bluuebunny/crossref_metadata_2025_split huggingface dataset:
741. Evaluation of Serotonin Syndrome with Linezolid and Serotonergic Agents at an Academic Medical Center
Authors: Kufel Wesley D , Blaine Bruce , Sepiol Riquel , Rubiconti Elizabeth , Khatsko Anna , McKnight Melissa , Parsels Katie A 
Published: December 2022

Abstract

Background
The risk of linezolid-associated serotonin syndrome based on the potency and number of serotonergic agents is unclear. Thus, the primary outcome was to evaluate the incidence of serotonin syndrome among hospitalized patients who are concurrently receiving linezolid with or without serotonergic agents. Secondary outcomes were to assess the potency, agent selection, and number of serotonergic agents.

Methods
This was a single-center, retrospective cohort study of hospitalized patients &gt;18 years of age who received &gt;1 dose of linezolid with or without a concurrent serotonergic agent between 1/1/14–6/30/2021. Patients were excluded if &lt; 18 years of age, had linezolid ordered but not administered, were pregnant, or incarcerated. Up to five concurrent serotonergic agents were recorded and potency was divided into low, moderate, and high potency based on if the drug strength was &lt; 33%, 33–66%, and &gt;66% of the maximum daily dose, respectively. Serotonin syndrome was identified by searching patients’ electronic medical record for ‘serotonin syndrome’ or ‘serotonin toxicity’. If either term was identified, Hunter and Sternbach criteria were applied. Descriptive statistics including number (percentages) and mean (standard deviation) were used.

Results
Of 2022 patients screened, 1743 were included. Mean age, weight, and linezolid duration were 58.5 years, 90.7 kg, and 4.1 days, respectively. Of patients included who received linezolid, 43.2%, 16.2%, 5.7%, 1.4%, and 0.5% received at least one, two, three, four, and five concurrent serotonergic agents, respectively. Most patients received either a moderate and/or high potency (53.8%) compared to a low potency serotonergic agent (46.2%). Only 2 patients (0.11%) were identified with ‘serotonin syndrome’ or ‘serotonin toxicity’. Patient 1 received escitalopram moderate potency and trazodone low potency but did not meet either Hunter or Sternbach criteria. Patient 2 received duloxetine moderate potency, vilazodone moderate potency, and metoclopramide low potency but only met Sternbach criteria.

Conclusion
Serotonin syndrome among hospitalized patients receiving linezolid with other serotonergic agents was exceedingly rare, even among those who received multiple and more potent serotonergic agents.

Disclosures
Wesley D. Kufel, Pharm.D., BCPS, BCIDP, AAHIVP, Melinta: Grant/Research Support|Merck: Grant/Research Support|Theratechnologies, Inc.: Advisor/Consultant.
1541. Impact on Reduction of Blood Culture Incubation Period from Five to Four Days from Large Tertitary Care Center
Authors: Patel Premalkumar M , Pagacz Michael , Tumarinson Taisiya , Yousefzadeh Michelle , Rivera Cynthia , Recine Monica 
Published: December 2022

Abstract

Background
Hospitals have been experiencing an increasing number of acutely ill patients as well as those requiring prolonged hospitalizations, further worsened by the COVID-19 pandemic. This has resulted in increased orders for blood cultures. Once collected, the culture bottles require an incubation period, typically 5 days. The BD BACTEC Fx, a blood culture incubation automated system, holds blood culture bottles until growth is demonstrated or for 5 days, whichever occurs first. New bottles are placed in the apparatus along with older bottles awaiting growth. Capacity is reached when the machine cannot accommodate new bottles due to limited space. When this occurs, manual plating of blood cultures on agar plates is required. Manual plating adds additional responsibility to already overwhelmed microbiology labs.

Methods
Following the institutional review board (IRB) approval, data were collected retrospectively at a 765-bed tertiary care center. Data was obtained from positive blood cultures from July 2017 to June 2020. We stratified positive blood cultures based on the day of positivity, from day one to day five. The charts were reviewed for positive blood culture results on day four and day five to evaluate for clinical significance. Clinical significance was determined by an Infectious Disease subspecialty team. Blood culture bottles that were positive on day 4 and day 5 in 1 bottle out of 2 bottles with coagulase-negative species of Staphylococcus, Corynebacterium spp, or Propionibacterium acnes were considered a contaminant and did not warrant further chart review.

Results
On a retrospective review of data from July 2017 to June 2020, the total number of blood cultures obtained was 120,320. Among them, 7,558 blood cultures were positive. 94% were positive on day 1, 4% positive on day 2, 2% positive on day 3, 1% positive on day 4 and &lt; 1% positive on day 5. Positive blood cultures on day 5 did not have any clinical significance, according to the chart review.

Conclusion
Our study demonstrated that four days of incubation is sufficient for the BD BACTEC Fx automated blood culture incubation system without compromising clinical significance. Implementation of a 4-day incubation period will help with reducing saturation of slots and will improve readiness to accommodate more blood culture bottles.

Disclosures
All Authors: No reported disclosures.
1243. Hepatitis D Virus and Hepatitis B Virus Epidemiology in Utah
Authors: Hesterman Matthew , Fallon Braden , Wilson Paul , Weller Melodie L 
Published: December 2022

Abstract

Background
Hepatitis Delta Virus (HDV) is a rare infectious disease that requires a helper virus (ex. Hepatitis B Virus (HBV)) for transmission. Worldwide, it is estimated that 12-72 million individuals are infected with HDV. Within the United States, an accurate measure of HDV prevalence is attenuated by limited testing and variable notifiable disease status. Recent reports have noted a significant shift in the international HDV epidemiology. This retrospective study was designed to further evaluate the prevalence and clinical features of HDV and HBV within the Utahn patient population.

Methods
Within University of Utah Health, patient demographics, diagnostic codes (ICD9, ICD10) for HBV and HDV, CPT test codes and lab results were evaluated from 2000-2020. Univariate and multivariate analyses were performed. Timeseries analyses, including Mann-Kendall (MK) trend test, Bayesian Information Criterion (BIC) and Autoregressive Integrated Moving Average (ARIMA) were performed to characterize trends in HDV and HBV prevalence.

Results
Between 2000-2020, 2878 HBV and 180 HDV patients were identified within the University of Utah Health system. The median age of the HBV and HDV patients was 45 years with 56% males and 42 years with 60% males, respectively. 10% of all HBV-tested patients were tested for HDV. The positivity rate of patients tested for HDV was 7%. Statistical analysis of race and ethnicity showed a significant difference in incidence and testing rates among the Utahn Asian population when compared against non-Asian populations. A significant increasing trend in the incidence of both HBV (MK=156, p=2.8e-6) and HDV (MK=83, p=0.01) was observed between 2000-2020. Within the timeframe analyzed, two structural breaks were observed for HDV/HBV incidence ratio.

Conclusion
Together, our analysis suggests a significant change in the incidence of HDV and, due to the global temporal trend observed, may be suggestive of a change in HDV transmission pattern. Active surveillance of HDV in the United States and worldwide is warranted to further define these observed changes in HDV incidence.

Disclosures
All Authors: No reported disclosures.
1649. Ceftolozane-Tazobactam or Ceftazidime-Avibactam Versus Best Available Therapy in the Treatment of Difficult-to-Treat Pseudomonas aeruginosa Infections: a Retrospective Comparative Effectiveness Analysis of 195 U.S. Hospitals, 2016–2020
Authors: Lawandi Alexander , Mishuk Ahmed Ullah , Yek Christina , Yu Amy , Li Xiaobai , Strich Jeffrey R , Sarzynski Sadia , Warner Sarah , Kadri Sameer S 
Published: December 2022

Abstract

Background
Infections due to Pseudomonas aeruginosa displaying difficult-to-treat resistance (DTR-PA) necessitate the use of sub-efficacious and/or toxic “reserve” antibiotics and are associated with considerable morbidity and mortality. Ceftazidime-avibactam (CAZ-AVY) and ceftolozane-tazobactam (CEF-TAZO) are novel ß-lactam/ß-lactamase inhibitors (BLBLI) that tend to retain in vitro activity against DTR-PA. However, little is known about their in vivo effectiveness compared to reserve agents.

Methods
Inpatients aged ≥ 18 years with ≥1 blood, urine, respiratory, or body fluid culture growing DTR-PA who received targeted therapy with either CAZ-AVY, CEF-TAZO, or Best-Available Therapy (BAT) were identified in the Premier Healthcare Database. Primary outcome was in-hospital mortality or discharge to hospice and secondary outcome was length of hospital stay (LOS) for survivors. The primary outcome was compared for CAZ-AVY vs CEF-TAZO and novel agents (CAZ-AVY or CEF-TAZO) vs BAT using overlap weighting and binomial regression with downstream adjustment controlling for patient and treatment characteristics. The secondary outcomes were compared using overlap weighting and poisson regression with downstream adjustment controlling for patient and treatment characteristics.

Results
Between 2016 and 2020, 1,552 patients with DTR-PA infections were identified at 105 hospitals, of which 202 (13.0%) were treated with CAZ-AVY, 906 (58.4%) with CEF-TAZO, and 444 (28.6%) with BAT. Patient characteristics were similar among treatment groups (Table 1, Table 2). Overall crude mortality was 15.5%. The adjusted risk of mortality was lower in patients treated with CAZ-AVI (12.5%, 95% CI 7.9–17.1) vs CEF-TAZO (18.8%, 95% CI 15.9–21.8) for a risk difference of 6.3% (95% 1.1–11.5, p = 0.02). The novel agents were not associated with a reduced mortality risk when collectively compared to BAT (risk difference -1.1%, 95% CI -5.4; 3.2%). LOS favoured novel agents and were comparable for CAZ-AVY and CEF-TAZO.

Conclusion
In this real-world observational study of patients with DTR-PA infections, the novel ß-lactam/ß-lactamase inhibitors were comparably effective against BAT, though the use of CAZ-AVY was associated with a reduced mortality compared to CEF-TAZO.

Disclosures
All Authors: No reported disclosures.
1364. Providing preventative care during the SARS-CoV-2 pandemic: Street medicine interventions amongst those experiencing unsheltered homelessness in the City of Detroit
Authors: Joshi Seema , Mann Yasmeen , Petersen Anneliese , Small Eliana , Ayyar Iven T , Abadejos Justin R , Venable Stephen , Ilagan Roxanne , Ho Brandon H , Shallal Anita , Chen Anne , Zervos Marcus , Bryce Richard 
Published: December 2022

Abstract

Background
In 2021, there were approximately 1300 people on a given day who have experienced homelessness within the city of Detroit, Michigan. Sheltered beds within the 24 homeless shelters in the city were drastically cut in half during the COVID-19 pandemic due to concerns of overcrowding perpetuating SARS-CoV-2 outbreaks. We aimed to describe the outreach efforts made by Street Medicine Organizations (SMO) of Detroit during the SARS-CoV-2 pandemic, highlighting infection prevention and control strategies, and promotion of COVID-19 vaccinations amongst the unsheltered homeless.

Methods
Health promotion interventions were directed at individuals who were unsheltered (defined as those living on the streets of Detroit, encampment sites and abandoned buildings). Education, which was provided through in-person sessions, as well as targeted COVID-19 informational pamphlets were distributed with every street-based run. Hygiene kits, which included masks, hand sanitizer and gloves were distributed thrice weekly at shelters and encampment sites. Since access to hand hygiene was drastically limited, the SMO constructed 10 hand washing stations throughout the city. COVID-19 vaccination in people experiencing homelessness started in April 2021.

Results
SMO prioritized a 60 square mile range within the city of Detroit, providing care to approximately 500 persons over the months of April 2020 to April 2021. Demographics for this population varied; age ranged from 23 to 76 years old, sex was 70% males, race were 67% Black, 29% White and 4% Hispanic. More than 2000 hygiene kits were distributed throughout this period. Ninety-one individuals experiencing unsheltered homelessness were provided the COVID-19 vaccine in April 2021.

Conclusion
Individuals experiencing unsheltered homelessness face unique challenges to accessing timely medical care, which has been further exacerbated during the pandemic. These individuals have limited or no access to necessary measures needed to prevent the spread and severity of diseases of SARS-CoV-2. We describe a focused and effective approach to preventing infection among these individuals as a model for organizations nationally.

Disclosures
All Authors: No reported disclosures.
1423. A Rare Case of Mycobacterium chelonae Septic Joint
Authors: Torres Jordan L , Zhao Yang , Gomez Mariana , Grider Douglas J , Griffin Daniel C 
Published: December 2022

Abstract

Background
Nontuberculous mycobacteria (NTM) are ubiquitous environmental organisms that can cause chronic soft tissue infections and which may affect underlying joints and bone by direct extension. NTM septic joint infections are rare and literature on their management is scarce.

Methods
Here we describe a case of septic ankle due to M. chelonae, a rapid grower NTM, and review treatment of these infections.

Results
An 86-year-old man presented to our hospital with complaints of a painful left ankle. Three months prior he noticed a pimple on his left foot after tripping over a lawnmower. The lesion evolved into erythema and painful swelling of the left ankle. Magnetic resonance imaging (MRI) of the left lower extremity revealed a fracture of the distal tibial metaphysis. Turbid joint fluid was aspirated showing 211,450 white blood cells with 97% neutrophils. Patient underwent partial removal of the left tibia with insertion of a drug implant device. Culture results showed acid fast bacilli at day three and the pathology report confirmed atypical mycobacterial infection (Fig 1, 2). Empiric meropenem, linezolid, and azithromycin were initiated until the identification of M. chelonae was obtained. Based on susceptibilities meropenem was discontinued and ciprofloxacin was added. A repeat MRI showed osteomyelitis and small abscesses about the left ankle leading to repeat debridement. Cultures from debridement were negative. Tobramycin IV three times a week was added and ciprofloxacin was discontinued. Patient soon developed acute renal failure, NSTEMI, and lactic acidosis. After a goals of care discussion with patient’s family, antibiotics were discontinued. He passed away soon thereafter.
The backbone of NTM treatment usually consists of a macrolide plus 2-3 other agents but susceptibilities can be misleading. Data correlating outcomes of in vitro susceptibility and clinical response is mixed. Consequently, management of NTM infections is often derived from case reports and from the tuberculosis literature. As seen in this patient, effective treatment can be elusive.
Neutrophils surround vacuoles filled with acid-fast staining organisms on Fite staining
H&E Stain shows pink stained organisms in vacuoles

Conclusion
NTM infections are often resistant to antimycobacterial therapy and require multi-drug regimens with surgical intervention. Due to this complexity, a multidisciplinary approach is vital to improve outcomes.

Disclosures
All Authors: No reported disclosures.
1816. Bloodstream Infection Following Arterial Aneurysm Repair: A Population-Based Study
Authors: Tabaja Hussam , Chesdachai Supavit , Baddour Larry M , DeMartino Randall , Lahr Brian D , DeSimone Daniel C 
Published: December 2022

Abstract

Background
Bloodstream infection (BSI) following arterial aneurysm repair may signify vascular graft infection (VGI). The incidence of BSI and its implications in patients with arterial grafts have received scant attention with limited contemporary study. Therefore, the aim of the current investigation is to describe the incidence and epidemiology of BSI following arterial aneurysm repair in a population-based cohort.

Methods
Retrospective case-cohort study using the expanded Rochester Epidemiology Project (e-REP) to identify all arterial aneurysm repairs performed in adults (&gt;18 years) residing in eight counties in southern Minnesota between January 1, 2010 and December 31, 2020. All repairs were performed at Mayo Clinic Rochester. Electronic health records were screened for initial BSI episode following aneurysm repair and complicating VGI.

Results
Overall, 643 patients underwent 708 aneurysm repairs: 417 endovascular and 291 open surgical repairs. Forty-two patients developed BSI during 2,992 cumulative person-years of follow-up. The median time from repair to BSI was 3.1 [interquartile range 0.5, 6.4] years. The BSI incidence rate, in cases per 1000 person-years, was 14.0 (95% CI 10.1-19.0) overall, including 18.2 (95% CI 11.9-26.7) following open surgical repair and 10.2 (95% CI 5.8-16.6) following endovascular repair (p=0.148). Thirty-nine (92.9%) of the BSI cases were monomicrobial, with 18 (46.2%) due to Gram-positive organisms and 21 (53.8%) due to Gram-negative organisms. Of the 42 patients with BSI, 10 (23.8%) had VGI. VGI occurred in 8/18 (44.4%) monomicrobial Gram-positive BSI as compared to 2/21 (9.5%) monomicrobial Gram-negative BSI (p=0.013). The 3-year mortality rate following BSI was 52.3%.

Conclusion
There was no statistically significant difference in incidence rates of BSI following open surgical repair and endovascular repair. Higher rates of VGI were seen with Gram-positive BSI as compared to Gram-negative BSI.

Disclosures
Larry M. Baddour, M.D., Boston Scientific: Advisor/Consultant|Botanix Pharmaceuticals: Advisor/Consultant|Roivant Sciences: Advisor/Consultant|UpToDate, Inc.: Royalty payments - authorship duties.
1819. Characterizing Treatment Duration of Viridans Group Streptococci Bacteremia in Neutropenic Cancer Patients: Is 14 Days Necessary?
Authors: Vu Yaling , Wong Jenny , Liu Catherine , Tverdek Frank P 
Published: December 2022

Abstract

Background
Neutropenic oncology patients often have mucosal barrier injury as a consequence of chemotherapy and are at risk of Viridans Group Streptococci (VGS) bacteremia. VGS is a commonly identified pathogen among oncology patients with neutropenic fever, however, limited data exists as to appropriate treatment duration.

Methods
The purpose of this study is to characterize the treatment duration and clinical course among neutropenic oncology patients with VGS bacteremia. A retrospective chart review of patients with VGS bacteremia from June 1, 2020 through January 31, 2022 at the University of Washington Medical Center (UWMC) and Seattle Cancer Care Alliance (SCCA). Eligible patients include adults ≥ 18 years with any cancer diagnosis, absolute neutrophil count ≤ 500 at time of blood culture collection, ≥ 1 positive blood culture for VGS, and treated with antibiotics for ≥ 48 hours. Polymicrobial infections were excluded.

Results
Among 86 patients identified with VGS bacteremia, 57 patients were included. Baseline characteristics are depicted in TABLE 1. Hematologic malignancy was present in a majority of patients. The mean duration of treatment was 12.4 (± 2.9) days. Mean time to defervescence was 3.7 days. The most common empiric regimen was cefepime + vancomycin (64.9%) with 78.9% of patients receiving ceftriaxone as definitive therapy. All VGS isolates were susceptible to at least one drug in their empiric regimen. Clinical outcomes are depicted in TABLE 2. There was 1 recurrence of VGS bacteremia and three deaths in the cohort. In TABLE 3, results are stratified by treatment duration.

Conclusion
There was significant heterogeneity in the duration of treatment of VGS bacteremia among neutropenic cancer patients utilizing levofloxacin prophylaxis, with &gt; 50% treated in excess of 14 days. Fever persisted for several days despite active antimicrobials consistent with prior reports. The low rate of recurrence and death at any treatment duration suggests that a shorter duration of less than 14 days for VGS bacteremia may be feasible. A prospective evaluation is needed to confirm these findings.

Disclosures
All Authors: No reported disclosures.
1882. Effects of BA.1/BA.2 Subvariant, Vaccination, and Prior Infection on Infectiousness of SARS-CoV-2 Omicron Infections
Authors: Qassim Suelen , Abu-Raddad Laith J , Chemaitelly Hiam , AlMukdad Sawsan 
Published: December 2022

Abstract

Background
Qatar experienced a large SARS-CoV-2 Omicron (B.1.1.529) wave that started on December 19, 2021 and peaked in mid-January, 2022. We investigated effects of Omicron subvariant (BA.1 and BA.2), previous vaccination, and prior infection on infectiousness of Omicron infections, between December 23, 2021 and February 20, 2022. The RT-qPCR cycle threshold (Ct) value of a SARS-CoV-2 infection represents the inverse of viral load and is correlated with culturable virus; thus, it can be used as a proxy for SARS-CoV-2 infectiousness.

Methods
The study population included all individuals with an RT-qPCR-confirmed SARS-CoV-2 infection in Qatar in the study period. All relevant data for this population were extracted from the national, federated SARS-CoV-2 databases. A SARS-CoV-2 infection with BA.1 was proxied as an S-gene “target failure” (SGTF) case, whereas infection with BA.2 was proxied as a non-SGTF case. The average Ct values of the N, ORF1ab, and S (if not an SGTF case) genes was used as the dependent variable. Univariable and multivariable regression analyses were conducted to estimate the association between Ct value and each of the Omicron subvariants, mRNA vaccination, prior infection, reason for RT-qPCR testing, study-period week of RT-qPCR test, and demographic factors.

Results
Compared to BA.1, BA.2 was associated with 3.53 fewer cycles (95% CI: 3.46-3.60), signifying higher infectiousness (Table 1). Ct value decreased with time since second and third dose vaccinations. Ct values were highest for those who received their boosters in the month preceding the RT-qPCR test—0.86 cycles (95% CI: 0.72-1.00) higher than for unvaccinated persons. Ct value was 1.30 (95% CI: 1.20-1.39) cycles higher for those with a prior infection compared to those without prior infection, signifying lower infectiousness.

Conclusion
BA.2 appears to be associated with substantially higher infectiousness than BA.1. This may reflect higher viral load and/or longer duration of infection, thereby explaining the rapid expansion of this subvariant in Qatar. Natural immunity from previous infection and strength of vaccine immunity correlated with less infectious breakthrough infections.

Disclosures
All Authors: No reported disclosures.