bluuebunny/crossref_metadata_2025_split huggingface dataset:
P-57. Durability of SARS-CoV-2 specific Cellular Immune Response after COVID-19 Vaccination in PLWH
Authors: Sehgal Amit , Nischal Neeraj , Ranjan Sanjay , Mahishi Niranjan , Jorwal Pankaj , Wig Naveet , Grover Pragati , Khan Maroof a , Awasthi Amit , Binayke Akshay 
Published: January 2025

Abstract

Background
People living with HIV (PLWH) face the dual challenge of human immunodeficiency virus(HIV) infection and severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. It is associated with severe outcomes and a higher risk of mortality.
In January 2021, the vaccination campaign against SARS-CoV-2 was launched in India and started mass administration of two types of vaccines. The two vaccines used on a large scale were, a recombinant, replication-deficient chimpanzee adenovirus vectored vaccine/ ChAdOx1 nCoV-19 (Covishield) and whole virion inactivated vaccine/ BBV152 (Covaxin).The study of cellular immune responses to COVID-19 vaccination in PLWH was vital for safeguarding this vulnerable population.

Methods
Study design: Prospective observational study
Study population: The individuals recruited in the study were vaccinated with at least 2 doses and/or booster dose of the COVID-19 vaccine (COVISHIELD/COVAXIN). The individuals were segregated into two groups (PLWH and non-HIV-infected healthy individuals).
Testing Method: Peripheral blood mononuclear cell (PBMC) were cultured to test the SARS-CoV-2-specific T cell immune response using activation induced marker/ intracellular cytokine staining (AIM/ICS) assay.
Distribution of CD4 T lymphocytes count in HIV patients with mean CD4 count 470 cell/µl.

Results
We conducted did this study in two phases. The first phase was conducted between August 2022 and December 2022, while the second phase, or the follow-up, took place from January 2023 to December 2023. In the first phase/ first visit (V1), we recruited 50 adult PLWH and 40 adult healthy controls. Subsequently, in phase 2/follow-up/ second visit (V2), we achieved a follow-up rate of 100% in each arm.
SARS-CoV2-specific cellular immune response after COVID-19 vaccination was comparable and durable IN PLWH as compared to healthy controls.

Conclusion
Comparable and durable immune response was observed in PLWH population on regular highly active antiretroviral therapy (HAART), with stable viral suppression and good CD4+ T cell counts. This was consistent over time across 1 year gap in both phases of the study and across different vaccine types. This outcome indicates that the cellular immune responses in our PLWH cohort is comparable and durable to that of the general population, which is a reassuring finding for the public health.
SARS-CoV-2-specific CD8 T-cell immune response (scatter plots displaying the results of CD8 T cell assays, specifically evaluating the production of various cytokines (IFNγ (Interferon-gamma), TNFα (Tumor Necrosis Factor-alpha), and IL-2 (Interleukin 2), Granzyme B (Gran-B) at two different time points V1 and V2 (visit 1 and visit 2) with p values mentioned at the top.

Disclosures
All Authors: No reported disclosures
P-79. Racial/ethnic disparities and facility-level variation in major lower limb amputation among patients with a new diagnosis of diabetic foot ulcer within the Veterans Health Administration
Authors: Suzuki Hiroyuki , Vaughan-Sarrazin Mary , Ohl Michael , Mecham Bradley , Mccoy Kimberly , Livorsi Daniel J 
Published: January 2025

Abstract

Background
Diabetic foot ulcers (DFU) are associated with high morbidity and mortality, including major lower limb amputation (LLA). Little is known about racial/ethnic disparities and facility level variation in major LLA in large healthcare systems, such as Veterans Health Administration (VHA). VHA cares for over 9 million Veterans in 140 facilities with no insurance-related barriers to care.Figure:Caterpillar plot of relative odds of major LLA in each medical center

Methods
This is a retrospective cohort study of all Veterans with a new diagnosis of DFU during 2016-2021. The outcome was major LLA within 12 months from DFU diagnosis. We conducted multivariable logistic regression with random facility intercepts to assess variation in major LLA across VHA facilities while adjusting for patient demographics, comorbidities, and the severity of DFU at initial diagnosis. We calculated odds ratios (ORs) and confidence intervals (CIs) for associations between patient-level variables and major LLA. We calculated the median OR (MOR) as a measure of facility-level variation in major LLA. The MOR can be interpreted as the median change in odds of major LLA associated with care in all pairs of facilities.

Results
There were 105,644 patients from 140 hospitals in the cohort. The median age was 67. Most patients were White (75.6%), followed by Black (18.5%) and Hispanic (6.0%). At presentation, 91.6% had an early-stage ulcer while the rest had complicated DFU. Major LLA occurred in 4055 patients (3.8%). In the logistic regression model, variables associated with higher odds of major LLA were Black (OR 1.77, 95%CI 1.62-1.92), Native American (OR 2.08, 95%CI 1.57-2.75), Hispanic (OR 1.38, 95%CI 1.19-1.60), complicated DFU (OR 3.36, 95%CI 3.11-3.64), chronic kidney disease (OR 1.11, 95%CI 1.01-1.21), peripheral vascular disease (OR 3.49, 95%CI 3.24-3.76) and myocardial infarction (OR 1.32, 95%CI 1.21-1.49). The facility-level variation in major LLA (MOR: 1.87, p&lt; 0.001) was larger than most of patient-level risk factors, suggesting that facility-level factors play an important role in the outcome of DFU.

Conclusion
Our study showed racial/ethnic disparities and facility-level variation in major LLA within the VHA. Future studies should investigate the reasons for this variation and develop strategies for reducing disparities in LLA.

Disclosures
Daniel J. Livorsi, MD, Merck: Grant/Research Support
P-99. Comparative Analysis of False Positive Results in Low and High Risk U.S. Populations: New Access HIV Ag/Ab combo Assay vs. Abbott ARCHITECT HIV Ag/Ab Combo Assay
Authors: Maher Danielle L , Jortani Saeed , Apple Fred S , Christenson Robert H 
Published: January 2025

Abstract

Background
The fully automated 4th gen HIV Ag/Ab combo assay by Beckman Coulter, Inc. on the DxI 9000 Access Immunoassay analyzer allows for separate reporting of HIV-1 p24 Ag and HIV-1/HIV-2 Ab results, with a time to first result of ̴30 minutes and a sample volume of 60µL. To evaluate its performance, a U.S. multisite study was conducted to compare the Access HIV Ag/Ab combo assay with the ARCHITECT HIV Ag/Ab Combo assay. False positive rates were assessed in low and high risk U.S. populations with unknown HIV status by comparing the new Access HIV Ag/Ab combo assay with the ARCHITECT HIV Ag/Ab Combo assay.1
Footnotes

Methods
The evaluation tested 6,981 low risk and 799 high risk samples (adult, pregnant, pediatric) at 3 clinical trial sites. Following the CDC recommended algorithm, samples that initially tested reactive were subjected to duplicate testing, if repeatedly reactive, were further confirmed using the HIV 1/2 differentiation assay (Geenius HIV-1/2 Supplemental Assay, Bio-Rad), and the HIV-1 RNA PCR Assay (Aptima HIV-1 Quantitative Dx Assay, Hologic, Inc).2

Results
The Access HIV Ag/Ab combo assay showed a lower incidence of false positive results (n=25) in the low risk group with a specificity of 99.6% (n=6981; 95% CI: 99.5-99.8%) compared to the ARCHITECT HIV Ag/Ab Combo assay (n=87) with a specificity of 98.8% (n=6981; 95% CI: 98.5-99.0%). Similarly, in the high risk group, the Access HIV Ag/Ab combo assay yielded fewer false positive results (n=1) with a specificity of 99.9% (n=799; 95% CI: 99.3-100.0%) than the ARCHITECT HIV Ag/Ab Combo assay (n=11) with a specificity of 98.6% (n=799; 95% CI: 97.6-99.2%).

Conclusion
Falsely reactive HIV test results can have significant consequences for patients and healthcare providers. Selecting an appropriate HIV assay with high sensitivity and specificity is essential. This study provides evidence that the Access HIV Ag/Ab combo assay is an attractive alternative to the ARCHITECT HIV Ag/Ab Combo assay with fewer false positive results, suggesting improved accuracy in identifying HIV infections in both low and high risk U.S. populations.

Disclosures
Fred S. Apple, PhD, Mindray: Advisor/Consultant|Werfen: Advisor/Consultant Robert H. Christenson, PhD, DABCC, FADLM, FACC, Beckman Coulter: Advisor/Consultant|Beckman Coulter: Grant/Research Support|Beckman Coulter: Honoraria|Becton Dickinson: Advisor/Consultant|Becton Dickinson: Grant/Research Support|Becton Dickinson: Honoraria|QuidelOrtho: Advisor/Consultant|QuidelOrtho: Grant/Research Support|QuidelOrtho: Honoraria|Roche Diagnostics: Advisor/Consultant|Roche Diagnostics: Board Member|Roche Diagnostics: Grant/Research Support|Roche Diagnostics: Honoraria|Siemens Healthineers: Advisor/Consultant|Siemens Healthineers: Board Member|Siemens Healthineers: Grant/Research Support|Siemens Healthineers: Honoraria
P-116. Impact of a gastrointestinal molecular panel in the tropics: going beyond E. histolytica
Authors: Agramonte-Medrano Alana M , Guzman-Marte Anel E , Rojas-Fermin Rita A , Sanchez-Marmolejos Ann S , Cedeño-Bruzual Maria Fernanda , Chaddy Báez Lia Michelle , Mejia De La Cruz Dolores Magdalena 
Published: January 2025

Abstract

Background
Acute diarrhea (AD) is a major cause of illness and hospital admissions, particularly in humid tropical climates. These infections can escalate rapidly, making an early and accurate diagnosis crucial for effective treatment. However, due to the variety of pathogens and the limitations of conventional diagnostic tests, clinicians often resort to empiric treatments based on epidemiological data. This study explores how effective a gastrointestinal molecular panel (GI panel) can be in identifying specific pathogens in a tertiary health center.

Methods
This observational, descriptive, cross-sectional study analyzed the clinical records of patients over 18 years old with symptoms of AD. These patients underwent treatment and took the FilmArray GI Panel between March 2021 and December 2022. The study also compared the results obtained by ova and parasite tests and/or stool culture, when available.
Viral, Bacterial & Parasitic infections
Source: Statistical registry of the authors

Results
Out of 59 patients (median age: 48 years; 57.63% female), the GI panel identified at least one pathogen in 66.1% (39/59) of samples, with 32.2% (19/59) showing two or more pathogens. Bacteria were the most common cause of infection (62.7%), with enteroaggregative E. coli (18.6%), Shigella/enteroinvasive E. coli (18.6%), and enteropathogenic E. coli (15.3%) being the most prevalent. Viruses accounted for 11.9% of cases, with Norovirus GI/GII (5.1%) and Adenovirus F 40/41 (3.4%) being the most common. Protozoa made up 6.8% of cases, primarily Cryptosporidium (5.1%) and Cyclospora cayetanensis (1.7%).
Out of 21 patients with a bacterial target in the GI panel, only one received a positive stool culture (Salmonella sp.). The 4 protozoa-positive samples were not detected through an ova and parasite test, and no stool sample was positive for Entamoeba histolytica (32 ova and parasite tests).

Conclusion
It is necessary to rethink the etiology of AD in low- and middle-income countries like the Dominican Republic, which has long been based on low-sensitivity routine tests. Despite being in the tropics, protozoa were not the most frequent pathogens, and E. histolytica was largely absent, regardless of the diagnostic method used. Diagnostic routine tests should be revised to include targets that may be missed due to method limitations.

Disclosures
Rita A. Rojas-Fermin, MD,FIDSA, Gilead: Advisor/Consultant|Pfizer: Advisor/Consultant|Pfizer: Honoraria
P-117. Wastewater-Based Surveillance (WBS) of Shiga Toxin-Producing Escherichia coli (STEC) in Alberta, Canada
Authors: Waddell Barbara Jean M , Du Kristine , Au Emily , Lee Jangwoo , Acosta Nicole , Bautista Chavarriaga Maria , Clark Rhonda , Conly John , Chui Linda , Berenger Byron M , Griener Thomas , Cabaj Jason , De Vinney Rebekah , Pang Xiaoli , Lee Bonita , O’Grady Christine , RJ Hubert Casey , Parkins Michael 
Published: January 2025

Abstract

Background
Shigatoxin-producing E. coli (STEC) are responsible for significant human morbidity, with the potential to cause severe food-borne illness and outbreaks. STEC incidence varies between communities and peaks in summer months (PMID 31652648). Leveraging a SARS-CoV-2 WBS program, we sought to explore genomic targets for STEC WBS.Figure 1.Prevalence of STEC differs across Alberta’s municipal sewer sheds

Methods
Composite-24h wastewater (WW) was collected from geographically disparate, and socioeconomically diverse Alberta communities (n=5) at the level of municipal WW treatment plants. From 04/2022-03/2024, monthly WW underwent pelleting and DNA extraction by Qiagen DNeasy PowerSoil Pro kit. WW extracts were assessed for four potential genomic STEC targets: Shiga Toxin 1 (stx1), Shiga Toxin 2 (stx2), Intimin (eae) and LPS O antigen gene specific for O157 (rfbEO157), by multiplex PCR. Each target was normalized by 16S rRNA-for total bacterial burden. WW STEC targets were assessed for correlation using Spearman’s and compared between communities and seasonality (July-Sept vs Jan-Mar) by Mann-Whitney U-test.Figure 2.STEC WBS demonstrates seasonal prevalence trends

Results
Of 111 WW samples assessed, 108 (97%) were positive for all targets, and individual targets were identified in 110 (99%) stx1; 110 (99%;) stx2; 111 (100%) eae, and 110 (99%) rfbEO157. Gene abundance for each STEC target exhibited strong correlations across sites (stx1 vs stx2, r=0.802, p&lt; 0.0001; stx2 vs rfbEO157, r=0.634, p&lt; 0.0001; eae vs rfbEO157, r =0.551, p&lt; 0.0001; stx2 vs. eae r=0.542, p&lt; 0.0001). WW measured STEC gene targets exhibited significant differences between municipalities (Figure 1) with strong seasonal trends (Figure 2).

Conclusion
WBS for STEC yielded patterns consistent with established patterns of disease (PMID 31652648). All four STEC genomic targets demonstrated significant correlation across sewersheds. STEC WBS may represent a novel tool to understand and monitor population-level activity and prevent disease.

Disclosures
All Authors: No reported disclosures
P-124. Ongoing Infections with Extensively Drug-Resistant Campylobacter jejuni Linked to Pet Store Puppies
Authors: Francois Watkins Louise , Stapleton G Sean , Joseph Lavin , Bennett Christy , Vahey Grace , Benedict Katharine , Cooley Laura A 
Published: January 2025

Abstract

Background
Campylobacter is the leading cause of enteric bacterial infections in the United States, causing an estimated 1.5 million illnesses annually. Antimicrobial therapy can reduce the duration of illness and limit complications; macrolides and fluoroquinolones are typically recommended as first- and second-line treatment, respectively. The Centers for Disease Control and Prevention (CDC) investigates emerging resistance in Campylobacter strains to identify potential sources and collaborate on approaches to reduce its spread. Here, we describe extensively drug-resistant (XDR) strains linked to pet store puppies.

Methods
State public health departments perform whole genome sequencing on Campylobacter isolates as resources allow and submit sequence data to CDC. CDC assesses isolate relatedness using core genome multilocus sequence typing (cgMLST) and screens isolate sequences for resistance determinants to predict antimicrobial resistance (older isolates sequenced retroactively are also screened). We considered isolates to be XDR if they showed predicted resistance to macrolides, fluoroquinolones, and ≥ 3 additional antibiotic classes. Persons with XDR isolates were interviewed about exposures when possible.

Results
We identified three strains of XDR C. jejuni; the oldest isolates were from 2007. Although these strains are not highly related phylogenetically ( &gt; 200 allele differences between strains by cgMLST), cases share epidemiological and clinical characteristics. As of June 30, 2023, CDC received reports of 274 cases associated with these strains. Affected individuals had a median age of 36 years (interquartile range, 20–52); 66% were female, and 23% were hospitalized. Of those affected, 97% reported contact with a dog before becoming ill, among whom 78% reported contact with a puppy from a pet store.

Conclusion
Clinicians should be aware that strains of XDR Campylobacter are circulating in the United States and should consider XDR infection when patients fail to respond to routine treatment, particularly if they have recently had contact with pet store puppies. Carbapenem antibiotics may be used for severe infections that are resistant to recommended treatment agents.

Disclosures
All Authors: No reported disclosures
P-130. A Case-Control Study of Post-Infectious Sequelae Following a Shiga Toxin-Producing Escherichia coli (STEC) Outbreak at a U.S. Marine Corps Recruit Depot
Authors: Kautz Michelle , Larson Derek , Sanders Terrel , Hsieh Hsing-Chuan , McAnany Jennifer , Khodr Zeina G , Castaneda Sheila F , Maves Ryan C , Lalani Tahaniyat 
Published: January 2025

Abstract

Background
In November 2017, an outbreak of Shiga toxin-producing Escherichia coli (STEC) O157:H7 and O26 occurred among male recruits at a United States Marine Corps Recruit Depot, San Diego, CA. We sought to evaluate the 6-year risk of hypertension (HTN), chronic kidney disease (CKD), and irritable bowel syndrome (IBS) following STEC infection by conducting a retrospective, case-control study utilizing medical record data.Table 1.Proportion of STEC cases and matched asymptomatic controls with post-infectious sequelae following November 2017 outbreak

Methods
Data from the outbreak investigation were used to identify cases and asymptomatic controls. Asymptomatic controls were recruits who were in the exposure area during the outbreak but remained asymptomatic and were negative for STEC by stool PCR. Cases were matched 1:4 with asymptomatic controls based on the duration of follow-up available in the Military Health System Data Repository (MDR). Controls could be matched to &gt; 1 case. Post-infectious outcomes were assessed using ICD-10 diagnostic codes in the MDR.

Results
239 cases were identified of whom 192 (80%) developed bloody diarrhea, 30 (13%) were hospitalized, and 17 (7%) developed hemolytic uremic syndrome (HUS). The stx-2 gene was detected in 39% of PCR positive cases. The median age of recruits was 19 years, and the median duration of MDR follow-up for cases and controls was 3.7 years (IQR: 2.9-5.4). There was no significant difference in the proportion of cases and controls with post-infectious sequelae (Table 1). Resolution of renal dysfunction was noted within 3 months after discharge for all HUS cases, and only 1 case remained hypertensive following discharge. There was no significant difference in the proportion of bloody diarrhea and HUS cases that developed IBS compared to controls. A limitation of the analyses was the short duration of MDR follow-up available for 6/30 hospitalized cases due to military separation after hospital discharge.

Conclusion
STEC infection in this cohort of young military recruits was associated with a good prognosis, even among cases of STEC-associated HUS, with resolution of renal dysfunction and no increase in incidence of IBS or HTN compared with asymptomatic controls. The findings suggest that STEC infection in young adults who recover from acute illness is not associated with a higher likelihood of post-infectious sequelae.

Disclosures
Ryan C. Maves, MD, AiCuris: Grant/Research Support|Biotest: Grant/Research Support|GeoVax: Grant/Research Support|Shionogi: Advisor/Consultant|Shionogi: Honoraria|Sound Pharmaceuticals: Grant/Research Support
P-131. Study of Enteric Parasitic Infections to Delineate Low Grade Inflammation in Patients with Functional Dyspepsia
Authors: Pant Sanjana , Ranjan Mirdha Bijay , Makharia Govind , Das Prasenjit , Singh Jadon Ranveer 
Published: January 2025

Abstract

Background
Growing evidence of chronic low-grade intestinal inflammation in post-infectious functional gastrointestinal disorders (FGID), including functional dyspepsia (FD), have been observed. Present study aimed to investigate the role of enteric parasitic infestations along with Helicobacter pylori and associated inflammatory cellular components among FD patients.

Methods
Prospective observational study included 183 adult patients with symptoms of FD consistent with the ROME IV criteria. All these patients were subjected to clinical evaluation, routine blood tests, and stool sample analyses for parasitological examination. Upper gastrointestinal endoscopic biopsy samples were examined for the presence of H. pylori and to extrapolate cellular components of low-grade inflammation.

Results
Among the 183 individuals, (85/183) 46.4% and (98/183) 53.6% belonged to the subtype post-prandial distress syndrome (PPDS) and epigastric pain syndrome (EPS) respectively. 46/183 (25.14%) of the stool samples tested positive for parasites, most common being Blastocystis species. The distribution of Blastocytis cells were 14/85 (16.47%) for PPDS and 16 (16.32%) for EPS patients. Histopathological analysis revealed significantly elevated duodenal mast cells and their degranulation among 85.24% and 76.5% FD patients respectively whereas, duodenal eosinophilia, duodenal eosinophil degranulation, and duodenal intra-epithelial lymphocytosis were observed in 3.28%, 15.3%, 1.7% respectively. Patients of the EPS subtype with intestinal parasitosis had elevated duodenal mast cell count, albeit statistically non-significant (p value = 0.078). There was no significant correlation between intestinal parasitosis or H. pylori with any of the clinical parameters examined, other than intestinal parasitosis with anemia (PPDS, p-value &lt; 0.02).

Conclusion
Presence of duodenal mast cells along with the presence of Blastocystis cells in some of the FD patients suggests their potential involvement in symptom generation, albeit lack of experimental studies. Our findings also give impetus to further understand the complex interplay between elevated duodenal mast cell count and mast cell degranulation with FD symptoms.

Disclosures
All Authors: No reported disclosures