bluuebunny/crossref_metadata_2025_split huggingface dataset:
Permutation Module Decomposition of the Second Cohomology of a Regular Semisimple Hessenberg Variety
Authors: Cho Soojin , Hong Jaehyun , Lee Eunjeong 
Published: December 2022

Abstract
Regular semisimple Hessenberg varieties admit actions of associated Weyl groups on their cohomology spaces of each degree. In this paper, we consider the module structure of the cohomology spaces of regular semisimple Hessenberg varieties of type $A$. We define a subset of the Białynicki–Birula basis of the cohomology space, which becomes a module generator set of the cohomology module of each degree. We use these generators to construct permutation submodules of the degree two cohomology module to form a permutation module decomposition. Our construction is consistent with a known combinatorial result by Chow on chromatic quasisymmetric functions.
The Impact of COVID-19 Prevention Measures on Interagency Hotshot Crews in 2020
Authors: Belval Erin , McCaffrey Sarah , Finney Trevor , Calkin David , Greer Shane 
Published: December 2022

Abstract
In the 2020 fire season, the fire management community developed and tested a wide range of new practices to meet challenges posed by the coronavirus pandemic. To better understand the effectiveness of different innovations and which should be considered for more permanent use, we surveyed Interagency Hotshot Crew (IHC) superintendents in January 2021. We focused on identifying innovations that, regardless of COVID-19, the IHCs would want to keep and why, as well as those that proved problematic. The survey focused on paperwork, briefings, and fire camp and incident command post setup. Results found clear benefits from many of the changes to operational efficiency and crew health and wellbeing; challenges were generally tied to logistical and communication issues. The results of this survey speak to the logistics of running large incident command operations and could be applied both outside the US and outside the field of wildland fire management.
Study Implications: There may be meaningful benefits beyond mitigation of COVID-19 spread for continuing to use virtual paperwork, virtual briefings, and dispersed camp setups while supporting large fire suppression operations. Operational efficiency was seen as a clear benefit of many of these changes, with the often-mentioned advantage to a particular practice enabling crews to spend more time on the fireline. The new practices also appear to contribute to overall crew physical health. However, the benefits to crew health, efficiency, and effectiveness will need to be assessed against the increased logistical support required from incident management teams.
In-hospital Outcomes for COVID-19 Patients in the Military Health System: Comparison of Military and Civilian Facility Treatment
Authors: Herrera-Escobar Juan P , Wang Joyce Y , Ye Jamie , Dalton Michael K , Koehlmoos Tracey , Schoenfeld Andrew J , Weissman Joel S , Cooper Zara 
Published: December 2022

ABSTRACT

Introduction
Beneficiaries of TRICARE, an insurance program of the military health system, can choose to receive care within the private sector (fee-for-service) or direct (budget-based facilities with salaried providers) care setting. Previous studies in several specialties have shown that there are disparities in both resource utilization and outcomes between the two settings. In this study, we sought to determine differences in outcomes between coronavirus disease 2019 (COVID-19) patients treated in the private sector versus direct care.

Materials and Methods
Using TRICARE claims data, we identified patients admitted to the hospital for COVID-19 between March and September 2020. Cases were classified, according to the facility where they were admitted for treatment, as private sector or direct care. We abstracted patient sociodemographic characteristics, comorbid conditions, and outcomes including in-hospital mortality, intensive care unit (ICU) admission, ventilator use, in-hospital complications, and 30-day readmission. We used multivariable regression models, adjusted for covariates, to determine the association between health care settings and outcomes.

Results
A total of 3,177 patients were included. Of these, 2,147 (68%) and 1,030 (32%) received care in the private sector and direct care settings, respectively. The average age of the study cohort was 52 years (SD = 21), and 84% had at least one medical comorbidity. In adjusted analyses, we found significant differences in the rates of ICU admission, with patients treated in private sector care having lower odds of being admitted to the ICU (odds ratio, 0.64; 95% CI, 0.53-0.76). There were no significant differences in the rates of in-hospital mortality, ventilator use, in-hospital complications, and 30-day readmissions.

Conclusion
With the exception of ICU admission rates, which are higher in the direct care setting, we encountered comparable hospital-based outcomes for patients treated for COVID-19 within the military health system, whether care was received under private sector or direct care.
95. Prolonged respiratory viral infection associated with presence of coinfections in an urban birth cohort
Authors: Teoh Zheyi , Conrey Shannon C , Cline Allison R , Mattison Claire , Payne Daniel C , McNeal Monica , Burke Rachel M , McMorrow Meredith L , Morrow Ardythe L , Staat Mary A 
Published: December 2022

Abstract

Background
Prolonged infection by respiratory viruses has been reported, especially in hospitalized or immunocompromised children. However, little is known of factors contributing to prolonged respiratory viral infection, particularly in asymptomatic and less severe infections. We examined characteristics associated with prolonged viral infection in a community-based birth cohort.

Methods
The PREVAIL cohort is a CDC-sponsored two-year birth cohort in Cincinnati, Ohio conducted during 4/2017 to 8/2020. Mid-turbinate nasal swabs were collected weekly from children and tested using the Luminex Respiratory Pathogen Panel. The primary outcome was prolonged viral infection, which was defined as a viral nucleic acid detection lasting 4 or more weeks. Proportions of prolonged viral infections were compared using Fisher’s exact test with Holms corrections. Adjusted odds ratios (aOR) and 95% confidence intervals were calculated using a mixed effects logistic regression model while controlling for within-subject clustering, viral species, child age, child sex, symptom status, and coinfection. This analysis was limited to subjects who provided at least 70% of weekly samples.

Results
Among 101 children, providing 7871 child-weeks of follow-up, we identified 780 viral infections. The median duration of infection across all respiratory viruses was 1 week, except for bocavirus and coronavirus NL63, each with 2 weeks; 40% of bocavirus and &gt;10% of adenovirus, coronavirus NL63, RSV A, human metapneumovirus, and parainfluenza 1 infections were associated with prolonged infection (&gt;4 weeks). No prolonged infections were detected for influenza A or B, coronavirus 229E or HKU1, or parainfluenza 2 or 4 infections. Viral coinfection (aOR=3.1, 95% CI 1.9, 5.0) and female sex (aOR 1.8, 95%CI 1.1, 2.9) were significantly associated with prolonged infection, while symptom status and child age were not.

Conclusion
In the PREVAIL cohort, detection of respiratory viruses lasting 4 weeks or longer was common for certain respiratory pathogens and was especially prolonged for bocavirus. Biological factors such as the presence of additional viral infections or child sex may affect the likelihood of prolonged infection.

Disclosures
All Authors: No reported disclosures.
797. Investigation of HIV Clusters Among Hispanic/Latino Gay or Bisexual Men in Metro Atlanta, Georgia
Authors: Saldana Carlos S , Hershow Rebecca , Philpott David , Hassan Rashida , Curran Kathryn , Gettings Jenna , Garlow Eleanor , Mauck Daniel , Cantos Valeria D , Holland David P , Freeman Dorian , Johnson Erica , Reed Karrie , Adame Jose , Orozco Humberto , Wortley Pascale 
Published: December 2022

Abstract

Background
In Metro Atlanta, Georgia, annual HIV diagnoses among Hispanic/Latino (H/L) adolescents and adults have increased since 2014 (Figure 1), and four HIV molecular clusters, consisting primarily of Hispanic/Latino gay or bisexual men and other men who have sex with men (HLGBM), were identified in 2021. In March 2022, the Georgia Department of Public Health, the Centers for Disease Control and Prevention, and four health districts of Metro Atlanta (Fulton, Gwinnett, DeKalb, and Cobb) launched an investigation to characterize the clusters, assess barriers to accessing HIV care and prevention services, and inform improvements to service delivery.

Methods
We described the four clusters using HIV surveillance data. We conducted semi-structured qualitative interviews with 29 HLGBM and 28 providers through purposive sampling. Iterative analyses were conducted daily, comparing findings across interviews to identify commonly mentioned barriers to accessing HIV care and prevention services.

Results
The four clusters varied in size (5–42 members) and proportion of H/L members (41–100%); one cluster included members reporting injection drug use (14%) (Table 1). Viral suppression among cluster members was high across clusters (87–100%). Overarching reported barriers to accessing medical services included lack of culturally and linguistically concordant services, fear of deportation, transportation, and financial barriers (Table 2). LGBTQ and HIV stigma, low STD/HIV awareness, low access to primary care and HIV screening in primary and urgent care settings, and limited community outreach and marketing were common barriers to accessing HIV prevention services. For pre-exposure prophylaxis (PrEP) specifically, fear of being perceived as promiscuous, limited PrEP knowledge, and concerns with side effects were barriers. Navigating the healthcare system was noted as the primary challenge in HIV care.

Conclusion
The investigation of four clusters affecting HLGBM identified opportunities to improve access to HIV prevention and PrEP services for this population. State and local partners are planning cluster response activities, including ways to provide low-barrier culturally and linguistically concordant services (Table 3).

Disclosures
All Authors: No reported disclosures.
1535. Harm Reduction: A Missing Piece in Holistic ID Care for Patients Who Inject Drugs
Authors: Fracasso Francis Sarah M , Beekmann Susan E , Polgreen Phillip M , Marks Laura R , Liang Stephen Y , Durkin Michael J , Nolan Nathanial S 
Published: December 2022

Abstract

Background
The rise in injection drug use (IDU) has led to an increase in drug-related infections and hospitalizations. Harm reduction is an important strategy for preventing infections among people who inject drugs (PWID). We set out to evaluate how infectious disease physicians counsel PWID with serious injection-related infections on harm reduction practices.

Methods
An electronic survey was distributed to 1,510 physician members of the Emerging Infectious Network (EIN) to determine which harm reduction principles ID physicians recommend to PWID to reduce infection risks. EIN members who do not care for PWID were excluded. Two weekly reminders were sent to increase the response rate.

Results
Three hundred ninety-nine (26%, still in progress) ID physicians responded to the survey. Practice settings included: university (37%), community (27%), non-university teaching (23%), or other (14%) hospital settings. Of those, 279 (70%) reported routinely caring for PWID. 274 (98%) performed screening for HIV and hepatitis, and 239 (86%) discussed the risk of these viral infections. 65% prescribed immunization against hepatitis and 44% discussed HIV PrEP. 57% (n=159) reported not counseling patients on safer injection strategies. Common reasons for not counseling included limited time and a desire to emphasize antibiotic therapy/medical issues (33%, n=91), lack of training (30%, n=85), and believing that it would be better addressed by other services (27%, n=75). Among physicians who reported counseling PWID, they recommended abstinence from IDU (38%, n=105), handwashing & skin cleansing prior to injection (33%, n=92), avoiding injecting areas of skin breakdown (27%, n=76), and cleaning needles between use (26%, n= 73). Finally, 17% (N=47) reported no access to any addiction services.

Conclusion
Almost all ID physicians screen PWID for HIV and viral hepatitis and discuss the risks of these infections. Despite frequently encountering PWID, less than half of ID physicians provide safer injection advice. Opportunities exist to standardize education of PWID on harm reduction, emphasizing safer injection practices in conjunction with other strategies (e.g. HIV PrEP, HAV/HBV vaccination) to prevent infections.

Disclosures
All Authors: No reported disclosures.
1174. Liposomal Co-Formulation of MPL and QS-21 Favors the Development of T-helper 1 Cells and Promotes the Induction of CD8+ T Cells Against SARS-CoV-2
Authors: van Haren Simon D , Thomas Sanya , Levy Ofer , Sanchez-Schmitz Guzman , Doss-Gollin Simon , Rodriguez Yamile Lugo 
Published: December 2022

Abstract

Background
Benefit of COVID-19 vaccines is limited by need for freezing, high cost, requirement for multiple boosters, and waning immunity. An unmet need for safe and effective vaccines that can be quickly deployed worldwide during a pandemic exists. A barrier to developing scalable low-cost vaccines is the restricted access to vaccine- or adjuvant-formulations due to protection by intellectual property rights. This limits research to understand their mechanism of action and potential applicability towards vulnerable populations or emerging pathogens.

Methods
We studied cellular and molecular mechanisms of action of adjuvant formulations developed for global open access in 4 distinct but complementary in vitro platforms that are human, age-specific, and enable the same individual to serve as control and test condition; generating data on adjuvant-induced responses in vitro that predict activity in vivo.

Results
Whole blood assay that models magnitude of innate immune activation and identifies cell types activated showed that liposomal co-formulation of MPL+QS-21 activated monocytes and natural killer cells and induced cytokine production; tissue construct assay that models monocyte extravasation and autonomous differentiation into dendritic cells (DC) showed that only MPL+QS-21 co-formulation promoted CD14+ cells towards DC phenotype; monocyte-derived DC (MoDC) assay that interrogates immune activation type showed that MPL+QS-21 co-formulation in lipid nanoparticles promoted MoDC maturation by increasing CD40, CD86, CCR7 and HLA-DR expression and Th1-polarizing cytokine secretion; and dendritic cell-T cell interface assay that assesses potential of formulations to re-activate SARS-CoV-2 Spike antigen-specific T cells showed that only MPL+QS-21 co-formulation enhanced activation of antigen-specific CD4+ and CD8+ T cells.

Conclusion
Thus, human in vitro modeling provides new insight into the mechanism of action and synergistic effects of MPL+QS-21, and positions us to study them in vulnerable populations to assess potential age-specific application on vaccine development. Precision vaccinology coupled with global access may enable marked public health progress by accelerating, de-risking, and advancing affordable adjuvanted vaccines to the most vulnerable.

Disclosures
All Authors: No reported disclosures.
1175. Low Treatment Rates and Associated Factors Among Pregnant Women with Syphilis in Zambia
Authors: Jones Anna V , Mubiana-Mbewe Mwangelwa , Xue Yumo , Kapesa Herbert , Mzumara Maureen , Manasyan Albert , Dionne Jodie 
Published: December 2022

Abstract

Background
Syphilis in pregnancy is common in Africa with prevalence as high as 10%. In high prevalence areas ( &gt; 5%), WHO recommends universal syphilis screening and benzathine penicillin G treatment at the first antenatal clinic (ANC) visit. Implementation barriers include global stock outs and supply chain issues. Our goal was to document treatment rates and factors associated with lack of treatment among pregnant women with syphilis in Zambia.

Methods
The retrospective cohort study analyzed medical record data from pregnant women who sought care in 10 public ANC clinics in Lusaka, Zambia during 2018-2019 and tested positive for syphilis. Syphilis was diagnosed based on positive RPR testing and treatment was defined as documented penicillin therapy at the same facility. Patient characteristics were compared across treatment status using Wilcoxon Rank Sum Test for continuous variables, and Pearson Chi-Square Test for categorical variables. Simple logistic models with treatment status as the binary outcome were conducted to evaluate potential factors associated with lack of syphilis treatment in pregnancy. A multivariable logistic model was performed and a 2-sided P &lt; 0.05 was accepted as statistically significant.

Results
Among 28,480 pregnant women screened for syphilis, 5.6% (n=1363) tested positive. Among those with syphilis, median age was 27 years, 21% of women were nulliparous and 43% were living with HIV. Most women (72%) had their initial ANC visit during the 2nd trimester and 96% were screened for syphilis at the first visit. The documented treatment rate was 42% and the only factor associated with lack of treatment was ANC entry in 2019 compared to 2018 (aOR 2.2; 95% CI 1.7-2.8; p &lt; 0.001). (refer to Tables 1-2).

Conclusion
Syphilis prevalence among pregnant women tested in ANC clinic in Zambia during 2018-2019 was 5.6%. Recommended penicillin treatment was only documented in 42% of cases. No maternal or clinic characteristic was associated with lack of therapy. Calendar year may have been associated with treatment for unclear reasons. Novel approaches to ensure access to universal diagnosis and early treatment of syphilis among pregnant women in Zambia are needed to improve maternal and neonatal outcomes.

Disclosures
All Authors: No reported disclosures.
1573. Impact of the COVID-19 Pandemic on Antibiotic Use among Hospitalized Adults in Argentina, Brazil, and Chile
Authors: Patel Twisha S , McGovern Olivia L , Mahon Garrett W , Boszczowski Icaro , Munita Jose M , Garzon Maria I , Lipari Flavio , Salomao Matias , Marssola Giovanna , Tavares Bruno , Francisco Debora , Gurgel Alessandra P A , Arantes Tiago , Bori Andrea , Nogueira Cassimiro , Peters Anne , Spencer Maria , Orellana Cristian , Barbe Mario , Roldán Analía , Lopez Constanza , Bortoletto Josefina , Stender Stacie C , Lessa Fernanda C 
Published: December 2022

Abstract

Background
Reports showing high rates of antibiotic use (AU) in patients with coronavirus disease 2019 (COVID-19) despite low rates of secondary bacterial infection have emerged from various countries across the globe. We evaluated the impact of the COVID-19 pandemic on AU in healthcare facilities (HCFs) in Argentina, Brazil, and Chile.

Methods
We conducted an ecologic evaluation of AU in inpatient adult acute care wards (excluding maternity wards) in 6 HCFs in Argentina, Brazil, and Chile; 2 HCFs per country. AU data for intravenously administered antibiotics commonly used to treat respiratory infections were collected from pharmacy dispensing records and aggregated to monthly defined daily dose (DDD)/1000 patient days. Graphs were created to depict AU and COVID-19 discharges over time throughout the 36-month study period (03/2018–02/2021). Relative changes in AU for all antibiotics combined and specific classes were calculated by comparing median AU for the 24-month pre-pandemic period (3/2018–2/2020) with the 12-month pandemic period (3/2020–2/2021). Only statistically significant differences (P&lt; 0.05) determined by the Wilcoxon signed-rank test are reported.

Results
Compared to the pre-pandemic period, the use of all included antibiotics combined increased in 4/6 HCFs (6.7–35.1%). In the 4 HCFs that experienced increases in AU, Figure 1 shows that use was high during months when COVID-19 patient surges occurred. In 3/4 of these HCFs, AU remained high despite significant decreases in COVID-19 discharges. Ceftriaxone use increased in 2/6 HCFs (27.1–51.6%). Use of β-lactam antibiotics with activity against Pseudomonas aeruginosa increased in 3/6 HCFs (31.3–82.5%) and decreased in 1/6 HCFs (-18.9%). Vancomycin and linezolid use increased in 3/6 HCFs (36.9–77.1%).

Conclusion
Increases in AU among hospitalized adults were observed in 4 of 6 South American HCFs included in this study. The high rates of broad-spectrum antibiotic use in the HCFs may impact further emergence of antibiotic resistance. Understanding how this increase in antibiotic use compares to rates of bacterial infections during this time period is critical.

Disclosures
Jose M. Munita, MD, BioMerieux: Grant/Research Support|MSD: Grant/Research Support|Pfizer: Grant/Research Support Matias Salomao, MD, Cepheid: Lecture.
1231. Microbial Profile of Biliary Stent, Bile and Surgical Site Cultures in Pancreaticoduodenectomy Patients – Implications for Surgical Prophylaxis
Authors: Hung Kai Chee , Lee Winnie , Kwa Andrea Layhoon , Koh Ye Xin , Goh Brian Kim Poh , Chung Jasmine 
Published: December 2022

Abstract

Background
Surgical site infection (SSI) rates post pancreaticoduodenectomy (PD) range from 20 to 40%. Biliary obstruction (± stent in situ) leads to colonization of the biliary tract with gut flora, and bile contamination during surgery increases SSI risk. Current guidelines recommend surgical prophylaxis (ppx) with 1st or 2nd generation cephalosporins. However, emerging data favor targeted ppx based on biliary cultures to reduce SSI. We reviewed the microbial profile of pathogens isolated from perioperative biliary stent and bile cultures, and evaluated the impact of ppx on culture positive SSIs within 30 days of PD.

Methods
This was a retrospective study conducted in Singapore General Hospital. Patients who had PD from 1/1/2013 to 31/12/2019 were included. The first positive cultures from perioperative biliary stent, bile, and SSI cultures obtained within 30 days of surgery were reviewed. Antibiotic use 30 days prior and during surgery was collected.

Results
A total of 341 patients with a mean age of 63.9 ± 11.3 years were included; 202 (59.2%) were male and 137 (40.2%) received antibiotics in the past 30 days. For surgical ppx, patients received either cephalosporins ± metronidazole (216 [63.3%] ceftriaxone, 25 [7.3%] cefazolin), piperacillin-tazobactam (TZP) (35 [10.3%)], ciprofloxacin ± metronidazole (16 [4.7%)] or other antibiotics (14 [4.1%]), while 35 had missing data. Of the positive cultures from 84 biliary stent, 86 bile and 79 SSI, the most common organisms isolated were Enteroccocus spp., E. coli, Klebsiella spp., Enterobacter spp. and Candida spp. Ceftriaxone susceptibility rates in E. coli were 50.0%, 54.8% and 22.2% in biliary stent, bile and SSI cultures respectively; similarly low rates were also seen in Klebsiella spp. (Tables 1-3). Antibiotic use 30-days prior was associated with higher ceftriaxone resistance rates in E. coli and Klebsiella spp. from bile cultures (70.8% vs 36.4%, p=0.019). In patients with biliary stents cultured, use of TZP ppx showed a trend towards lower rates of culture positive SSIs compared to non-TZP ppx (9.1% vs 29.4%, p=0.054).

Conclusion
Our local gram-negative bacteria susceptibility rates to ceftriaxone are low in biliary stent, bile fluid cultures, and even lower for SSI post PD. Antibiotic ppx for PD in high-risk patients may need to be broadened.

Disclosures
All Authors: No reported disclosures.