteria when positive had increased odds for triggering UC reflex (Table 2). In the multivariable model, LE had the highest odds of triggering UC reflex (OR 1.73, 95% CI: 1.68-1.78). Conclusion Despite frequent UA orders, only 31.8% reflexed to UC. Following these results, retrospective chart review will be completed to characterize patients with symptomatic UTI vs. ASB based on review of progress notes. These data will identify whether certain UA criteria are more highly correlated with symptomatic UTI and will help inform the need for revised UA and UC diagnostics. Disclosures Elizabeth B. Hirsch, PharmD, FCCP, FIDSA, GSK: Advisor/Consultant|GSK: Honoraria

P-821. Invasive Streptococcus pyogenes Infections: Is Anti-toxin Therapy Necessary?

Abstract Background Invasive Streptococcus pyogenes or group A Streptococcus (GAS) carries a high morbidity and mortality rate. In addition to penicillin, adjunct anti-toxin therapy (AT) with linezolid or clindamycin is the standard of care. Although the use of AT is supported by in vitro data and observational studies, there are limited conclusive data supporting its efficacy in reducing GAS mortality. Our study aimed to compare clinical outcomes of patients receiving AT versus those who did not. Methods This was a retrospective cohort study of hospitalized patients with positive blood cultures for GAS at our five-hospital system from June 2013 to August 2023. Patients were identified through Microsoft SQL Server. Patients who received AT therapy for > 48 hours were defined as the AT group; the control group did not receive AT therapy. Patients who received AT for < 48 hours were excluded. Collected variables included demographics, infection & microbiological characteristics, and clinical outcomes. Data was analyzed using SPSS. Results 265 patients were included in the study of whom 179 (68%) received AT (Table 1). About half were female, and the median age was 58 years. Comorbidities were overall similar between the two groups. Persons who inject drugs or with chronic hepatitis C were more common in the control group. Abscess/cellulitis was the most common clinical syndrome in both groups. Shock requiring vasopressors, need for dialysis and mechanical ventilation, and toxic shock syndrome were prevalent in the AT group. There was no difference in the duration of bacteremia, clindamycin resistance, and management between the two groups except for receipt of intravenous immunoglobulin (IVIG), which was more common in the AT group (Table 2). Outcomes, including length of stay, readmission for infection-related complications, and 30-day mortality, were similar between the two groups. Conclusion Utilization of AT for invasive GAS infections correlated with severity of illness, but clinical outcomes did not significantly differ between patients receiving AT and those who did not, suggesting a potential opportunity for antimicrobial stewardship. Further research is needed to determine whether AT should be reserved for patients with select infectious syndromes Disclosures Rachel M. Kenney, PharmD, BCIDP, Medtronic Inc: Spouse is an employee, stockholder

500. Finding AP Gap: An Assessment of Antibiotic Use in Acute Pancreatitis

Abstract Background American Gastroenterology Association (AGA) guidelines recommend against the use of prophylactic antibiotics for acute pancreatitis. Antibiotic therapy is recommended for culture-proven infection in pancreatic necrosis or when infection is strongly suspected (e.g. gas in collection, bacteremia, sepsis, or clinical deterioration). Carbapenems, metronidazole, third or fourth generation cephalosporins, and fluoroquinolones are preferred agents. Data to support use of piperacillin/tazobactam also exists. There is limited data evaluating adherence to these guidelines.Table 1:Baseline Characteristics Methods This was a retrospective cohort study of adult patients hospitalized in The MetroHealth System from January 1, 2021 through December 31, 2022 who received antibiotics for a diagnosis of acute pancreatitis. Exclusion criteria included multiple indications for antibiotics or antibiotics given in the emergency department (ED) only. Only the first hospitalization per patient was included. The primary outcome was the percentage of encounters for which antibiotic use was adherent to AGA guidelines. Secondary outcomes included descriptions of antibiotic choice/duration and microbiologic results.Table 2:Antibiotic Use Results Of 538 inpatient encounters with a diagnosis of acute pancreatitis, antibiotics for any indication were prescribed in 322 (60%). For the 83 unique patient encounters meeting inclusion criteria, antibiotic use was not adherent to AGA guidelines in 49 (59%). Table 1 compares characteristics of patients in whom antibiotic therapy was adherent vs non-adherent. Carbapenems, piperacillin/tazobactam, cephalosporins, and vancomycin were prescribed for pancreatitis during 42%, 51%, 41%, and 25% of encounters respectively (table 2). The average duration of antibiotics for all study patients was 8.5 days. Microbiologic testing was performed in 64 (77%) patients with no MRSA isolated in any cultures (Table 3).Table 3:Microbiologic Results Conclusion Antibiotic use in more than half of patients was not adherent to AGA guidelines. Carbapenems, piperacillin/tazobactam, and cephalosporins were commonly used. Vancomycin was often used, although no MRSA was isolated. Significant opportunities for antimicrobial stewardship for acute pancreatitis exist. Disclosures All Authors: No reported disclosures

P-1718. Use of Collaboration to Harmonize Antimicrobial Registry Measure (CHARM) to Assess Antibiotic Prescribing in Dental Practices

Abstract Background Dentists account for 10% of all antibiotic prescriptions in the United States. Limited data exist describing antibiotic use in dental practices; however, it appears that many antibiotics may not be warranted or consistent with treatment guidelines.1,2,3 Of particular concern is the unwarranted use of clindamycin. No standardized methods exist for gathering data and assessing the concordance of use related to antibiotic use in dental practices. Objectives Describe patterns of antibiotic prescribing in dental clinics within the CHARM network. Identify areas for stewardship intervention within dental practices. top 5 antibiotic prescription in dental clinics name of antibiotic, the number of prescriptions, percentages, and average duration Methods Dental practices were identified from 5 dental clinics that participate in CHARM. The CHARM database is a registry containing data collected from the electronic medical records of partnering health systems about outpatient antibiotic prescribing. Episodes of antibiotic prescribing were identified in dental clinics and extracted between January 2022 to June 2023. Data collected included the ICD-10 code, antibiotic, and regimen used. When a diagnosis was provided, the appropriateness of antibiotic selection was assessed in concordance with guidelines. The most common antibiotics and diagnoses were identified. Results 4,028 antibiotic prescriptions were written by 42 prescribers in 5 dental clinics. The most prescribed antibiotics were amoxicillin (n=2,400; 59.6%), penicillin (n=700;17.3%), and clindamycin (n=400;9.9%). The average length of therapy was 7.0, 8.2, and 6.9 days for amoxicillin, penicillin, and clindamycin, respectively. ICD-10 codes were recorded for 1,722 (43%) prescriptions. No indication/diagnosis was provided for 2,278 (57%) antibiotic prescriptions. While many prescriptions were not linked to any diagnosis (n=2,300; 57.1%), the most common diagnosis codes were general dental exam (n=1,400; 34.8%) and general dental infection (n=300; 7.4%). Conclusion For visits where the dentist prescribed antibiotics, clindamycin was prescribed about 10% of the time. Clindamycin is no longer recommended for use in most procedures that dentists manage.4 Reducing clindamycin use in dental practices represents a stewardship opportunity in dental practices. Disclosures Minji Sohn, PhD, Emergent BioSolutions, Inc.: Grant/Research Support

P-1682. Evaluation of Antibiotic Prescribing Practices for Pediatric Acute Otitis Media and Community-Acquired Pneumonia in an Emergency Department

Abstract Background Acute otitis media (AOM) and community-acquired pneumonia (CAP) are common reasons for antibiotic prescriptions in children. As a result, antimicrobial stewardship efforts ensuring evidence-informed antibiotic prescriptions may be impactful. The objective of this study was to assess whether antibiotic prescriptions for AOM and CAP in a pediatric emergency department (ED) are consistent with current guidelines, and to identify opportunities for improvement. Duration of antibiotics prescribed for acute otitis media Bar graph depicting prescribed durations of therapy for acute otitis media, Prescriptions consistent with current guideline recommendations are in blue, while those that aren’t are in orange. Guidelines advise 10 days, rather than 5 days, of antibiotic therapy for children <2, perforated otitis media, treatment failure and recurrent otitis media. Methods We conducted a retrospective review of outpatient antibiotic prescriptions for AOM and CAP in the ED of a pediatric hospital from September 2022 to September 2023. Patients ages 0 – 18 years discharged from the ED with a diagnosis of AOM or CAP were identified using the electronic medical record system. Exclusion criteria included absence of a new antibiotic prescription, concomitant infections requiring antibiotic treatment, hospital admission, and patients with immunocompromising conditions or medications. Prescriptions were considered consistent with guidelines if they followed the Canadian Paediatric Society recommendations. Descriptive statistics were used for analysis. Duration of antibiotics prescribed for community-acquired pneumonia Bar graph depicting prescribed durations of therapy for community-acquired pneumonia. Prescriptions consistent with current guideline recommendations are in blue, while those that aren’t are in orange. Results A total of 1143 and 765 cases of AOM and CAP were included, respectively. Of the prescriptions for AOM, 688 (60%) were consistent with current guidelines. The 454 prescriptions that were not guideline-consistent were due to duration (n=281, 62%, Figure 1), dosing interval (n=142, 31%), antibiotic selection (n=74, 16%), and dose (n=38, 8.4%). Deferred prescriptions were provided to 177 (16%) patients; an additional 139 (12%) were eligible, but prescribed treatment. For CAP, 146 (19%) prescriptions were consistent with current guidelines. Of the 618 prescriptions that were not consistent, the majority were due to duration (n=576, 92%, Figure 2), dosing interval (n=134, 22%), antibiotic selection (n=38, 6%) and dose (n=14, 2%). Conclusion A significant number of patients with AOM (40%) and CAP (79%) were given antibiotic prescriptions that were not consistent with current guideline recommendations, with the most common reason being prolonged duration. This identifies an important antimicrobial stewardship opportunity in the ED and likely other outpatient settings. Disclosures Kathryn E. Timberlake, PharmD, Avir Pharma: Advisor/Consultant|Sanofi: Honoraria|Wolters Kluwer: Advisor/Consultant

P-1617. Clinical and microbiologic outcomes associated with implementation of MALDI-TOF on patients with anerobic, fungal, and non-lactose fermenting specimens

Abstract Background MALDI-TOF is a rapid-diagnostic technology that improves the speed and accuracy of organism identification. Using it to identify resistant pathogens and fastidious organisms is a high impact diagnostic stewardship opportunity. This study aims to evaluate its effect on the management of infections caused by non-lactose fermenting (NLF) Gram-negative rods (GNRs), anaerobes, and yeast from sterile sites.Figure 1.Screening Process Methods This was a single center, quasi-experimental study of patients with NLF GNRs in respiratory specimens and anaerobes and/or yeast from sterile sites before and after the implementation of MALDI-TOF from 2021-2023. There were no changes in antimicrobial stewardship culture review or audit and feedback processes during the study period. The primary outcome was time to organism identification. Secondary endpoints were time to antimicrobial adjustment, inpatient antibiotic duration, and in-hospital mortality. Categorical descriptive data was expressed as percentages and as median/interquartile range (IQR) if continuous. Chi-squared/Fisher’s Exact test and Mann-Whitney-U were used as appropriate to compare endpoints between groups.Table 1.Patient characteristics and Secondary Endpoints by MALDI-TOF Identified Organism Results Of 225 patients screened, 108 were included (Figure 1). The median Charlson score was 3 (1-5). The overall length of stay was 30 (13-54) days; 75 (70%) patients had an ICU stay with a median ICU length of stay of 17 (4-31) days. The most common organisms identified were Pseudomonas aeruginosa, Bacteroides spp, Candida albicans, and Nakaseomyces glabratus (formerly C. glabrata) (Figure 2). Time from Gram-stain to organism identification was reduced from 77 (41-119) hours to 41 (26-56) hours (p< 0.001) (Table 1). Time to antimicrobial adjustment and inpatient duration of antibiotics were not different between pre- and post- implementation of MALDI-TOF for infections caused by anaerobic and NLF GNRs but was reduced in patients with yeast in sterile sites. There was no difference in in-hospital mortality.Figure 2.Percentages of Organisms Identified by MALDI-TOF Conclusion Implementation of MALDI-TOF for identification of these organisms improved culture processing turn-around time, antimicrobial optimization, particularly for yeast, and stewardship efforts at our institution. Disclosures Daniel Diekema, MD, MS, D(ABMM), Affinity Biosensors: Grant/Research Support|bioMerieux, Inc: Grant/Research Support

P-1582. Comparing Contamination Rates in Single-Site vs Multi-Site Blood Culture Sampling

Abstract Background The utility of blood cultures relies on optimal sampling - two samples obtained from separate sites at different times. We noted repeated instances where, according to the electronic medical record (EMR), 2 sets of blood cultures were obtained in the emergency department (ED) with identical time stamps. When these cultures, presumed to be from a single site, return positive for commensal organisms in both sets, treatment might be initiated for a probable contaminant. This study aimed to compare the recovery rate of commensal organisms in both sets of blood cultures obtained from presumed single-site sampling (SSS) versus multi-site sampling (MSS). Methods This is a retrospective analysis utilizing data from microbiology and hospital administrative databases. The incidence rates of blood culture contaminants in patients who had two sets of blood cultures drawn with an identical time stamp for both sets (aka SSS) and in patients who had different time stamps within 1 hour of each other for each set (aka MSS) were compared. Rates from ED and selected non-ED inpatient locations were also compared. Results There were 1500 positive blood cultures from 720 patients, and 385 patients had 2 sets of blood cultures drawn with at least 1 positive culture for a commensal pathogen (Table). 312/385 patients (81.0%) had samples obtained via SSS and 73 (19.0%) via MSS. Of the 312 SSS patients, 99 (31.7%) had 2/2 sets positive for a commensal, while 15 of 73 MSS patients (20.5%) had 2/2 sets positive for a commensal (p=0.06). In the ED, 251 patients had samples obtained via SSS and 55 via MSS. 84/251 SSS patients (33.4%) had 2/2 sets positive for a commensal, while 12/55 MSS patients (21.8%) had 2/2 sets positive for a commensal (p=0.09). Conclusion Blood cultures obtained via SSS had higher rates of 2/2 set positivity for a commensal as compared to cultures obtained via MSS; however, this study was underpowered to demonstrate statistical significance. Other limitations include the assumption that EMR time stamp for collection of blood cultures accurately represents blood culture collection time. Diagnostic stewardship opportunities include potential EMR modifications and/or additional training related to documentation of timing of blood culture collection. Disclosures Melvin P. Weinstein, MD, Helixbind: Advisor/Consultant|Safeguard Biosystems: Advisor/Consultant|Selux Diagnostics: Advisor/Consultant Keith S. Kaye, MD, MPH, Allecra: Advisor/Consultant|CARB-X: Advisor/Consultant|GSK: Advisor/Consultant|Merck: Advisor/Consultant|Shionogi: Advisor/Consultant|Spero: Advisor/Consultant

Improving UTI Diagnostics in Oncology: Reliability of Reflex Urine Culture in Immunosuppressed Neutropenic and Non-neutropenic Cancer Patients.

Urinary tract infections are prone to overdiagnosis, and reflex urine culture protocols offer a valuable opportunity for diagnostic stewardship in this arena. However, there is no recommended standard testing approach. Cancer patients are often excluded from reflex urine culture protocols, especially if severely immunosuppressed or neutropenic. The aim of this study was to evaluate the performance characteristics of urine screening studies, including dipstick urinalysis for nitrite and leukocyte esterase and urine microscopy for white blood cell count, to detect significant pathogen growth. A retrospective study of 58,098 urine cultures with a paired dipstick urinalysis with or without urine microscopy was performed at Memorial Sloan Kettering Cancer Center in New York City, evaluating data from January 1, 2018, to December 31, 2020. A dipstick urinalysis was considered negative only if leukocyte esterase and nitrite were undetected. A negative dipstick urinalysis had a negative predictive value (NPV) of 98% for clinically significant bacteriuria in voided urine, and 95% for catheterized urine. Notably, a negative urine dipstick test screen maintained a high NPV among patients with neutropenia and in those with antibiotic exposure before testing. Finally, the presence of pyuria ≥10 white blood cells per high power field on urine microscopy offered negligible incremental diagnostic benefit in samples with a negative dipstick urinalysis. Reflex urine culture protocols contingent upon a screening dipstick urinalysis are a safe and effective platform for diagnostic stewardship in patients with cancer including those with neutropenia.

Adenoviral Pneumonia Outbreak in Immunocompetent Adults-A Missed Antimicrobial Stewardship Opportunity?

Background/Objectives: While the concept of viral community-acquired pneumonia (CAP) changed with COVID-19, the role of non-influenza viruses as a cause of CAP is less clear. The aim of this study was to describe the clinical course, risk factors, inflammatory profiles, antibiotic use, outcomes and complications of adenoviral (AdV) CAP. Methods: A prospective, non-interventional, observational cohort study included consecutively hospitalized immunocompetent adult patients with AdV CAP during an 18-month period. Clinical and laboratory data, including lymphocyte subpopulations and serum cytokine profiles were collected and correlated to clinical outcomes. Results: Fifty-eight patients with AdV CAP were included; 81% were males, with a median age of 33 (IQR 28-41) years and 62% without any comorbidities. All patients initially had high-grade fever for a median duration of 6 (5-7) days and respiratory symptoms. Increased CRP and procalcitonin, lymphopenia, mild thrombocytopenia and liver injury were frequent. Radiographic findings mimicked bacterial pneumonia (83% had unilateral involvement). Twenty-two patients (38%) had criteria for severe CAP, and these patients had higher procalcitonin, NLR, AST, ALT, LDH and CK, and lower T-lymphocyte CD4+ count. In comparison to influenza and bacterial CAP, patients with AdV had higher serum IL-2, IL-1β, IL-8, IL-10, CXCL10 and MCP-1, and lower TGF-β1 concentration. Thirteen patients required low-flow oxygen therapy, and 13 advanced respiratory support. Complications occurred in 29%, with one fatal outcome. While all patients received empirical antibiotic therapy, after AdV detection it was stopped in 21%, although only one patient had detected a possible bacterial coinfection. Conclusions: Since AdV CAP in immunocompetent patients is clinically and radiologically indistinguishable from bacterial CAP, it is associated with prolonged clinical course and lack of clinical response to antibiotics. This emphasizes the importance of AdV testing which could lead to more rational antimicrobial treatment.

Evaluation of Microbiology and Antibiotic Prescribing Behavior of Foot Puncture Wound Infection: An Opportunity for Antimicrobial Stewardship

Evaluation of Microbiology and Antibiotic Prescribing Behavior of Foot Puncture Wound Infection: An Opportunity for Antimicrobial Stewardship

Planetary Health in Rehabilitation: A Call to Arms… and Legs, Gait Aids, and Other Equipment.

Sometimes out of necessity and sometimes out of convenience, medicine is wasteful. Resource stewardship is a critical and expanding field for reducing wasteful practices. Numerous international organizations are driving resource stewardship globally, including >20 countries worldwide participating in Choosing Wisely initiatives. However, opportunities for environmental stewardship have been long overlooked. Planetary health, climate action, and environmental stewardship in medicine consider opportunities which offer a co-benefit to the planet while improving or maintaining appropriate patient care across the healthcare continuum, including acute care, transitions in care, and postacute care, as well as in primary, secondary, and tertiary care settings. As rehabilitation is necessary across all healthcare settings, developing a culture among rehabilitation care providers that is conscientious about planetary health is imperative for sustainability of rehabilitation medicine and the health of our planet. We devised a recommendation for Choosing Wisely Canada's planetary health focus: don't dispose of adaptive equipment, mobility devices, orthoses, and prostheses that could be reused or recycled. This brief report discusses 1) why rehabilitation providers should engage with planetary health and climate action; 2) the rationale for the Choosing Wisely Canada Physical Medicine & Rehabilitation planetary health recommendation; and 3) existing avenues and novel opportunities for rehabilitation care providers worldwide to reduce waste in rehabilitation.

The Heterogeneous Syndrome of Noninfectious Causes of Persistent Fever in Neutropenic Patients With Hematologic Malignancy: Another Opportunity for Stewardship?

Although occult fungal, viral, and multidrug-resistant bacterial infections can cause persistent fever in neutropenic patients with hematologic cancer, a variety of noninfectious entities should be considered on a case-by-case basis in the context of negative diagnostic workup for infection.

Antibiotic Use in Medical-Surgical Intensive Care Units and General Wards in Latin American Hospitals.

The objective of this study was to identify antibiotic stewardship (AS) opportunities in Latin American medical-surgical intensive care units (MS-ICUs) and general wards (Gral-wards). We conducted serial cross-sectional point prevalence surveys in MS-ICUs and Gral-wards in 41 Latin American hospitals between March 2022 and February 2023. Patients >18 years of age in the units of interest were evaluated for antimicrobial use (AU) monthly (MS-ICUs) or quarterly (Gral-wards). Antimicrobial data were collected using a standardized form by the local AS teams and submitted to the coordinating team for analysis. We evaluated AU in 5780 MS-ICU and 7726 Gral-ward patients. The hospitals' median bed size (interquartile range) was 179 (125-330), and 52% were nonprofit. The aggregate AU prevalence was 53.5% in MS-ICUs and 25.5% in Gral-wards. Most (88%) antimicrobials were prescribed to treat infections, 7% for surgical prophylaxis and 5% for medical prophylaxis. Health care-associated infections led to 63% of MS-ICU and 38% of Gral-ward AU. Carbapenems, piperacillin-tazobactam, intravenous (IV) vancomycin, and ampicillin-sulbactam represented 50% of all AU to treat infections. A minority of IV vancomycin targeted therapy was associated with documented methicillin-resistant Staphylococcus aureus infection or therapeutic drug monitoring. In both units, 17% of antibiotics prescribed as targeted therapy represented de-escalation, while 24% and 15% in MS-ICUs and Gral-wards, respectively, represented an escalation of therapy. In Gral-wards, 32% of antibiotics were used without a microbiologic culture ordered. Half of surgical prophylaxis antibiotics were prescribed after the first 24 hours. Based on this cohort, areas to improve AU in Latin American hospitals include antibiotic selection, de-escalation, duration of therapy, and dosing strategies.

221 Opportunities for Antibiotic Stewardship for Pediatric Urinary Tract Infection for Outpatient Emergency Department and Urgent Care Encounters

221 Opportunities for Antibiotic Stewardship for Pediatric Urinary Tract Infection for Outpatient Emergency Department and Urgent Care Encounters