bluuebunny/crossref_metadata_2025_split huggingface dataset:
1854. Response to an Intravenous versus Oral Antibiotic Regimen in Brucellosis Bacteremia: A Single-Center Experience
Authors: Nazir Imran , Almatrafi Mohammed A , Imran Iffat , Rahman Sayed , Abdullahi Hanan , Muddassir Rabia , Farouk Ahmad , Alsahaf Nouf , Maksood Lama , Ahmed Waleed 
Published: December 2022

Abstract

Background
Human brucellosis is an infectious multisystem disease that varies in severity and clinical course. Bacteremia in brucellosis is common; however, data on epidemiology and management of Brucella bacteremia are scarce. The World Health Organization recommends using doxycycline with rifampicin or an aminoglycoside for brucellosis. This study aims to compare the efficacy of the two treatment regimens (oral doxycycline/rifampicin or ciprofloxacin versus IV gentamicin plus oral doxycycline/rifampicin or ciprofloxacin) in Brucella bacteremia.

Methods
In this single-center, retrospective cohort study, we analyzed the outcomes of 93 adults with confirmed Brucella bacteremia from 2017 to 2020. The diagnosis of brucellosis was based on positive blood culture for Brucella species. The patients were divided into two cohorts according to the treatment regimen received (oral versus IV). Blood culture negativity after four weeks and clinical cure rate at end of therapy were the co-primary endpoints, while side effects were secondary endpoints. Fisher's exact test and Pearson's chi-square test were applied to compare the two groups. The data were analyzed using SPSS version 23. A P-value &lt; .05 was considered significant.

Results
A total of 93 cases of Brucella bacteremia were enrolled, with 64 (68.8%) patients being male, and the group mean age being 44.3 ± 19.2 years. Overall, 37 (39.8%) patients received IV regimen, while 56 (60.2%) received oral treatment. Follow-up blood culture negativity after four weeks for both groups was 90.3% (n=84) with no difference between the oral and IV regimens (87.5% (n=49) versus 94.6% (n=37); P= .348, respectively). The overall clinical cure rate was 93.5% (n=87) for both groups combined, with no significant difference between the oral and IV groups (91% (n=51) versus 97.3% (n=36); P= .397, respectively). Transaminitis (7.1% vs. 5.4%), vomiting (5.4% vs. 8.1%), and acute kidney injury (0% vs. 2.7%) were all reported in the oral and IV groups, respectively, with no statistically significant difference between the two groups (P =.590). No deaths were reported over this period.

Conclusion
Oral and IV antimicrobial regimens have the same response rates in Brucella bacteremia patients.

Disclosures
All Authors: No reported disclosures.
2318. A Composite Peptide Vaccine Comprised of Conserved SARS-CoV-2 and Influenza Epitopes Generated Antisera Reponses to Both Coronavirus and Influenza
Authors: Rikhi Nimisha , Muema Kevin , Kroscher Kellie , Schuman Richard F , Assiaw-Dufu Aba , Sei Clara J , Fischer Gerald W 
Published: December 2022

Abstract

Background
While influenza and SARS-CoV-2 virus can be severe, co-infection with these viruses has the potential for worsening the clinical outcome. The combined infection of influenza A virus (IAV) and SARS-CoV-2 in animal models has also shown elevated SARS-CoV-2 viral load and pneumonia. Co-vaccination may provide a useful option in prevention of combined infection. In this study, a composite peptide vaccine comprised of highly conserved influenza neuraminidase (NA) and matrix protein (M2e) epitopes, in combination with either conserved spike protein (SP) or RNA polymerase (POL) epitopes of SARS-CoV-2 generated robust immune responses to both coronavirus and influenza virus.

Methods
Mice were immunized with 20µg of Coronavirus Pep02 (CorPep02, comprised of POL) or Coronavirus Pep05 (CorPep05, comprised of POL and NA+M2e) or Coronavirus Pep11 (CorPep11, comprised of SP and NA+M2e), formulated with AddaVax™. Serum antibody titers to both coronavirus and influenza peptides, and whole viruses were analyzed using ELISA. Antisera neutralizing activity against IAV was determined using microneutralization assay (MNA).

Results
CorPep05 immunization generated enhanced IgG1 and IgG2b antisera responses to the immunogens compared to CorPep02, starting at Day-21. Immunization with CorPep05 or CorPep11 induced strong IgG1 and IgG2b immune responses to the composite coronavirus peptides, influenza NA and M2e peptides, coronavirus POL and SP peptides. Antisera from CorPep05 and CorPep11 groups bound to both viruses (IAV and human coronavirus NL-63 (HCoV NL-63)) and demonstrated neutralizing activity against IAV, with titers &gt;5000.

Conclusion
A composite peptide vaccine comprised of both influenza (NA+M2e) and coronavirus (POL) epitopes generated enhanced immune responses in comparison to peptide containing only POL. Th1 and Th2 immune responses to coronavirus POL and SP were observed. Serum neutralizing activity was demonstrated against IAV. Studies are underway to examine neutralizing antibodies against HCoV NL-63 and multiple variants of SARS-CoV-2. Highly conserved epitopes in these composite peptide vaccines may provide an important strategy to prevent infections with IAV or SARS-CoV-2 and mitigate the threat of co-infection.

Disclosures
All Authors: No reported disclosures.
1873. Comparative performance of RTqPCR vs RTddPCR for the detection of SARS-CoV-2 in wastewater (WW) collected from a range of sites and scales across the sewer network of Calgary, Alberta
Authors: M. Waddell Barbara Jean , Oberding Lisa , Acosta Nicole , Chavarriaga Maria Bautista , McCalder Janine , Toppings Noah , Du Kristine , Pradhan Puja , Sedaghat Navid , Beaudet Alexander , Man Lawrence , Cabaj Jason , Bhatnagar Srijak , Ruecker Norma J , Achari Gopal , Cathryn Ryan M , Meddings Jon , Conly John M , Frankowski Kevin , Hubert Casey R J , Pillai Dylan , Parkins Michael 
Published: December 2022

Abstract

Background
We sought to compare WW SARS-CoV-2 RNA detection across a range of sites and scales using RTqPCR and RTddPCR. Figure.

Methods
Composite-24h WW was collected from a WW treatment plant (WTP; n=18), a neighborhood (Nb1; n=12) and three hospitals; H-1, H-2, and H-3 (3-sites; A-C)(n=84). RNA was extracted using the 4S-silica column method. RTqPCR (QuantStudio5, ThermoFisher) and RTddPCR (C1000 Thermal Cycler and QX200 Droplet Reader, BioRad) quantified SARS-CoV-2 RNA nucleocapsid (N2, US CDC) and envelope (E Sarbeco, Corman et al 2020) in triplicate. Fisher’s exact test was used to compare assay sensitivity. Correlations between modalities and RNA - clinically-confirmed COVID-19 cases (defined by postal code of primary residence using 5-day rolling average) was assessed using Persons correlation.

Results
114 samples were tested (02/23/2021-04/22/2021). SARS-CoV-2-N2 was identified in 90/114 (79%) by RTqPCR and 89/114 (78%) by ddPCR (p=1). SARS-CoV-2 E was found in 72/114 (63%) by RTqPCR and 90/114 (79%) by ddPCR, p=0.01. Correlations between modalities were strongest for N2 relative to E across all sites (see Table).
N2 correlated with clinically diagnosed cases for both modalities greater at the level of the WTP (RTqPCR; r=0.8972, p&lt; 0.0001and ddPCR; 0.933, p&lt; 0.0001) relative to neighborhood (RTqPCR; r=0.6, p=0.04 and ddPCR; 0.60, p=0.04). E correlated to a lesser degree with cases at WTP (RTqPCR; r=0.65, p=0.0035 and ddPCR; 0.88, p=&lt; 0.001) and neighborhoods (RTqPCR; r=0.40, p=0.20 and ddPCR; r=0.43, p=0.16).

Conclusion
SARS-CoV-2 detection of N2 was similar between RTqPCR and RTddPCR across a range of sites and scales in the sewershed, and this correlated best with clinical cases whereas E detection was superior with ddPCR.

Disclosures
All Authors: No reported disclosures.
1878. Demographic and Clinical Characteristics of COVID-19 Reinfection
Authors: Hoard Robert , Coate Eric , Macias Elizabeth A , Jackson Luke B , Barsoumian Alice E , Okulicz Jason , Markelz Elizabeth 
Published: December 2022

Abstract

Background
COVID-19 reinfection is generally defined as having 2 positive SARS-CoV-2 tests greater than 90 days apart. The clinical implications and impact of COVID-19 reinfection are not completely understood. We evaluated clinical and demographic characteristics of patients with COVID-19 reinfection.

Methods
All SARS-CoV-2 polymerase chain reaction (PCR) tests performed at Joint Base San Antonio (JBSA), from March 27, 2020 through January 19, 2022 were analyzed. COVID-19 reinfection was defined as having 2 positive PCR tests &gt;90 days apart. Available data for comorbidities, travel, COVID-19 vaccination status, SARS-CoV-2 genotype, symptoms, hospitalization, and treatments were compared for first and second infections.

Results
A total of 310,704 SARS-CoV-2 PCR tests performed of which 25,543 (8.2%) were positive at JBSA during the study period. Patients with COVID-19 reinfection (n=532; 4.2%) were identified and 266 (50%) charts reviewed. The mean age was 36.5 (±15) years and approximately half were males and active duty members (Table 1). The median time from first to second infection was 326 days (IQR 160-385). Patients were predominantly unvaccinated (91.4%) at initial infection, however unvaccinated status was less common (40.2%) at second infection (40.2%; P&lt; 0.0001). A significantly higher proportion of patients were symptomatic at first infection (88.3%) compared to second infection (51.5%; P&lt; 0.001). Pneumonia diagnosis was significantly higher (4.9% vs. 0.4%; P=0.0011) whereas hospitalization was similar (2.6% vs. 2.3%; P=0.0788) for first compared to second infection. Among hospitalized patients, critical illness was common for first infection (57.1%) but none of the patients were critically ill with their second infection. A third episode of infection was rarely observed (1.5%). Of 80 genotype samples available, 14 (30%) were paired samples. Among all paired samples different genotypes were responsible for reinfection (Table 2).

Conclusion
Patients with COVID-19 reinfections were less likely to be symptomatic, had lower severity of illness, and typically had a different SARS-CoV-2 genotype at second infection. Reinfection occurred despite COVID-19 vaccination in many patients, which highlights the need to develop novel strategies for vaccination.

Disclosures
All Authors: No reported disclosures.
2320. Novel checkpoint modifier lowers T cell activation threshold and enhances and broadens vaccine-induced responses to chronic viral infections
Authors: Hasanpourghadi Mohadeseh , Luber Andrew , Currie Sue , Magowan Colin , Zhou Xiangyang , Ertl Hildegund C J 
Published: December 2022

Abstract

Background
Vaccines aim to induce immune responses that prevent disease. They may also clear chronic infections or reduce tumor progression. Vaccine adjuvants augment immune responses, in general, by providing stimulatory signals. Our focus has been on a different type of adjuvant that enhances vaccine-induced T cell responses by modulating the herpes virus entry mediator (HVEM) pathway. The B and T cell attenuator (BTLA) is expressed on naïve T cells and, upon binding to HVEM on antigen presenting cells, dampens signaling through the T cell receptor. HVEM binds with a different domain to the co-stimulator LIGHT. Within a trimolar BTLA-LIGHT/HVEM complex, inhibition prevails. Herpes simplex virus (HSV-1) glycoprotein D (gD) attaches to the BTLA binding site of HVEM and as it has higher binding affinity outcompetes BTLA binding and allows for co-stimulation through LIGHT. This results in enhanced signaling through the T cell receptor and thereby augments and broadens CD8+ T cell responses as we showed with chimpanzee adenovirus (AdC) vector vaccines for several viral antigens.

Methods
Immunogenicity in rodents was evaluated following one or two immunizations with AdC vectors expressing antigens of HIV (gag), HPV-16 (E7/6/5), HBV (core & pol), influenza virus (nucleoprotein) and SARS-CoV2 (nucleoprotein), with or without gD. Vaccine-induced CD8+ T cell responses, including their magnitude, functions, duration, and breadth were characterized. Vaccine efficacy was also evaluated.

Results
Vaccination with gD-antigen fusion proteins increased CD8+ T cell frequencies to all of the antigens tested (Fig) and improved efficacy. Addition of gD increased stimulation of CD8+ T cells to subdominant epitopes and thereby enhanced breadth of responses.

Conclusion
Checkpoint modification of the HVEM pathway with a gD-antigen fusion protein produces potent, prolonged, and broad responses of CD8+ T cells to immunodominant and subdominant epitopes. The latter is especially important for chronic viral infections, where, due to exhaustion of T cells to dominant epitopes therapeutic efficacy of vaccines may rely on expansion of T cells to subdominant epitopes. Clinical studies to evaluate therapeutic vaccination for chronic HBV are planned.

Disclosures
All Authors: No reported disclosures.
1888. Implementation of COVID-19 Surveillance Testing Procedures in Dental School
Authors: Shoemaker Holly , Bullock Jeri , Stratford Kristina , Weller Melodie L , Hobson-Rohrer Wendy L , Hobson-Rohrer Wendy L , Samore Matthew H , Mayer Jeanmarie , Visnovsky Lindsay D 
Published: December 2022

Abstract

Background
Dental practitioners and students of dentistry are potentially at increased risk of COVID-19 infection due to frequent usage of aerosol-generating procedures. To mitigate risk to patients and providers, the University of Utah School of Dentistry began regular surveillance PCR testing of its patient-facing faculty, staff, and students in May 2020.

Methods
Surveillance testing occurred every other week for non-vaccinated individuals and continued through February 2022. After May 2021, fully vaccinated individuals were tested monthly and encouraged to seek additional testing if symptoms or an exposure occurred. We assessed risk of positive test among faculty, student, and staff groups through a Cox proportional hazards regression, accounting for multiple events and time-dependent variables with the Andersen-Gill model. To account for inconsistent testing after vaccination, time was examined as number of tests rather than calendar time.

Results
In total, 410 participants were followed during the observation period, with an average of 22 (SD 10.0, RNG 1-50) tests per person. A total of 9,452 tests were performed. There were 158 positive tests, with 60 (38%) occurring in January 2022 alone. When analyzed by themselves, staff and student groups were significantly more likely to test positive (HR 1.98, 95% CI 1.15-3.42; HR 2.16, 95% CI 1.29-3.63 respectively) compared to faculty. However, once additional covariates were accounted for, the relationship was no longer significant (Staff: HR 2.15, 95% CI 0.92-5.05; Students: HR 2.38, 95% CI 0.88-6.40).
Risk of COVID-19 within Dental School
Hazard Ratios for testing positive for COVID-19 among different groups within the dental school. Vaccination is accounted for as time since last vaccine, with separate categories for one dose, and 2 or more doses combined. Time examined as test number.

Conclusion
More than a third of all positive tests during the 22-month study occurred during one month of the Omicron wave. This sudden increase in positive tests was not observed in previous surges, and demonstrates the intensity of the Omicron wave. Additionally, we did not find a significant difference between patient-facing groups who had different work exposures. While this may be due to effective preventative measures, within the dental setting we do not see evidence that work role and resulting exposures increase risk.

Disclosures
All Authors: No reported disclosures.
1895. SingHealth COVID-19 Disease Registry
Authors: Shoon Jin Yee , Conceicao Edwin P , Yang Yue , Arora Shalvi , Ong Eng Hock Marcus , Chan Sze Ling , Sim Xiang Ying Jean , Venkatachalam Indumathi 
Published: December 2022

Abstract

Background
One of Singapore’s national strategies for the COVID-19 pandemic was containment. Efforts included a fourteen-day quarantine of close contacts, were subjected to an entry and exit SARS-CoV-2 PCR test, the latter being done between 11-14 days post exposure. Additionally, symptomatic contacts were tested for SARS-CoV-2. We aim to determine the trend in COVID-19 incubation periods during three distinct pandemic waves corresponding to different SARS-CoV-2 variants.
Incubation Period
Incubation period of the prevalent SARS-CoV-2 variant in circulation

Methods
This is an ecological study and information collected from the SingHealth COVID-19 Registry, a database of all inpatients admitted to any of the SingHealth hospitals. For patients under quarantine, the start date of the quarantine period was assumed to be the last date of exposure to the index case. Incubation period was determined by the duration between date of exposure and date of the first positive SARS-CoV-2 PCR test. The prevalent strain in circulation was identified from the Singapore database in the GISAID collection. Only variants of concern, as categorized by WHO, Alpha (23rd Jan 2020 – 1st Mar 2021), Delta (5th May 2021 – 31st Oct 2021) and Omicron (1st Jan 2022 – Present) were considered. For the Omicron variant, quarantine was discontinued, hence the last date of arrival from international travel was assumed to be the date of exposure.

Results
From January 2020 to March 2022, there were 19,905 patients in the COVID-19 registry, of whom 11,235 were under quarantine and 8,612 had preceding international travel. Of the 11,235 patients under quarantine, 8,189 patients were infected when SARS-CoV-2 Alpha variant and 3,046 patients were infected when SARS-CoV-2 Delta variant were in circulation. Of the 8,612 patients with preceding travel, 6,503 patients were infected when SARS-CoV-2 Omicron variant was in circulation. The median incubation period for the Alpha variant was 11 days (IQR: 7-14 days) versus 3 days (IQR: 2-4 days) for the Delta variant versus 3 days (IQR: 0-5 days) for the Omicron variant. Pairwise comparisons between the variants were (p-value = &lt; .001)

Conclusion
The significant differences between incubation periods of the SARS-CoV-2 variants in circulation poses a challenge to containment efforts and has emphasize the importance of dynamic national strategies.

Disclosures
All Authors: No reported disclosures.
1907. Initiation of Comfort Measures Only Care in the Medical Intensive Care Unit during the COVID-19 Pandemic
Authors: Jacobs Max , Rovnan Helene , Ramanujam Deeksha , Hamza Amina , Caucci Stephen , Cheema Tariq 
Published: December 2022

Abstract

Background
The COVID-19 pandemic brought an unprecedented disruption to many hospital standard operating procedures including changing family visitation policies. As an infection control policy, most hospitals denied or limited visitors and patient families were updated via phone or video conferencing. There are several plausible reasons to suspect that altered communication techniques and heightened public awareness of critical illness during the pandemic impacted end of life care and decision making.

Methods
We conducted a retrospective observational cohort study from a tertiary care hospital to determine if more patients in the ICU were transitioned to comfort measures only (CMO) care during COVID than in the same period the year before when COVID had not yet arrived in the United States (“pre-pandemic”). Collected information included demographics (Table 1), reason for ICU, co-morbidities, code status at admission, length of ICU stay, cost of care during ICU admission, and disposition at discharge. All analyses began using the Kolmogorov -Smirnov test. Normally distributed continuous variables are compared between groups using the independent-samples t-test. Non-normally distributed continuous variables are compared between groups using the Mann-Whitney U test.

Results
There were no statistically significant differences in baseline demographic and clinical characteristics of patients admitted to the medical ICU during the pre-pandemic versus pandemic periods (Table 1). Among the 266 patients admitted during the pre-pandemic period, 11.7% (31/266) were discharged with CMO code status. Among the 160 patients admitted in the pandemic period, 8.8% (14/160) were discharged with CMO code status (Table 2). The median APACHE score was significantly higher in the pre-pandemic period ([median=18 (interquartile range = 11) compared to the pandemic period ([median=15 (interquartile range = 1), (Mann-Whitney U = 17146.50, p = .008). The cost of an ICU admission during the pandemic period increased 0.099%. Table 1Baseline demographic and clinical characteristics of patients admitted to the medical ICU pre- versus post-pandemic (n = 426).Table 2Discharge status code and outcomes of patients admitted to the medical ICU in the pre- versus post-pandemic (n = 426).

Conclusion
This study shows that despite the highmorbidity and mortality associated with COVID, during the study time periods, the limitation of in-person visitors did not have an impact on the frequency of patients transitioned to CMO or decreased hospital expenditure.

Disclosures
Tariq Cheema, MD, GSK,BI,ASTRA ZENECA,Regenoron: Honoraria.
1910. A Highly Effective ID Physician and Infection Preventionist-led Interactive Webinar Series for Infection Prevention and Control Training Among Frontline Healthcare Workers
Authors: Ostdiek Riley P , Salman Ashraf M , Soma Mounica , Fadul Nada , Stream Sarah , German Dan K , Tyner Kate , Cortes-Penfield Nicolas W 
Published: December 2022

Abstract

Background
Nebraska Infection Control Assessment and Promotion Program (ICAP) is funded by Nebraska Department of Health and Human Services through Centers for Disease Control and Prevention (CDC) grants to support Infection Prevention and Control (IPC) activities in the state. In early 2022, ICAP launched COVID-19-specific basic infection prevention and control (IPC) training to frontline healthcare providers (HCPs) through a discussion-based webinar series using curricular materials created by the CDC Project Firstline. Here, we report pre- and post-training survey responses demonstrating improvement in participants' perceived knowledge across a number of IPC domains.

Methods
Training was completed over a 14-week period via a weekly, interactive 30-minute webinars with a new topic covered each week. A survey was administered to participants prior to the webinar series and at the conclusion of training to assess effectiveness. The pre-survey evaluated HCP confidence in their knowledge of each of the 14 topics to be covered in the course. The post-survey evaluated both confidence and perceived value in each of the training topics.

Results
Prior to the training series, a mean 40.3% of participants judge themselves “very confident” in IPC topics, versus 52.7% “somewhat confident” and 7.1% “not confident” (figure 1); by the end of the training, these levels had improved to 85.4%, 14.3%, and 0.4%, respectively (figure 2). The largest gains in the category “very confident” concerned “source control” (+65%) and “COVID-19 variants” (+63%). A majority of participants perceived each topic covered in the series to be “very valuable” (figure 3); 98% of participants indicated interest in a future IPC training series and 95% indicated that they would recommend the training series to a colleague. Figure 1Results of a pre-course survey on knowledge of training topics completed by participants.Figure 2Results of a post-course survey on knowledge of training topics completed by participants.Figure 3Results of a post-course survey on value of the training course completed by participants.

Conclusion
This survey data suggests that a discussion-based webinar using CDC Project Firstline materials is highly effective at conveying fundamental concepts in infection control to frontline HCPs. Moreover, HCPs rated themselves as likely to return, suggesting this format is a promising modality for simple and widespread dissemination of IPC training.

Disclosures
M. Salman Ashraf, MBBS, Merck & Co. Inc: Grant/Research Support.