bluuebunny/crossref_metadata_2025_split huggingface dataset:
481. Trends in SARS-CoV-2-related Pediatric Hospitalizations in the Canadian Nosocomial Infection Surveillance Program, March 2020 to December 2022
Authors: Lee Diane , Mitchell Robyn , Pelude Linda , Frenette Charles , Lee Bonita , Lefebvre Marie-Astrid , Comeau Jeannette L , Srigley Jocelyn , Thampi Nisha 
Published: November 2023

Abstract

Background
National surveillance can provide insights into trends in pediatric SARS-CoV-2-related hospitalizations during the pandemic and healthcare-associated infections.Figure:Proportion of all pediatric hospitalizations by age group and wave

Methods
From March 1, 2020, to December 31, 2022, the Canadian Nosocomial Infection Surveillance Program collected patient-level data on pediatric patients (under age 18 years) hospitalized with laboratory-confirmed SARS-CoV-2 from 9 pediatric and 25 mixed adult-pediatric hospitals. Pediatric COVID-19 vaccines became available for 12-17 years in May 2021 and for 5-11 years in November 2021.

Results
Of 4,878 pediatric patients, most (80.3%) were hospitalized with SARS-CoV-2 infection during the Omicron-dominant period (since Jan 2022); a higher proportion involved patients under five years of age (58.5% vs 46.9%, p &lt; 0.001). Most hospitalizations pre-Omicron involved children not vaccinated against COVID-19 (92%) versus 70% during Omicron (p &lt; 0.001). However, a lower proportion required intensive care during Omicron (15% vs 20%, p &lt; 0.001). There was no difference in pre-existing comorbidities or mortality between periods.
Overall, there were 257 healthcare-associated COVID-19 infections (HA-COVID) reported (5.4%); 89% occurred during Omicron. While there was no difference in median ages of patients with HA-COVID and community-associated COVID-19 infections (CA-COVID), 62% of patients with HA-COVID had a pre-existing comorbidity compared to 44% with CA-COVID (p &lt; 0.001), and 24% remained in hospital at 30 days after HA-COVID, compared to 2.2% with CA-COVID (p &lt; 0.001). Nearly 50% of patients with HA-COVID had received at least one vaccine dose, compared to 25% with CA-COVID.

Conclusion
During the Omicron-dominant period, a higher proportion of admitted patients with SARS-CoV-2 infection were under five years, but a lower proportion were unvaccinated and a lower proportion required intensive care and mortality was comparable between both periods. Only 5.4% of pediatric COVID-related hospitalizations were HAI, with most during Omicron. Patients with HAI were more likely to have a pre-existing comorbidity and increased hospital stay, potentially related to their underlying conditions.

Disclosures
All Authors: No reported disclosures
486. Phenotypic Clusters of Clinical Presentation and Severity Among Children with Multisystem Inflammatory Syndrome — United States, February 2020–October 2022
Authors: Ma Kevin , Yousaf Anna R , Lindsey Katherine N , Melgar Michael , Miller Allison D , Shah Ami B , Wu Michael J , Campbell Angela P , Zambrano Laura D 
Published: November 2023

Abstract

Background
Multisystem inflammatory syndrome in children (MIS-C) is an uncommon but severe hyperinflammatory syndrome occurring weeks after SARS-CoV-2 infection. Presentation can vary and overlap with other conditions, including acute COVID-19 and Kawasaki disease. Identifying clusters of MIS-C phenotypes informs efforts to reduce misclassification, characterize pathogenesis, and tailor treatments. Here we describe clusters of presentation using the largest collection of U.S. MIS-C cases to date.

Methods
We analyzed 9131 MIS-C cases reported to CDC from 55 U.S. health departments; onset dates ranged from February 2020–October 2022. Thirty-one dichotomous clinical variables were selected for clustering after excluding ones with high (≥ 15%) missingness or rare (≤ 10%) or high (≥ 90%) prevalence. We excluded 595 cases with ≥ 5 missing variables and conducted multiple imputation on the remaining 8536 cases. Latent class analysis (LCA) was run using the poLCA R package; the number of clusters was selected based on decreasing information criteria and automated variable selection.

Results
LCA identified five clusters, two of which were characterized by distinct organ system involvement: a respiratory symptom-driven cluster primarily affecting older children (N = 483 [5.7% of cases]; median age 14.4 years), and a mucocutaneous symptom-driven cluster primarily affecting young children (N = 1956 [22.9%]; median age 5.8 years) (Fig. 1). The remaining three clusters delineated a spectrum of clinical severity, with clinically mild and moderate clusters with infrequent shock (N = 2566 [30.0%] and N = 1650 [19.3%], respectively), and a severe cluster (N = 1881 [22.0%]) with shock and ICU admission for nearly all cases (Fig. 2). The proportion of cases belonging to this clinically severe cluster decreased over time as proportions of the mild/moderate clusters increased (Fig. 3). The case fatality ratio was highest in the respiratory (5.0%) and clinically severe clusters (1.6%) compared with other MIS-C cases (0.2%; P &lt; 0.001).Figure 1.Prevalence of respiratory and mucocutaneous/dermatologic symptoms for the respiratory and mucocutaneous clusters compared to all other MIS-C cases.Figure 2.Prevalence of organ system involvement, shock, and ICU admission for the three severity-defined clusters.Figure 3.Proportions of MIS-C cases by LCA-inferred cluster and month (primary y-axis); number of monthly MIS-C cases (secondary y-axis).

Conclusion
MIS-C cases reported to CDC national surveillance clustered into five groups with distinct symptoms and severity. Use of MIS-C phenotypic clusters in future studies may inform treatment decisions and assist with prognosis.

Disclosures
All Authors: No reported disclosures
492. Risk Factors for COVID-19 Mortality in ≥90 year old Inpatients: Retrospective Case Series
Authors: Pineda Raphaela Martina C , Castro Monica , Boy Gerald Kristoffer E , Pant Sushil 
Published: November 2023

Abstract

Background
Despite what we know about COVID-19, current literature is still lacking on some aspects of the disease. This is probably because the disease continues to evolve and there is still much to discover. COVID-19 outcomes in the elderly is one aspect that has not been fully explored.
This study investigated short-term outcomes of COVID-19 Infection on ≥90 year old patients in the context of COVID vaccination availability. We sought to identify risk factors for in-patient all-cause mortality during the peak of daily COVID-19 infections in this population.

Methods
52 admitted patients aged ≥90 years old with SARS-CoV-2 RT-PCR positive observed from Nov 2021 to Mar 2022 at New Rochelle Hospital in NY, USA.
We conducted a retrospective case study of ≥ 90 years old patients admitted at New Rochelle Hospital in NY, USA from Nov 2021 to Mar 2022. Electronic health records were reviewed.
Logistic regression was used to determine odds ratio for risk factors that contribute to COVID-19 mortality. Univariate analysis was used to analyze patients’ comorbidities, symptoms, lab abnormalities, and imaging with mortality as the independent variable.

Results
The most frequent risk conditions for COVID-19 mortality are congestive heart failure (p&lt; 0.048) and atrial fibrillation (p&lt; 0.009). The odds of dying from COVID19 is 5 times greater for nursing home residents than those patients residing at home or already admitted in the hospital. Shortness of breath and fever were found to be statistically significant with COVID 19 mortality. Patients who had x-ray results typical for COVID (p&lt; 0.004), leukocytosis (p&lt; 0.039), acute kidney injury (p&lt; 0.003), and elevated transaminases (p&lt; 0.001) are more at risk for dying from COVID.

Conclusion
Managing elderly individuals with COVID-19 can be challenging due to increased risk of severe illness and complications associated with age. We found that certain risk factors such as co-morbidities, previous residence, presenting symptoms and laboratories are associated with increased mortality in patients ≥ 90 years old. Currently, limited guidelines and studies are available for the geriatric population. Further research can be done by stratifying severity of comorbidities, determining vaccination status, and increasing sample size.

Disclosures
All Authors: No reported disclosures
494. Real-world effectiveness of tixagevimab/cilgavimab for COVID-19 pre-exposure prophylaxis in solid organ transplant recipients during the Omicron variant period
Authors: Rojanakit Gun , Kiertiburanakul Sasisopin , Boongird Sarinya , Sutharattanapong Napan , Yingchoncharoen Teerapat , Sobhonslidsuk Abhasnee , Bruminhent Jackrapong 
Published: November 2023

Abstract

Background
Pre-exposure prophylaxis (PrEP) with a combination of long-acting monoclonal antibodies with tixagevimab/cilgavimab (T/C) have provided viral neutralizing activity against SARS-CoV-2 and protected solid organ transplant recipients (SOTRs) that produced poor immunogenicity after COVID-19 immunization. However, real-world data on the effectiveness and safety of T/C in SOTRs during the Omicron wave is limited.

Methods
A prospective study at a single transplant center was conducted to evaluate the effectiveness and adverse events (AE) of T/C among SOTRs during the BA.2.75 Omicron lineages period (August 2022 to February 2023). T/C of 150/150 and 300/300 mg doses were provided from August 2022 to December 2022 and after, respectively.

Results
A total of 39 SOTRs comprising kidney (n= 29), liver (n=2), and heart (n=8) transplant recipients were included in the study. Thirty-three (85%) and 6 (15%) SOTRs received 150/150 and 300/300 mg of T/C, respectively. The median (IQR) age was 52 (35-62) years. Twenty-two (56%) had a prior history of COVID-19. The median (IQR) number of COVID-19 vaccine was 4 (3-4) doses. During the median follow-up of 6.35 (5-8.33) months, COVID-19 developed in 5 (12.8%) out of 39 SOTRs with a median (IQR) time of 73 (36-115) days from receiving T/C. None of those who received a 300/300 mg dose developed COVID-19. There was no severe COVID-19 or death observed. Five (12.8%) SOTRs reported mild and reversible AEs with pain at injection (n=2), fever (n=3), and muscle aches (n=1). There was no allograft rejection reported.

Conclusion
Breakthrough SARS-CoV-2 infection remains among fully vaccinated SOTRs receiving T/C as PrEP and subjects to concurrent circulating strain in the community. However, the disease severity appears mild, and the short-term safety profile seems tolerable.

Disclosures
All Authors: No reported disclosures
500. Durability of antibody response after booster vaccination against SARS-CoV-2 in kidney transplant recipients with or without prior infection
Authors: Ueaphongsukkit Thornthun , Banjongjit Athiphat , Avihingsanon Yingyos , Udomkarnjananun Suwasin , Townamchai Natavudh , Jutivorakool Kamonwan , Vanichanan Jakapat 
Published: November 2023

Abstract

Background
Kidney transplant recipients (KTR) are at increased risk of severe COVID-19 infection due to their immunosuppressive drugs. COVID-19 vaccination is recommended to prevent infection and severe illness. However, the knowledge on the durability of vaccine response and appropriate timing of booster vaccination is not well established. This study aimed to evaluate the anti-SARS-CoV-2 S antibody response &gt; 12 weeks after the fourth vaccination and to identify factors associated with a good antibody response in KTR.

Methods
This single-center cross-sectional study was conducted at King Chulalongkorn Memorial hospital in Bangkok, Thailand between January and April 2023. It enrolled adult KTR who had been transplanted for more than 6 months and had received the fourth COVID-19 vaccine dose for more than 12 weeks. KTR with prior long acting antibody (LAAB) were excluded. Baseline characteristics, laboratory data, COVID-19 vaccine certificates, and history of prior infection were collected. Blood samples were taken at enrollment for anti-SARS-CoV-2 S antibody testing (Elecsys®, Cobas e 411 analyzer; Roche Diagnostics, Basel, Switzerland). An antibody level ≥ 1,000 BAU/mL was considered a high sustained response. All statistical analyses were performed using Stata 15.1 (Stata Corp., College Station, TX, USA).

Results
A total of 132 KTR were enrolled. The median age was 52 years, and 60% were male. Most KTR received two doses of viral vector vaccine as their first two primary shots with two doses of mRNA vaccine as the additional primary and booster shots. The overall anti-SARS-CoV-2 S antibody level was 4,917 (IQR 884.4 – 16,888.5) BAU/mL at the median of 261.5 (IQR 202 – 297.5) days since last vaccination. There were 96 (73%) of KTR with antibody level ≥ 1,000 BAU/mL. Baseline characteristics were shown in Table 1. History of COVID-19 infection was significantly associated with a good antibody response after multivariate logistic regression analysis with adjusted OR of 3.87 (95% CI 1.64 – 9.08) (Figure 1).

Conclusion
This study showed a high anti-SARS-CoV-2 S antibody response in KTR after the 4th vaccine dose, with 73% achieving a good response at &gt; 6 months. Prior COVID-19 infection was associated with a good antibody response, indicating role of hybrid immunity among this patient population.

Disclosures
All Authors: No reported disclosures
511. Risk Factors for Seeking Medical Care Following Nirmatrelvir-Ritonavir (Paxlovid) Treatment For COVID-19
Authors: Bhargava Ashish , Szpunar Susan M , Sharma Mamta , Saravolatz Louis 
Published: November 2023

Abstract

Background
In December 2021, the FDA issued an emergency use authorization (EUA) for nirmatrelvir-ritonavir (Paxlovid). This was based on the randomized placebo-controlled trial data from the EPIC-HR study which showed that high-risk non-hospitalized patients given Paxlovid had an 88.9% reduction in the relative risk of progression to hospitalization or death by Day 28 in coronavirus disease 2019 (COVID-19). We aimed to study the risk factors for seeking medical care following Paxlovid treatment.

Methods
In this historical cohort study, we assessed risk factors for high-risk non-hospitalized patients treated with Paxlovid from January 1, 2022, to December 31, 2022, at outpatient facilities associated with Ascension St. John Hospital. Our outcome variable was the composite of subsequent evaluation in the Emergency Department (ED) or inpatient admission within four weeks of their Paxlovid treatment. Data were analyzed using SPSS v. 29.0. The study was approved by the IRB.

Results
Of 371 patients who received Paxlovid treatment, the mean (SD) age was 59.4 (±13.8) years; 63.9 % (237) were female, and 77.7% (282) white. The mean body mass index (BMI) of the cohort was 31.3 ± 7.8 kg/m2. The incidence of the composite event was 6.7% (25/371). The risk of the composite event was higher in patients with a history of myocardial infarction (MI) (28 % vs 9.3%), congestive heart failure (CHF) (12 % vs 2.3%), chronic lung diseases (CLD) (48 % vs 26.4%) and diabetes mellitus (DM) with complication (24% vs 4.1%), respectively. Alcohol users were less likely to seek medical care following Paxlovid (40 % vs 63.7%, respectively). There were no differences in BMI, tobacco use or vaccination rates between the groups. In multivariable logistic regression, factors associated with seeking medical care post-Paxlovid were female sex (OR 4.6; 95% CI 1.4-15.3; p= 0.013), alcohol use (OR 0.4; 95% CI 0.2-0.9; p= 0.039), MI (OR 4.0; 95% CI 1.4-11.8; p=0.011), DM with complications (OR 6.9; 95% CI 2.0-23.3; p= 0.002), CLD (OR=3.9, 95% CI 1.1-13.5; p=0.03), at the time of Paxlovid treatments.

Conclusion
Independent risk factors for seeking medical care following Paxlovid treatment for COVID-19 were MI, CHF, CLD, and DM with complications while alcohol users were less likely to seek medical care following the Paxlovid treatment.

Disclosures
All Authors: No reported disclosures
528. Matched Retrospective Study, Comparing Molnupiravir to Nirmatrelvir-Ritonavir (Paxlovid) in the Treatment of Mild-Moderate COVID-19 in Immunocompromised Cancer Patients
Authors: Haddad Andrea , Moussa Mohammad , Hachem Ray Y , Jiang Ying , Dagher Hiba , Chaftari Patrick , Chaftari Anne-Marie , Raad Issam I 
Published: November 2023

Abstract

Background
Paxlovid has been shown to reduce the risk of progression (hospitalization/death) by 88% as compared to placebo, while molnupiravir reduced that risk by 31%. However, these two agents have not been compared in the same study patient population. We therefore conducted a matched controlled study, comparing molnupiravir to paxlovid in terms of safety (adverse events and drug-drug interactions) and efficacy (progression and rebound events) in the treatment of mild-moderate COVID-19 in immunocompromised cancer patients.

Methods
This is a single center, retrospective study that included 240 cancer patients diagnosed with COVID-19 in 2022. Patients who received molnupiravir were matched to those who received paxlovid on a 1:2 ratio, based on age group (18-64 years vs. ≥ 65) and type of cancer (lung cancer, hematologic malignancy, or other solid tumors). We collected patient demographics, comorbidities, malignancy history and treatment, vaccination status, as well as post-treatment progression and safety information. We used margins of 10% with 95% confidence intervals to determine the equivalence of outcomes.

Results
As shown in table 1, the two groups had comparable demographics, underlying malignancies, and most comorbidities, however smoking history, underlying CKD, and CAD were more common in the molnupiravir group. Similarly presenting symptoms were comparable, but cough, dyspnea and sore throat were more prevalent in the molnupiravir group.
By multivariate analysis, 3 factors were independently associated with progression: hypertension, cough on presentation and failure to complete the 5-day course of antiviral therapy - P &lt; 0.037. However, multivariate analysis failed to show any difference between the 2 groups in terms of progression to severe/disease and rebound events with equivalent margins within 10%.
Patients who received paxlovid however were significantly more prone to drug-drug interactions/adverse events (28% vs. 0 - P &lt; 0.0001).
Comparing patients treated with molnuprivir versus those treated with paxlovid

Conclusion
In the treatment of mild to moderate COVID-19 in cancer patients, molnupiravir was comparable to paxlovid in preventing progression to severe disease/death and rebound events, with a superior safety profile.

Disclosures
Issam I. Raad, Distinguished Professor, Novel Anti-Infective Technologies, LLC: Technology License
540. A Dose-Comparison Study of Methylprednisolone on Mortality in COVID-19 Patients Require Oxygen in A Tertiary Hospital in Thailand
Authors: Piyapan Pattraporn , Masamhisak Viranpat 
Published: November 2023

Abstract

Background
Dexamethasone 6 mg IV for 10 days or an equivalent dose of another corticosteroid like methylprednisolone (MP) is recommended for severe COVID-19 patients. A higher dose has been reported as beneficial for severe patients. We aimed to compare the effect of &lt; 3 and ≥ 3 mg/kg/day (MKD) of MP in patients who require conventional oxygen therapy or high-flow nasal cannula

Methods
A retrospective study was conducted between June and October 2022 in Bhumibol Adulyadej Hospital by reviewing the medical record of COVID-19 patients requiring conventional oxygen therapy or high-flow nasal cannula. The patients were divided into two groups by the dosing of MP to ≥ 3 MKD and &lt; 3 MKD to compare baseline characteristics, treatment, and clinical course. Multivariate logistic regression was used to identify factors associated with mortality.

Results
There are 197 patients included in the study: 100 from ≥ 3 MKD group and 97 from &lt; 3 MKD group. The mean daily dose of MP was 4.16 (± 0.93) and 2.25 (± 0.55) MKD. There were no statistical differences between the baseline characteristic of the two groups except enoxaparin prophylaxis were more used and LDH were higher in ≥ 3 MKD group. Mortality at 28 days was 26% in ≥ 3 MKD group vs 8.2% in &lt; 3 MKD group (adjusted odd ratio, 3.52 [95% CI, 1.44-8.62]; P = 0.006). Age &gt; 65 is also an independent factor associated with mortality (P = &lt; 0.001). Bacteremia occurred in 10% VS 2% of ≥ 3 and &lt; 3 MKD groups, respectively (odd ratio, 0.19 [95% CI, 0.04-0.89]; P = 0.02).

Conclusion
During the fourth wave of the COVID-19 pandemic with the Delta variant in Thailand, we found patients requiring conventional oxygen therapy or high-flow nasal cannula who received a higher dose of MP (≥ 3 MKD) were associated with significant 28-day mortality.

Disclosures
All Authors: No reported disclosures
547. Molnupiravir and Nirmatrelvir/Ritonavir Effectiveness in Reducing the Risk for COVID-19 Disease Progression and Death
Authors: Paraskevis Dimitrios , Gkova Mary , Mellou Kassiani , Mellou Kassiani , Gkolfinopoulou Kassiani , Kostaki Evangelia Georgia , Loukides Stylianos , Kotanidou Anastasia , Skoutelis Athanasios , Thiraios Eleftherios , Saroglou George , Zografopoulos Dimitrios , Mossialos Elias , Zaoutis Theoklis , Gaga Mina , Antoniadou Anastasia , Tsiodras Sotirios 
Published: November 2023

Abstract

Background
Molnupiravir (M) and Nirmatrelvir/Ritonavir (N/R) have been authorized for use in COVID-19 patients at high risk for severe disease. We aimed to evaluate the effectiveness of M and N/R in highly vulnerable SARS-CoV-2 patients using a retrospective cohort study design.

Methods
The study population consisted of SARS-CoV-2 infected non-hospitalized patients in Greece, aged 65 years or older, that received M between February 2 and March 25, 2022 and N/R between March 26 and July 20, 2022. The impact of each drug was determined via comparisons with age-matched control groups of SARS-CoV-2-positive patients who did not receive oral antiviral therapy, using as outcome (i) hospital admission with COVID-19 within 10 days after tested positive, and (ii) death from COVID-19 within 35 days from positive test.

Results
Overall, 4,240 M and 13,861 N/R recipients were enrolled. Administration of M significantly reduced the risk of hospitalization (Odds Ratio [OR] = 0.40, p &lt; 0.001) and death (OR = 0.31, p &lt; 0.001) among these patients based on data adjusted for age, previous SARS-CoV-2 infection, vaccination status, and time elapsed since the most recent vaccination. The reductions in risk were most profound among elderly patients (≥75 years old) and among those with high levels of drug adherence. Administration of N/R also resulted in significant reductions in the risk of hospitalization (OR = 0.31, p &lt; 0.001) and death (OR = 0.28, p &lt; 0.001). Similar to M, the impact of N/R was more substantial among elderly patients and in those with high levels of drug adherence.

Conclusion
N/R and M use prevented hospital admissions and death in a large real-world study of highly vulnerable patient populations.

Disclosures
All Authors: No reported disclosures