bluuebunny/crossref_metadata_2025 huggingface dataset:
P-1231. Optimal vancomycin AUC target in children with MRSA bacteremia: based on Bayesian-guided dosing
Authors: Lee Yonghee , Kim Gahee , Lee Jina
Published: January 2025

Background

Despite the widespread use of vancomycin in methicillin-resistant Staphylococcus aures (MRSA) infections, there is still a lack of clinical data elucidating the optimal target concentration of vancomycin in the pediatric population.

Methods

From September 2013 to December 2021, a retrospective analysis was conducted on pediatric patients (3 months- 18 years of age) with MRSA bacteremia. Vancomycin area under the concentration-time curve (AUC) was estimated by Bayesian software.

Results

A total of 56 patients with MRSA bacteremia were included, with median age of 2.4 years. 92.9% had underlying medical conditions, most of which were associated with catheter-associated infections. Persistent bacteremia ≥ 48 hours, recurrent bacteremia, 30-day all-cause mortality, and acute kidney injury (AKI) were observed in 17.9%, 14.8%, 3.7%, and 7.1%, respectively. AUC24-48 ≥ 400 did not demonstrate clinical benefit in the above outcomes. Persistent bacteremia was associated with source control, 30-day all-cause mortality, and AKI. As an AUC target, AUC24-48 ≥ 528.2 mg·h/L was associated with persistent bacteremia (P < 0.01), and AUC24-48 ≥ 536.8 mg·h/L was associated with AKI (P = 0.01). No significant factors associated with 30-day mortality and recurrence were identified.

Conclusion

We suggest an AUC24-48 < 528.2 mg·h/L as the optimal target for children aged ≥ 3 months with MRSA bacteremia. The lower bound of the target range was not identified.

Disclosures

All Authors: No reported disclosures
P-1232. PK/PD Analysis and Dose Optimization of Tebipenem and Faropenem against ESBL-Producing Enterobacterales in Patients with UTI Considering Renal Function
Authors: Hamada Yukihiro , Maruyama Takumi , Kasai Hidefumi , Yagi Yusuke , Matsunaga Nobuaki
Published: January 2025

Background

Tebipenem (TBPM) and faropenem (FRPM) have been proposed as effective treatments for urinary tract infections caused by ESBL-producing Enterobacterales. However, appropriate dosage according to renal function needs to be considered. This study utilized PK/PD analysis to investigate the optimal dosage.

Methods

Monte Carlo simulation using the model of Nakashima et al, 2009 for TBPM and Hirooka et al. 2005, for FRPM generated blood concentration profiles for 1000 cases stratified by renal function. The optimal dose metric was defined as the Probability of Target Attainment (PTA) of 90 percent or more for PK/PD parameters at the MIC90. The PK/PD parameters for TBPM and FRPM were defined as 24h free AUC/MIC/dosing interval 34.58 or more, and free time above MIC 20 and 40 percent or more. The MIC90 values were set at 0.03 and 2 mg/L, respectively.

Results

For TBPM, the dose achieving PTA of 90 percent or more was 150 mg (q12h) for creatinine clearance (Ccr) less than 30 and 300 mg (q8h) for Ccr 30 or more and less than 80 mL/min. For Ccr 80 mL/min or more was not achieved. None of the doses for FRPM achieved PTA of 90 percent or more.

Conclusion

The dose for TBPM suggested the need for an even higher dose for Ccr 80 mL/min or more. Cases of post-treatment relapse have been reported for FRPM. Therefore, the optimal dosage considering PK/PD analysis with urinary concentrations needs further validation.

Disclosures

All Authors: No reported disclosures
431. Engraftment of donor derived anaerobic taxa and durable long-term multidrug resistant organism decolonization following fecal microbiota transplantation
Authors: Babiker Ahmed , Brink Catherine , Lohsen Sarah , Van Riel Julia , Strudwick Amanda F , Kraft Colleen S , Satola Sarah W , Konstantinidis Kostas , Woodworth Michael H
Published: January 2025

Background

Microbiome restoration through fecal microbiota transplantation (FMT) is a promising decolonization approach that leads to reduction in multidrug resistant organism (MDRO) colonization and infections. The precise mechanisms by which FMT reduces MDRO colonization are not well elucidated, and long-term follow up (LTF) data from patients treated with FMT for MDRO decolonization are lacking. We enrolled participants of a recently conducted trial of FMT for MDRO decolonization (PREMIX, NCT02922816) to a LTF study to estimate long-term engraftment dynamics of donor derived anaerobic taxa and their association with MDRO decolonization.

Methods

Participants provided stool every 6 months for up to 5 years. Stool underwent selective culturing for MDROs by plating on selective chromogenic agars, and confirmation by MALDI-TOF and vitek2. MDROs underwent whole genome sequencing (WGS), and stool samples underwent metagenomic sequencing (mNGS). WGS resolved mNGS tracking of MDROs and metagenome-assembled genomes (MAG) of donor anaerobic taxa was performed. Pairwise comparison of baseline and long-term follow up (LTF) MDRO isolates was performed with a unique strain defined as 99.95% average nucleotide identify difference.

Results

Six PREMIX participants were enrolled to the LTF study, five of whom received FMT and one control. 80% (4/5) of FMT treated patients have remained decolonized (culture negative) while 0% (1/1) of control patients have remained decolonized at most recent follow up (median[IQR] 3.6 [3.4,4.0] years). For the FMT treated patient who had an MDRO detected on LTF sample, the MDRO represented a new acquisition (after broad-spectrum antibiotic exposure close to time of FMT), while the MDRO detected in LFT sample of the control patient was the same MDRO detected at baseline. mNGS revealed persistence of donor anaerobic strains in LTF samples (Agathobaclulum ammoniilyticum, Akermanisa muciniphila, Alistipes putredinis, Bacteroides uniformis, Barnesiella intestinihominis, Eubacterium xylanophilum, Gemmer formicilis), indicative of engraftment and persistence.

Conclusion

FMT was associated with long-term durable decolonization potentially mediated by the engraftment and persistence of donor derived anaerobic strains.

Disclosures

Ahmed Babiker, MBBS, Beckman Coulter Inc.: Advisor/Consultant Colleen S. Kraft, MD, MSc, Ferring/Rebiotix: Advisor/Consultant|Seres LLC: Advisor/Consultant
P-1289. Trends, Treatments, and Outcomes in Vibrio Species Infections: The UTMB Galveston Experience
Authors: Torres Grant Bradley , Brondeel Kimberley C , Cummins Andi J , Mesa Camila Franco , Klinnert Joshua , Branski Ludwik , Hornak Joseph Patrik , Cabada Miguel M , Reynoso David
Published: January 2025

Background

V. vulnificus, V. parahaemolyticus, and other species thrive in coastal water of areas such as the East Coast of Texas. There are few large-scale, single-institution retrospective studies investigating Vibrio spp. infections. Our study aims to determine the clinical presentation, management, and outcomes of infections caused by Vibrio spp. treated at the University of Texas Medical Branch (UTMB) in Galveston.

Methods

A retrospective chart review was conducted for patients with culture-positive Vibrio spp. samples at the UTMB from 2016-2023. Primary outcomes include clinical characteristics, antibiotic treatment, surgical management, and outcomes of Vibrio spp. infections. Secondary outcomes include demographic data, comorbidities, and causative agents for Vibrio spp. infections. This study was performed in collaboration with the infectious disease department and plastic surgery division at UTMB.

Results

25 patients treated for Vibrio-related infections were included. Patient demographic data is as follows: 24 (96%) were Caucasian, 23 (92%) were non-Hispanic, 21 (84%) were male, and the average age was 62.2 years. Nearly all cases occurred in Galveston County and the surrounding area, with 18 (72%) associated with water/aquatic exposure. 13 (52%) patients noted contact with marine life shortly before admission, comprising most of the 12 (48%) patients noting underlying injury before symptom onset. 8 patients had localized soft tissue infections, while 17 developed systemic infections. Most systemic manifestations developed secondary to soft tissue infection. Surgical intervention was required in nearly half of the patients. V. vulnificus was noted in 18 patients (mostly systemic), and V. parahaemolyticus was noted in 7 patients. The most common empiric antibiotics were Vancomycin, Piperacillin-Tazobactam, and Doxycycline—followed by Ceftriaxone, and Clindamycin.

Conclusion

In areas along the coast with warm seawater or brackish water, infections due to Virbio spp. warrant hefty consideration and prompt treatment—as over 2/3 of our patients quickly developed systemic infection and nearly half required surgical intervention. This is especially true for patients with open wounds exposed to these aquatic environments, and those in contact with marine life.

Disclosures

Joseph Patrik Hornak, MD, Innoviva Specialty Therapeutics: Advisor/Consultant|Innoviva Specialty Therapeutics: Advisor/Consultant
P-1291. Racial disparities in Lyme disease among beneficiaries of US Medicaid and Medicare
Authors: Hannah Gould L , Willis Sarah J , Prener Christopher G , Duench Stephanie A , Yu Holly , Moisi Jennifer , Stark James H
Published: January 2025

Background

Lyme disease (LD) is the most common vector-borne disease in the US. Manifestations range from a localized rash to neurologic, cardiac, and musculoskeletal conditions during disseminated stages. LD incidence is highest among White persons in the US, but evidence suggests that people from racial and ethnic minority groups experience more severe disease.

Methods

We used a claims-based algorithm (≥ 1 LD ICD-10 code and appropriate antibiotics within 30 days) to identify LD cases among Medicaid (age < 19 and ≥ 19 years) and Medicare fee-for-service (age < 65 [persons with disabilities] and ≥ 65 years old) beneficiaries living in 16 high incidence states ( > 10 cases/100,000 population for ≥ 3 years) during 2016-2021. We calculated prevalence ratios for disseminated disease and hospitalization by racial group using White persons as the reference.

Results

There were 62,055 LD cases identified among Medicaid beneficiaries and 90,882 among Medicare beneficiaries. In Medicaid, 85% of cases were in White persons, 6% in Hispanic, 4% in Black, 4% in Asian/Pacific Islander, and 1% in Native American persons. In Medicare, 96% of cases were in White persons, with 1% or less reported in other groups. Non-White persons were more likely to be hospitalized at diagnosis, diagnosed outside of primary care, diagnosed outside of the peak months for LD transmission, to be female, and to have disseminated disease (Table 1). Medicaid beneficiaries and Medicare beneficiaries ≥ 65 years old who identified as Black, Asian/Pacific Islander, or Hispanic had a higher likelihood of disseminated disease than White persons. Among Medicaid beneficiaries < 19 years old, those who identified as Black, Asian/Pacific Islander, or Hispanic had a higher likelihood of being hospitalized at diagnosis than those who identified as White. Black Medicaid beneficiaries ≥ 19 and Medicare beneficiaries < 65 also had a higher likelihood of hospitalization (Table 2).

Conclusion

These data illustrate disparities in LD by race and ethnicity and suggest possible disparities by other characteristics including sex and, given the high rates of disseminated disease in Medicare beneficiaries < 65 years old, disability. Equitable interventions are needed to reduce disparities in LD recognition and severity.

Disclosures

L. Hannah Gould, PhD, MS, MBA, Pfizer: Employee|Pfizer: Stocks/Bonds (Public Company) Sarah J. Willis, PhD, MPH, Pfizer, Inc.: Employment|Pfizer, Inc.: Stocks/Bonds (Private Company) Christopher G. Prener, PhD, Pfizer, Inc.: Employee|Pfizer, Inc.: Stocks/Bonds (Public Company) Stephanie A. Duench, PhD, Pfizer Inc.: Employee|Pfizer Inc.: Stocks/Bonds (Public Company) Holly Yu, MSPH, Pfizer: Employee|Pfizer: Stocks/Bonds (Public Company) Jennifer Moisi, PhD, Pfizer: Employee|Pfizer: Stocks/Bonds (Public Company) James H. Stark, PhD, Pfizer: Employee|Pfizer: Stocks/Bonds (Public Company)
P-1311. Infectious diseases trends in migrant populations at a safety-net community hospital in Chicago
Authors: Khan Mashaal , Vergara-Mojica Stephanie , Zodo Alexandra , Ali Mirza , Mena Lora Alfredo J
Published: January 2025

Background

Chicago's recent increase in migrant populations has placed new demands on public health systems, particularly in managing infectious diseases within community hospitals. This study examines the impact of migration on the incidence of infectious diseases in a community hospital's emergency department (ED). Understanding disease patterns in migrants can inform public health strategies and improve healthcare delivery.

Figure 1. Chickenpox and measles cases per year

Methods

We conducted a retrospective review of infection prevention records from a 151-bed Chicago safety-net community hospital was conducted, focusing on migrant patient visits and infection prevention needs between 2022 and 2024. Descriptive statistics were used to evaluate the changes over the period.

Figure 2. Infectious diseases cases in migrant populations per month

Results

In 2022, 2023 and 2024, the reported cases of chickenpox rose from 0 to 5 and then 11, respectively. This represents a 450% increase in chickenpox cases from 2023 to 2024 (Figure 1). No measles cases were reported in the first two years, increasing to 2 cases in 2024. From October 2023 to March 2024, a total 18 chickenpox cases, 2 measles cases and two cases of tuberculosis were reported (Figure 2). Airborne precautions in the ED were needed for 22 cases.

Conclusion

We report a notable increase in vaccine preventable conditions such as chickenpox and measles in a Chicago hospital associated with a migrant influx. Added needs for airborne precautions in the ED were required during this period. These trends highlight the need for public health measures, such as enhanced vaccination efforts and healthcare access for migrants, to prevent disease outbreaks and protect community health. Infection prevention readiness should involve clear protocols for identifying and isolating conditions requiring airborne precautions.

Disclosures

All Authors: No reported disclosures
P-1344. Molecular Characterization of Daptomycin Non-susceptible Staphylococcus aureus
Authors: Suleyman Geehan , Kaur Jagjeet , Zhang Xiangmin , Tibbetts Robert , Zervos Marcus , Alangaden George J
Published: January 2025

Background

Staphylococcus aureus (SA) is the leading cause of bacteremia in hospitalized patients. With limited therapeutic options, increasing use of daptomycin (DAP) has resulted in the emergence of DAP non-susceptible (DNS) SA strains. Nevertheless, the mechanisms of resistance in DNS SA are not fully understood. Proposed mechanisms include genetic and phenotypic changes affecting the cell membrane and cell wall. However, studies have been limited to single pairs of isolates or isolates that are laboratory derived.

Methods

We performed whole-genome sequencing (WGS) on clinically obtained SA blood isolates at Henry Ford Health, a comprehensive, integrated, health care organization in Southeast Michigan from 2005-2023. DNS was defined as MIC >1. Sequencing libraries were created using QIAseq FX DNA Library Kit (Qiagen, USA) according to manufacturer’s instructions and sequenced on NovaSeq 6000 (Illumina, San Diego, USA). FastQ files were further analyzed for the presence of genetic variations using a WGS bioinformatic pipeline based on de novo assembly.

Results

We sequenced 199 SA isolates from 59 patients, of which 88 (44%) were DNS. 43 (73%) patients had multiple isolates, whereas 16 (27%) only had one. All DNS isolates except one were MRSA. 46 (52%) DNS isolates had amino acid substitution in the MprF and 2 (2%) in the cls genes, which are known to be associated with DNS. 10 (11%) DNS isolates were found to have substitutions (S829L and L406I) in the MprF gene that have not been previously reported. Mutations in cls, rpoB, rpoC, walK and agrA genes were also detected. All isolates with known mutations were exposed to DAP prior to development of DNS. 30 (34%) DNS isolates did not have mutations associated with resistance. Of these, only 13 (43%) had prior exposure to DAP, 9 (30%) were only exposed to vancomycin, and 11 (37%) were not exposed to any antibiotics. ST5 and ST8 were the most common sequence types.

Conclusion

In this study involving a large number of clinical SA isolates, the majority of patients who developed DNS due to MprF mutations were exposed to DAP, likely due to selection pressure. However, more than one-third of DNS isolates did not exhibit resistance mutations. Further studies are needed to identify other mechanisms of DAP resistance, especially in those with no prior antibiotic exposure.

Disclosures

Marcus Zervos, MD, Johnson and johnson: Grant/Research Support|Moderna: Grant/Research Support
P-1348. Acquired Carbapenemase-Producing Gram-Negative Organisms (CPOs) Across the Pond: Surveillance of Antibiotic Resistance in CPOs in England from 2020-2023
Authors: Henderson Katherine L , Guy Rebecca L , McCormick Jacquelyn , Patel Bharat , Jeyaratnam Dakshika , Mirfenderesky Mariyam , Hopkins Katie L , Hope Russell
Published: January 2025

Background

Acquired carbapenemase-producing Gram-negative organisms (CPOs) threaten viable antibiotic treatment options. This is the first national look at CPO phenotypic antimicrobial resistance (AMR) rates since becoming statutorily notifiable in England on 01/10/2020.Table 1.Summary of all big-5 CPO isolates reported from October 2020 to December 2023

Methods

All acquired big-5 (NDM, KPC, OXA-48-like, VIM, IMP) CPO reported specimens and antibiotic susceptibilities were extracted from national laboratory surveillance databases between Oct-2020 to Dec-2023. Records were deduplicated by patient, specimen group (invasive/screening/other), bacterial species and CPO mechanism per year. Regional big-5 CPO population rates were calculated; 2023 AMR data were assessed by mechanism and species.Figure 1.Regional notifications per 100,000 population of acquired CPOs by big-5 carbapenemase mechanisms in England, 2023

Results

In total, 13,022 episodes from 9,945 patients were reported; median age was 70y, 54% were male. The dominant mechanisms were OXA-48-like (n=4,884; 37.6%), NDM (n=3,927; 30.2%) and KPC (n=3,045; 23.4%); (Table 1) with large regional variation (Figure 1). NDMs became more dominant in 2023 than OXA-48-like. Screening samples accounted for 72% (n=9,378), and < 5% (n=591) were from invasive samples. Thirty-three patients with invasive samples had dual-mechanisms detected: 61% were NDM & OXA-48-like; Klebsiella pneumoniae was the dominant species (patients=21).

In 2023, the lowest reported resistance for the most frequently isolated species (n=5,535/5,711; Table 2) was for colistin (4-7%R) for all big-5 mechanisms in Escherichia coli, Enterobacter spp., Citrobacter spp., whilst higher for Klebsiella spp. and Pseudomonas spp. (10-17%R). Similarly, lower Enterobacterales resistance was observed for KPC and OXA-48-like to ceftazidime/avibactam (9-12%R) and amikacin (7-8%R), except for Klebsiella spp., which was higher (22%R). Ciprofloxacin and gentamicin had ≥ 35% resistance. Fosfomycin resistance in E. coli was low (≤ 9%).

Proportion of big-5 CPO isolates (n=5,535) resistant to other antimicrobials by most frequently isolates species in England, 2023

Conclusion

Continued national CPO and associated AMR surveillance is crucial, particularly for new antimicrobials, to inform guidance and local, empiric prescribing by region, given the geographical variation in CPO mechanism. Further enhancement via data linkage to ethnicity and clinical characteristics to identify risk factors, and tracking changes in patients’ antibiograms over time would help further target national guidance.

Disclosures

All Authors: No reported disclosures
502. Epidemiology and Outcomes of Broad-Spectrum Antibiotic De-escalation in Patients with Suspected Sepsis in US Hospitals
Authors: Kam Kai-Qian , Chen Tom , Kadri Sameer S , Lawandi Alexander , Yek Christina , Walker Morgan , Warner Sarah , Fram David , Chen Huai-Chun , Shappell Claire N , DelloStritto Laura , Jin Robert , Klompas Michael , Rhee Chanu
Published: January 2025

Background

Guidelines recommend de-escalation of broad-spectrum antibiotics initiated for suspected sepsis based on clinical status and microbiological results after 48-72 hours, yet real world patterns of de-escalation remain unknown. We aimed to evaluate the frequency, hospital-level variation, predictors, and clinical outcomes of antibiotic de-escalation in suspected sepsis.

Methods

We used the PINC AITM Healthcare Database to retrospectively analyze adults admitted to 236 US hospitals between 2017-2021 with suspected sepsis (blood culture and lactate drawn) and minimal 4-day stay who received ≥2 days of empiric anti-MRSA and anti-pseudomonal antibiotics on admission, in the absence of any beta-lactam resistant gram-positive or ceftriaxone-resistant gram-negative organisms in the clinical cultures by day 4.De-escalation was defined as cessation or switching to narrower spectrum intravenous or oral agents by day 4. We utilized a multivariate logistic regression model with 82 covariates to predict the likelihood of de-escalation; the probabilities from this model were then used for propensity-score matching.

Results

Among 124,577 patients who met inclusion criteria, 36,806 (29.5%) had antibiotics de-escalated (21.8% narrowed, 7.7% stopped) (Figure 1). The median hospital-level de-escalation rate was 29.4% (IQR: 21.3-38.0%) and varied across hospital types (Figure 2). Predictors of de-escalation included clinical indicators of less severe disease (especially on days 3-4), positive cultures, and negative/absent MRSA nasal swabs (Figure 3). De-escalation was also associated with medium, large or teaching hospitals in the Northeast or Midwest region. On propensity-matched analysis (effective sample size of 32,964 and 36,803 in control and treated groups, respectively), de-escalation was associated with lower rates of acute kidney injury (OR 0.91, 95% CI 0.85-0.96), inpatient mortality (OR 0.89, 95% CI 0.83-0.96), and a trend towards fewer C.difficile infections (OR 0.84, 95% CI 0.71-1.01) (Table 1).

Conclusion

In this large US cohort, antibiotic de-escalation in patients with suspected sepsis was infrequent and variable across hospitals. De-escalation was influenced by clinical and microbiologic factors and associated with lower risk for adverse outcomes.

Disclosures

Michael Klompas, MD, MPH, AHRQ: Grant/Research Support|CDC: Grant/Research Support|UpToDate: Royalties
P-1384. Rates of Follow-Up Testing for Chlamydia trachomatis and Neisseria gonorrhoeae Among Active-Duty Service Members
Authors: Marsh James J , Aleman-Reyes David Manuel , Marcus Joseph
Published: January 2025

Background

All patients who test positive for Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (GC) should get retested at three months to evaluate for re-infection. The United States military has previously been reported to have high rates of CT and GC, but follow-up rates have not been established for active-duty service members (ADSM) who test positive for CT or GC. This study evaluates factors associated with follow-up CT or GC testing in ADSM.

Methods

Positive cases of CT and GC among ADSM who were stationed at Joint Base San Antonio between January and June 2023 were evaluated. Demographic characteristics, location of testing, and the presence of symptoms were described. A patient was determined to have had follow-up testing if they had a repeat CT/GC test within 3-12 months after their initial positive test. Follow-up rates were compared among groups based on demographics, clinical setting of testing, and presence of symptoms using chi-square or Fisher’s exact test.

Results

Of the 200 ADSM who tested positive for CT or GC during the study period, 101 (51%) were male and the median age was 23 [IQR: 20-26] (Table 1). Women were significantly more likely to receive follow-up testing as compared to men (71% vs. 51%; p=0.003), without significant difference in follow-up testing by clinic, race, service, or original STI organism (Table 2). Women who were symptomatic at time of initial test were significantly more likely than symptomatic men to have a follow-up test (76% vs. 49%; p=0.003), but this difference did not hold for asymptomatic patients (64% vs. 53%, p=0.28) (Table 3).

Conclusion

Despite standardized follow-up testing recommendations, there were significantly lower follow-up testing rates in men, with the greatest difference in testing in patients who were symptomatic at presentation. While ADSM have universal access to care, the difference in follow-up testing between men and women based on presence of symptoms reinforces concerns about stigma in obtaining treatment and follow-up. Future work should study how standardization of guidelines in these populations promotes improvement in follow-up testing.

Disclosures

All Authors: No reported disclosures
P-1394. Scenario Projections of Congenital Syphilis Cases in California, 2023–2030
Authors: Linton Natalie , Burghardt Nicole , de Guzman Natalie , Snyder Robert , León Tomás M , Jain Seema , Jacobson Kathleen
Published: January 2025

Background

The yearly number of congenital syphilis (CS) cases in California is at its highest point since 1950. We explored how efforts in California to 1) reduce syphilis cases; and 2) increase adequate syphilis treatment among infected pregnant persons could impact CS case projections through 2030.

Yearly projected incidence by scenario comparing the baseline scenario to a 10% reduction in infections, 10% increase in treatment adequacy, and both interventions combined

Methods

We developed a scenario modeling framework to project CS incidence between 2023–2030 using California 2015–2022 surveillance data on CS cases and female syphilis cases of childbearing age (15–44 years). We compared a baseline scenario where existing trends continued without additional interventions to scenarios that considered 1) the impact of an absolute reduction of 2–10% in the rate of female syphilis cases per year; and 2) a 2–10% increase in the proportion of pregnant persons adequately treated for syphilis.

Results

A reduction in the absolute rate of female syphilis cases by 2–10% led to an 8–31% decrease in cumulative CS cases between 2023–2030. Increasing the proportion of pregnant persons adequately treated for syphilis by 2–10% over baseline led to a 1–8% decrease in cumulative CS cases. Combining both scenarios resulted in an 8–37% reduction in cumulative cases.

Conclusion

This model shows that to reduce CS case incidence in California, the most important upstream intervention is to reduce the rate of syphilis among females. To this end, syphilis screening and treatment among those who infect females must be improved. Additionally, even assuming no changes in syphilis incidence in females, CS cases could be reduced to a lesser extent by increasing the proportion of pregnant persons with syphilis who are adequately treated above current rates. The results of this study can inform syphilis screening and treatment recommendations, and the magnitude of future CS case reduction will depend on intervention scope and implementation.

Disclosures

All Authors: No reported disclosures
P-1413. Association of Electronic Patient Portal Use and HIV Viral Suppression and Retention in Care among People Living with HIV at an Urban Academic Medical Center
Authors: Zimmer Daniela , Laiteerapong Neda , Shetty Raj , Ridgway Jessica
Published: January 2025

Background

Electronic patient portals are secure websites that give patients access to health information and allow for secure messaging with providers. Portal use has been associated with improved patient engagement in care, better patient-provider communication, and improved health outcomes in non-HIV patient populations, but portal use is under-studied among PLWH. We sought to assess the relationship between patient portal (MyChart) utilization and HIV-related outcomes among PLWH.

Methods

We collected electronic health record data for PLWH who attended an HIV care visit at an urban academic medical center over 2 years, including demographics, laboratory results, medical encounters, and MyChart status. We compared the demographic characteristics of PLWH with and without an active MyChart account using chi-square. We used logistic regression to assess if MyChart status was associated with outcomes of viral suppression (< 200 copies/mL), retention in care (using the six-month gap definition, i.e., PLWH who attended an HIV care appointment in the prior 6 months are retained), and CD4 count >200 cells/mm3, after controlling for age, race, and sex.

Results

Among 785 PLWH, the mean age was 47 years (SD=14.9), 70% were male, and 83% were Black/African-American. Black PLWH were significantly less likely than White PLWH to have an active MyChart account (83.6% (543/649) vs. 95.8% (91/95), p< 0.01). PLWH with an active MyChart had increased odds of HIV viral suppression (Odds Ratio [OR]: 2.02, 95% CI [1.3 - 3.7]); retention in care (OR: 2.2 95% CI [1.4 -3.4]); and CD4 >200 (OR: 3.3, 95% CI [1.8 to 6.0].

Conclusion

MyChart utilization at the urban academic HIV clinic is associated with positive health outcomes. However, Black PLWH are less likely to utilize MyChart than White PLWH. Additional work is needed to increase MyChart access for non-white patients PLWH, to decrease the digital divide, improve engagement in care and other health outcomes.

Disclosures

Jessica Ridgway, MD, Gilead Sciences: Expert Testimony
P-1422. Low Use of Oral Antibiotics for People Hospitalized with Serious Injection-Related Infections: the CHOICE+ Cohort
Authors: Flores Hannah E , Omari Habib , Derenoncourt Meghan , Stevens Jasmine , Vaish Ishan Kumar , Raman Sumitha , Fujita Ayako Wendy , Carpenter Joseph E , Catalanotti Jillian S , Kattakuzhy Sarah , Steck Alaina , Kuo Irene , Reece Becky , Rosenthal Elana S , Traver Edward C
Published: January 2025

Background

Oral (PO) antibiotics are a convenient alternative to parenteral antibiotics and decrease the need for inpatient care. Increasing evidence shows PO antibiotics are effective even in severe infections. We aim to assess PO antibiotic use among hospitalized people who inject drugs (PWID).

Methods

CHOICE+ is a multisite retrospective cohort study of adults hospitalized at four healthcare systems with infections resulting from injection opioid use between 1/1/2018 and 3/31/2022. Data were collected by abstraction of the electronic medical record. Patients were categorized by intended route of the antibiotic course. Data were analyzed by the chi-square test, Fisher’s exact test, and multivariate logistic regression.

PO, oral; SSTI, skin and soft tissue infection.

Results

1631 patients had an intended treatment plan with either PO (17%) or parenteral (83%) (intravenous, long-acting infusion, or other) antibiotics (Table 1). There was no difference in PO antibiotic use based on gender or unstable housing. PO antibiotics were more likely to be used when planned antibiotic duration was ≤2 weeks (p< 0.0001) and when only skin and soft tissue infection (SSTI) was present (p< 0.0001, Table 2). Alternatively, infectious disease consultation was associated with lower use of PO antibiotics (p< 0.0001). From 2018 to 2022, PO antibiotic use decreased (p< 0.0001, chi-square for trend, Figure 1). Those treated with PO antibiotics were less likely to have ID follow-up scheduled (p=0.0002) and less likely to attend ID follow up (p=0.0024, Figure 2).

PO, oral.

Conclusion

PO antibiotics were rarely used in this large multisite cohort of PWID, especially for infections other than SSTI. Surprisingly, use decreased over the study period, despite emerging evidence for PO antibiotics in complex infections for people who do not inject drugs. PWID with complex infections require long courses of antibiotics, but face barriers to prolonged hospitalization and outpatient infusions due to underinsurance, unstable housing, and untreated addiction. PO antibiotics may facilitate antibiotic completion while reducing patient-directed discharge, and therefore are likely underutilized for PWID.

PO, oral.

Disclosures

Elana S. Rosenthal, MD, Gilead Sciences: Grant/Research Support|Merck: Grant/Research Support
P-1519. Susceptibility of Clinical Non-Morganellaceae Enterobacterales Isolates from Bloodstream and Respiratory Tract Infections to Imipenem/Relebactam and Comparators: SMART United States 2020-2022
Authors: Wise Mark G , Andrew DeRyke C , Esterly John , Bauer Karri A A , Siddiqui Fakhar , Young Katherine , Motyl Mary , Sahm Daniel F
Published: January 2025

Background

Enterobacterales with multidrug-resistance (MDR) or difficult-to-treat resistance (DTR) present clinicians with limited treatment options. Imipenem/relebactam (IMR) is a combination of imipenem with relebactam, a β-lactamase inhibitor of class A and C β-lactamases. We examined the activity of IMR and comparators against isolates of non-Morganellaceae Enterobacterales that were the etiological agents of bloodstream and respiratory infections in the United States.

Methods

In 2020-2022, 26 clinical labs in the U.S. participated in the global SMART surveillance program each collecting up to 250 consecutive gram-negative pathogens per year. Only isolates from patients with bloodstream and respiratory tract infections were included in this study. MICs were determined using CLSI broth microdilution and interpreted with 2024 CLSI breakpoints. MDR was defined as resistance to ≥3 sentinel agents (amikacin, aztreonam, cefepime, ceftazidime, colistin, imipenem, levofloxacin, and piperacillin/tazobactam). DTR phenotypes were defined by isolates nonsusceptible (intermediate or resistant) to all β-lactams (including aztreonam, ceftazidime, cefepime, imipenem, meropenem, piperacillin-tazobactam), as well as fluoroquinolones (levofloxacin).

Results

Among 4,763 collected NME isolates, 575 (12.1%) were MDR and 33 (0.7%) were DTR. Escherichia coli (n=1695) and Klebsiella pneumoniae (n=958) were the most common species collected and their MDR rate was 12.2% and 13.5%, respectively, while their DTR rate was 0.1% and 1.8%, respectively. Against the full collection, IMR and meropenem were the most active agents, each inhibiting 98.7% of the population (Figure). Ertapenem, amikacin and imipenem alone were also active, inhibiting >93%. IMR retained its activity versus the MDR subset, as 97.0 were interpreted as susceptible, the highest percentage among comparator drugs. IMR also showed activity against the challenging DTR subsets with 81.8% susceptible, approximately 30 percentage points higher than amikacin.

Conclusion

Based on these in vitro data, IMR appears to be an excellent therapeutic choice for use against NME infections from blood and respiratory tract sources, including those identified as MDR and DTR.

Disclosures

Daniel F. Sahm, PhD, Pfizer, Inc.: Advisor/Consultant
P-1567. Urinary Tract Infections Broadly Impact Quality of Life Among People with Neurogenic Bladder
Authors: Fitzpatrick Margaret A , Wirth Marissa , Solanki Pooja , Suda Katie J , Burns Stephen , Weaver Frances , Collins Eileen , Safdar Nasia , Evans Charlesnika T
Published: January 2025

Background

Although recurrent urinary tract infections (UTI) are common complications in people with neurogenic bladder (NB), limited data exist on the specific ways UTIs impact quality of life (QoL) in this population. These data could help tailor patient-centered approaches to improving UTI care in people with NB.

UTI Impacts on Feelings and Emotional Well-being

Methods

We mailed surveys to 289 Veterans with NB due to spinal cord injury/disorder (SCI/D), multiple sclerosis, or Parkinson’s Disease who had at least one in-person encounter associated with a UTI diagnosis at four Veterans Affairs Medical Centers between May 2022-May 2023. The survey was adapted from existing instruments and previously collected qualitative data. An expert panel refined the survey using a Delphi process, followed by cognitive interviews with Veterans with NB (n=8). The QoL section contained 15 survey items with 5-point Likert scale response options (higher values = greater QoL impact) which assessed how UTIs affect feelings, emotional well-being, daily activities, sex life, and social participation. To account for missing and ‘not applicable’ responses, scaled QoL scores were calculated by multiplying total survey score by the ratio of 15 / the number of items answered. Descriptive statistics summarized respondent characteristics and QoL scores.

UTI Impacts on Activities

Results

Respondents (n=71) were older [median age (range) = 72 (36-88)], male (92%), and white (79%). Most had SCI/D (77%) and used urinary catheters (77%). 85% of respondents answered at least 13 items. Other than feeling often or always frustrated or bothered by UTIs (n=22; 31%), most respondents did not report that UTIs frequently impact feelings or emotional well-being (Figure 1). In contrast, UTIs had a strong impact on activities (Figure 2), with many respondents agreeing their UTIs have impacted diet (n=35; 50%), travel (n=37; 53%), and sex life (n=24/40 responses; 60%). Mean [standard deviation (SD)] scaled total QoL score was 40.8 (15.3) out of a possible maximum score of 75, with a mean (SD) per item score of 2.7 (1.0) out of 5.

Conclusion

People with NB experience substantial QoL impacts from UTIs, particularly on their daily and social activities. Patient-centered interventions focused on reducing negative impacts on QoL from UTIs are urgently needed for this population.

Disclosures

All Authors: No reported disclosures
574. Early Post-Marketing Safety Surveillance for the Respiratory Syncytial Virus Prefusion F Protein Vaccine (RSVPreF3 OA)
Authors: Verheust Céline , Deraedt Quentin , Bryan Philip
Published: January 2025

Background

RSVPreF3 OA (GSK) received its first approval on 3 May 2023 in the United States (US), for the prevention of lower respiratory tract disease caused by respiratory syncytial virus (RSV) in ≥ 60-year-olds. By 15 March 2024 (data lock point [DLP] of this analysis), RSVPreF3 OA was also approved in all European Economic Area countries, and > 10 additional countries across both hemispheres. We summarized the post-marketing safety surveillance data following vaccination with RSVPreF3 OA.

Methods

Exposure was based on RSVPreF3 OA doses distributed and administered. The spontaneous adverse events (AEs) reported from 3 May 2023 up to DLP were retrieved from GSK’s Global Safety Database. Observed-to-expected (O/E) analyses were performed for reports of Guillain-Barré syndrome (GBS) and transverse myelitis.

Results

Up to DLP, > 9.1 million RSVPreF3 OA doses were distributed globally, of which > 7.8 million doses were administered to adults in the US. There were 1,301 reports including 3,278 AEs following RSVPreF3 OA administration, of which 91.34% were considered non-serious (Table). Most reported AEs were consistent with the expected reactogenicity profile, as observed in clinical trials and listed in the prescribing information. O/E analysis of GBS (N=9) and transverse myelitis (N=1) found that the reporting rates did not exceed the expected background incidence (16 and 6 expected cases, respectively); no other neuroinflammatory events were reported. Nineteen reports of atrial fibrillation were reported and more plausibly reflect the epidemiology of the older adult population being vaccinated. Of all reports, 539 (41.43%) described medication errors, of which 85.34% were without associated symptoms. Although RSVPreF3 OA is not indicated for pregnant women, 263 cases of exposure during pregnancy (48.79% of the medication errors) were reported.

Conclusion

Based on the data from the first 10 months of post-marketing surveillance, the safety profile of RSVPreF3 OA was shown to be consistent with that observed in clinical trials. The available evidence does not suggest a causal association between RSVPreF3 OA and neuroinflammatory events or atrial fibrillation. Along with the vaccine efficacy shown in clinical trials, the data supports a favorable benefit-risk profile.

Funding: GSK

Disclosures

Céline Verheust, PhD, GSK: Salary as GSK employee, with stock options included|GSK: Stocks/Bonds (Public Company) Quentin Deraedt, PhD, GSK: Salary as GSK employee, with stock options included|GSK: Stocks/Bonds (Public Company) Philip Bryan, PhD, GSK: Salary as GSK employee, with stock options included in salary|GSK: Stocks/Bonds (Public Company)
P-1598. Evaluating the Utility of MRSA Nares Testing as an Antimicrobial Stewardship Tool
Authors: Morado Faiza , Nanda Neha , Lee Rebecca
Published: January 2025

Background

A common challenge for antimicrobial stewardship programs is limiting vancomycin usage as overuse is linked with significant clinical consequences such as nosocomial infections. While Methicillin-resistant Staphylococcus aureus (MRSA) nasal screens are widely used to rule out MRSA in lower respiratory tract infections, studies evaluating its use in non-pneumonic processes are limited. The purpose of this study was to evaluate the utility of MRSA nasal screens by estimating its predictive value for various clinical cultures.

Methods

This retrospective cohort study was conducted at an academic medical hospital from October 1, 2021 to January 31, 2024. Patients with an MRSA nasal swab collected within 48 hours of admission and a clinical culture within 14 days of the nasal swab were included. Chromogenic media was used for detection of MRSA colonization. Clinical cultures were defined as blood, body fluid, respiratory, wound, and tissue cultures. Patients with a history of an MRSA infection within prior 90 days or received 10 or more days of an anti-MRSA antibiotic prior to nasal swab collection were excluded. Microbiological and clinical data were collected for included patients. The primary endpoint was to determine the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for a positive MRSA clinical culture.

Results

A total of 11391 clinical cultures collected from various anatomical sites were included in this study. The distribution of clinical cultures were as follows: 55.4% blood, 11.9% wound, 11.9% body fluid, 15.7% respiratory, and 5.1% tissue. The total MRSA prevalence for any clinical culture was 1.3%. The sensitivity, specificity, PPV, and NPV for all clinical cultures were 55%, 96.8%, 18.5%, and 99.4%, respectively. Results for each clinical culture site are listed in table 1.

Conclusion

The results of an MRSA nasal screen via chromogenic media had a high NPV for MRSA growth in blood, body fluid, respiratory, wound, and tissue cultures up to 14 days after MRSA nasal swab collection.

Disclosures

All Authors: No reported disclosures
P-1607. Comparison of In-House Versus Reference Laboratory Antifungal Susceptibility Testing on De-Escalation Rates of Echinocandin Therapy for Candidemia
Authors: Webb Joseph , Mondy Kristin , Jaso Theresa , Rose Dusten T T
Published: January 2025

Background

The Mycoses Study Group Education and Research Consortium recommends healthcare facilities who routinely manage invasive fungal infections have access to “timely antifungal susceptibility testing,” and the Infectious Disease Society of America recommends antifungal de-escalation in candidemia within seven days to mitigate excessive drug costs and fungal resistance. In 2020, Ascension Seton hospital network converted from in-house (INH) antifungal susceptibility testing (AFST) to reference laboratory (RFL) testing.

Methods

This was a multicenter, retrospective cohort study evaluating the stewardship, clinical, and financial impact of RFL use for AFST in patients with candidemia. AFST was performed INH for isolates from May 2017 to Jul 2020 and by RFL for isolates from Aug 2020 to Sep 2023. The primary outcome was rate of antifungal de-escalation from echinocandin to azole therapy by day 7. Secondary outcomes include cost of antifungal treatment, hospital and intensive care unit (ICU) length of stay, days to targeted therapy, turn around time of test (TAT), and all-cause hospital mortality. Inclusion criteria were candidemia diagnosis and empiric echinocandin treatment. Exclusion criteria were diagnoses of candidemia with ocular, meningeal, or cardiac involvement; candidemia due to C. auris; or death before susceptibility resulted. Outcomes were analyzed by Wilcoxon rank sum.

Results

This study included 85 patients (42 INH and 43 RFL). The most common infectious species were C. albicans (31% INH vs 35% RFL) and N. glabrata (36% INH vs 49% RFL).Rate of de-escalation by day 7 was higher in the INH than RFL group(, 67 vs 35%, p< 0.01) . RFL use significantly increased days to targeted therapy (2 INH vs 6 RFL, p < 0.01), turn around days of test (5 INH vs 12 RFL, p < 0.01), echinocandin days (4 INH vs 9 RFL, p < 0.01), and cost of antifungal treatment ($1145 INH vs $2290 RFL, p < 0.01). There were no differences in additional secondary endpoints.

Conclusion

Reference laboratory use for AFST was associated with significantly decreased echinocandin de-escalation rate, leading to longer turn around time of test, time to targeted therapy, and cost of antifungal treatment. In-house AFST offered faster susceptibility results and possibly cost savings.

Disclosures

All Authors: No reported disclosures
P-1608. No Targets, No Problem: Evaluation of Patients with Bloodstream Infections without a Molecular Target Detected by a Rapid Diagnostic Assay
Authors: Shah Megan , Williamson Julie E , Davidson Lisa , Boger Michael S
Published: January 2025

Background

Early identification and management of sepsis is essential in improving patient outcomes. Blood culture rapid diagnostic testing (RDT) allows for early targeting of antimicrobial therapy, particularly when paired with antimicrobial stewardship (AMS) intervention. Hospitalized patients with positive blood cultures are reviewed daily by AMS pharmacists in our health-system, regardless of the RDT result. Limited data exist on the impact of AMS assessment in patients with a positive blood culture with an organism that is not a target identified by RDT. The objective of this study is to describe the microbiology and antimicrobial management of patients with a positive blood culture, but no molecular target detected (NMTD) on the BioFire® Blood Culture Identification 2 (BCID2) panel.

Methods

This retrospective review evaluated patients within the Atrium Health Greater Charlotte Market who had ≥ 1 positive blood culture with a BCID2 result of NMTD from January to May of 2023. The primary endpoint was to identify the most common organisms recovered by standard of care methods following a NMTD result. Secondary endpoints were evaluated in hospitalized patients and included change in antimicrobials in response to the Gram stain result and percentage of patients on active therapy at organism identification and/or susceptibility testing. Data were analyzed using descriptive statistics.

Results

160 organisms were identified in 149 patients with a BCID2 result of NMTD. The most common organisms identified were Micrococcus luteus (14.3%), Corynebacterium spp. (9.4%), non-fragilis Bacteroides spp. (8.1%), Clostridium spp. (7.5%), and Fusobacterium spp. (4.4%) (Table 1). Contamination was suspected in 34% of patients; however, when the organism was considered a true pathogen by the treating provider, the most common infection sources were intra-abdominal (26%) and skin/skin structure (12%). Antibiotics were modified after the Gram stain or NMTD results in 38% of patients, and 79/85 (93%) of patients were on active therapy at organism identification or susceptibility testing if considered a true infection.

Conclusion

Even when RDT fails to yield a molecular target, AMS review of patients with positive blood cultures may ensure adequate antimicrobial therapy

Disclosures

All Authors: No reported disclosures