bluuebunny/crossref_metadata_2025 huggingface dataset:
P-623. Multicentric Prospective Study on Invasive Pneumococcal Disease (IPD) and Community Acquired Pneumonia (CAP) in hospitalized children, Serotype distribution and Antimicrobial Susceptibility Test (ATS) in Argentina after 11 years of Pneumococcal Conjugated Vaccine (PCV13) in National Immunization Program (NIP)
Authors: López Eduardo L , Uriarte Valeria , García Mariel , Gomila Andres , Ezcurra Gustavo Cesar , Vozza Lola , Bertoni Liliana , Morales Adrián , Teplitz Eduardo , Argüello Claudia Diaz , Aguirre Clarisa , Lara Claudia , Corso Alejandra , Contrini María M
Published: January 2025

Background

PCV13 was included in Argentina NIP in 2012 with 2 +1 schedule at 2, 4 and 12-15 mo of age. After 11 yrs program, from May´23-Mar´24 we carried out a multicentric prospective study to evaluate impact of pneumococcal disease, S.pneumoniae (Spn) serotype(S) distribution and AST.

Methods

Study Population: 1 mo to 10 yr old hospitalized children by IPD and/or CAP at 8 pediatric centers; f-up 6 mo. Clinical record was completed for subjects who met inclusion criteria after written Inform Consent from parents/legal guardian was obtained. Spn isolates from normally sterile fluids were sent to National Reference Laboratories for serotyping by Quellung reaction and AST by agar dilution (CSLI 2024).

Results

Subjects: 149; mean age(±SD): 49.2(±34) mo; male 83(55.7%). Age distribution: <1yr: 23(15.4%); 1-2 yr: 36(24.1%); 3-5 yr: 49(32.9%); >5 yr: 41(27.5%). Two main risk factors for IPD/CAP were: smoker at home 51(34.2%) and daycare attendance 41(30.2%). Diagnosis on admission: CAP 97(65.1%); pneumonia with empyema 54(36.2%); bacteremia 22(14.8%); meningitis 7(4.7%); peritonitis 5(3.4%); other 13(8.7%). Spn vaccination status was verified in 137/149(90.5%) subjects; being complete by age in: <1yr: 65.2%; 1-2yr: 80.6%; 3-5yr: 89.8%; >5yr: 87.8% subjects. Among 40 Spn the most prevalent S (72.5%) were (n): 12F(6), 3(4), 19A(3), 24B(3), 38(3), 24F(2), 23B(2), 1(2), 10A(2) and 11A(2). Other S were: 13, 14, 34, 15A, 15B, 16F, 17F, 22F, 23A, 7C and 9N. % No-susceptibility (NS) was: penicillin (PEN) meningitis/no meningitis 35/5, cefotaxime meningitis/no meningitis 7.5/0. All were 100% susceptible to rifampicin, vancomycin, ceftaroline and ceftobiprole. NS-PEN (CIM ≥0.12ug/ml) was associated with S 24B, 24F, 19A, 23B (71.4%). S coverage was 25%(10/40) for PCV13 (S 3, 19A and 14); and 55%(22/40) for PCV20 (S 12F, 3, 19A, 10A, 11A, 14, 15B and 22F).

Conclusion

1. Children < 1yr old have the highest rate of incomplete Spn vaccination rate,then it is needed to improve the vaccine coverage in this age group in Argentina

2. Our preliminary data show an estimated coverage of 25% with PCV13 and 55% with PCV20

3. According to Spn S detected in IPD and CAP, PCV20 could increase the coverage by 30% in children in Argentina

Disclosures

All Authors: No reported disclosures
P-629. The Health and Economic Impact of the PCV15 and PCV20 Priming Series during the First Year of Life in the US
Authors: Rozenbaum Mark , Althouse Benjamin , Tort Maria J , Cane Alejandro D , Farkouh Raymond
Published: January 2025

Background

Two pneumococcal conjugate vaccines, 15- (PCV15) and 20- (PCV20) valent formulations, are currently recommended for US infants in a 3+1 schedule. The first 3 doses are administered during the first year of life (‘priming doses’ at 2, 4, and 6 months) while the booster dose is given at 12 to 15 months. This study evaluated the health and economic impact of priming doses within the first year of life.

Methods

Using a decision-analytic model, we calculated the health outcomes and economic implications from a healthcare payer perspective over a 12-month duration. Our epidemiological data were drawn from peer-reviewed studies. Estimates for vaccine effectiveness on invasive pneumococcal disease (IPD), inpatient and outpatient community-acquired pneumonia (CAP), and otitis media (OM) were extrapolated from established PCV13 effectiveness and PCV7 efficacy studies and adjusted for current serotype coverage of PCV15 and PCV20. Direct medical costs related to the treatment of IPD, CAP and OM were extracted from the literature and inflated to 2024 dollars. Aligned with CDC assumptions, we projected that children would experience 75.6% of the full vaccine effectiveness in their first year of life.

Results

Vaccination of newborns in the United States at 2, 4, and 6 months using PCV20 could potentially prevent an estimated 137 cases of IIPD, 3,150 cases of pneumonia, 54,000 cases of OM, and 38 deaths during the first year of life. This could result in savings of approximately 76M dollars in direct medical costs. When compared to universal administration of PCV15, PCV20 offers greater case prevention due to its broader serotype coverage. Specifically, using PCV15 instead of PCV20 would result in 54 fewer prevented cases of IPD, 26,200 fewer cases of otitis media, 1,526 fewer pneumonia cases, and 16 fewer prevented deaths.

Conclusion

This study showed that, in the US, vaccinating with PCV20 would yield a significantly greater health and economic return during the first 12 months of life compared to PCV15 due to the 5 additional serotypes covered by PCV20.

Disclosures

Mark Rozenbaum, PhD, M.B.A., Pfizer: Stocks/Bonds (Public Company) Benjamin Althouse, PhD, Pfizer: Stocks/Bonds (Public Company) Maria J. Tort, PhD, Pfizer Inc: Stocks/Bonds (Public Company) Alejandro D. Cane, MD, PhD, Pfizer: Employee|Pfizer: Stocks/Bonds (Public Company)|Pfizer: Stocks/Bonds (Public Company) Raymond Farkouh, PhD, Pfizer: Stocks/Bonds (Public Company)
P-635. “Exploring Knowledge and Barriers to HPV Vaccination among Mothers of 9-14 Years Olds - a Descriptive Study in a Tertiary Care Hospital”
Authors: Nair Tara B , Kumar C Dr Shiju , Vishnu Dr B S , Vincent Dr Lizy
Published: January 2025

Background

Human Papillomavirus (HPV) vaccination is pivotal in preventing cervical cancer and other HPV-related diseases. However, uptake remains suboptimal, partly due to parental knowledge gaps and barriers

Association between Knowledge Level & Factors Hindering Vaccination

Methods

This prospective descriptive study was conducted in a tertiary care hospital in Trivandrum, Kerala. A structured preformed questionnaire was administered to total of 268 participants who were mothers of girl children aged 9-14 years attending outpatient pediatric department. The questionnaire assessed knowledge about HPV, the vaccine available for HPV, and factors influencing vaccinations.

Results

Among the 268 study subjects, a significant majority, comprising 91.4%, demonstrated a commendable level of understanding regarding the HPV vaccine. Various factors were identified as barriers to vaccination uptake, with safety concerns being the most prevalent, cited by 91% of respondents. Additionally, a notable percentage (36.9%) expressed uncertainty regarding potential future infertility concerns linked to the vaccine, while 67.2% cited the high costs associated with it as a deterrent. Nevertheless, an overwhelming majority (99.6%) acknowledged the indispensable role of vaccines in disease prevention.

Conclusion

The substantial knowledge observed within our study cohort can be credited to the state's commendable literacy rates and the concerted efforts of governmental and non-governmental entities to fortify healthcare awareness. This study provides valuable insights the gaps in knowledge and measures to augment HPV vaccination rates among adolescents.

Disclosures

All Authors: No reported disclosures
P-667. The Impact of Delay in the Start of Effective Antibiotics on the Course of Pseudomonas aeruginosa Pneumonia: a Retrospective Study
Authors: Ito Takanori , Kanai Osamu , Fujita Kohei , Tanizawa Kiminobu
Published: January 2025

Background

The decision to target up to Pseudomonas aeruginosa at the start of antibiotic treatment of bacterial pneumonia is a major turning point. Since P. aeruginosa itself is a mildly virulent bacterium, we experience that P. aeruginosa pneumonia is improved even targeting P. aeruginosa after its detection. We studied the differences in mortality among P. aeruginosapneumonia cases depending on whether antibiotics with anti-P. aeruginosa activity were administered from the first time (empirical group, group E) or after the detection of P. aeruginosa (definitive group, group D).

Methods

We retrospectively studied patients who received antibiotics with anti-P. aeruginosa activity for P. aeruginosa pneumonia at our hospital from October 2016 to December 2023. The primary endpoint was 30-day mortality, and the secondary endpoints were total duration of treatment, length of hospital stay, and adverse events. This study was conducted with the approval of the Ethics Committee of our hospital (approve number: 23-075).

Results

There were 95 applicable participants. The group E had 62 patients and the group D had 33 patients. In the background between the two groups, clinical frailty scale was significantly worse, and impaired consciousness and hypotension. The 30-day mortality was not significantly different between the two groups (group E vs. group D, 1.6% vs. 3.0%, p > 0.99). And there were also no significant differences in mean total duration of antibiotics treatment, mean length of hospital stays, or incidence of adverse events between the two groups (13.2 days vs. 12.9 days, 83.8 days vs. 58.5 days, 54.8% vs. 63.6% in the group E vs. group D, respectively).

Conclusion

There was no statistical difference in mortality by the delay in targeting P. aeruginosa for treatment of P. aeruginosapneumonia. It was suggested that this could lead to appropriate use of broad-spectrum antibiotics that target even P. aeruginosa.

Disclosures

All Authors: No reported disclosures
P-687. Respiratory Syncytial Virus (RSV) Testing Patterns among Medically Attended Cases of Acute Respiratory Illness from 2016 to 2023
Authors: Singer David , Wang Yan , Wu Aozhou , Horn Emily K , La Elizabeth M , Gerber Susan , Boland Joanna , Betts Keith A
Published: January 2025

Background

Historically, respiratory syncytial virus (RSV) has been an underrecognized cause of acute respiratory illness (ARI) in adults and patients have been infrequently tested for RSV. This study aimed to describe RSV testing patterns among adults over time and by setting of care.

Methods

This was a retrospective cohort study, analyzing the Optum de-identified Electronic Health Record data set (Optum EHR) from October 2015 to June 2023. Medically attended ARIs were identified (using ICD-10-CM codes) in adults aged ≥ 50 years with ≥ 12 months of activity in the Optum EHR. Individuals could have multiple ARIs included over the study period. ARIs were classified by epidemiological year (July 1 to June 30), RSV season, and by most intensive setting of care during the ARI (outpatient, emergency department [ED], or inpatient). The percentage of ARIs tested for RSV was reported by time period and other characteristics. Influenza and SARS-CoV-2 testing patterns were also reported for context.

Results

The study included 22,475,891 ARIs among adults aged ≥50 years. The mean age at the time of ARI was 67.3 years. Key baseline characteristics of ARI episodes are reported in Table 1. The percentage of ARIs tested for RSV generally increased each epidemiological year, from 1.3% in 2016-17 to 5.9% in 2022-23 (Table 2). RSV testing was higher during RSV seasons than outside of seasons prior to the COVID-19 pandemic period. Across epidemiological years, the percentages of medically attended ARIs tested for RSV was highest among ARIs that involved inpatient care (9.5-27.5%), followed by ED visits (1.4-17.9%), and outpatient visits (0.3-1.4%).

Conclusion

Despite increased awareness of the importance of RSV as a pathogen in older adults and adults with comorbidities, RSV testing remains infrequent. RSV testing has increased over time, particularly among ARIs involving inpatient care. These findings suggest that studies relying on recent real-world data could substantially underestimate RSV burden. Future research may further explore ARI or patient characteristics associated with RSV testing.

FUNDING: GSK (study identifier: VEO-000617)

Disclosures

David Singer, PharmD, MS, GSK: employee|GSK: Stocks/Bonds (Public Company) Yan Wang, ScD, Analysis Group: Employee Aozhou Wu, PhD, Analysis Group: Employee Emily K. Horn, MSc, GSK: employee|GSK: Stocks/Bonds (Private Company) Elizabeth M. La, PhD, GSK: employee|GSK: Stocks/Bonds (Private Company) Susan Gerber, MD, GSK: Employee Joanna Boland, PhD, MS, Analysis Group: Employee Keith A. Betts, PhD, Analysis Group: Employee
P-690. Quantifying The Health Equity-Related Public Health Impact of Influenza Vaccination: A Pilot Study for United Kingdom
Authors: Biundo Eliana , Soares Victoria G , Jansen Irshaad , Mrkvan Tomas
Published: January 2025

Background

While influenza vaccination is known to positively impact health equity, vaccination recommendations vary by country and may not always optimize equity considerations. For example, while the US recommends vaccination for everyone aged ≥6 months, the UK’s recommendations are limited to adults aged ≥65 years, those aged < 65 years at higher risk, and specific age groups of children. This pilot study measured the health equity-related impact of broader UK vaccination recommendations.

Methods

Data availability determined that this analysis focused on adults aged ≥50 years in England. Health equity impact was assessed by Index of Multiple Deprivation Quintiles (IMDQ) and age (50–64, ≥65 and ≥50 years). Influenza risk and prevented cases were estimated using influenza hospital admission rates, vaccination effectiveness and coverage (flu season 2022/23). An exploratory analysis was conducted assuming extension of UK national guidance to all ≥50-year-olds with equal vaccine uptake in 50–64-year-olds as in ≥65-year-olds.

Results

This study estimated vaccination currently prevents ∼80% of all preventable cases in ≥65-year-olds vs. 47% in 50–64-year-olds. Influenza risk is highest in IMDQ1 (most deprived group) across age and vaccination status. Influenza prevention from vaccination of 50–64-year-olds (coverage ∼50%) in England is greatest in IMDQ1 (16% of all preventable cases prevented vs. 4% in IMDQ5, least deprived) (Table 1). Assuming extension of UK national guidance to all ≥50-year-olds with similar coverage to ≥65-year-olds (∼80%) may prevent ∼26% of preventable cases in IMDQ1 and ∼8% in IMDQ5 (Tables 1−3).

Conclusion

Expanding influenza vaccination to other age groups can help increase health equity by improved influenza prevention. Greater vaccination coverage would enable the highest reduction in cases, especially in the most socially disadvantaged groups.

Funding: GSK

Disclosures

Eliana Biundo, MSc, GSK: Employee|GSK: Stocks/Bonds (Private Company) Victoria G. Soares, MBA, GSK: Advisor/consultant Irshaad Jansen, MSc, GSK: Employee|GSK: Stocks/Bonds (Private Company) Tomas Mrkvan, PhD, GSK: Employee|GSK: Stocks/Bonds (Private Company)
P-697. Increases in Ages and Bacterial Coinfection in Hospitalized Children with Respiratory Syncytial Virus Infection in Taiwan:2019- 2023
Authors: Yi Gui Jia , Hsing En-Wei , Huang Chong-Wei , Tsao Kuo Chien , Hsieh Yu-Chia , Chen Chih-Ho
Published: January 2025

Background

Efforts to expand RSV epidemiological data are crucial, especially considering upcoming interventions such as long-acting monoclonal RSV-neutralizing antibodies and maternal vaccines for RSV prevention, which have the potential to alter the landscape.

Methods

A retrospective study was conducted at Chang Gung Memorial Hospital, analyzing children hospitalized with RSV infection before, during and after the COVID-19 pandemics from 2019 to 2023. Clinical data were collected and stratified by year for analysis. Plasma microbial free-DNA sequencing (mcfDNA) was performed on selected cases with C-reactive protein > 100 mg/L to enhance diagnostic yields.

Results

A total of 997 children hospitalized for RSV infection was enrolled. In 2019, 2022, and 2023, the incidence of RSV-related hospitalization among children aged 0-4 years remained relatively stable, ranging between 600-700 per 100,000. However, in 2020 during a strict national nonpharmaceutical intervention, there was a notable spike, doubling to reach a peak, followed by an 80% decrease in 2021. In age subgroup analyses comparing 2022 and 2023 to 2019, the incidence of RSV-related hospitalization among children aged < 2 years gradually decreased from 1576 per 100,000 in 2019 to 1212 per 100,000 in 2022 (P=0.03) and 1262 per 100,000 (P=0.07) in 2023. Conversely, the incidence of RSV-related hospitalization among children aged 2-4 years significantly increased from 124 per 100,000 in 2019 to 347 per 100,000 in 2022 (P< 0.001) and 419 per 100,000 in 2023 (P< 0.001). Independent risk factors for CRP >100 mg/L in RSV cases were year 2023 (aOR:4.03, P=0.008) and age 2-4 years (aOR:3.33, P< 0.001). In 2023, among 23 children with CRP >100 mg/L, Hemophilus influenzae was identified in two children receiving bronchoalveolar lavage, and in 73% (11/15) of samples underwent plasma mcfDNA.

Conclusion

Following the COVID-19 pandemic, there was a proportional shift in RSV cases towards children over 2 years of age. Increase in age exhibited a higher rate of bacterial infections, particularly with Haemophilus influenzae. These findings offer critical implication for RSV prevention strategies and treatment of community-acquired pneumonia.

Disclosures

All Authors: No reported disclosures
P-698. Evaluating Modes of Influenza Transmission (EMIT-2): An Ongoing Controlled Human Influenza Virus Infection Transmission Trial (CHIVITT)
Authors: Lai Jianyu , Coleman Kristen K , Tai Sheldon , Hong Filbert , Maldonado Isabel Sierra , Esparza Yi , Sobhani Hamed , Srebric Jelena , Bhattacharya Proma , DeVoe Don L , Chen Wilbur , Milton Donald K
Published: January 2025

Background

The relative importance of inhalation, spray, and touch transmission remains poorly understood. We implemented a randomized controlled trial incorporating community-acquired cases using behavioral, personal protective equipment, and environmental interventions as tools to understand the pathway of influenza transmission.Figure 1.Study design and timeline of cohorts with naturally infected influenza Donors

Methods

We recruited healthy volunteer Recipients and influenza Donors with PCR-confirmed community-acquired infection to a hotel quarantine. We randomized healthy volunteers to Intervention (hand hygiene and face shield) and Control Recipients. Donors and Recipients interacted in an “Event Room” with controlled ventilation (0.2–0.5 air changes per hour) and relative humidity (20-40%). We collected ambient air and personal bioaerosol exposure samples using NIOSH BC-251 samplers. We also deployed a novel cascade to liquid media bioaerosol sampler. Donors provided exhaled breath samples using a Gesundheit-II (G-II) sampler. We analyzed samples using dPCR and florescent focus assay.Figure 2.Viral RNA load in GII samples and MTS

Results

We ran four cohorts (February 2023 and January-February 2024); two with naturally infected influenza Donors (Figure 1). We exposed 11 Recipients (mean age: 36; 55% female) to 5 influenza Donors (mean age: 21; 80% female). Preliminary results show that eleven G-II fine (< 5µm), one G-II coarse (≥5µm) (Figure 2), four NIOSH ambient air (three ≥4µm and one 1-4µm), and three NIOSH personal bioaerosol exposure samples (two 1-4µm and one less than 1µm) were PCR positive. Virus was cultured from an ambient bioaerosol sample. No Recipient developed influenza-like illness or PCR-positive swabs; serology is pending.

Conclusion

We demonstrated that it is feasible to recruit Donors with new onset community-acquired influenza infections and expose Recipients under highly controlled conditions. Although initial experiments did not produce PCR-positive secondary infections, much will be learned by analyzing the immunity of the exposed Recipients and the inhaled dose of virus. This unique randomized controlled trial will provide a definitive assessment of the role of inhalation transmission and critical data on which to build effective interventions to prevent transmission.

Disclosures

Donald K. Milton, MD, DrPH, Lumen Bioscience, Inc: Advisor/Consultant|Lumen Bioscience, Inc: Stocks/Bonds (Private Company)
P-702. Epidemiology of Respiratory Pathogens and the Impact of Seasonality, Patient Demographics, and Diagnostic Testing Approach: A Retrospective Analysis from 2022 to 2023
Authors: Gonzalez Kaisha
Published: January 2025

Background

Respiratory tract infections (RTIs) are a significant concern for public health due to their widespread transmission and high rates of illness and death reported globally. The use of multiplex molecular methods has allowed for the detection of a broad range of respiratory viruses and their subtypes, as well as some bacteria. This study investigates the epidemiology of respiratory pathogens detected in different demographic populations, emphasizing the importance of a flexible diagnostic testing approach to adapt to the complex dynamics of respiratory pathogens during the peak season.

Distribution Rates of Respiratory Targets in Young, Adult, and Elderly Patients (n=1,520)

Analysis of distribution rates of 19 respiratory targets during the respiratory season of 2022-2023, stratified by age.

Methods

During the 2022-23 respiratory disease season, the Diasorin LIAISON PLEX® Respiratory Flex Assay was used to prospectively test 1,520 patients across six clinical sites in the United States. As part of an observational study, retrospective analyses were conducted to compare the detection rates and frequencies of 19 respiratory targets (14 viral and 5 bacterial targets). The results were stratified by age.

Results

Many respiratory pathogens displayed age- and season-specific patterns. Enterovirus/rhinovirus was detected more frequently in patients < 21 years old (27%) than in the adult group (14%) and elderly group (9%), p< 0.01. Flu A prevalence was found to be higher in adults (21-65 y) at 25% and 33% in the elderly ( >65 y) population, p≤0.05. Individuals < 21 years had a lower incidence of SARS-CoV-2 (8%) compared to adults (35%) and the elderly (40%), p< 0.001. The most common viruses found in all three populations were flu A, human coronavirus, SARS-CoV-2, and flu A-H1, while the other pathogens were more population-specific.

Conclusion

The results of the study offer valuable insights into the complex dynamics of respiratory pathogens. They emphasize the importance of flexible multiplex PCR testing strategies that consider the different circulating patterns of these pathogens across different populations. This approach can help customize respiratory testing based on factors such as seasonality, patient demographics, and acceptable costs, and in line with diagnostic stewardship, adapt testing protocols to meet the specific needs of respiratory testing.

Disclosures

All Authors: No reported disclosures
P-722. Troponin I Levels on Admission as a Predictor of Clinical Outcomes in Respiratory Viral Infection
Authors: Sherchan Robin , Morones Rosalba Gomez , Covarrubias Gonzalez Miguel A , Morales-Aseff Daniela , Aguayo-Millan Claudia , Arellano Lopez Alonso Benjamin , Martinez Felipe Salinas , Goldin Evan , Beenhouwer David , Rodriguez-Barradas Maria C
Published: January 2025

Background

Cardiac troponin I (Tn) is a biomarker for myocardial injury, often elevated in acute coronary syndrome (ACS), sepsis, and acute respiratory viral infection (ARI). The significance of elevated Tn in patients admitted with ARI is not clear. We evaluated readmission due to cardiovascular (CV) events (ACS, heart failure (HF), or stroke) and all-cause mortality in hospitalized ARI patients with elevated Tn on admission.

Methods

This is a 2-VA site sub-study of SUPERNOVA (Surveillance Platform for Enteric and Respiratory Infectious Organisms in the VA), that included patients with positive nasopharyngeal viral polymerase chain reaction and Tn obtained within 48 hours of admission during 3 ARI seasons (S): S1, 10/2016-9/2017; S2, 10/2017-9/2018; and S3 11/2021-1/2022. Outcomes assessed were 30, 90, and 365-day all-cause mortality and 365-day readmissions due to CV events.

Results

450 patients were included with >90% males. The mean age (years) and Charlson Comorbidity Index (CCI) for elevated Tn and normal Tn groups were 71 and 67, and 6.5 and 5.1, respectively. Rhinovirus (22%) and Influenza A (20%) were the predominant viruses in the first two seasons. All S3 patients had SARS-CoV-2 (34%) (Table 1). The elevated Tn group had significantly higher 90-day mortality in S1 and S3, and 365-day mortality in S3 (Table 2). For all seasons combined, the elevated Tn group had significantly higher 90-day mortality (17% vs 6%), 365-day mortality (26% vs 16%), and higher HF readmissions (18% vs 7%) than the normal Tn group (Table 3). When adjusted for CCI, the difference was not significant for 365-day mortality (p=0.29), but the composite outcome for 365-day mortality and readmission for HF (40% vs 22%) remained significant (p=0.02). The 365-day mortality was not significantly different for the elevated Tn group across seasons.

Conclusion

ARI patients with elevated Tn had a higher risk of all-cause mortality and HF readmission within one year, which remained statistically significant after adjustment for comorbidities for the 90-day mortality and HF readmission. The composite outcome of 365-day mortality and HF readmission was significantly higher in the elevated Tn group. These findings underscore the prognostic value of Tn in predicting CV and mortality outcomes in hospitalized patients with ARI.

Disclosures

All Authors: No reported disclosures
P-736. No Air Don’t Care: Lack of gas on imaging is associated with a longer time to surgical intervention in patients with necrotizing fasciitis
Authors: Stevens Amanda , Salar Aveen , Silva America , Huang Alex , Touleyrou Lauren , Dhar Sorabh , Monday Lea
Published: January 2025

Background

Although necrotizing fasciitis is a life-threatening infection, initial symptoms may be non-specific. The presence of gas on plain X-ray or computed tomography scan can be diagnostic, but is missing in up to 1/4 of cases.Figure 1.Stratification of patients with necrotizing fasciitis

Methods

We performed a retrospective cohort study of adult patients admitted in 2022-2023 with necrotizing fasciitis (diagnosis code M72.6) at an urban level 1 trauma center, who received surgical intervention, and at least 1 dose of linezolid or clindamycin in addition to other antibiotics. Patients transferred from an outside hospital, who had no imaging results, or no surgical intervention were excluded. Patients with and without gas on initial imaging result were compared (Fig1). Primary outcome was whether a lack of gas on imaging correlated with longer time to surgical intervention. Time 1 was defined as the time radiographic images were attested, or the time of surgery consult (whichever was later). Time 2 was the documented operating room (OR) surgical start time. Clinical and microbiologic outcomes were also recorded.Table 1:Characteristics of patients with necrotizing soft-tissue infection with and without gas on initial imaging

Results

79 patients were included in the analysis (60 and 19 patients with and without gas on imaging, respectively). Cohorts were evenly matched in terms of illness severity and comorbidities, except that patients without gas on imaging were more often female (P=0.014) with higher rates of CPK elevation (P=0.033) (Table 1). Site of infection did not differ between groups (Fig2), nor did microbiologic OR culture results (figure not included, P=0.105). Patients without gas on imaging had significantly longer time to OR compared to those with gas (median 15.7 verses 4.3 hours, respectively, P=0.0128) (Figure 3a). Length of stay, repeat trips to OR, and mortality did not differ between groups, however, patients without gas had high rates of readmission (P=0.041) (Fig3b).

Conclusion

Almost a quarter of necrotizing fasciitis patients presented without gas on initial imaging result. Despite having a similar degree of illness and poor prognostic laboratory parameters, these patients had a significantly longer time to OR compared to those with gas on initial imaging. Infectious diseases physicians should strive to provide valuable insight to our surgical colleagues for a syndromic approach to this illness regardless of the imaging results.

Disclosures

All Authors: No reported disclosures
P-740. Prevalence of Methicillin-Resistant Staphylococcus Aureus and Pseudomonas in Wounds of Patients with Substance Use Disorder
Authors: Yang Jerry , Traver Edward C , Tung Chih Chun , Harris Anthony , Baghdadi Jonathan
Published: January 2025

Background

Wound infections among patients with substance use disorder are frequently treated with empiric antibiotic coverage for Methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa. To guide appropriate empiric antibiotics, we evaluated the prevalence of these pathogens in the wounds of patients with substance use disorder using a large database.Table 1.Prevalence of Pathogens in Wound and Non-Wound Clinical Cultures from Patients with Substance Use Disorder in a Large Administrative Database

Methods

Encounters between January 2019 and March 2021 for patients with substance use disorder in the Premier Healthcare Database were identified by current or previous diagnosis code for opioid use, current or previous prescription of medications for opioid use disorder, or a diagnosis of Hepatitis C under the age of 55. Clinical cultures from any specimen besides stool were included.

Results

Overall, 18,797 clinical cultures were collected during 10,720 encounters for patients with substance use disorder at 119 hospitals. 516 cultures from 378 encounters at 23 hospitals were explicitly labeled as being collected from wounds. Results from wound and non-wound clinical cultures are provided in Table 1. 426 wound cultures (83% of 516) demonstrated Gram-positive organisms, 230 (45%) demonstrated Gram-negative organisms, and 278 (54%) were polymicrobial. The most common organism identified was Staphylococcus aureus (n=252, 49% of wound cultures), 64% of which was MRSA. Pseudomonas was identified in 35 wound cultures (7%).

Conclusion

Wound cultures from patients with substance use disorder are frequently polymicrobial. Though MRSA is extremely common, Pseudomonas is rare. Empiric antibiotic coverage of Pseudomonas should not be automatic.

Disclosures

Anthony Harris, MD, MPH, Innoviva: Advisor/Consultant|UpToDate: Infection Control Editor
P-743. Correlating Climate Conditions with Pseudomonas aeruginosa Prevalence in Diabetic Foot Infections within the United States
Authors: Winski Rebecca , Mergenhagen Kari A , Chan Arthur , Xu Jiachen , Wattengel Bethany A
Published: January 2025

Background

Diabetes-related foot infections (DFIs) are often difficult to treat and can result in amputation or even death if allowed to progress. The 2023 ‘International Working Group on the Diabetic Foot (IWGDF)/Infectious Disease Society of America (IDSA) Guidelines on the Diagnosis and Treatment of Diabetes-Related Foot Infections’ provides recommendations on which pathogens to target with empiric antibiotic therapy depending on which solar climate region a patient is from. The United States (US) has numerous different climate zones that can be classified using the US Department of Energy International Energy Conservation Code (IECC), which utilizes annual temperature and precipitation data to assign a climate designation to each county within the US.

IECC Climate Map

Methods

This study was a retrospective national cohort study of all Veterans aged 18 years of age or older between 1/1/2010 – 3/23/2024 with diabetes mellitus and a cultured lower extremity wound. National Veteran data was obtained from the VA Corporate Data Warehouse (CDW) via Structured Query Language (SQL) Server Management Studio. SQL coding was used to acquire demographic information, ICD diagnoses, lower extremity culture results, and Charlson Comorbidity Index for all patients who met inclusion criteria.

Pseudomonas Prevalence

Results

The prevalence of Pseudomonas significantly varied between US climates. Pseudomonas was most prevalent within the Hot Humid climate, where it was isolated in 13.2% of DFI cultures. Pseudomonas was least prevalent within the Cool Dry climate, where it was only isolated in 7.2% of cultures.

Conclusion

The prevalence of DFI organisms varies within different US climates. Utilization of local climate information may allow for more accurate and targeted empiric antibiotic selection when treating DFIs.

Disclosures

All Authors: No reported disclosures
P-747. Surgical Site Infections Following Cesarean Sections Across a Large Safety Net Public Hospital System
Authors: Akter Khaleda , Folks Megan A , Bakare Temilola-Azeezat , Episcopia Briana , Fornek Mary , Abdallah Marie , Quale John
Published: January 2025

Background

Surgical site infections (SSIs) following Cesarean section (CSEC) can be associated with serious adverse outcomes. Pre-operative and intra-operative protocols have been established to minimize the risk of developing SSIs.

Methods

Patients undergoing CSEC in an 11-hospital public health system in New York City in 2023 were reviewed. SSIs were defined according to National Healthcare Safety Network criteria. Propensity score matching, using six variables (age, body mass index, diabetes mellitus, surgery duration, American Society of Anesthesiology score, and wound class), was used to create a control group for the patients with SSIs.

Results

Among the 4643 CSEC surgeries, 73 SSIs were recorded, including 49 superficial incisional, 6 deep incisional, and 18 deep/organ space SSIs. SSIs were detected during the initial admission in 7 cases, repeat hospitalizations in 33 cases, and in outpatient settings in 33 cases. A higher rate of SSIs was observed from four hospitals; zip codes for these patients had higher poverty levels than for those patients from the four hospitals with the lowest infection rates (23.4±8.6 vs. 17.7±9.7 per cent, P=.08).

Comparing the SSI and control groups, no differences were found in race, ethnicity, blood loss, or surgical team composition. Although both groups had a similar proportion of patients residing in shelters, the SSI group had more recent immigrants than the control group (15 vs. 3, P=.004). Notably, recent immigrants with SSIs had fewer prenatal visits compared to the rest of the SSI group (5.53±3.44 vs. 7.72±3.98, P=.04), and 14 of the 15 SSIs in the recent immigrants were detected post-discharge from CSEC.

Conclusion

In a large public healthcare system, overall rates of SSIs following CSEC were low. Most infections were detected following discharge; living in neighborhoods of high poverty and being a recent immigrant appear to be risk factors for SSIs. While pre- and intra- operative protocols have been established to prevent SSIs, it appears postoperative factors (including wound care following discharge) warrant emphasis as well.

Disclosures

All Authors: No reported disclosures
P-757. Microbiological and clinical characteristics of extrapulmonary nontuberculous mycobacterial disease in a Chinese general hospital
Authors: Yao Yumeng , Bao Rong , Pan Jue , Hu Bijie
Published: January 2025

Background

Data on extrapulmonary nontuberculous mycobacterial disease (ENTM) in China is lacking. We aim to explore the microbiological and clinical characteristics of ENTM in a general hospital.

Methods

Laboratory extrapulmonary samples positive for nontuberculous mycobacteria in Zhongshan Hospital, Fudan University between Jan. 2017 and Dec. 2021 were retrospectively searched. The respective patient data were reviewed and followed until Dec. 2022. Thirty-three confirmed ENTM cases were included. Demographic, microbiological, clinical characteristics, as well as treatment and prognosis were analyzed.

Results

A total of 33 confirmed ENTM cases were included. The average age was (49±16.3) years. Twenty-three cases (69.7%) were female and one third of the patients were immunocompromised. Skin and soft tissue infection, bone and joint infection, and disseminated NTM disease were the most common types (57.6%, 18.2%, and 15.6%). Healthcare-associated infections accounted for 51.5% (17/33) of the cases. Mycobacterium abscessus complex (42.4%) among rapidly growing mycobacteria (RGM) was the most common causative species. Patients received combination therapy with an average of (3.5±0.8) drugs for 6.3 (4.3,9.6) months. Most cases recovered (69.7%) or improved clinically (18.2%). Compared with RGM, infections with slowly growing mycobacteria (SGM) were seen in older individuals (60.2±15.0 vs 42.6±14.0, P<0.05) and were more often community-acquired (83.3% vs 28.6%, P<0.05).

Conclusion

Skin and soft tissue infection is the most common type of ENTM, with Mycobacterium abscessus complex being the most important causative species. SGM infections affect older population and are more often community-acquired. Treatment of ENTM is challenging and lacks standardized protocol, future researches are warranted.

Disclosures

All Authors: No reported disclosures
P-771. Demographic and Clinical Characteristics of Adverse Reactions to anti-Tuberculosis Therapy: A Retrospective Analysis
Authors: Zaçe Drieda , Benedetta Rossi , Minardi Maria Letizia , Alessio Grazia , Alborghetti Leonardo , Muratore Gianmarco , Moccione Martina , Coppola Luigi , Compagno Mirko , Campogiani Laura , Marco Iannetta , Sarmati Loredana
Published: January 2025

Background

Adverse reactions (AR) to anti-tuberculosis (anti-TB) therapy pose a significant challenge, leading to decreased treatment compliance, increased morbidity and mortality rates, and prolonged hospital length-of-stay.

Methods

This study examines the demographic, clinical, and laboratory profiles of patients diagnosed with tuberculosis and hospitalized at the Tor Vergata Policlinic in Rome between 2013-2023, who experienced adverse reactions requiring the interruption, suspension, or modification of anti-tuberculosis therapy, in the period 2013-2023.

Results

Out of 242 patients receiving treatment for tuberculosis, data regarding AR were available for 136 cases. Of these, 35.3% (48/136) experienced an AR attributable to anti-tuberculosis therapy, median age of 39 years (IQR 26.5-57), 72.9% male, 60.4% non-italians, and 41.6% undergoing treatment for pulmonary TB. The most common AR were hypertransaminasemia (52.2%), allergic reaction (25%), and cholestasis (8.3%).

Patients with AR characterized by hypertransaminasemia/cholestasis compared to those with allergic reactions were younger (31 years (IQR 25-45) vs. 60.5 (IQR 36-69.5); p=0.012), more frequently of non-italian nationality (74.2% vs. 25.8%; p= 0.013), and had more frequently a negative Quantiferon test (41.9% vs. 8.3%; p= 0.03).

Pirazinamide emerged as the drug most frequently linked to AR, being suspended in 62.5% of cases (20/29 due to hypertransaminasemia; 8/12 due to allergic reaction). In 76.2% of cases, the drug responsible for the AR was discontinued in favor of a fluoroquinolone. All ARs resolved upon suspension of the implicated drug.

Among patients with AR, 65.3% recovered, and 13% died. Patients with AR had a lower lymphocyte count at treatment initiation compared to patients without AR (median 1150 (IQR 780-1940) vs 1460 (IQR 1035-2020), p=0.04) and had more frequently a negative Quantiferon test (29.2% vs 10.2%; p=0.012).

Conclusion

AR during TB therapy affected 35% of patients in our sample. Pyrazinamide was the most commonly implicated drug, and the reactions resolved upon discontinuation. A lower lymphocyte count at TB diagnosis in patients with AR might indicate an immune component, similar to IRIS, in their onset. However, further studies are warranted to explore this aspect.

Disclosures

All Authors: No reported disclosures
P-773. Mycobacterium Tuberculosis Liver Abscess in Kidney Transplant Recipients
Authors: Dyal Natasha , Vikram Holenarasipur R , Venkatachalam Thilagavathi , Kodali Lavanya
Published: January 2025

Background

Recipients of solid organ transplant (SOT) have higher risk for infections, and the prevalence of mycobacterium tuberculosis liver abscess (MTB-LA) without pulmonary/disseminated MTB is 0.34%. However, there is little research on MTB-LA in SOT recipients.

Mycobacterium tuberculosis Liver Abscess Cases

Upon extensive literature review, this chart details all published, English-language cases of mycobacterium tuberculosis liver abscess in solid organ transplant recipients.

Methods

We conducted an extensive literature review of MTB-LA in adult SOT recipients.

Results

Our review showed 4 cases of MTB-LA in SOT recipients (table below). We detail 1 additional case.

A 58-year-old male with ESRD due to type 2 diabetes mellitus, and latent MTB underwent kidney transplantation in March 2023. He completed a 6-month course of isoniazid and vitamin B6 for latent MTB 1 month before transplant. His post-operative course was uncomplicated; he was discharged to follow up with his nephrologist. He later developed norovirus illness with fever, which was conservatively managed. He developed new fevers 3 months post-transplant and CT of the abdomen/pelvis revealed a liver abscess, which was treated with empiric broad spectrum antibiotics, and was not amenable to aspiration. At his 4-month post-transplantation, he complained of fatigue, night sweats, poor appetite, and weight loss requiring hospitalization, wherein an MRI of the abdomen/pelvis identified a 3.6 x 3.2 x 6.2 cm liver abscess. The liver abscess aspirate was positive on acid fast bacilli smear and MTB polymerase chain reaction. He was initiated on antituberculosis therapy with isoniazid, rifabutin, pyrazinamide, and ethambutol. Susceptibilities identified pyrazinamide resistance, and led to substitution with levofloxacin. Labs, imaging and microbiology testing were negative for evidence of pulmonary/disseminated MTB. His donor’s information was reviewed; no obvious risk factors for active MTB were found. The recipient of the mate kidney is doing well without evidence of MTB infection. After 2 months of 4-drug antituberculosis therapy, ethambutol was discontinued. CT scan of the abdomen and pelvis at 4 months post anti-tuberculosus therapy revealed a 3 cm area of residual inflammation at the site of prior MTB-LA, in the setting of resolution of prior symptoms.

Conclusion

Early imaging and diagnostic aspiration of liver abscess with specific stains, culture and PCR testing can facilitate rapid diagnosis and initiation of antituberculosis therapy.

Disclosures

All Authors: No reported disclosures
The ‘crisis’ of antitrust economics
Authors: Padilla Jorge
Published: January 2025

The extant antitrust frameworks in the EU, UK, and US are being challenged conceptually, ideologically, and empirically. In particular, they are criticized for downplaying the economic and political cost of under-enforcement. In this article I accept, for the sake of the argument, that enforcement has been excessively lenient, though I believe the jury is still out, and focus on investigating whether the alleged under-enforcement of the competition laws is caused by the move towards a ‘more-economics approach’ to competition law enforcement. In my opinion, the evidence is mixed. Yet, the answer should not be less economics but better economics and greater scrutiny of both economic and non-economic evidence when they fail to point in the same direction.
Competition policy and labour market power: new evidence and open questions
Authors: Kariel Joel , Schneebacher Jakob , Walker Mike
Published: January 2025

Emerging evidence on pervasive and rising market power in US labour markets has led some competition agencies to wonder if the prevailing focus on product market power is too narrow. We survey existing competition enforcement in labour markets and the empirical evidence on the extent and impact of labour market power, with a particular focus on the UK. We find that in contrast to the US, labour market power in the UK has not risen substantially. Nonetheless, workers vary in their exposure and, for some, labour market power has significant economic costs. Labour market power also appears to interact in significant ways with other labour market policies. We argue these findings underscore the danger of making policy decisions based on evidence from other countries, or by analogy with product markets. We survey what these findings mean for existing tools available to competition agencies and conclude by laying out four types of open questions: theoretical, empirical, legal, and normative.
Towards an effective merger review policy: a defence of rebuttable structural presumptions
Authors: Lancieri Filippo , Valletti Tommaso
Published: January 2025

We discuss the design of an effective merger review policy for the twenty-first century. We argue that the practice of the past decades is inadequate and propose a move towards much stronger rebuttable structural presumptions. These presumptions establish that all mergers above certain thresholds are illegal unless the merging parties can prove that merger-specific efficiencies will be shared with consumers and yield tangible welfare gains. These presumptions are grounded on solid economics and also acknowledge the real-world limitations in enforcement resources and information asymmetries between companies and regulators. We outline how to establish such presumptions in practice, defending the implementation of an ex ante system that selects in advance (rather than per transaction) which companies and markets are subject to the presumption. Finally, we outline which merger-related efficiencies can rebut the presumption.
New directions in competition policy: an overview
Authors: Cowan Simon , Ormosi Peter , Perkins Joe
Published: January 2025

Competition policy has faced increasing scrutiny in recent years, with tension between traditional antitrust frameworks and contemporary critiques, including the ‘hipster antitrust’ movement. Some of the critics contend that competition policy has failed to address the growing market power of dominant firms, especially in the digital sector. This issue of the Oxford Review of Economic Policy explores the validity of these claims and their potential implications for the future of competition policy. It also examines how emerging methodologies, particularly those rooted in data science, can enhance our understanding both of how firms behave and how competition authorities and courts make decisions. This article summarizes a diverse range of contributions from academics, regulators, and practitioners in law and economics. It concludes with a discussion of how competition economics might adapt to the challenges posed by the hipster antitrust movement and the rapid changes in how firms compete.
Immune checkpoint inhibitor-associated linear IgA bullous dermatosis with recalcitrant ocular involvement: a rare presentation
Authors: Saeed Lina , Hosking Anna-Marie , Grando Sergei A
Published: January 2025

Programmed death-1 (PD-1) and programmed death ligand-1 (PD-L1) receptor inhibitors have become imperative in the treatment of advanced solid organ malignancies such as metastatic melanoma. With this disinhibition of certain immune responses to induce an antitumour response, numerous adverse events have been reported, many of which affect the skin. While rare, PD-1/PD-L1 inhibitor-associated severe cutaneous adverse reactions (SCARs) can cause significant morbidity and/or mortality. New SCARs are reported with increasing frequency as immune checkpoint inhibitors become more widely used. Here, we present a rare case of recalcitrant ocular linear IgA bullous dermatosis associated with a PD-1 inhibitor. Awareness of this entity will allow more rapid recognition and initiation of appropriate management and treatment, which would reduce the morbidity and/or mortality associated with these serious adverse reactions.