bluuebunny/crossref_metadata_2025_split huggingface dataset:
P-2199. Empowering Healthcare Providers in the Appalachian Region to Manage Hepatitis C Infection: A Descriptive Study
Authors: de la Espriella Mariana Gomez , Peterson Christopher , Faulhaber Jason R , Ravagli Cara , Chitwood Crystal , Nowak Elizabeth , Rubio Marrieth , Baffoe-Bonnie Anthony 
Published: January 2025

Abstract

Background
Hepatitis C virus (HCV) infection disproportionately affects people living in Southwest Virginia, with low treatment rates exacerbating the issue furthermore. Rural residents face barriers like limited access to services and lengthy referral processes. Since January 2019, Virginia Medicaid has removed the restriction for primary care providers to manage HCV independently. To improve access to Hepatitis C treatment in our communities,we developed a concise, free training program aimed at empowering rural primary care providers in our health system to screen, diagnose, and treat HCV.

Methods
We invited Family Medicine (FM) practitioners from our health system in rural areas to participate. Offering a convenient seven-part video series led by infectious disease and gastroenterology specialists, alongside monthly webinars, patient resources, and hands-on coaching, we tailored the program to fit their busy schedules. Consultation with specialists and a dedicated treatment coordinator supported complex cases was also part of the program.

Results
Twenty-two FM providers, including 17 physicians and 5 advanced practitioners, engaged in the program. Within a month, HCV screening by program participants increased by 53%. Treatment initiation time decreased significantly from 178 days to 46 days compared to traditional specialist referral methods.

Conclusion
Our findings demonstrate that leveraging specialist knowledge through virtual training programs, coupled with remote support, significantly enhances HCV care accessibility. Shortening the time to treatment initiation, especially when managed by primary care providers, improves HCV detection and treatment outcomes in rural areas. This program represents a vital step towards addressing the Hepatitis C burden in underserved communities.

Disclosures
Cara Ravagli, PA, Gilead: Grant/Research Support
P-2225. Interactions between phage and host bacteria in immunized rabbit serum
Authors: Herren Sebastian , Karau Melissa J , Koscianski Christina , Christensen Trace A , Patel Robin 
Published: January 2025

Abstract

Background
Phage therapy is being evaluated to treat bacterial infections. Host-related factors that might abrogate phage efficacy remain incompletely characterized. Phage aggregation has been hypothesized to protect phages in harsh environments. Herein, effects of immunized rabbit sera on phage aggregation were assessed.

Methods
Three New Zealand rabbits were immunized weekly for 3 weeks by intramuscular injection of phage K. Serum samples were collected weekly at times 0, 7, 14, 21 and 28. Development of an antibody response was confirmed by ELISA. Phage K was exposed to immunized serum with or without heat-inactivated host bacterium (Staphylococcus aureus ATCC 19685) as follows. 45 µl of phage K (1010±1 plaque forming units/mL [pfu/ml]) was mixed with 5 µl immunized serum diluted 1:1000 with or without heat-inactivated bacterial host in phosphate buffered saline (PBS). After incubation, exposed phage was visualized using transmission electron microscopy (TEM, JEOL) at 80kV.

Results
Phage K immunization elicited a strong IgG response. Exposure to immunized serum led to a decrease in viable phage over time, abrogated by adding heat-inactivated bacteria (Fig 1). TEM imaging showed phage clustering with exposure to immunized serum (Fig 2A); clusters appeared disorganized with concomitant exposure to heat-inactivated host bacteria (Fig 2B). Exposure of phage to heat-inactivated bacteria without serum yielded evenly distributed phage, with minimal clustering (Fig 2C).

Conclusion
Phage K exposure elicited a neutralizing immune response associated with decreased phage survival in immunized serum, prolonged by adding heat-inactivated host bacteria. TEM imaging showed phage K clustering in different ways depending on the microenvironment encountered. Biological relevance and mechanistic underpinnings of these phenomena need further characterization.

Disclosures
Robin Patel, MD, a patent on Bordetella pertussis/parapertussis PCR issued, a patent on a device/method for sonication with royalties paid by Samsung to Mayo Clinic, a: See above|MicuRx Pharmaceuticals and BIOFIRE: Grant/Research Support|PhAST, Day Zero Diagnostics, Abbott Laboratories, Sysmex, DEEPULL DIAGNOSTICS, S.L., Netflix, Oxford Nanopore Technologies and CARB-X: Advisor/Consultant|Up-to-Date and the Infectious Diseases Board Review Course.: Honoraria
P-2227. Real-Life Utilization and Clinical Impact of Karius Testing in Solid Organ Transplant Recipients: A Retrospective Analysis
Authors: Shah Jesal R , Rizwan Sohail M , Al Mohajer Mayar , Khalil Sarwat 
Published: January 2025

Abstract

Background
Metagenomic next-generation sequencing such as Karius test (KT), is increasingly being used for microbial detection in various clinical syndromes, including sepsis, Fever of Unknown Origin (FUO), pneumonia, and cardiovascular infection. However, data regarding the utility of KT in solid organ transplant recipients (SOTR) are lacking. There is a need to assess its clinical impact and appropriate use considering its cost, potential for detection of commensal organisms, and lack of antimicrobial susceptibility data. Our study focuses on the real-world clinical impact of KT in SOTR.

Methods
We performed a retrospective review of all adult SOTR who underwent KT at Baylor St Luke’s Medical Center from March 2017 to February 2023. Clinical impact (positive, neutral, and negative) was assessed using standardized objective criteria utilized in prior studies. Descriptive analysis with patient and clinical characteristics was completed.

Results
A total of 113 KT in liver (42%), kidney (35%), lung (20%) and heart (13%) transplant recipients were completed in the study period (Table 1). The most common clinical syndromes where KT was ordered included: pneumonia (36%), FUO (16%), and intrabdominal infections (15%). Majority (81, 72%) of the KT results were positive for microbiological organisms (Table 2). Overall, 52 (46%) of conventional microbiological tests (CT) were also positive. Ultimately, 27 (24%) of cases were identified with positive clinical impact from KT testing, 87 (77%) neutral, and 4 (4%) negative, respectively (Table 3).

Conclusion
In SOTR, KT can add a positive clinical impact and identify microorganisms beyond conventional microbiological testing across clinical syndromes. However, larger prospective studies are needed to define the optimal timing and utilization in diagnostic evaluation algorithms for syndrome-specific work-up in SOTR.

Disclosures
M. Rizwan Sohail, MD, Medtronic: Advisor/Consultant|Medtronic: Honoraria|Philips: Advisor/Consultant|Philips: Honoraria
P-2229. Comparative Evaluation of Multimodal Large Language Models with Vision in Infectious Diseases Cases with Clinical Images
Authors: Non Lemuel , Hodges Jacob 
Published: January 2025

Abstract

Background
Real-world patient scenarios often involve a composite of text and various clinical images. We explored the performance of advanced multimodal Large Language Models (LLMs) equipped with image-to-text models (vision) in diagnosing complex infectious disease cases containing both text and clinical images.Figure 1:Case #19003; Right foot cutaneous lesion [Photography]. Partners’ Infectious Disease Images; Accessed on April 4, 2024 from https://www.idimages.org/images/detail/?imageid=2356
A sample image from IDImages.org showing a physical exam finding and the descriptions from the AI chatbots.

Methods
We assessed the performance of two publicly accessible LLMs with vision—GPT-4 and Claude Opus—on a series of 25 complex infectious disease scenarios with 67 clinical images sourced from www.IDImages.org. Prompts were standardized for each case, including instructions to identify the diagnosis, generate differential diagnoses, and describe each image. The models' accuracy in identifying the diagnosis and including it within the differential diagnoses was evaluated using a binary scoring system (0 or 1). Image description quality was assessed using a Likert scale ranging from 0 to 2 comparing the models' outputs against provided descriptions (Figure 1). Scoring was conducted by two independent clinicians, with the final scores being computed as averages.
Figure 2
Mean scores of GPT-4 and Opus (1 denoting maximum accuracy) in correctly identifying the diagnosis (left) and in including the main diagnosis in the list of differential diagnoses (right).

Results
Opus achieved a higher mean accuracy (0.74) compared to GPT-4 (0.56) in determining the correct diagnosis, with the observed difference being statistically significant (p = 0.043). Nevertheless, both models demonstrated comparably high accuracy in incorporating the primary diagnosis within the differential diagnoses, with scores of 0.90 for GPT-4 and 0.88 for Opus (Figure 2). Additionally, both models (GPT-4 average score 1.79 ± 0.43, Opus 1.75 ± 0.50) performed well in providing accurate descriptions of different clinical images. In terms of image type, they performed best in interpreting images with physical findings (GPT-4 1.92 ± 0.23, Opus 1.83 ± 0.46), followed by radiographic images (GPT-4 1.80 ± 0.41, Opus 1.83 ± 0.36), and worst in pathological specimens (GPT-4 1.61 ± 0.58, Opus 1.57 ±0.58) (Figure 3). No statistical differences were found between the two models in their overall ability to describe images or within each image category.
Figure 3
Mean accuracy scores of GPT-4 and Opus (up to 2) in interpreting clinical images grouped according to image type.

Conclusion
The two models demonstrated comparable accuracy in handling complex infectious disease scenarios that integrated both texts and images, suggesting potential utility in enhancing clinical support.

Disclosures
All Authors: No reported disclosures
P-2231. The Impact of Cell-free DNA Sequencing in the Evaluation and Management of Infections
Authors: Marshall Maurice , Monday Lea M , Laporte Matthew , Fairfax Marilynn , Kennedy Timothy R , Abdel-Haq Nahed M , Salimnia Hossein , Dhar Sorabh 
Published: January 2025

Abstract

Background
Cell-free DNA Sequencing is a novel diagnostic test that utilizes next generation sequencing to detect pathogens directly from plasma. Microbial cell-free DNA (mcfDNA) can be detected for a large number of pathogens with high analytic sensitivity and specificity; however, testing may be cost prohibitive and the direct impact on clinical care decisions is unclear.

Methods
A retrospective review was performed at a large inner-city tertiary care medical center from 9/2021 to 3/2024 to assess the results of mcfDNA sequencing (using the Karius Test®) on committee approved patients for whom infection was suspected, and without a definitive diagnosis on traditional microbiologic testing or in patients not improving on current antimicrobial therapy. Clinical, microbiologic, and outcome data were collected, and the impact of a positive or negative test on clinical care decisions was abstracted. Test results were defined as impactful if they led to change in the antimicrobials (e.g. additional agents, dosing adjustment, or discontinuation of antimicrobials).

Results
Testing was completed on 25 patients, ranging from 5 months to 63 years (mean age 17 years), 16 (64%) female, 12 (48%) immunocompromised. The average result reporting time was 2.6 days. 23 (92%) patients received antibiotics prior to testing with an average duration of 30.8 days. A total of 13 (52%) of tests were positive by mcfDNA (with a mean of 1.6 organisms (SD=0.65) detected), and 7 (53.8%) polymicrobial results. The positive vs negative did not vary by suspected site, though sample size was small (Fig1). A total of 15 (60%) patients were positive by traditional microbiology tests with an organism correlation of 5 (20%). The mcfDNA results were impactful in 9 (36%) of the patients. A positive test was more likely to be impactful than a negative test (p=0.01). Ninety-day mortality was noted in 10 (40%) of patients and the average duration of hospitalization was 75.5 days – with no difference among patients with a positive mcfDNA (Table 1).

Conclusion
A positive mcfDNA sequencing result was noted to be clinically impactful in 36% of cases. Our data suggests that testing would be most beneficial for patients that lack a definitive infectious diagnosis or those not responding to appropriate therapy.

Disclosures
All Authors: No reported disclosures
P-2236. Performance Characteristics of Procalcitonin in the Inpatient Setting
Authors: Park Albert , Nakasone Trisha S , Kaushal Amit , Renault Cybele 
Published: January 2025

Abstract

Background
Procalcitonin (PCT) is a marker used in clinical decision-making for suspected bacterial infections. While its efficacy in guiding antibiotic de-escalation when used as a trend is well-established, its use as a stand-alone value is prevalent in both ICU and non-ICU settings despite the absence of evidence-based guidelines. Our study evaluates the performance of PCT as individual values and aims to discern organisms associated with true positive or false negative PCT values.Figure 1.Performance characteristics of PCT by site of infection

Methods
We performed a retrospective cohort study of patients at the Palo Alto Veterans Affairs Medical Center who underwent PCT testing from 1/1/2020 to 9/28/2023. We identified cultures drawn within 3 days of each PCT value to characterize the diagnostic performance of individual PCT values. Subsequently, we excluded organisms identified within 1 week of each other and performed one-sample z-tests for proportions to identify organisms associated with true positive (TP) or false negative PCT values based on site of infection.Figure 2.Microorganisms associated with true positive vs. false negative PCT from all culture sites

Results
3204 patients underwent PCT testing during the study period and 4027 cultures were drawn. Blood culture PCT sensitivity was 0.618, specificity 0.580, positive predictive value (PPV) 0.204, and negative predictive value (NPV) 0.896 (Figure 1). Respiratory culture PCT sensitivity was 0.555, specificity 0.594, PPV 0.620, and NPV 0.529. 2495 organisms separated by at least 1 week from each other were identified by culture. Enterobacterales (TP rate 82.2%), Staphylococcus aureus (TP rate 81.6%), Streptococcus pneumoniae (TP rate 84.6%), and non-pneumococcal Strep. (TP rate 74.1%) were strongly associated with positive PCT values in blood cultures (Figures 2 and 3). Enterobacterales (TP rate 63.1%) and Strep. pneumoniae (TP rate 74.2%) were strongly associated with positive PCT values in respiratory cultures.Figure 3.Microorganisms associated with true positive vs. false negative PCT by site of infection

Conclusion
While the NPV of individual PCT values is 89.6% for blood cultures, individual PCT values otherwise have limited diagnostic accuracy for active infections. Certain organisms show stronger associations with positive PCT values. Further investigation may offer insights into specific bacterial characteristics that drive PCT response in infected patients. However, in most cases, culture-identified organisms do not reliably correlate with positive PCT values.

Disclosures
All Authors: No reported disclosures
P-2239. RNA Signatures for Diagnosing or Predicting Febrile Illness: A Descriptive Analysis
Authors: Kozlowski Hannah N , Womersley Rebecca , Brophy-Williams Sam , Di Chiara Costanza , Huang Ryan S , Wong Nikki , Lee Katie , Peresin Joelle , Morris Shaun 
Published: January 2025

Abstract

Background
Fever is a common sign of illness; it may self-resolve or be present in serious illnesses requiring hospitalization. Investigating the cause of fever can be extremely resource intensive requiring multiple diagnostic tests and healthcare providers thereby delaying time to diagnosis. RNA molecules present in the blood can be easily detected and reflect a patient’s disease state, making them ideal biomarkers.
Our objective was to identify RNA common to signatures that diagnose and predict the outcome of febrile illnesses. Our secondary objectives were to assess whether signatures are being validated and translated.

Methods
We conducted a scoping review of published research articles, including preprints, from EMBASE and Medline that measured blood RNA in patients with febrile illness. Here we are analyzing a articles that used array or RNA-seq to generate original signatures.

Results
We identified 248 original blood RNA signatures for the diagnosis or prognosis of febrile illness. 154 were diagnostic, 56 prognostic, 15 diagnostic/prognostic and 23 exploratory. The most common illnesses studied were sepsis (n=83), viral infections (n=74) and tuberculosis (n=38). From all sepsis signatures there were 214 unique RNA and 74 RNA present in multiple signatures. The most common RNA, C3AR1 (complement receptor) and MPO (myeloperoxidase), appeared in 5 signatures. For viral infections there were 54 signatures, and IFI27 (interferon) appeared in 8 signatures. For tuberculosis there were 26 signatures, and the most common RNA were BATF2 (transcription factor) and FCGR1B (Fc receptor) each appearing in 4 signatures.
158/248 signatures were validated. Clinical sensitivity and specificity in validation groups were 54-100% and 79-97%, respectively. 9/248 studies claimed that they had filed or were filing for a patent.

Conclusion
Blood RNA molecules can be used for the diagnosis and prognosis of febrile illnesses. Currently, &lt; 65% of RNA signatures are validated and &lt; 5% of signatures are commercialized. In conducting this analysis, we encountered a lack of standardization in methods reporting. Further work to improve transparency and encourage validation is needed so RNA signatures can be adapted into simple, molecular diagnostic tests and translated for patient use.

Disclosures
Shaun Morris, MD, MPH, DTM&H, FRCPC, FAAP, GSK Canada: Advisor/Consultant|GSK Canada: Honoraria|Pfizer: Advisor/Consultant|Pfizer: Honoraria|Sanofi Canada: Advisor/Consultant|Sanofi Canada: Honoraria
P-2257. Pseudomonas aeruginosa and other Bacterial Infections After Lung Transplant: Risk Factors, Airway Stenosis and other Clinical Outcomes
Authors: Hernandez Acosta Ruben Alfonso , Gupta Simran , Chamberlin Elene , Woehl Ella , Connolly Erin M , O’Neill Audra , Coppolino Antonio , Sharma Nirmal S , Baden Lindsey R , Woolley Ann E 
Published: January 2025

Abstract

Background
Pseudomonas aeruginosa (PsA) and other bacterial infections after lung transplant can lead to worse patient outcomes. The aim of this study was to investigate whether isolation of microbial pathogens post-lung transplantation increased the risk of airway stenosis requiring bronchoscopic interventions.
Table 1Table 1.Demographic, donor/recipient characteristics, peri-operative/post-operative characteristics and outcomes.

Methods
A single-center retrospective study of lung transplant recipients (LTR) between January 2017 and October 2023 was performed. Our center performs routine surveillance bronchoscopies at 1, 3, 6 and 12 months. Donor/recipient characteristics, microbiologic data, bronchoscopy findings and interventions, and 1-year outcomes were analyzed.

Results
In this 6.8-year study period, 327 subjects underwent lung transplant with survival greater than 30 days. The most common indication for lung transplant was restrictive lung disease. 64 (20%) had PsA infections, 77 (23%) had non-PsA bacterial infections (infect), and 186 (57%) did not have a bacterial infection within 6-months post-transplant. Recipient and donor characteristics were similar among the cohorts. A greater proportion of the PsA and infect cohorts required dialysis and mechanical ventilation and/or ECMO for &gt;48 hours and had a longer index hospitalization than the uninfected cohort [Table 1]. A greater proportion of the PsA and infect cohorts developed airway stenosis requiring bronchial intervention (22% vs 17% vs 2%, p=&lt; 0.001). The median time to first infection post-transplant occurred prior to the development of stenosis (72 vs 112 days; 52 vs 110 days). 44% of LTR with PsA growth had fluoroquinolone resistance on the initial culture. Rates of rejection and 1-year survival were not statistically different among the cohorts.

Conclusion
PsA and other bacterial infections within the first 6-months post lung transplantation led to a higher incidence of airway stenosis requiring bronchial intervention but was not associated with increased mortality or rejection at 1-year. The impact of treating bacterial colonization and other strategies to minimize post-transplant bacterial infections and decreasing the occurrence and time to airway stenosis needs further study.

Disclosures
All Authors: No reported disclosures
P-2258. Characterizing real world infection risk in multiple myeloma patients receiving teclistamab
Authors: Guare Emma , Song Chen , Inoue Yoshitaka , Sandhu Manpreet , Sivik Jeffrey , Rakszawski Kevin , Naik Seema , Minagawa Kentaro , Mineishi Shin , Paules Catharine I 
Published: January 2025

Abstract

Background
Teclistamab is an anti-B-cell maturation antigen (BCMA) bispecific antibody used in relapsed, refractory multiple myeloma (MM) that induces durable responses but is associated with high rates of infectious complications. Real world data are needed to further characterize infection risk in patients receiving teclistamab.Table 1.Patient characteristics between infected and non-infected patients

Methods
A retrospective single-center study of teclistamab treated patients with relapsed, refractory MM from 1/1/2023 to 11/20/2023. Patients received teclistamab according to a step-up dosing regimen, with Day 0 defined as first step-up dose. The primary objective was to report the incidence, type, and timing of infection. Differences in demographics and clinical characteristics were described between infected and non-infected patients.Table 2.Patient outcomes on teclistamab between infected and non-infected patients

Results
19 patients received teclistamab; median age 72 years, 73.7% white, and 26.3% with Karnofsky performance status ≥ 80 (Table 1). 11 (57.9%) patients developed infections and 5 had more than one infection. There were 3 bacteremias, 6 other bacterial infections (urinary tract infection, pneumonia, cholangitis, osteomyelitis, sinusitis), 6 respiratory viral infections, and 2 cytomegalovirus (CMV) reactivations. There were no documented infections with herpes simplex virus, varicella zoster virus, Pneumocystis jirovecii, or fungal pathogens. The median time to any infection was 17 days (range 2, 266), with a median of 20 days (range 2, 123) to bacterial infection and 31 days (range 3, 266) to viral infection (Figure 1). Patient characteristics and antimicrobial prophylaxis strategies were largely similar between infected and non-infected patients (Table 1). There was a nonsignificant trend toward increased immune effector cell-associated neurotoxicity syndrome (ICANS) and increased use of steroids in the infected group. 10 patients in the infected group discontinued teclistamab (p=0.013) and 3 died (p=0.108, Table 2).Figure 1.Cumulative incidence of any infection (A), bacterial infection (B), and viral infection (C).

Conclusion
The incidence of infection was high amongst patients receiving teclistamab and increased with time. Individuals with infections were more likely to discontinue teclistamab. Further data are needed to inform guidance regarding infection prevention strategies and criteria for teclistamab interruption or discontinuation in this MM population with few other treatment options.

Disclosures
Kevin Rakszawski, MD, AstraZeneca: Speakers Bureau|Pfizer: Speakers Bureau Seema Naik, MD, ADC Therapeutics: Advisor/Consultant|ADC Therapeutics: Board Member|ADC Therapeutics: Honoraria|Janssen: Advisor/Consultant|Janssen: Board Member|Janssen: Honoraria|Onclive: Honoraria|Onclive: Speaker