bluuebunny/crossref_metadata_2025_split huggingface dataset:
686. Management and Outcomes of Patients Referred to a Specialty Clinic for C. difficile Infection
Authors: Hunt Aaron , Danziger Larry H , Johnson Stuart , Skinner Andrew M 
Published: November 2023

Abstract

Background
Clostridioides difficile infection (CDI) poses an urgent threat in the United States with an estimated 223,900 cases of hospitalization and 12,800 estimated deaths in 2017. CDI manifestations range from diarrhea, pseudomembranous colitis, to fulminant colitis. Due to spores that are unaffected by current antimicrobial therapies, recurrence remains a common challenge. Patients with 2 or more episodes have an estimated 40-65% rate of recurrence. We reviewed the management and outcomes of patients referred to our specialty CDI clinic.

Methods
A retrospective chart review was conducted on all new patients presenting to the Loyola University Medical Center CDI clinic between 01/01/2021 and 12/31/2021. Each chart was reviewed for demographic information, comorbidities that may confound diagnosis, and characteristics that place the patient at high risk of recurrent CDI. Visits were characterized by the number of prior CDI episodes, timeline of recurrences, and prior therapies used. 30- and 60-day symptom recurrence were assessed.

Results
A total of 48 new patients presented to the CDI clinic. The median age was 63 years, 64.5% were white, and 64.5% were female. Patients presenting with recurrent CDI accounted for 79% of cases (38/48), with 48% (13/48) of patients having two or more recurrences. The most common decision for initial management was to not give further antimicrobials and monitor for symptoms (35%). 12% of patients only required monitoring while 23% of patients had a questionable CDI diagnosis and were referred elsewhere for further evaluation. For the 30 patients who received treatment, vancomycin or fidaxomicin tapers were selected 73% (22/30) and bezlotoxumab 20% (6/30) of the time. 8.6% (2/23) of patients with a history of two or more CD episodes had recurrence. Overall, patients experienced a subsequent recurrence rate of 12.5% (6/48) and 15% (7/48) at 30 and 60 days, respectively.

The number of times each management approach was selected for initial patient appointments.

The number of times each treatment regimen was selected when a patient was deemed to need antibiotic therapy.

The percentage of patients who had either recurrence or resolution at 60 days after the end of therapy.

Conclusion
CDI is a difficult-to-treat infection with many patients suffering from multiple recurrences. Dedicated outpatient follow-up is important for monitoring therapy and excluding alternate etiologies. Expert management of CDI through a dedicated clinic results in lower recurrence for high-risk patients and spared 35% of patients further antimicrobial exposure.

Disclosures
Larry H. Danziger, PharmD, Ferring Pharmacetuicals: Advisor/Consultant Andrew M. Skinner, MD, Academy for Continued Healthcare Learning: Honoraria|American Society of Healthcare Pharmacists: Honoraria|Ferring Pharmaceuticals: Honoraria|MJH Life Sciences: Honoraria
688. Risk of Clostridioides difficile Infection and Antibiotic Associated Diarrhea in Patients Receiving Outpatient Parenteral Antimicrobial Therapy
Authors: Jaramillo Mario , Musmar Ahmad S , Shi Aishan , Al Momani Shaden , Alexander Perry D , Zangeneh Tirdad 
Published: November 2023

Abstract

Background
The colonic microbiome plays a critical role in resisting the ingrowth of pathogenic microbes like Clostridioides difficile (C. difficile). Disruption of the microbiome by antibiotics is known to cause antibiotic-associated diarrhea (AAD) and C. difficile infection (CDI). Outpatient parenteral antimicrobial therapy (OPAT) reduces hospital length of stay and exposure to healthcare-associated pathogens which may decrease the incidence of CDI. Previous studies that compared patients who received metronidazole for non-CDI indications with those who did not found a reduction in CDI among patients who received metronidazole. The aim was to study the incidence of AAD and CDI in the OPAT patient population and compare the incidence rate between patients who received oral metronidazole for non-CDI indications with those who did not.

Methods
We retrospectively reviewed a cohort from our facility's OPAT program. We included adult patients (18 years or older) discharged to home or skilled nursing facility (SNF) on OPAT over a 2-year time span, regardless of diagnosis. Pregnant patients, patients with active CDI before starting OPAT, and those who were receiving an associated CDI treatment were excluded. Antibiotic-associated diarrhea was defined as 3 or more loose or watery stools per day with negative CDI testing or spontaneous improvement after stopping antibiotics. Community-onset and healthcare facility–associated CDI (CO-HCFA CDI) was defined as 3 or more watery stools per day with a positive stool C. difficile diagnostic test in the community or within the first 3 days of readmission, provided the diagnosis was made less than 4 weeks since discharge from a healthcare facility.
Demographics of Patients Discharged on OPAT.
Patients selected between June 1, 2018 and June 2020, grouped by whether or not they developed Clostridioides difficile infection (CDI). SD= standard deviation; Q1= 1st quartile; Q3= 3rd quartile.

Results
Of the 617 charts that met inclusion criteria, 31 had AAD and 3 had CO-HCFA CDI. Incidence of CO-HCFA CDI was &lt; 1%; &lt; 1 per 1000 person-day and incidence of AAD was 5.02%. The protective role of metronidazole could not be studied due to the rarity of CDI in this study.
Patients with positive CDI after initiation of OPAT and associated characteristics.

Conclusion
Although our study was not able to answer our initial question when comparing the effect of metronidazole within OPAT groups and rates of CDI, our data is promising for showing low rates of CDI in patients receiving OPAT. This study demonstrates the putative benefits of OPAT with reduced CDI incidence regardless of use of anti-CDI drugs.

Disclosures
Tirdad Zangeneh, DO, AiCuris: Grant/Research Support
689. Significant Improvement in Hand Hygiene Compliance and Decline in Clostridioides difficile Infections with Implementation of Infection Prevention Interventions
Authors: Kaushik Ashlesha , Beal Kristen , Gupta Sandeep 
Published: November 2023

Abstract

Background
Per CDC, C. difficile is an urgent microbial threat. Despite use of CDC diagnostic criteria, 2-step testing protocol and antimicrobial stewardship interventions limiting broad spectrum antimicrobial use, we witnessed an increase in infections in 2022, therefore, additional interventions were implemented.

Methods
A multifaceted QI intervention program to improve IPC (infection prevention and control) practices was implemented in July 2022 at a 160-bed tertiary care center serving the tristate area of Iowa, South Dakota and Nebraska. Interventions included: auditing and real time observations for health care personnel (HCP) hand hygiene compliance; monitoring soap/sanitizer usage; educational interventions including posters posted throughout the hospital emphasizing hand hygiene, “A clean in and clean out” approach and contact precautions reminders posted in patient rooms/nursing stations, weekly nursing huddles focused on nursing and ancillary staff education, provider counseling and continued coaching. Pre-intervention period (P1: 1/10/2021- 6/30/2022) was compared with Intervention period (P2: 07/01/2022-3/31/2023) for hand hygiene compliance and C. difficile infection rates.

Results
Overall adequate hand hygiene compliance rates for all health care personnel (HCP) increased from 71% during P1 to 85% during P2 (P&lt; 0.05). All categories of HCP showed a significant improvement in hand hygiene compliance from P1 to P2, with rates for physicians increasing from 74% to 92% (p&lt; 0.05), nurses from 68% to 94% (p&lt; 0.001); nurse practitioners/physician assistants from 75% to 90% (p&lt; 0.05), ancillary staff (chaplain, medical technicians, social workers) from 60% to 89% (p&lt; 0.01)]. Hand hygiene product use increased significantly and soap usage alone increased from 45% to 75% in P2 (p&lt; 0.05). C. difficile infections declined significantly from a mean of 1.9 infections per 1000 patient days during P1 to 0.5 infections per 1000 patient days during P2 (p&lt; 0.001); SIR (Standardized infection ratio) decreased from 1.14 during P1 to 0.4 during P2 (p&lt; 0.01). No C. difficile related mortality was observed.

Conclusion
With implementation of multifaceted IPC interventions, significantly improved hand hygiene rates and a significant decline in C. difficile infections were observed.

Disclosures
All Authors: No reported disclosures
699. Clinical Outcomes and Management of NAAT-Positive/Toxin-Negative Clostridium difficile Infection: A Systematic Review and Meta-Analysis
Authors: Prosty Connor , Hanula Ryan , Katergi Khaled , Longtin Yves , McDonald Emily , Lee Todd C 
Published: November 2023

Abstract

Background
Standalone nucleic acid amplification tests (NAATs) are increasingly used to diagnose Clostridium difficile infections (CDI), although they may be unable to distinguish colonization from disease. A two-stage algorithm pairing NAAT with a toxin immunoassay (Toxin) has been proposed to improve specificity. We sought to evaluate clinical outcomes among patients testing NAAT+/Toxin+ vs NAAT+/Toxin- by conducting a systematic review and meta-analysis. We further compared outcomes between NAAT+/Toxin- patients who were and were not treated.

Methods
We searched EMBASE and MEDLINE from inception to September 17, 2022 for articles comparing CDI outcomes among symptomatic patients tested by NAAT and Toxin tests. The risk differences (RD) of all-cause mortality and CDI recurrence were computed by random effects meta-analysis between NAAT+/Toxin+ and NAAT+/Toxin- patients, as well as between treated and untreated NAAT+/Toxin- patients.

Results
Twenty-three observational studies comprising 11749 patients were included. 30-Day all-cause mortality was not significantly different between NAAT+/Toxin+ and NAAT+/Toxin- patients (8.4% vs 6.8%, respectively; RD=0.2%, 95%CI -2.4, 2.9; I2=52.9%). Recurrence at 60 days was significantly higher among NAAT+/Toxin+ (19.8%) vs NAAT+/Toxin- patients (11.0%) (RD=7.7%, 95%CI=4.6, 10.7, I2=37.4%). Among treated compared to untreated NAAT+/Toxin- patients, the all-cause 30-day mortalities were 5.0% and 14.9%, respectively (RD=-9.5%, 95%CI=-15.0, -3.9, I2=0.0%), but 60-day recurrence was not significantly different (11.6% vs 7.0%, respectively; RD=5.3%, 95%CI -1.7, 12.2; I2=47.0%).

Conclusion
Compared to NAAT+/Toxin- patients, NAAT+/Toxin+ patients had a greater risk of recurrence at 60 days, but not all-cause mortality. Treatment of NAAT+/Toxin- patients was associated with reduced all-cause mortality, but not recurrence. While subject to the limitations of observational studies including the potential for confounding by indication and immortal time bias, these results suggest that treatment of NAAT+/Toxin- patients may be beneficial. A strategy comparing standalone NAAT or staged testing with up front combined NAAT/Toxin testing could be the topic of a randomized controlled trial to determine cost and efficacy.

Disclosures
All Authors: No reported disclosures
712. Dynamics of Colonization with Multi-Drug Resistant Organisms and Clinical Outcomes in Critically Ill Patients: A Prospective Cohort Study
Authors: Adelman Max W , Rydell Kirsten B , Detranaltes Andrea M , Atterstrom Rachel , Virk Muhammad H , Schettino Marissa G , Amaya Abigail A , Malikzad Husna , Jones Mary N , Pimentel Maya , Hanson Blake M , Shelburne Samuel A , Savidge Tor , Arias Cesar A 
Published: November 2023

Abstract

Background
Critically ill patients have frequent intestinal colonization with multi-drug resistant organisms (MDRO). However, the duration of colonization and its impact on clinical outcomes are unknown.

Methods
We performed a prospective cohort study of adult patients admitted to ICUs at a tertiary care hospital. All patients had stool samples collected twice weekly for up to four weeks or until discharge from the ICU. Stool samples were cultured with selective media for vancomycin-resistant enterococci (VRE), extended-spectrum β-lactamase-producing Enterobacterales (ESBL-E), and carbapenem-resistant Enterobacterales (CRE). We characterized patient demographics and compared outcomes between patients with and without colonization.

Results
A total of 102 patients were included. Mean age was 62 years (SD±15), 62 (61%) were men, 67 (66%) were white, and 34 (33%) were admitted from a separate healthcare facility. Thirty-nine (38%) were colonized with ≥1 MDRO at ≥1 time point. There were no statistically significant differences in baseline characteristics between patients with and without colonization. Of the 39 patients with colonization, 23 (59%) were colonized with VRE at ≥1 time point, 18 (46%) with ESBL-E, and 7 (18%) with CRE; 8 (20%) were colonized with &gt;1 organism (Figure 1). Notably, most patients (13/23 with VRE, 15/18 with ESBL-E, and 4/7 with CRE colonization) were colonized with each MDRO type at only one time point during their ICU stay (Figure 1). In-hospital mortality did not differ according to colonization status (21% with any colonization vs. 17% without, p=0.70). When assessing mortality according to specific MDRO type, VRE colonization was associated with in-hospital mortality (35% with VRE colonization vs. 14% without, p=0.02).
Figure 1.
Results of serial stool samples tested for target multi-drug resistant organisms in intensive care unit patients. Each horizontal line represents a different patient included in the study (N=102) and each circle represents a separate stool sample.

Conclusion
Nearly 40% of ICU patients were colonized with VRE, ESBL-E, and/or CRE, although colonization duration was generally limited, possibly reflecting antibiotic pressures and microbiome dynamics in critically ill patients. More research is needed to identify clinical, microbiome, and organism genomic factors that facilitate persistence and loss of colonization.

Disclosures
All Authors: No reported disclosures
713. Prevalence of Microbicide Resistance Genes in Clinical Isolates of Acinetobacter baumannii
Authors: Chatterjee Piyali , Hwang Munok , Choi Hosoon , Dhar Sorabh , Kaye Keith S , Donskey Curtis , Jinadatha Chetan 
Published: November 2023

Abstract

Background
The persistence of Acinetobacter on different surfaces and the continuous exposure of bacteria to disinfectants such as quaternary ammonium compounds (QACs) in the healthcare environment have led to microbicide tolerance. Acinetobacter baumannii have also rapidly acquired carbapenem resistance. Here we determined the prevalence of microbicide resistance genes in carbapenem susceptible and resistant clinical isolates of Acinetobacter.

Methods
All clinical isolates were collected from two separate hospitals in Detroit between 2017-2021. Following DNA isolation using Qiagen kit, Nextera Flex kit was used for library preparation of Acinetobacter clinical isolates. Whole genome sequencing (WGS) was performed via Illumina NextSeq 550 using the prepared DNA library. The FASTQ files from the sequencing run were then subjected to bioinformatic analysis with Bionumerics software v7.6. ResFinder was used for determination of presence or absence of QAC resistant genes and results were tabulated by Carbapenem-Resistant Acinetobacter baumannii (CRAb) or Carbapenem-Susceptible Acinetobacter baumannii (CSAb) with or without the QAC resistant genes.

Results
Out of the 139 Acinetobacter patient isolates, 70/139 (50.4%) were CRAb containing carbapenemase blaOXA-23 and 69/139 (49.6%) belonged to CSAb (Table 1). Figure 1. shows the prevalence of antimicrobial resistance (AMR) genes in CRAb and CSAb isolates with qacE genes. For CRAb isolates, 56% had qacE genes while 39% of CSAb had qacE genes. About 42% of CRAb isolates were multi-drug resistant (MDR), indicating a prevalence of qacE genes among the MDR isolates. Table 2 shows the presence of qacE genes by sequence type (ST). In the ST2 (Pasteur) and ST406 (Pasteur) strains, qacE gene was mainly present. Interestingly, most of the Acinetobacter isolates that belong to ST2 (ST195 and ST281, Oxford) are CRAb with qacE gene.Figure 1:Different AMR genes and qacE in both CRAb and CSAb isolates

Conclusion
Clinical isolates in our study had an even distribution of both CRAb and CSAb. The presence of qacE gene was more prevalent in the CRAb isolates compared to the CSAb isolates. While different STs harbored the qacE gene, the prevalence of qacE gene was highest in ST2 among all isolates. Future studies are needed to determine the reduced susceptibility to other commonly used hospital disinfectants.

Disclosures
Keith S. Kaye, MD, MPH, Abbvie: Advisor/Consultant|Abbvie: Honoraria|Entasis: Advisor/Consultant|Entasis: Honoraria|GSK: Advisor/Consultant|GSK: Honoraria|Merck: Advisor/Consultant|Merck: Honoraria|Shionogi: Advisor/Consultant|Shionogi: Honoraria|VenatoRx: Advisor/Consultant|VenatoRx: Honoraria
722. Risk Factors for Infection or Colonization with Ceftolozane/Tazobactam Non-Susceptible Extensively β-Lactam Resistant Pseudomonas aeruginosa
Authors: Lee Michelle , Nagel Jerod , Wangchinda Walaiporn , Pierce Virginia M , Smith Aaron , Bishop Olivia , Pogue Jason M 
Published: November 2023

Abstract

Background
Treatment of infections due to multidrug resistant (MDR) Pseudomonas aeruginosa is complicated by co-resistance amongst traditional anti-pseudomonal β-lactams, as 50% of MDR isolates exhibit extensive β-lactam resistance (EBR, non-susceptible to cefepime, ceftazidime, piperacillin/tazobactam, and meropenem). Ceftolozane/tazobactam (C/T) was developed to combat MDR and EBR P. aeruginosa. Unfortunately, C/T resistance has proliferated. We designed this retrospective case-control study to identify risk factors for C/T non-susceptibility (NS) amongst EBR P. aeruginosa.

Methods
Between 2015 to 2020, hospitalized adult patients infected or colonized with EBR P. aeruginosa were identified. C/T susceptibility was defined per the 2023 Clinical and Laboratory Standards Institute (CLSI) guidelines (susceptible (S) if minimum inhibitory concentration (MIC) ≤ 4 mg/L, NS if MIC ≥ 8 mg/L). Patients with an EBR P. aeruginosa NS to C/T were classified as cases, whereas those with S isolates were controls. Patients with multiple EBR P. aeruginosa isolates over the study period were only included once. If a patient had a C/T NS isolate, they were classified as cases and the first C/T NS isolate was included as the index culture. If the patient did not have a C/T NS isolate over the study period, they were considered a control and the first C/T S isolate was the index culture. Bivariate and multivariate modeling was performed to identify independent predictors for C/T NS.

Results
188 unique patients with C/T susceptibility performed were included in the study; 96 (51%) were C/T NS and 92 (49%) were C/T S. Table 1 shows the bivariate comparisons of key baseline characteristics between groups. Independent predictors of C/T NS are displayed in table 2.

Conclusion
Independent predictors for C/T NS amongst EBR P. aeruginosa isolates were a history of cancer, cystic fibrosis, and isolation of EBR P. aeruginosa in the past 90 days. While receipt of cefepime or ceftazidime in the past 90 days was associated with C/T NS in bivariate comparisons, the association did not remain in multivariate modeling. C/T exposure was not a statistically significant risk factor, but it was numerically associated with NS and the lack of significance was likely due to the small number of patients (n = 15) who received it.

Disclosures
Virginia M. Pierce, MD, FIDSA, UpToDate, Inc.: Authorship royalties jason M. Pogue, PharmD, AbbVie: Advisor/Consultant|Entasis: Advisor/Consultant|Ferring: Advisor/Consultant|GSK: Advisor/Consultant|Merck: Advisor/Consultant|Merck: Grant/Research Support|Qpex: Advisor/Consultant|Shionogi: Advisor/Consultant
729. I Can CPO Clearing Now, the Iso is Gone
Authors: Schwartz Danielle , Trepanier Kailee , Lytvyak Ellina , Zakhary Michael , Kim Joseph , Chandran Uma 
Published: November 2023

Abstract

Background
There is little research or guidance about clearing patients who are colonized with carbapenemase-producing organisms (CPO). The use of isolation precautions to reduce transmission needs to be balanced with the potential negative impacts of isolation on patient experience, quality of care and non-infection patient safety and outcome measures. Our objective was to develop and implement a standardized provincial protocol for clearing patients of their CPO-positive status.

Methods
PubMed, Web of Science, EMBASE and Cochrane Library were searched from January 2000 to February 2023. Randomized control trials, retrospective and prospective cohort studies, cross-sectional studies and case series were included. This information was used to create a CPO clearing protocol for use by Alberta Health Services (AHS) Infection Prevention and Control (IPC). The protocol will be monitored through the provincial surveillance system (ProvSurv) to guide future changes.

Results
The literature showed that although CPO colonization can be prolonged (more than 12 months), a significant number of patients tested CPO-negative by 3 months since the last positive test. In addition, one-third of patients with 1 or 2 negative swabs subsequently tested CPO-positive. Therefore, the proposed provincial guidance is to re-screen patients 3 months after their last CPO-positive result. Three negative sets (without antibiotic pressure) done at least one week apart are required to clear a CPO flag; where a negative set includes a rectal swab or stool culture, cultures of previously positive sites if still clinically relevant, and additional currently relevant sites.

Conclusion
This project aimed to create a standardized provincial protocol for clearing patients of their CPO-positive status to decrease the duration of isolation, while also balancing resource management and patient-centred care. After implementation, next steps include evaluation by monitoring compliance and examining specific CPO-related indicators. There is potential for use by other healthcare institutions and organizations.

Disclosures
All Authors: No reported disclosures