bluuebunny/crossref_metadata_2025_split huggingface dataset:
P-631. RSV Prophylaxis with Nirsevimab in Infants: Systematic Review of Early Real-World Evidence on Effectiveness and Impact
Authors: Wick Moritz , Meyer Anna C , Damm Oliver , Wülfing Annika , Martyn Oliver , Kramer Rolf , Knuf M 
Published: January 2025

Abstract

Background
Respiratory syncytial virus (RSV) is a leading cause of respiratory tract infections and hospitalizations among infants worldwide. In 2023, the universal RSV immunization of all infants with the novel monoclonal antibody nirsevimab was introduced in several countries. This systematic review aims to summarize early real-world evidence on achieved immunization rates as well as on the impact and effectiveness of nirsevimab prophylaxis among infants.

Methods
A systematic literature search for full-text publications was conducted in the databases PubMed and Embase. The review included observational studies that investigated the impact or effectiveness of nirsevimab in routine use. Clinical research, decision analytic modeling studies, and studies describing the disease burden of RSV without direct reference to nirsevimab use were excluded.

Results
Five studies fulfilled the inclusion criteria, including one from the United States (US), one from Luxembourg, and three studies from different regions in Spain. Population-wide immunization rates were reported in Luxembourg and several Spanish regions, all exceeding 80%. Four studies estimated the effectiveness of nirsevimab in preventing RSV-related hospitalizations, including two population-based cohort studies and two case-control studies. The effectiveness of nirsevimab in preventing RSV-related hospitalizations was calculated at 88.7% (95%-CI: 70-96), 84.4% (95%-CI: 77-90), and 82.0% (95%-CI: 66-90) in the Spanish studies and 90% (95 %-CI 75-96) in the US. While no effectiveness estimate was reported in Luxembourg, the number of RSV-related hospitalizations among infants under 6 months decreased by 69% after nirsevimab introduction compared to the same period of the previous year.

Conclusion
High uptake was observed in both Luxembourg and Spain. Despite methodological differences between studies and varying implementation strategies between countries, observed effects of recommending nirsevimab to all infants were largely consistent. International evidence suggests that nirsevimab substantially reduces RSV-related hospitalizations and thus relieves the burden on healthcare systems during the RSV season.

Disclosures
Moritz Wick, MSc, Sanofi: Employee|Sanofi: Stocks/Bonds (Public Company) Anna C. Meyer, PhD, Sanofi: Employee Oliver Damm, PhD, Sanofi: Employee Annika Wülfing, PhD, Sanofi: Employee and may hold stocks Oliver Martyn, MPH, Sanofi: Employee of Sanofi|Sanofi: Stocks/Bonds (Public Company) Rolf Kramer, PhD, Sanofi: Employee of Sanofi|Sanofi: Stocks/Bonds (Public Company)
P-650. In vitro Activity of Cefiderocol and Comparator Agents Against Global Enterobacterales Isolates From Hospitalized Patients with Pneumonia Collected as Part of the SENTRY Surveillance Program (2020-2022)
Authors: Bryowsky Jason J , DeJonge Boudewijn L , Nguyen Sean T , Maher Joshua , Mendes Rodrigo E , Longshaw Christopher M , Takemura Miki , Yamano Yoshinori 
Published: January 2025

Abstract

Background
The in vitro activity of cefiderocol (CFDC) and comparator agents was evaluated against Enterobacterales isolates collected from patients with pneumonia during 2020-2022 as part of the SENTRY Antimicrobial Surveillance Program.

Methods
5,793 Enterobacterales (40.5% Klebsiella spp., 19.6% E. coli, 13.6% Serratia spp., 11.6% Enterobacter spp., 5.1% Proteus spp., 5% Citrobacter spp., 4.6% other) were collected from pneumonia patients and tested for susceptibility (%S) using CLSI broth microdilution with cation-adjusted Mueller-Hinton broth (CAMHB) or iron-depleted CAMHB for CFDC. Comparator agents included β-lactam/β-lactamase inhibitor (BL/BLI) combinations ceftazidime-avibactam (CZA), ceftolozane-tazobactam (C/T), imipenem-relebactam (I-R) meropenem-vaborbactam (M-V), piperacillin-tazobactam as well as meropenem (MEM), cefepime and ceftazidime . Susceptibility was interpreted according to 2024 CLSI|FDA, and EUCAST breakpoints. Carbapenem resistant Enterobacterales (CRE) was defined as resistant to imipenem and MEM. Multidrug-resistant (MDR) Enterobacterales was defined as nonsusceptible to at least 1 drug from ≥3 classes and extensively drug resistant (XDR) as susceptible to ≤2 classes per 2024 CLSI criteria.

Results
47% and 53% of isolates were from North America and Europe, respectively. CFDC, MEM, CZA, I-R and M-V all showed high susceptibility against all Enterobacterales isolates ( &gt;94/ &gt;97 %S using CLSI|FDA/EUCAST breakpoints). Against CRE, CFDC (99.7/83.5 %S CLSI|FDA/EUCAST) was the most active agent while CZA was the second most active (74.7%S CLSI|FDA and EUCAST). CFDC, CZA, I-R, M-V were most active against MDR isolates ( &gt;93/ &gt;94 %S CLSI|FDA/EUCAST) however, CFDC (94.4/81.1 %S CLSI|FDA/EUCAST) was the only agent with appreciable activity against XDR isolates.

Conclusion
CFDC demonstrated high in vitro activity against Enterobacterales isolated from hospitalized patients with pneumonia, including MDR and XDR isolates. Susceptibility for comparator agents, comprising BL/BLI combinations, was generally lower against isolates with CRE and XDR phenotypes. CFDC represents an important treatment option for pneumonia infections caused by Enterobacterales with presumed or defined CRE, MDR, or XDR phenotypes.

Disclosures
Jason J. Bryowsky, PharmD, MS, Shionogi: Employee Boudewijn L. DeJonge, PhD, Shionogi Inc.: Employee Sean T. Nguyen, PharmD, Shionogi Inc.: Employee Rodrigo E. Mendes, PhD, GSK: Grant/Research Support Christopher M. Longshaw, PhD, Shionogi BV: Employee Miki Takemura, n/a, Shionogi & Co., Ltd.: Employee Yoshinori Yamano, PhD, Shionogi & Co., Ltd.: Employee
P-652. Evaluation of Empiric Antibiotic Use for Community Acquired Pneumonia
Authors: Plechot Kamryn , Lee Helen , Park Steven 
Published: January 2025

Abstract

Background
Pneumonia is one of the most common infections resulting in hospitalization. Timely and appropriate empiric antibiotic treatment is crucial to improve prognosis in patients with community-acquired pneumonia (CAP). However, the use of empiric broad spectrum antibiotics is associated with serious consequences including development of antibiotic resistance and unintended adverse drug reactions. The Infectious Diseases Society of America (IDSA) guideline for the treatment of CAP recommends evaluation of specific risk factors to determine the need for empiric broad spectrum antibiotic coverage. The purpose of this study is to evaluate empiric antibiotic adherence to the IDSA CAP guideline.

Methods
This single center retrospective cohort study evaluated hospitalized adult patients aged 18 years and older who were started on empiric antibiotics for treatment of CAP in the emergency department. Patients were excluded if they were transferred from an outside hospital or were admitted with COVID-19. Baseline characteristics recorded included categorization of non-severe vs severe pneumonia, risk factors for multi-drug resistant organisms, empiric antibiotic therapy, and culture results. The primary outcome evaluated the percentage of patients who received appropriate empiric antibiotic treatment for CAP according to the IDSA guideline.

Results
A total of 150 patients were included in this study. Approximately 35% of patients presented with severe community acquired pneumonia. The initial antibiotic regimen administered in the emergency department for treatment of suspected CAP was consistent with the IDSA CAP guidelines in 48% of cases. Within twenty-four hours after admission, nearly 25% of cases were optimized to guideline directed therapy. Of the patients with positive culture results, empiric antibiotics were optimized within approximately 48 hours.

Conclusion
More than half of patients who were started on empiric antibiotics for CAP received broad spectrum antibiotics that were not indicated according to the IDSA guidelines. Most patient’s antibiotic regimen was optimized according to the guidelines within 48 hours. Additional stewardship efforts should be implemented in the emergency department to reduce empiric broad spectrum antibiotic use.

Disclosures
All Authors: No reported disclosures
P-655. Validation Of DRIP Score And Derivation of Local Score Predicting Multi-Drug Resistant Pathogens in Patients with Community Acquired Pneumonia
Authors: Ibragimova Nayle , Siegrist Emily A , Sassine Joseph , Neely Stephen , McCloskey Cindy B , White Bryan 
Published: January 2025

Abstract

Background
A subset of patients with community acquired pneumonia (CAP) may develop pneumonia due to multi-drug resistant organisms (MDROs), and identifying risk factors for MDROs can be challenging. The 2019 CAP guideline recommends using “locally validated risk factors” to determine the need for empiric treatment of MDROs. The Drug Resistance in Pneumonia (DRIP) score is a commonly used tool to predict MDROs in CAP and was validated in various institutions. We performed this study to validate the performance of the DRIP score in our patient population and to derive a local risk prediction score.

Methods
This was a retrospective chart review of patients with positive cultures from respiratory samples, blood, or pleural fluid for organisms known to cause pneumonia with data obtained from March 1, 2021 to January 31, 2023. Data on disease severity, comorbidities, previous hospitalizations, prior antibiotic use, and history of infections with MDROs were used to locally validate the DRIP score, and to derive local risk prediction score using logistic regression.

Results
Utilizing data from 201 patients, the DRIP score demonstrated a sensitivity of 52%, specificity of 86%, positive predictive value (PPV) of 74%, and negative predictive value (NPV) of 70% for an MDRO as the microbiological etiology of CAP, using a threshold of &gt; 4 points. Logistic regression analysis showed that history of infection with MDROs within 1 year, antibiotic use within 60 days, tube feeding, and chronic pulmonary disease were additional local risk factors in predicting CAP caused by an MDRO with a sensitivity of 49%, specificity of 86%, PPV of 73%, and NPV of 68%.

Conclusion
At our institution the DRIP score performed with lower sensitivity and lower NPV than the original DRIP validation study. The locally derived score based on the above 4 risk factors also demonstrated decreased performance. These findings may represent limitations of retrospective design where previous antibiotic history, hospitalization, and laboratory data were not always available, resulting in false-positive and false-negative results. Additionally, a proportion of false-negative results occurred in patients who had a post-influenza or post-COVID-19 secondary bacterial pneumonia due to methicillin-resistant Staphylococcus aureus.

Disclosures
Joseph Sassine, MD, Ansun BioPharma: Grant/Research Support|Cidara Therapeutics: Grant/Research Support|Community Infusion Solutions: Grant/Research Support|F2G: Grant/Research Support|Shionogi: Grant/Research Support Bryan White, PharmD, BCPS, BCIDP, Melinta: Advisor/Consultant|Shionogi: Grant/Research Support
P-669. Characteristics of hospitalized adult patients with hMPV infection in the post-covid era
Authors: Pyrpasopoulou Athina , Zarras Charalampos , Kouroupis Dimitrios , Michailidou Chrysi , Soukiouroglou Prodromos , Pateinakis Panagiotis , Mpani Konstantina , Terzaki Maria , Molyvas Dimitrios , Vagdatli Eleni 
Published: January 2025

Abstract

Background
Human Metapneumovirus (hMPV) is a recently described respiratory tract virus with significant morbidity among children of younger age. The widespread molecular diagnostic testing has identified hMPV as an important pathogen of the upper and lower respiratory tract even in adults, especially the older and immunosuppressed. The aim of this study was to identify patients hospitalized with hMPV infection and describe their characteristics.

Methods
Rhinopharyngeal samples of admitted patients with respiratory tract infection in the years 2021-22, 2022-23 and 2023-24 from October 1st – March 31st were tested by multiplex PCR analysis (Film array Respiratory panel, Biomerieux, France). Positive patients aged &gt;18 years for hMPV were included in the analysis. Demographic data, clinical and laboratory characteristics were recorded, and correlated with the duration of admission.

Results
In total, 1993 samples were tested (76 in 2021-22, 554 in 2022-23, and 1363 in 2023-24). Among those, 0, 13 and 8 adults were found to be positive respectively, 8 male and 13 female with a mean age of 68,1 years (±17,8). Upon admission, 52,4% of the patients had pulmonary infiltrates on X-Ray. Median CRP was 101,1mg/L (nv &lt; 5mg/L). In 39,1% of the patients another pathogen was isolated from clinical samples (in 4 patients from urine, in 2 from sputum and in 2 from blood cultures). All patients received antibiotics, 61,9% systemic steroids and 81,0% inhaled bronchodilators. One patient aged 94 years died. CRP levels were not associated with the detection of other pathogens (p=0,485). Mean duration of admission (7,3±4 days) was not associated with age. The co-isolation of other pathogens, and CRP levels tended to correlate with longer duration of hospitalization (p=0,100, and p=0,068 respectively), Table I.

Conclusion
HMPV is implicated in respiratory tract infections. Clinical presentation is associated with respiratory distress with significantly elevated inflammatory markers, requiring inhaled bronchodilators and systemic steroids. The significant majority of the patients recovers without sequelae.

Disclosures
Athina Pyrpasopoulou, MD PhD, Gilead: Honoraria|Pfizer: Honoraria
P-673. Respiratory Syncytial Virus (RSV) Hospitalizations During Off-Season Months Among Infants in US
Authors: Law Amy W , Lin Jay , Judy Jennifer , Cane Alejandro D , Pugh Sarah J 
Published: January 2025

Abstract

Background
The CDC currently recommends two prevention options to help protect infants against RSV-associated lower respiratory tract disease during a typical RSV season, defined as October through March. However, annual and geographic variability in RSV seasonality exists. The study evaluated the burden of RSV hospitalizations occurring outside a typical season (i.e., April – September).

Methods
Infants aged &lt; 12 months old hospitalized with RSV were identified from the PINC AI Healthcare Database (7/1/2018 to 6/30/2023) for this descriptive cohort study. Because age is reported in years, a prior birth hospitalization record was required to determine age in months for RSV hospitalization. A surveillance year was defined by the period of July 1 of each year to June 30 of the following year. Monthly RSV hospitalizations were tallied for each of the 9 U.S. census divisions and by age group (&lt; 3, 3-5, 6-8, 9-11 months). Seasonality of RSV cases among all infants &lt; 1 year, regardless of the ability to identify age in months, was evaluated as a sensitivity analysis.

Results
A total of 56,425 RSV hospitalizations were identified among infants &lt; 1 year of age, of which, 36% (n=20,531) of patients had a birth record. RSV hospitalization counts during the 5 surveillance years were 4,574 (2018/19), 4,926 (2019/20), 452 (2020/21), 4,344 (2021/22), and 6,235 (2022/23). Overall, 22% (n=4,510) of RSV hospitalizations occurred during off-season months, with 83% of these off-season cases occurring in June – September across various divisions (Fig. 1). Of all RSV hospitalizations that occurred during off-season, 45.5% (n=2,054) were among infants &lt; 3 months. Seasonal patterns were similar across age groups (Fig. 2). A sensitivity analysis showed consistent seasonal patterns among all infants &lt; 1 year of age.

Conclusion
This large-scale, real-world database analysis showed over 1 in 5 infants hospitalized with RSV were infected during off-season with varying rates by geography. The current recommendations may limit protection options for infants exposed to RSV outside the typical season.

Disclosures
Amy W. Law, PharmD, Pfizer Inc.: Employee|Pfizer Inc.: Stocks/Bonds (Public Company) Jay Lin, PHD, MBA, Pfizer: Advisor/Consultant Jennifer Judy, MS, PhD, Pfizer: Employee|Pfizer: Stocks/Bonds (Public Company) Alejandro D. Cane, MD, PhD, Pfizer: Employee|Pfizer: Stocks/Bonds (Public Company)|Pfizer: Stocks/Bonds (Public Company) Sarah J. Pugh, PhD, MPH, Pfizer Inc.: Employee|Pfizer Inc.: Stocks/Bonds (Public Company)
P-675. Online Clinician Education Curriculum Results in Performance Changes in Clinical Practice for Recommending Available Respiratory Syncytial Virus Vaccines in Older Adults
Authors: Nair Arun S , Capparelli Catherine , Misiuta Iwona 
Published: January 2025

Abstract

Background
This study examined whether online continuing medical education (CME/CE) focused on evidence-based best practices for recommending available respiratory syncytial virus (RSV) vaccines would result in improved understanding of adults disproportionally affected by RSV, the clinical guidance of available vaccines, and communication strategies to encourage older adults to get vaccinated for RSV.

Methods
Clinicians who participated across a curriculum of 3, live and online, 30-minute CME/CE video discussions between experts. Performance was assessed by inviting learners to complete a survey 30-60 days post-education, identifying practice changes and the degree to which clinicians experience barriers to those changes. The data was collected from 12/29/2023 to 04/04/2023.

Results
There were 13,232 learners consisting of PCPs, Pharmacists, Advanced Practice Providers, and others who completed the survey. The analyses from the program showed that ∼90% of learners made a practice change or had practices reinforced due to education. Five key practice changes to recommending available RSV vaccines included:
Educate eligible patients/caregivers on the risk of RSV in older adults (93% PCPs, 93% Pharm, 95% NPs/Nurses, 92% PAs)
Recommending available RSV vaccines for older adults (93% PCPs, 93% Pharm, 95% NPs/Nurses, 93% PAs)
Use alternative communication methodologies with patients (15% PCPs, 21% Pharm, 14% NPs/Nurses, 16% PAs)
Collaborate with different members of the patient’s care team (11% PCPs, 22% Pharm, 13% NPs/Nurses, 16% PAs)
Some of the practice barriers identified by the learners include:
Lack of clear recommendations from evidence-based guidelines
Lack of time to educate patients on the importance of getting vaccinated for RSV
Patient concerns/questions regarding available RSV vaccines
Organizational limitations to providing the vaccine

Conclusion
The practice changes identified in this assessment provide compelling evidence that participation in online CME/CE prompts adoption of changes in practice related to RSV vaccination. Future education is needed to address the barriers identified in this assessment.
Acknowledgement:
This education was supported by an independent educational grant from Pfizer Inc. and in partnership with Immunize.org

Disclosures
All Authors: No reported disclosures
P-676. Risk Factors Associated with Longer Hospital Stay in Elderly Patients with Respiratory Syncytial Virus Infections
Authors: Bhargava Ashish , Szpunar Susan M , Sharma Mamta , Saravolatz Louis 
Published: January 2025

Abstract

Background
Annually, 3-7% of healthy older patients and 4-10% of high-risk adults develop respiratory syncytial virus (RSV) infections. Elderly patients above 65 years of age, with congestive heart failure, chronic lung disease, or weakened immune systems are at high risk for severe RSV infections. Little is known about the factors that are associated with the length of hospital stay (LOS) among these elderly individuals.

Methods
A multicenter historical cohort study was conducted on elderly patients ( &gt;65 years of age) hospitalized for laboratory-confirmed RSV-related diseases in Ascension hospitals in Southeast Michigan between January 2017 and December 2022. Hospitalized patients were identified using ICD 10 codes for RSV-related diseases. Electronic medical records were reviewed after IRB approval. LOS was categorized as below the mean LOS or at the mean and above. Data were analyzed using Student’s t-test, the chi-squared test, the Mann-Whitney U test and logistic regression using SPSS v. 29.0.

Results
Of 239 patients, the mean (sd) age of the cohort was 78.3 + 8.4 years, 157 (65.7%) were female and 176 (73.6%) were white. The mean body mass index (BMI) was 29.5 + 8.8 kg/m2. The mean Charlson Weighted Index of Comorbidity (CWIC) score was 2.4 + 2.0. The mean hospital LOS was 7.5 + 5.1 days. Prolonged LOS was noted in 89 (37.2%) patients. Factors associated with longer LOS ( &gt;7.5) in univariable analysis were chronic lung disease, solid tumors, CWIC score, smoking status, home oxygen, oxygen requirement during hospitalization, qSOFA, abnormal admission chest x-ray (CXR), lower respiratory tract infection, and respiratory failure requiring intubation. The multivariable logistic regression revealed that predictors for prolonged LOS among elderly patients were smoking status (OR, 2.2; 95% CI 1.2-4.0), abnormal admission CXR (OR, 2.1; 95% CI 1.2-3.7), and respiratory failure requiring intubation (OR, 9.4; 95% CI 2.6-34.4).

Conclusion
Our study finds that patient’s smoking status, abnormal admission CXR and respiratory failure requiring intubation were significantly associated with prolonged LOS among elderly patients with RSV infections. Knowing these risk factors may help identify patients who would benefit from early interventions to mitigate the duration of hospitalization.

Disclosures
All Authors: No reported disclosures