bluuebunny/crossref_metadata_2025_split huggingface dataset:
550. Effectiveness of Remdesivir for Treatment of COVID-19 in the Outpatient Setting
Authors: Vo Vinny P , Lu Shu , Shah Madiha , Nguyen Hien 
Published: November 2023

Abstract

Background
Remdesivir (REM) was the first FDA-approved treatment for COVID-19. A clinical trial evaluated the effectiveness of REM for the outpatient treatment of COVID-19, showing an 87% lower risk of hospitalization and death when given within the first 7 days of infectious symptoms in confirmed infection. "Real-world" studies evaluating the outpatient use of REM when Omicron was the predominant variant have not been published. We aim to evaluate the use of REM in the outpatient setting (REM-OP) at our institution.

Methods
VA Northern California Health Care System developed an outpatient clinic for the treatment of COVID-19 after FDA approval of REM-OP in January 2022. Patients had to meet institutional criteria for outpatient management of COVID-19 with REM, including a confirmed positive PCR test, lack of supplemental oxygen, risk for severe disease, and reliable transportation. We retrospectively evaluated patients given REM-OP from 1/21/2022 - 413/2022 when Omicron was the predominant variant in our region. Data were obtained using a data query of outpatient REM prescriptions. Subsequently, the administrations of REM were verified and patient variables, including risk factors for progression to severe disease, COVID vaccination, history of previous infection, and subsequent hospitalization or death within 30 days, were collected via manual chart review.

Results
88 patients received REM-OP with a mean age of 70.0 (SD +/- 11.4) with a predominantly male (92%) and white (67%) population. Most patients had received a least one dose of COVID-19 vaccination but 17% were unvaccinated. The most common risk factors for progression to severe disease included age (75% were over age 65), diabetes (45%), hypertension (64.8%), and cardiovascular disease (31.8%). 98% of patients met at least one risk factor for progression to severe disease and 95% completed REM-OP. 93% of patients received REM within 7 days of symptom onset. Of the 88 patients who were treated, 5 patients were admitted within 30 days (2/5 were due to COVID-19 infection), and 2 patients died (1 of which was attributed to COVID-19).
Patient Characteristics
Comparison to PINETREE Clinical Trial

Conclusion
REM-OP during the Omicron surge in our single-center retrospective study had comparable effectiveness to its use in a clinical trial during the Delta surge.

Disclosures
All Authors: No reported disclosures
588. Ceftolozane/Tazobactam Susceptibility of Carbapenem-Resistant Pseudomonas aeruginosa and Carbapenem-Resistant Enterobacterales Isolates in a Tertiary Hospital in Korea
Authors: Kim Kye-Hyung , Moon Seulgi , Ko Mee Kyung , Yi Jongyoun 
Published: November 2023

Abstract

Background
Carbapenem-resistant Enterobacterales (CRE) and carbapenem-resistant Pseudomonas aeruginosa (CRPA) are significant nosocomial pathogens that pose significant challenges in treatment due to their multidrug-resistant nature. Ceftolozane/tazobactam (C/T) is a novel antimicrobial agent that has shown promising activity against these pathogens. However, there is limited data
available on its susceptibility against these resistant isolates in Korea. The aim of this study is to determine the in vitro susceptibility of C/T against CRE and CRPA isolates in a tertiary hospital in Korea.

Methods
Blood isolates of CRE and CRPA were collected from a tertiary hospital between September 2017 and September 2022. A carbapenemase test was performed using NG test CARBA-5. For non-carbapenemase-producing CRE and CRPA, the minimum inhibitory concentration of C/T was determined using the Etest and interpreted according to the CLSI breakpoints.

Results
A total of 120 blood isolates, including 55 CRE and 65 CRPA, were analyzed. Carbapenemase-producing isolates were found in 60.0% of CRE and 27.7% of CRPA samples. Among the CRE isolates, KPC (50.9%), NDM (7.3%), and OXA-48-like (1.8%) carbapenemases were identified, while NDM (21.5%), IMP (3.1%), and VIM (3.1%) were found in CRPA isolates. For the non-carbapenemase-producing isolates, the susceptible, intermediate, and resistant rates to C/T were 9.1%, 7.3%, and 23.6%, respectively, for CRE, and 67.7%, 3.1%, and 1.5%, respectively, for CRPA.

Conclusion
This study provides important information on the in vitro susceptibility of C/T against CRE and CRPA isolates in Korea. The findings will help guide empirical antibiotic therapy and improve patient outcomes. Further studies are needed to evaluate the clinical efficacy of C/T against these resistant pathogens in Korea.

Disclosures
All Authors: No reported disclosures
628. A meta-analysis of Tick Paralysis in humans globally
Authors: Matthews Sarah N , Harfouch Chawki 
Published: November 2023

Abstract

Background
Tick paralysis is a neurological disease that causes acute ascending motor paralysis and sparing of sensory function. It is caused by a neurotoxin released from the tick during hematophagy. Due to the rare occurrence of tick paralysis cases and the lack of a surveillance system, literature is limited and the exact number of cases in the world cannot be quantified.

Methods
We conducted a meta-analysis of medical literature documenting 121 tick paralysis cases from 1940 to present day using PubMed. Cases were stratified based upon geographic location, tick species, and clinical manifestations.

Results
The compilation includes 71 cases in North America, 14 cases in Australia, 33 cases in Asia, two cases in South America, and one case in Africa. In North America, 36.62% of cases (n=26) were caused by Dermacentor andersoni and in Australia, 50% of cases (n=7) were caused by Ixodes holocyclus. Dermacentor, Amblyomma, Rhipicephalus, and Hyalomma tick species were the primary culprits in Asia. The ticks involved in the cases in South America and Africa were not identified. Facial palsy was the most commonly reported primary symptom documented in 35 cases, followed by gait ataxia seen in 26 cases. Three cases involved patients with advanced disease causing respiratory depression and cardiopulmonary arrest.Table 1:Tick Paralysis Cases Documented 1940-PresentTable 2:Tick Paralysis Cases Documented 1940-PresentTable 3:Tick Paralysis Cases Documented 1940-Present

Conclusion
This collection of cases illustrates a wider geographic distribution of tick species than previously documented and suggests the evolving climate and urbanization have significant effects on the expansion of their habitable environments and subsequently, human exposure and illness. Additionally, the meta-analysis supports the need for further education regarding this rare type of tick-borne disease for healthcare providers to ensure prompt diagnosis, appropriate treatment, and improved patient outcomes.

Disclosures
All Authors: No reported disclosures
647. Comparative Analysis of Two Sample -to - Answer Nucleic Acid Amplification Assays for the Detection of Respiratory Viral Pathogens from Pediatric Respiratory Specimens
Authors: Sasidharan Anjana , Banerjee Dithi , Hayes Amanda M , Petty Sydnie , Schuster Jennifer E , Goldman Jennifer , Selvarangan Rangaraj 
Published: November 2023

Abstract

Background
Rapid and accurate diagnosis of acute respiratory infection (ARI) in children is crucial for proper patient management, and nucleic acid amplification tests are the gold standard. Nasal swabs are preferred for surveillance studies due to their ease of use, mainly in children. Our study compares the performance of two sample-to-answer (STA) platforms for detecting multiple viruses in self-collected nasal swabs from symptomatic children.

Methods
Between January 2023 and March 2023, self-collected nasal swabs in UTM from children and staff with ARI symptoms were collected as part of an ongoing school-based surveillance study in a large Missouri school district. Samples were tested on the QIAstat-Dx Respiratory SARS-CoV-2 Panel and the fully automated Hologic Panther Fusion system, which can detect a total of 21 respiratory viruses. Percent Agreement analysis was performed to compare the performance of each platform.

Results
Of 200 samples collected, QIAstat detected viruses in 111 samples (55.5%) and Hologic in 115 samples (57.5%). Both assays showed high overall agreement (90%), with a PPA (Positive percentage agreement) of 89%, an NPA (Negative percentage agreement) of 94%. Parainfluenza (PIV) showed 100% PPA and NPA followed by adenovirus (Adv) (PPA: 100%; NPA: 97.9%) and rhinovirus (RV) (PPA: 92% and NPA: 94%). Human metapneumovirus (hMPV) had the lowest PPA (47%) but a high NPA (99%) (Table 1). The median CT values for QIAstat and Hologic were 28.8 (IQR 23.65 - 32.5) and 29.3 (IQR 24.2 – 34.5), respectively. QIAstat missed 19 detections, including hMPV (9, 53%), coronavirus NL63 (4, 16%), and RV (4, 8%), with a corresponding median Ct of 39.1 (IQR 34.5 – 41.2) on Hologic. Hologic missed 12 detections, with RV being the most common target (9, 17%), and a corresponding median Ct of 32.9 (IQR: 30.3-35.5) on QIAstat.

Conclusion
QIAstat and Hologic exhibit comparable performance (overall agreement 90%) for detecting viral respiratory pathogens from self-collected nasal swabs. Viral detections missed by QIAstat assay had low viral loads, while targets missed by Hologic assay had moderate viral load; additional investigation is needed. Our findings suggest that both STA platforms are suitable for diagnosing respiratory viral infections in self-collected nasal swabs in school-setting.

Disclosures
Rangaraj Selvarangan, BVSc, PhD, D(ABMM), FIDSA, FAAM, Abbott: Honoraria|Altona Diagnostics: Grant/Research Support|Baebies Inc: Advisor/Consultant|BioMerieux: Advisor/Consultant|BioMerieux: Grant/Research Support|Bio-Rad: Grant/Research Support|Cepheid: Grant/Research Support|GSK: Advisor/Consultant|Hologic: Grant/Research Support|Lab Simply: Advisor/Consultant|Luminex: Grant/Research Support
654. Changing trends of molecular characteristics and antimicrobial susceptibility of hypervirulent Klebsiella pneumoniae in community-acquired liver abscess before and after COVID-19 outbreak in South Korea
Authors: Hyun Miri , Lee Ji Yeon , Kim Hyun ah 
Published: November 2023

Abstract

Background
Hypervirulent Klebsiella pneumoniae (K. pneumoniae, hvKP) causes invasive infections, usually community-acquired liver abscess. In this study, we aimed to compare the molecular characteristics and antimicrobial susceptibility of hvKP in community-acquired liver abscess over times, especially before and after COVID-19 outbreak.

Methods
This study was performed on K. pneumoniae isolates of community-acquired liver abscess collected from Keimyung University Dongsan Hospital from 2014-2015 and 2020-2021. Clinical and microbiologic data were collected from medical records. Capsular serotypes and virulence factors were identified by polymerase chain reaction using specific primers.

Results
A total 79 patients were analyzed, 39 (49.4%) of 2014-2015 and 40 (50.6%) of 2020-2021. Capsular serotype K1 (61.5% vs. 62.5%) and K2 (25.6% vs. 30.0%) were no significant differences between the two periods. In virulence factors, IutA (82.1% vs. 97.5%) was significantly increased in 2020-2021 compared to 2014-2015 (p=0.028). RmpA (84.6% vs. 90.0%), kfu (61.5% vs. 70.0%), allS (56.4% vs. 67.5%) were showed no significant changes between two periods. Antimicrobial susceptibility of ciprofloxacin (100.0% vs. 95.0%), ceftriaxone (97.4% vs. 89.7%), and imipenem (100.0% vs. 97.5%) were no significant differences between the two periods.Table 1.Molecular characteristics of hypervirulent Klebsiella pneumoniae in community-acquired liver abscess

Conclusion
In liver abscess, the virulence factors showed a tendency to increase during the study period such as IutA, but the limitation is that there were small numbers of isolates included in this study. Further studies with larger number of isolates will be required to findout the changing characteristics of hvKP over times.

Disclosures
All Authors: No reported disclosures
656. Cryptosporidiosis in Immunocompromised Patients with Cancer Receiving Chemotherapy, CAR-T Cell Therapy and Hematopoietic Stem Cell Transplantation: A Retrospective Analysis
Authors: Mann Inderjit , Okhuysen Pablo C 
Published: November 2023

Abstract

Background
Cryptosporidium is a parasitic protozoan that causes severe and potentially life-threatening diarrheal disease in immunocompromised patients. Infections can be asymptomatic, cause self-limited disease, or chronic diarrhea and in some cases result in biliary and pulmonary disease

Methods
We performed a detailed retrospective analysis of patients that presented with diarrheal illness, and Cryptosporidium infection diagnosed by GI multiplex (Biofire) at UT MD Anderson Cancer Center between January 2017 and March 2023.

Results
We identified 51 patients aged 24 to 89 years with cryptosporidiosis. Hematological malignancies (HM) were present in 44% of patients, while non-hematological malignancies (NHM) in 55%. Thirty-seven percent of patients had received hematopoietic stem cell transplantation (HSCT), 8% chimeric antigen receptor T-cell (CAR-T) therapy, 18% immunosuppressive therapy, and 65% received chemotherapy in the last 90 days. Two patients had human immunodeficiency virus (HIV). All patients presented with diarrhea, 39% with nausea, 43% with abdominal pain, and 51% had fever. The median duration of symptoms was 3 days. About 41% were severely neutropenic, and 61% had severe lymphopenia. Computed tomography (CT) abdomen was normal in 43% of patients, 16% had colitis, 12% had enteritis, and 4% had enterocolitis. All patients were treated with Nitazoxanide, with a median duration of therapy (DOT) of 14 days. The DOT was longer in HM than in NHM (14 ± 7.9 vs. 9.9 ± 5.6, p= 0.016) and in HSCT/CAR-T patients than without HSCT/CAR-T (13.8 ± 6.1 vs. 10.3 ± 7.3, p = 0.009). About 18% of patients had co-infections with other enteropathogens. Death from other causes occurred in 13 of 51 (23%) of patients. All cause mortality between HM and NHM (p=0.207), HSCT/CAR-T and non-HSCT/CAR-T (p=0.52), or chemotherapy vs. without chemotherapy (p=0.34) was similar. Most infections were encountered in the month of October.

Conclusion
We observed a limited response to nitazoxanide at our center, contributing factors and confounders included co-infections with other pathogens, active chemotherapy, or HSCT/CAR-T induced intestinal epithelium injury. Controlled, double blinded studies with new agents are needed to determine the optimal management of cryptosporidiosis in this population.

Disclosures
Pablo C. Okhuysen, M.D., FACP, FIDSA, Astra Zeneca: Stocks/Bonds|Beam Therapeutics: Stocks/Bonds|Biontech: Stocks/Bonds|Deinove Pharmaceutucals: Grant/Research Support|Ferring: Advisor/Consultant|GSK PLC: Stocks/Bonds|Haleon: Stocks/Bonds|Johnson and Johnson: Stocks/Bonds|Melinta Pharmaceuticals: Grant/Research Support|Merk Sharp and Dohme: Grant/Research Support|Moderna: Stocks/Bonds|Napo Pharmaceuticals: Advisor/Consultant|Napo Pharmaceuticals: Grant/Research Support|Novavax: Stocks/Bonds|Pfizer: Stocks/Bonds|SNIPR Biome: Advisor/Consultant|Summit Pharmaceuticals: Grant/Research Support
684. Characteristics of Patients with Initial Clostridioides difficile Infection (CDI) That Are Associated With Increased Risk of Multiple CDI Recurrences
Authors: Guh Alice , Li Rongxia , Korhonen Lauren C , Winston Lisa Gail , Parker Erin , Czaja Christopher A , Johnston Helen , Basiliere Elizabeth , Meek James , Olson Danyel M , Fridkin Scott , Wilson Lucy E , Perlmutter Rebecca , Holzbauer Stacy , D’Heilly Paige , Phipps Erin , Flores Kristina , Dumyati Ghinwa , Pierce Rebecca , Ocampo Valerie , Wilson Christopher , Watkins Jasmine , Gerding Dale , Clifford McDonald L 
Published: November 2023

Abstract

Background
Recent advancements in treating Clostridioides difficile infection (CDI) include therapeutics to prevent further recurrence in patients with recurrent CDI (rCDI). However, little is known about which patients are at increased risk for multiple recurrences (≥ 2 rCDI). We sought to identify predictors of multiple rCDI (mrCDI) in adults at the time of presentation with initial CDI (iCDI).

Methods
The Centers for Disease Control and Prevention’s Emerging Infections Program (EIP) conducts population-based CDI surveillance in 10 U.S. sites. We defined iCDI as a positive C. difficile test during January 2018–August 2019 in a person aged ≥ 18 years with no prior positive test reported to EIP. rCDI was defined as a positive test ≥ 14 days from the previous positive test within 180 days after iCDI. All patients with community-onset iCDI and a random sample of patients with healthcare-facility onset iCDI (i.e., hospital-onset, long-term care facility onset) had full chart reviews. Multiple imputation was performed on missing race/ethnicity. Candidate variables determined a priori to be potentially associated with mrCDI were entered into an initial multivariable logistic regression model. Patients without mrCDI who died within 180 days of their iCDI were excluded from the model. Candidate variables with a p-value &lt; 0.1 in the initial model were included in the final model.

Results
Of 18,829 patients with iCDI, 882 (4.7%) had mrCDI, ranging from 2 to 5 rCDI per patient in the 180 days following iCDI. Median time between each rCDI was 43 days (interquartile range: 27–65 days). Full charts were reviewed for 435 iCDI patients with mrCDI and 7474 iCDI patients without mrCDI. Characteristics of patients with and without mrCDI are shown in Table 1. In multivariable analysis, age ≥ 65 years, recent hospitalization, chronic hemodialysis, and recent nitrofurantoin use were significantly associated with mrCDI (Table 2).

Conclusion
Patients with iCDI who are older, on hemodialysis, or had recent hospitalization or nitrofurantoin use may be at increased risk of mrCDI and may benefit from early use of adjunctive therapy to prevent mrCDI. If confirmed, these findings would aid in clinical decision making.

Disclosures
Ghinwa Dumyati, MD, Pfizer: Grant/Research Support
687. Zinplava Expert Retrospective Observations (ZERO) Study Findings on Clostridioides difficile Recurrence
Authors: Jacobs Micah , Morris Sharon 
Published: November 2023

Abstract

Background
Describe real world experience in the use of bezlotoxumab (BZT) for the prevention of recurrent Clostridioides difficile(CDI) infection with a 1 year follow up following administration. The original BZT studies showed approximately 16% rate of recurrence at 12 weeks with other baseline and outcome data as noted in Figure 1.

Methods
Retrospective study of patients administered BZT in a community based private practice infusion suite from May 2017 to October 2020. A total of 50 consecutive patients were included with background demographics, relevant medical history and CDI history obtained through chart review. In addition to the chart review, patients were contacted at least 1 year after BZT administration to see if there were any recurrences and if other treatments were required. Primary objective was to show the rate of CDI recurrence in the 1 year after BZT administration. All BZT was administered in an outpatient setting in patients who were responding to initial Standard of care (SOC) therapy.

Results
50 patients were included with infusion dates from May 2017 to October 2020. Baseline patient characteristics (Figure 2) include median Age of 69 and 74% female. CDI history (Figure 3) includes an average of 2.06 episodes including the current episode at time of time treatment and median of 19.5 days to BZT administration from last positive episode (positive test or starting a new treatment course for presumed positive). SOC treatments over the course of patient’s episodes are listed in Figure 3, most patients received more than agent.
In the 1 year following BZT only 4 patients had recurrence (Figure 4) with 2 going on fecal microbiota transplant. There were 3 deaths reported, all at least 3 months after BZT and none had CDI recurrence.

Conclusion
In our real-world use, BZT administered in an outpatient setting to patients who responded to SOC treatment resulted in only 8% recurrence after 1 year compared to 16% after 12 weeks in the trial. This supports the existing guidelines on the use of BZT in patients over 65 and with recurrent CDI to prevent further recurrence. Our data also supports administration later in the course of therapy when patients have achieved initial response.

Disclosures
MICAH JACOBS, Micah Jacobs, MD, FIDSA, FACP, Abbvie: Honoraria|Cumberland Pharmaceuticals: Honoraria|Merck: Grant/Research Support|Spero Pharmaceuticals: Advisor/Consultant
691. Association between Clostridioides difficile Colonization, Rectal Swab NAAT Positivity, and Environmental Contamination
Authors: Lee Mary Morgan , Hink Tiffany , Newcomer Erin , Fishbein Skye , Reske Kimberly , Struttmann Emily , Iqbal Zainab , Cass Candice , Kwon Jennie H , Olsen Margaret A , Burnham Carey-Ann , Dantas Gautam , Dubberke Erik R 
Published: November 2023

Abstract

Background
Clostridioides difficile (CD) colonization is common among hospitalized patients. Screening for toxigenic CD (TCD) colonization with rectal swab nucleic acid amplification tests (NAAT) may identify people at risk for CDI and help prevent onward TCD transmission, especially in immunocompromised patients with long hospitalizations. The study objective was to test whether rectal swab NAAT could detect TCD colonized patients and whether NAAT results identify patients that contribute to environmental contamination.

Methods
This was a prospective cohort study on two BMT/Leukemia units. Stool specimens, rectal swabs, and environmental swabs (bedrail, room sink, keyboard) were collected from patients at admission and weekly and cultured semi-quantitatively for TCD. NAAT (Cepheid) was performed on rectal swabs (eSwabs; Copan Diagnostics). The relationship between stool TCD concentration, NAAT Ct, and a positive environmental culture was evaluated using univariate logistic regression. Bleach was used for daily and terminal discharge cleaning of all rooms. Toxigenicity was determined by detection of tcdA or tcdB by whole genome sequencing (WGS).

Results
From January 2019 - July 2019, 659 stool specimens and 495 rectal swabs were collected from 384 patients. Specimens from 554 patient-days were cultured and 126 (23%) were positive. Of those, 88 (70%) were TCD. 21 of 987 (2%) environmental swabs were TCD positive; 18 (86%) were from bedrails. Among 61 unique patient calendar days with paired rectal swab NAAT and stool culture results (paired samples), overall sensitivity of rectal swab NAAT to detect toxigenic CD colonization compared to culture was 44%, with 4/16 (25%) of people colonized with &gt; 0 - &lt; 10,000 CFU/g of TCD and 7/9 (78%) with ≥ 10,000 CFU/g TCD (Figure 1). There was no relationship between stool culture or rectal swab NAAT result and risk of a positive environmental swab (Figure 2).
Figure 1. Toxigenic C. difficile semi-quantitative culture and rectal swab NAAT on paired patient-day of specimen collection (N=61 patient-days) Figure 2. Toxigenic C. difficile semi-quantitative stool and rectal swab NAAT results and environmental contamination by paired patient-day of specimen collection

Conclusion
Rectal swab NAAT may not be sufficiently sensitive to screen for TCD colonization that contributes to environmental contamination.

Disclosures
Erik R. Dubberke, MD, MSPH, Abbott: Advisor/Consultant|AstraZeneca: Advisor/Consultant|Ferring Pharmaceuticals: Advisor/Consultant|Ferring Pharmaceuticals: Grant/Research Support|Merck and Co.: Advisor/Consultant|Pfizer: Advisor/Consultant|Pfizer: Grant/Research Support|Seres Therapeutics: Advisor/Consultant|Summit: Advisor/Consultant|Theriva Biologics: Grant/Research Support