Montefiore Medical Center

Chronic subdural hematoma (cSDH) is one of the most common types of intracranial hemorrhages, particularly in the elderly. Despite extensive research regarding cSDH diagnosis and treatment, there is conflicting data on predictors of postoperative mortality (POM). We conducted a large retrospective review of patients who underwent a cSDH evacuation at a single urban institution between 2015 and 2022. Data were collected from the electronic medical record on prior comorbidities, anticoagulation use, mental status on presentation, preoperative labs, and preoperative/postoperative imaging parameters. Univariate and multivariate analyses were conducted to analyze predictors of mortality. Mortality during admission for this cohort was 6.1%. Univariate analysis showed the mortality rate was higher in those presenting with a history of dialysis. In addition, those who presented with altered mental status, were intubated, and lower GCS scores had higher rates of POM. Usage of Coumadin was correlated with higher rates of POM. Examination of preoperative labs showed that patients who presented with anemia or thrombocytopenia had higher POM. Imaging data showed that cSDH volume and greatest dimension were correlated with higher rates of POM. Finally, patients that were not extubated postoperatively had higher rates of POM. Multivariate analysis showed that only altered mental status and being not being extubated postoperatively were correlated with a higher risk of mortality. In summation, we demonstrated that altered mental status and failure to extubate were independent predictors or mortality in cSDH evacuation. Interestingly, patient age was not a significant predictor of mortality.

Introduction/Objective Neuroendocrine tumors (NETs) in the biliary system are extremely uncommon and often pose a diagnostic challenge due to their non-specific presentation and radiological features. While typically NETs form mass lesions causing biliary obstruction, to the best of our knowledge, microscopic neuroendocrine cell proliferation without mass formation has not been formally reported in the literature. This study aims to describe the clinicopathological features of a series of NETs/neuroendocrine cell proliferation involving the biliary tree. Methods/Case Report Surgical resections of NETs/neuroendocrine cell proliferation affecting the extrahepatic bile ducts and gallbladder were identified from the electronic pathology databases of five institutions between January 2010 and May 2023. The clinical data was obtained through chart review, and histologic findings were reviewed by a gastrointestinal pathologist at each institution. Results (if a Case Study enter NA) The study involved six patients with a mean age of 66 years (range: 58-75 years, males:3, females:3). The patients presented with abdominal pain or biliary obstruction. Pathologic examination revealed that three cases showed visible mass-forming lesions (1.6-2.4 cm) in the gallbladder or common bile duct, diagnosed as well-differentiated NETs. The remaining three cases had no grossly visible masses but showed incidental microscopic neuroendocrine cell proliferation/NETs (either in cystic duct or common bile duct) ranging from 0.2-0.4 cm, all associated with biliary lithiasis. All patients recovered after surgical resection without metastasis or recurrence, except for one patient who died a month after surgery due to an unrelated cause (multisystem organ failure). Conclusion This study highlights the spectrum of neuroendocrine proliferation in the biliary tree, ranging from microscopic incidental findings to grossly visible mass-forming NETs, which may result in variable clinical management and outcomes. Notably, incidental neuroendocrine proliferations were found to be associated with biliary lithiasis in all 3 cases, raising a possibility of a potential neuroendocrine metaplastic pathogenesis, which should be explored more via additional studies.

Background Actinomyces species are known colonizers of human mucosal surfaces but are rarely associated with disease in immunocompetent hosts. Pediatrics studies are limited to case reports. This retrospective study aims to describe the characteristics of skin and soft tissue actinomycosis (SSTA) and the frequency and risk factors of recurrence in pediatric patients. Methods We conducted this study of patients aged ≤21 years with Actinomyces growth in abscess cultures obtained under sterile conditions between January 2019 and December 2022 (Figure 1). Patient demographics were collected using the EMR, and all patients had at least a one-year follow-up period in which to ascertain recurrence. Results One hundred four patients met inclusion criteria; median age 19 (IQR 17-20) years, 68.3% female, 46.2% Black and 47.1% Hispanic. Body mass index (BMI) was > 25 in 59.8% of patients. Actinomyces turicensis (n=47) was the most commonly isolated subspecies and 71.2% of Actinomyces cultures were monobacterial. Clindamycin and trimethoprim-sulfamethoxazole were the most commonly used antibiotics. Only 7 patients had consultation with pediatric infectious diseases. Patients who had a prior abscess at the same anatomic site made up 29.8% of the study cohort and 33.7% had documented recurrence after the first SSTA episode, within median 10 (IQR 6-16) months after initial episode (Figure 2 and Table 1). Monobacterial culture growth (85.7% vs 63.8%, p=0.02), patients with BMI >25 (75% vs 52.6%, p=0.04) and patients with prior abscess in the same area (51.4% vs 18.8%, p=0001) were significantly higher in patients with recurrent actinomycosis (Table 2). In univariate analysis, monobacterial growth (OR= 3.4, 95% CI 1.2-9.9), BMI >25 (OR=2.7, 95% CI=1.1-7.0) and prior abscess (OR=4.6, 95% CI=1.9-11.2) were associated with increased odds of recurrence. Conclusion Our findings suggest that patients with SSTA were generally adolescents with elevated BMI. Monobacterial culture growth, BMI >25, and prior abscess in the same area were significantly associated with recurrence. High recurrence rate, suboptimal antibiotic utilization and very low rates of consultation with infectious diseases suggest that providers should be informed and updated regarding this rare but difficult to treat infection. Disclosures All Authors: No reported disclosures

Background Carbapenem-resistant Acinetobacter baumannii (CRAB) are considered an urgent public health threat responsible for causing severe infections with high associated mortality. CRAB isolates are often resistant to several antibiotic classes thereby limiting treatment options. Eravacycline is a novel tetracycline antibiotic with potent in vitro activity against CRAB. Per the recent Infectious Diseases Society of America (IDSA) Guidance on the Treatment of Antimicrobial-Resistant Gram-Negative Infections, clinical data are limited for eravacycline use for CRAB infections. The purpose of this study was to evaluate clinical outcomes of patients treated with eravacycline for CRAB infections at Montefiore Medical Center. Methods This was a retrospective chart review of patients 18 years of age and older who received eravacycline for at least 72 hours for the treatment of an infection due to CRAB between January 1, 2019 to February 28, 2023. Patients were excluded if they had a urinary tract infection. Patient demographics, risk factors, type/source of infection, clinical outcomes, etc. were collected. Results Eighteen patients received eravacycline for the treatment of non-urinary CRAB infections (Table 1). Ventilator-associated pneumonia was the predominant infection, representing 14/18 (78%) cases. High rates of antibiotic non-susceptibility were demonstrated in all cases. Median eravacycline minimum inhibitory concentration (MIC) was 1 mg/L, with a range of 0.19 – 6 mg/L. Median duration of eravacycline therapy was 7 days. Overall, the clinical success rate was 33% (6/18). Four patients (22%) experienced progression or worsening of symptoms that required a change in antibiotics. Of 11 evaluable patients, three patients (27%) had a recurrent infection caused by CRAB within 30 days of completion of eravacycline therapy. All-cause 30-day mortality was 56% (10/18), with six deaths (33%) attributed to CRAB infection. Conclusion CRAB infections pose a significant challenge in the healthcare setting and are associated with high mortality rates. Eravacycline remains a last resort option for these difficult to treat infections. Further study is warranted for eravacycline use for CRAB infections. Disclosures All Authors: No reported disclosures

Background Plasma cell-free metagenomic next-generation sequencing (cf-mNGS) offers potential for rapid, noninvasive diagnosis of complex infections, though clinical impact remains incompletely characterized. Here, we describe impacts on diagnosis and antimicrobial management among patients evaluated with plasma cf-mNGS. Methods Patients evaluated with plasma cf-mNGS (Karius®) in the Mount Sinai Health System from January 1, 2019 to December 23, 2022 were included. Cases were each reviewed independently in the medical record by two investigators using a standardized data collection form with discrepancies adjudicated collectively. Data were analyzed descriptively. Results Plasma cf-mNGS was sent for 37 patients of whom 29 (78%) were immunocompromised. 26 (70%) had prior invasive diagnostics. Median time from admission to NGS was 15 days. NGS was positive in 24 cases (65%), with results reflecting 20 bacterial infections, 9 viral, and 4 fungal (14 monomicrobial, 10 polymicrobial). Results were deemed clinically relevant in 18 cases (49%) including 12 positive and 6 negative tests. Testing led to antimicrobial changes in 11 cases (30%), discontinuation in 3 cases (8%), and no change in 23 cases (62%). After plasma cf-mNGS (compared with prior), fewer patients received 3 or 4 antimicrobials, while more received 0, 1, or 2 antimicrobials (Fig. 1A); fewer patients received combined antibiotic/antifungal therapy, while more received no antimicrobials or antifungal therapy alone; there was no change in use of antibiotic therapy alone (Fig. 1B). Final diagnoses included 15 bacterial infections (41%), 9 fungal (24%), 0 viral, and 7 noninfectious conditions (19%). Final diagnoses were attributed to NGS in 6 cases (16%), other diagnostics in 9 cases (24%), and both NGS and other diagnostics in 6 cases (16%); in the latter group, NGS provided a diagnosis prior to another study in 3 cases by intervals of 13, 19, and 72 days, respectively. A. Changes in number of antimicrobials, B. Changes in classes of antimicrobials Conclusion Plasma cf-mNGS, as an adjunct to traditional methods, may provide unique or expedited diagnosis of bacterial or fungal infections, accelerate diagnosis of noninfectious conditions, or inform changes in broad-spectrum antimicrobial regimens. Continued study is warranted to delineate clinical impact and optimal use of plasma cf-mNGS. Disclosures All Authors: No reported disclosures

Background Inappropriate vancomycin use in patients with febrile neutropenia (FN) can contribute to emergence of resistant organisms, acute kidney injury, and infusion related adverse effects. Methicillin resistant Staphylococcus aureus (MRSA) nares Polymerase Chain Reaction (PCR) testing has a high negative predictive value for invasive MRSA infections and therefore, offers a rapid tool to help avoid or de-escalate anti-MRSA therapy. In this study, we aimed to assess the impact of MRSA nares PCR on the utilization of vancomycin in a hematology/bone marrow transplant (BMT) unit. Methods Our hematology/BMT unit is a closed 32-bed unit with patients undergoing BMT, receiving care for complications related to BMT or undergoing chemotherapy for hematologic malignancies. Nasal MRSA PCR testing was added to our institutional FN treatment protocol in September 2021 to help guide antibiotic use for this patient population. As part of our antimicrobial stewardship program’s audit and feedback and antimicrobial utilization monitoring, we measured the use of intravenous (IV) vancomycin on the unit before (August 2020-August 2021) and after (October 2021-March 2023) updating our guidelines to include MRSA PCR. Vancomycin utilization, which was obtained from data submitted to National Healthcare Safety Network (NHSN), was measured using unit-level days of therapy (DOT) per 1000 days present. The incidence density rates were compared using the NHSN statistics calculator. Results Mean IV vancomycin use pre-MSRA PCR implementation was 91.27 DOT per 1000 days present, compared to 52.69 DOT per 1000 days present post MRSA PCR implementation (p < 0.001) (Figure 1). The monthly trend of vancomycin DOT per 1000 days present is shown in Figure 2. Conclusion Vancomycin utilization significantly decreased after the implementation of MRSA nares PCR as a part of the neutropenic fever workup. This study highlights its utility as a tool to guide therapy specifically in immunocompromised patients with significant antibiotic exposure. Disclosures All Authors: No reported disclosures

Background Updated cascade reporting of antimicrobial susceptibility (CRAS) for high-risk AmpC-producing Gram-negative organisms was implemented by the antimicrobial stewardship (ASP) and microbiology teams in June 2022 based on recent IDSA guidance. The CRAS focuses on highlighting weak inducers and poor substrate antibiotics such as cefepime and meropenem for AmpC-producing organisms: H. alvei, E. cloacae, C. freundii, K. aerogenes, and Y. enterocolitica (HECK-Yes). Methods A retrospective, observational, quasi-experimental study was conducted comparing the appropriateness of antimicrobials prescribed for infections with HECK-Yes organisms between pre-implementation period (July 2021-April 2022) and post-implementation period (July 2022-April 2023). Patients >18 years old with a positive blood or respiratory culture with any HECK-Yes organisms were included. The primary outcome of the study was the frequency of patients on appropriate antibiotics within 24 hours of final susceptibility report. Secondary outcomes included time to appropriate antibiotic order and administration, clinical success, microbiological failure, mortality, and reinfection/readmission within 30 days. Results Fifty patients were included in the pre- and post-implementation groups. Baseline characteristics were similar between the two groups (Table 1). A relative increase of 38.7% was observed in the appropriateness of antibiotics within 24 hours of final culture & susceptibility report (pre: 62% vs. post: 86%, p = 0.01). No significant difference was observed between the two groups in time to appropriate antibiotic order (pre: 4.8 hours vs. post: 3.3 hours, p = 0.37) or administration (pre: 5.9 hours vs. post: 8.0 hours, p = 0.53). There was a trend towards a lower 30-day mortality rate in the post-implementation group (pre: 24% vs. post: 14%, p = 0.10). No significant difference was observed for clinical success, microbiological failure, and reinfection/readmission within 30 days (Table 2). Conclusion Updating CRAS effectively increased the frequency of appropriate antibiotic prescribing for the treatment of HECK-Yes infections. The collaborative efforts of ASP and microbiology teams optimized antimicrobial prescribing for infections with HECK-Yes organisms at our institution. Disclosures All Authors: No reported disclosures

Background Hospital-onset Clostridioides difficile infection (HO-CDI) is a nosocomial infection that adversely impacts length of stay, morbidity, and mortality, and contributes to 6 billion dollars in U.S. healthcare expenditures. Our aim was to identify and categorize antibiotic prescribing patterns amongst patients with HO-CDI at our institution and design targeted interventions based on these findings. Methods A physician-assigned review of electronic medical records for all laboratory-confirmed cases of HO-CDI was conducted at Montefiore Medical Center Moses Campus (Bronx, NY) from July 2022 to March 2023. HO-CDI was defined using the CDC’s NHSN definition as a positive stool test for Clostridium difficile occurring after 3 days of hospital admission. Our hospital follows a 2-step testing algorithm: a positive test occurs when both glutamate dehydrogenase (GDH) and C. difficile toxin are detected. If there is discordance at this stage, a confirmatory polymerase chain reaction (PCR) test is performed. Formed stool specimens are rejected and Montefiore has institutional guidance for appropriate C. difficile testing. Antimicrobial choice, indication, and duration were reviewed. We characterized the inappropriateness of antibiotic use into 3 non-mutually exclusive categories (inappropriate indication, spectrum of activity, or duration). Results 77 HO-CDI cases were identified from 15 inpatient services encompassing medical, surgical, and intensive care services. Exposure to one or more antibiotics within 30 days prior to CDI diagnosis was seen in 88% of cases (n=68). Of these, 16 (23.5%) had inappropriate antibiotic use (Table 1). Antibiotics were used for longer than clinically indicated in 11 (69%) cases. Inappropriately broad-spectrum antibiotics were used in 9 (56%) cases. Antibiotic use was deemed unnecessary in 4 (25%) cases (Figure 1). The most frequently used antibiotics were piperacillin/tazobactam in 8 (50%) cases, followed by ceftriaxone in 5 (31%) cases, and meropenem in 2 (12.5%) cases (Figure 2). Conclusion Targeting inappropriate antibiotics is an important strategy to reduce HO-CDI. We intend to follow-up with directed provider feedback and education and heightened antibiotic stewardship efforts. Disclosures All Authors: No reported disclosures

Background Metagenomic next-generation sequencing (NGS) of microbial cell-free DNA is a relatively novel diagnostic technique that may potentially expedite and/or supplement pathogen-specific infectious disease diagnoses, minimize the time to appropriate antibiotic therapy, and reduce unnecessary and invasive testing. However, careful diagnostic stewardship is necessary to ensure that such tests are being ordered in the appropriate patient population. Methods A retrospective chart review of all patients for whom the Karius NGS test was sent at our institution between Jun 13, 2020-Jul 22, 2022 was performed. Clinically relevant pathogens were defined as diagnoses that led to change in antimicrobial therapy. Stata statistical software (version 17.0, College Station TX) was used to analyze patient and hospitalization risk factors associated with Karius testing. Results Thirty cases among 29 unique patients for whom Karius testing was performed were included in our review. Patient characteristics are shown in Table 1. Twenty-one patients (72%) were immunocompromised, including 14 (47%) with solid organ transplant (SOT) and 9 (30%) with malignancy. Mean hospital length of stay (LOS) prior to Karius test collection was 15.8 days (+/- 21.6 days, range 1-120). Reasons for sending Karius are shown in Fig 1. Three patients (10%) had tissue-specific NGS testing performed in addition to Karius. On average, patients received 13.9 days of antibiotics prior to Karius (+/-10.11, range 0-37). Mean turnaround time for Karius results was 38.3 hours (+/- 16.5, range 23-79). Ten (34.5%) Karius results identified no pathogens. Karius identified fungal organisms in 3 (10%) tests, one of which correlated with true infection. Karius results correlated with other infectious diagnostics (such as viral PCR or cultures) in 10 (33%) cases. Clinically relevant pathogens (not identified by other testing) were identified by Karius in only 3 (10%) cases. There was no statistically significant correlation between pathogen detection by Karius and history of HIV (p=0.27), transplant (p=0.70), malignancy (p= 0.21), or number of days from admission to test (p=0.66) Table 1 Patient characteristics (N=29 unique patients, 30 tests) Figure 1 Reasons for Karius test Conclusion Metagenomic NGS is an exciting area of diagnostic innovation, but more studies are needed to determine when and where this test is best utilized. Disclosures All Authors: No reported disclosures

Background Prolonged SARS-CoV-2 infections in immunocompromised hosts may predict or source the emergence of highly mutated variants of concern. The types of immunosuppression placing patients at highest risk for prolonged infection and associated intra-host viral evolution remain unclear.Table 1.Characteristics at enrollment of immunocompromised patients with SARS-CoV-2 infection — IVY Network, 5 U.S. States, April 11, 2022 – February 1, 2023Abbreviations: AIDS = acquired immunodeficiency syndrome; IQR = interquartile range; RT-PCR = reverse transcription-polymerase chain reactionFigure 1.Cycle threshold (Ct) values for SARS-CoV-2 N1 (nucleocapsid) and virus culture isolation over time by immunocompromised group — IVY Network, 5 U.S. States, April 11, 2022 – February 1, 2023, N=150 Methods Adults aged ≥18 years were enrolled and followed at 5 hospitals in the Investigating Respiratory Viruses in the Acutely Ill (IVY) Network from 4/11/2022 – 2/1/2023. Eligible patients were SARS-CoV-2-positive by RT-qPCR in the previous 14 days and had an immunocompromising condition, including malignancy, solid organ or hematopoietic stem cell transplant (SOT/HSCT), autoimmune/autoinflammatory condition on immunosuppression, AIDS, or primary immunodeficiency. Nasal specimens were collected and tested by RT-qPCR every 2–4 weeks until negative in 2 consecutive specimens. All specimens underwent viral culture and whole genome sequencing. A Cox proportional hazards model was used to assess factors associated with prolonged infection.Figure 2.Cox proportional hazards model* depicting association between type of immunosuppression and prolonged SARS-CoV-2 infection by reverse transcription-polymerase chain reaction (RT-PCR) — IVY Network, 5 U.S. States, April 11, 2022 – February 1, 2023, N=150* Cox proportional hazards model was adjusted for age, sex, race, ethnicity, vaccination history (receipt of any vaccine doses vs. none) and COVID-19 antiviral drug use (receipt of any drugs 90 days before enrollment or 7 days after visit) Results 150 patients were enrolled with the following conditions: B cell malignancy or anti-B cell therapy (n=18), SOT/HSCT (n=59), AIDS (n=5), non-B cell malignancy (n=23), and autoimmune/autoinflammatory (n=45, Table 1). 37 (25%) were RT-qPCR-positive and 11 (7%) were culture-positive ≥21 days after infection onset. Patients with B cell dysfunction had prolonged infection compared to those with autoimmune/autoinflammatory conditions (aHR 0.28, 95% CI 0.14–0.58) (Figures 1, 2). The within-host evolutionary rate was similar in prolonged (≥ 21 days) and shorter (< 21 days) infections (Figure 3). Consensus spike mutations were identified in 4 individuals who were RT-qPCR-positive ≥ 56 days; 68% were in the receptor-binding domain (RBD) (Figures 4, 5). The common spike mutations in this analysis were rare (< 2%) in global circulation.Figure 3A.Type of de novo mutations over time among immunocompromised patients with SARS-CoV-2 infection — IVY Network, 5 U.S. States, April 11, 2022 – February 1, 2023, N=150Figure 3B.Evolutionary divergence by mutation type in patients with self-limited (<21 days, n = 89) and prolonged (>=21 days, n = 15) SARS-CoV-2 infections — IVY Network, 5 U.S. States, April 11, 2022 – February 1, 2023, N=150Figure 4.Shared de novo mutations across the entire SARS-CoV-2 genome among immunocompromised patients — IVY Network, 5 U.S. States, April 11, 2022 – February 1, 2023, N=150 Conclusion In this prospective cohort of immunocompromised patients during the Omicron variant period, prolonged SARS-CoV-2 infections were uncommon. While the within-host evolutionary rates are similar between prolonged and shorter infections, individuals with infections lasting ≥ 56 days accumulated mutations in the spike protein. These appear distinct from those seen globally.Figure 5.Heatmaps of mutations in SARS-CoV-2 spike protein among immunocompromised patients with ≥2 sequenced specimens and ≥56 days of positive specimens by reverse transcription-polymerase chain reaction (RT-PCR) — IVY Network, 5 U.S. States, April 11, 2022 – February 1, 2023, N=4. Bisected squares indicate more than one genomic mutation produced the same amino acid mutation. RBD is highlighted in gray. Disclosures Emily T. Martin, PhD, MPH, Merck: Grant/Research Support Natasha B. Halasa, MD, MPH, Merck: Grant/Research Support|Quidell: Grant/Research Support|Quidell: donation of kits|Sanofi: Grant/Research Support|Sanofi: vaccine support Carlos G. Grijalva, MD, MPH, AHRQ: Grant/Research Support|CDC: Grant/Research Support|FDA: Grant/Research Support|Merck: Advisor/Consultant|NIH: Grant/Research Support|Syneos Health: Grant/Research Support Adam S. Lauring, MD, PhD, Roche: Advisor/Consultant|Sanofi: Advisor/Consultant

Background Infections with multidrug resistant organisms (MDROs) are common in liver transplant recipients. We aimed to understand the prevalence and risk factors for MDRO infections during the peri-transplant period. Methods We conducted a retrospective chart review of adults ( >18 years) who underwent deceased donor liver transplant (LT) from Jan 2018-Dec 2020. Demographics and clinical information, including antibiotic use, microbiological data, and adequacy of perioperative antibiotics based on CLSI breakpoints, were reviewed. Peri-transplant period was defined as 12 months pre- and 3 months post-transplant. MDRO was defined as resistance to one or more classes of antibiotics. Statistical analysis was performed with IBM SPSS 29.0, using Chi2 or Fischer’s exact tests as appropriate for categorical variables and independent t-test for continuous variables. Results Baseline demographics for the 121 LT recipients are summarized in Table 1. In the 3 months post-transplant, 47 patients (38.8%) were noted to have positive cultures, of which 22 were MDRO. MDRO distribution for pre- and post-transplant infections is shown in Figure 1. Univariate analyses of predictors for post-transplant MDRO infection are shown in Table 2. Mean length of stay for patients with post-transplant MDRO infection was 65.3 days versus 28.6 days in those without MDRO infection (p< 0.001). Among 36 patients with positive cultures < 1month post-transplant, 55% (n=20) received perioperative antibiotics covering the identified organism. Eleven of 23 patients (47.8%) who received ampicillin-sulbactam (AS) and 3 of 8 patients (37.5%) who received piperacillin-tazobactam (PT) perioperatively developed infections not covered by their respective regimens < 1-month post-transplant. In the first month post-transplant, 17 patients had organisms cultured which were resistant to AS, of which all but one was also resistant to PT.Table 1Baseline Demographics Conclusion Admission to the intensive care unit, antibiotic use prior to transplant, and longer transplant hospitalizations were associated with MDRO infections. Tailoring of surgical prophylaxis may be indicated for high-risk patients as PT did not offer superior coverage over AS. Disclosures All Authors: No reported disclosures

Background Infectious complications of substance use are rising nationally among people who use drugs (PWUD), highlighting the need to integrate Infectious Diseases (ID) practice with addiction care. Training experiences among ID fellows, whose practice patterns are likely to be impacted by this syndemic, remain unknown. We conducted a national survey to understand U.S. ID fellows’ training, practices, and perspectives regarding care of PWUD. Methods An 18-item survey was developed to assess program characteristics, clinical practices, and perspectives regarding knowledge, comfort, and scope of practice. Recruitment was conducted via emails to fellowship programs, social media (Twitter, Mastodon), and IDSA platforms. Responses were collected over three weeks. Statistical analyses were conducted by chi square test. The study was deemed exempt from institutional review. Results 196 U.S. ID fellows completed the survey (≅24% response rate), with representation from 9 of 9 geographic regions. All respondents cared for PWUD during their training. 49% had formal curriculum in their programs and 64% reported faculty advocates. 50% typically (in half or more encounters) counseled on harm reduction; 37% referred to outpatient resources and 33% recommended medications for opioid use disorders (MOUD) and naloxone. Respondents were unsure of community resources (e.g. syringe services, 48%; supervised consumption, 57%). 69% rated harm reduction counseling as extremely within scope of ID practice, versus 20% for the practice of recommending MOUD; 25% and 11%, respectively, reported feeling extremely comfortable with these skills. Engagement in discussions of harm reduction, MOUD, naloxone, and outpatient resources was significantly associated with presence of a faculty advocate (p< 0.01 for all). Self-reported engagement in clinical practices among Infectious Diseases fellows Perspectives on comfort level and scope of practice among Infectious Diseases fellows Availability and knowledge of resources at Infectious Diseases training sites Conclusion U.S. ID fellows frequently care for PWUD but infrequently engage in integrated care practices. Harm reduction counseling is seen as highly within ID scope of practice, however, comfort and knowledge are low. Both comfort and perception of scope are low for discussing MOUD, though this appears to be impacted by faculty modeling. Our findings highlight an opportunity to formalize training in ID fellowship to better address the need for integrated ID/addiction care nationally. Disclosures All Authors: No reported disclosures

Background (1,3)-β-D-glucan (BDG) has been utilized as an indirect marker for Pneumocystis jirovecii pneumonia (PJP). The clinical utility of BDG, however, is limited because of uncertainty in interpreting quantitative values. A correlation was drawn between quantitative BDG and the diagnosis of PJP in hospitalized patients living with human immunodeficiency virus (HIV) at four affiliate campuses of the Montefiore Health System in the Bronx, NY. Methods All Pneumocystis direct fluorescent assays (DFA), polymerase chain reactions (PCR) either from bronchoalveolar lavage (BAL) fluid or sputum, and quantitative BDG assays either from serum or BAL fluid were retrieved from the Montefiore microbiology laboratory (date range: 8/1/18 - 8/31/22). Results from hospitalized patients with HIV whose CD4 count within 3 months were available, with either PJP DFA or PCR result within 7 days of serum BDG and lactate dehydrogenase (LDH) test were selected (n = 146). CD4 count was grouped into < 50 (n = 106), 50-100 (n = 15), 100-200 (n = 16), and >200 (n = 9). BDG, LDH, and CD4 were considered as input variables in a logistic regression model for true PJP status. The area under the curve (AUC) of the empirical receiver operating characteristic (ROC) curve with 95% confidence intervals (CI) was estimated based on trapezoidal area. Comparisons between ROC curve areas were performed via contrast matrix to take differences of the AUC of the empirical ROC curves and chi-square testing. Results Of the 146, 29 had PJP detected and 117 did not. When BDG only was considered, the AUC of the ROC curve was 0.78. When LDH quartiles (cutoffs: 232, 334, and 480 U/L) were considered with BDG, there was a statistically significant increase in AUC (0.84 vs. 0.78; p = 0.025). Adding CD4 group did not influence AUC. Figure 1 ROC curves for BDG only, BDG with CD4 count, BDG with LDH quartile, and BDG with CD4 group and LDH quartile combined Table 1 Area under the curve calculated for the ROC curves for BDG only, BDG with CD4 count, BDG with LDH quartile, and BDG with CD4 group and LDH quartile combined Conclusion The test characteristics (AUC) improved when LDH quartiles were used in conjunction with BDG, suggesting a better prediction of PJP diagnosis when BDG and LDH were considered together. This result supports further investigation of clinical markers of PJP given the limitations of establishing a microbiologic diagnosis. Further steps of the investigation will involve analyzing if other clinical factors including HIV viral load, oxygen saturation, and radiographical reading, influence predictability of PJP. Disclosures All Authors: No reported disclosures

Background Data on the severity of RSV-associated hospitalizations in adults compared with COVID-19- and influenza-associated hospitalizations are limited. We compared characteristics and clinical outcomes among adults hospitalized with RSV vs. COVID-19, and RSV vs. influenza. Methods Adults aged ≥18 years hospitalized with acute respiratory illness (ARI) who tested positive for RSV, SARS-CoV-2, or influenza by nucleic acid amplification or antigen test were enrolled at 25 hospitals in 20 U.S. states participating in the Investigating Respiratory Viruses in the Acutely Ill (IVY) Network during January 31, 2022 to April 11, 2023. Patients with respiratory viral co-infections were excluded. Clinical data were abstracted from medical charts. Advanced respiratory support was defined as receipt of high flow nasal cannula, non-invasive ventilation, or invasive mechanical ventilation (IMV) during hospitalization. Characteristics were compared using Chi-square tests. Severe illness was compared for RSV vs. COVID-19 and RSV vs. influenza using multivariable logistic regression models adjusted for age, sex, race and ethnicity, number of chronic medical condition categories, admission date, and geographic region. Results Of 8,334 hospitalized adults included, 6% tested positive for RSV (n=478), 80% for SARS-CoV-2 (n=6,664), and 14% for influenza (n=1,192). Median age of patients with RSV was 65 years (IQR = 53–75), similar to patients with COVID-19 and influenza (Table 1). Shortness of breath was more frequently reported by patients with RSV compared to patients with COVID-19 (78% vs. 62%, P< 0.0001) and influenza (78% vs 72%, P=0.005). Patients with RSV were more likely to be hypoxemic compared to those with COVID-19 (aOR 1.92, 95% CI = 1.52–2.42) (Table 2). Patients with RSV were also more likely to receive advanced respiratory support compared to those with COVID-19 (aOR 1.88, 95% CI = 1.51–2.33) or influenza (aOR 1.83, 95% CI = 1.4–2.4); however, use of IMV did not differ between these groups. Conclusion In this prospective, multicenter network, prevalence of RSV among adults enrolled with ARI was lower than patients with COVID-19 and influenza; however, adults hospitalized with RSV experienced more severe respiratory illness compared to patients hospitalized with COVID-19 or influenza. Disclosures Adit A. Ginde, MD, MPH, AbbVie: Grant/Research Support|Faron Pharmaceuticals: Grant/Research Support Ithan Peltan, MD, Asahi Kasei Pharma: Institutional support|Regeneron: Institutional support Adam S. Lauring, MD, PhD, Roche: Advisor/Consultant|Sanofi: Advisor/Consultant Emily T. Martin, PhD, MPH, Merck: Grant/Research Support

Background Several observational studies and a recent meta-analysis suggest there is a mortality benefit associated with acquiring repeat blood cultures for gram-negative bacterial bloodstream infections (GNBSI). However, limited data are available among patients with febrile neutropenia. We sought to evaluate the utility of obtaining follow-up blood cultures (FUBC) in GNBSI among neutropenic hematological malignancy patients. Methods A retrospective chart review was conducted to identify all patients with a hematologic malignancy admitted with a diagnosis of neutropenic fever due to gram-negative rod bacteremia (GNRB) from 2018-2021 at a large urban academic medical center. We collected demographics, cancer diagnosis and treatment data, microbiology and antibiotic information, and death at discharge, 30 days, and 90 days. Descriptive statistics and chi-square tests were used. Results A total of 47 episodes of GNBSI among 43 patients were included. Mean age was 57 years, 61% were male, 49% were White, and 14% were Latino. Most patients had AML (47%), and most common chemotherapy regimen was R-CHOP (19%). 32% of GNRB were due to K. pneumoniae, in the setting of long-term central venous catheter (53%), and from a gastrointestinal source (49%). FUBC were collected among most patients (87%), but only two patients (5%) had positive FUBC. ESBL resistance profiles were uncommon (6%), and most were treated with beta-lactams (55%). Patients who died at discharge were less likely to have FUBC collected (p< 0.001). We also found an association between acquiring FUBC and mortality at 30 (p=0.01) and 90 days (p=0.02). However, there was no association between having a positive FUBC and mortality at discharge (p=0.47), 30 days (p=0.93), and 90 days (p=1.00). Conclusion Among patients with neutropenic fever found to have GNBSI, acquiring repeat blood cultures was associated with decreased mortality. Due to their immunocompromised status, patients with neutropenic fever and GNRB should have repeat blood cultures collected. Disclosures All Authors: No reported disclosures

Background On September 1, 2022, the Advisory Committee on Immunization Practices recommended a bivalent mRNA COVID-19 booster dose for persons who had completed at least a primary COVID-19 vaccination series ≥2 months earlier. Early data showed high effectiveness of a bivalent booster in preventing COVID-19-associated hospitalization within 45 days of receipt; however, little is known about the durability of this protection. Methods Data from the Investigating Respiratory Viruses in the Acutely Ill (IVY) Network were used to conduct a case-control analysis measuring bivalent vaccine effectiveness (VE) against COVID-19–associated hospitalization over time. During September 8, 2022–April 1, 2023, immunocompetent, hospitalized adults aged ≥65 years with COVID-19-like illness were enrolled at 25 hospitals in 20 U.S. states. COVID-19 case-patients tested positive for SARS-CoV-2 by a nucleic acid or antigen test within 10 days of illness onset, while control-patients tested negative for SARS-CoV-2 during the same interval. Multivariable logistic regression was used to measure absolute and relative bivalent VE adjusted for age, sex, race and ethnicity, admission date, and U.S. Health and Human Services region. Unvaccinated patients and patients who received 2–4 doses of monovalent-only mRNA vaccine were used as the reference group for absolute and relative VE, respectively. Bivalent VE was calculated for 7–89 days and 90–179 days from booster dose receipt to illness onset. Results A total of 2,787 immunocompetent, hospitalized adults aged ≥65 years were enrolled in the IVY Network during the study period (1,236 COVID-19 case-patients and 1,551 control patients). Absolute VE of a bivalent booster dose against COVID-19-associated hospitalization was 58% (95% CI=42%–70%) after 7–89 days and 27% (95% CI= -7% to 50%) after 90–179 days. Relative VE of a bivalent booster dose was 54% (95% CI=41%–64%) after 7–89 days and 19% (95% CI= -8% to 39%) after 90–179 days (Figure). Conclusion Bivalent mRNA vaccination provided moderate protection against COVID-19-associated hospitalization within 90 days of receipt among adults aged ≥65 years, with waning protection after 90 days. Additional booster doses could improve protection against COVID-19-associated hospitalization among older adults. Disclosures Adit A. Ginde, MD, MPH, AbbVie: Grant/Research Support|Faron Pharmaceuticals: Grant/Research Support Ithan Peltan, MD, Asahi Kasei Pharma: Institutional support|Regeneron: Institutional support Emily T. Martin, PhD, MPH, Merck: Grant/Research Support Matthew Exline, MD, Abbott Labs: Honoraria|Regeneron: Grant/Research Support Adam S. Lauring, MD, PhD, Roche: Advisor/Consultant|Sanofi: Advisor/Consultant

Background There is a high burden of hepatitis B virus (HBV) in West Africa. Over the past 20 years, West African immigration to the U.S. has been increasing, especially to the Bronx. Prevalence of HBV infection in West Africa has been reported to be as high as 5-10%. We sought to understand knowledge and attitudes of and barriers and facilitators to HBV screening, vaccination, and treatment in a cohort of people living with and at risk for HBV. Methods We recruited participants through an HBV outreach program (The Starfish Program) which provides free HBV education, screening, and vaccination with a focus on West Africans. We conducted one-on-one in-depth, in-person qualitative interviews with West African immigrants over the age of 18 residing in the Bronx. Our interviews were guided by the modified socioecological model (SEM), which includes individual, social network, community, and societal domains. The interviews assessed participants’ understanding of HBV, social issues surrounding HBV in their community, and structural factors affecting their ability to seek healthcare. Data were analyzed in an iterative process using a thematic analysis. Results Participants (n=23) had origins in 6 different West African nations, although mainly from Ghana and Nigeria, with a median age of 49.5 (IQR 40-66). 56.5% were female. 7 were HBV surface antigen (HBsAg) positive, 6 were HBsAg negative, and 10 had unknown status at the time of interview. Median time since immigrating was 15.5 years (IQR 4-21). Key barriers included limited knowledge of HBV, HBV-related stigma, lack of health insurance, and undocumented immigration status/fear of deportation. Key facilitators included trust in U.S. healthcare providers and healthcare system, social support networks, and ease of accessing healthcare after obtaining health insurance. Demographics of interview participants Conclusion Raising awareness of HBV, addressing social and structural barriers such as stigma and health insurance, and improving access to culturally sensitive programs among West African communities could help increase HBV screening, vaccination, and treatment in this vulnerable population. Disclosures Samuel Sigal, MD, Eli Lilly: Grant/Research Support|Gilead Sciences: Grant/Research Support|Gilead Sciences: Speakers Bureau|Intercept: Grant/Research Support|Mallenchrodt: Advisor/Consultant|Mallenchrodt: Grant/Research Support

PURPOSE Knowledge of thyroid eye disease (TED) is based on predominantly Caucasian populations. To date, no studies in the United States examine the presentation in Black and Hispanic patients. The purpose of this study is to introduce the presentation of TED in two previously undescribed populations. METHODS This is a retrospective, cross-sectional, chart review study of patients with TED at a tertiary center using the Strengthening the Reporting of Observational Studies in Epidemiology checklist. The main outcome measure for severity was the European Group on Graves’ Orbitopathy 2016 Severity Scale. RESULTS Of the 2905 charts reviewed, 99 met the inclusion criteria. The mean age was 51 (standard deviation 16) years with 78% women. Race was 49.4% Black, 39.1% Hispanic, 9.2% Caucasian, and 2.3% Asian. Smoking rates were 25% current smokers and 14% former smokers. Manifestations were proptosis (94% Hispanic and 91% Black), eyelid retraction (85% Hispanic and 79% Black), extraocular muscle (EOM) restriction (79% Hispanic and 63% Black), eyelid edema (41% Hispanic and 30% Black), chemosis (24% Hispanic and 14% Black), and optic neuropathy (18% Hispanic and 9% Black). Overall, disease severity was 22% mild, 65% moderate to severe, and 13% sight-threatening. Older patients had increased rates of optic neuropathy ( P = 0.04). Younger patients had increased rates of proptosis ( P = 0.02). Socioeconomic status was not associated with disease severity ( P = 0.67). CONCLUSION Hispanic and Black patients with TED presented with higher than previously established rates of proptosis, EOM restriction, and optic neuropathy. Including research of different races broadens understanding of presentation and management, improving patient outcomes.