bluuebunny/crossref_metadata_2025_split huggingface dataset:
1799. Impact of COVID 19 on urgent care diagnoses and stewardship metrics
Authors: Hersh Adam , Stenehjem Edward A , Samore Matthew H , Wood Traci , Spivak Emily S , Ricker Hollis , Mueller Heather 
Published: December 2022

Abstract

Background
The percentage of all respiratory diagnoses prescribed an antibiotic is an outpatient stewardship metric and was introduced as a HEDIS measure in 2022. Given a stable case mix, this metric is not affected by differences in coding practices between clinicians or health systems since all respiratory diagnoses are considered together. The onset of the COVID-19 pandemic introduced a high number of viral illness episodes where antibiotics are not recommended. The impact of this shift in case mix on respiratory diagnosis coding and prescribing metrics has not been explored.

Methods
We examined antibiotic prescribing rates for respiratory diagnoses in a network of urgent care clinics affiliated with the University of Utah during two periods. Pre-Pandemic was Mar 2019-Feb 2020 and Pandemic was Mar 2020-Mar 2022. Respiratory diagnoses were identified using ICD10 codes and further stratified into 3 Tiers (Tier 1: antibiotics indicated; Tier 2: antibiotics sometimes indicated; Tier 3: antibiotics not indicated). We examined trends in antibiotic prescribing across these periods including the percentage of all respiratory visits prescribed antibiotics and by Tier and the distribution of diagnoses by Tier. No formalized stewardship interventions were introduced during these periods.

Results
There were 146,897 urgent care visits during the study period (47,423 Pre Pandemic and 99,474 Pandemic). The respiratory prescribing rate declined from 42.3% Pre Pandemic to 26.2% during the Pandemic (Figure). The distribution of respiratory diagnoses by Tier and prescribing within Tier are shown in the Table. Tier 3 diagnoses increased from 48% to 67%, while Tier 2 diagnoses declined from 47% to 31%. Antibiotic prescribing declined for both Tier 2 and Tier 3 diagnoses. 15,429 (23%) of Tier 3 diagnoses during the Pandemic were coded as COVID-19. 50% of the reduction in prescribing is attributable to changes in Tiers alone. FigureTable

Conclusion
The COVID 19 pandemic was associated with a reduction in the percentage of respiratory diagnoses prescribed antibiotics. Half was due to an increase in Tier 3 encounters although declines in prescribing occurred with Tiers in addition. Using this metric for benchmarking requires accounting for the impact of case mix differences over time or between systems and clinicians.

Disclosures
All Authors: No reported disclosures.
1803. Pediatric Antimicrobial Stewardship: Beyond the Core Elements
Authors: Fernandez Marisol , Downey Rachel , Gilbreath Peter , Wakefield Toni , Keyburn Hanh , Schwartz Joanna , Cossey Melissa , Sapozhnikov Julia , Whitaker Winnie , Kienstra Andrew , Floyed Rebecca , Pillay Devika , Robles Tiffany , Woerner David , Forbes Marion 
Published: December 2022

Abstract

Background
Facility treatment guidelines for antibiotic choice and duration are a priority in the CDC Core Elements of hospital antimicrobial stewardship (AMS). Urinary tract infection (UTI) and community acquired pneumonia (CAP) are common pediatric diagnoses with potential for AMS impact in both inpatient and outpatient settings.
We describe a project at a free-standing children’s hospital that was implemented through a collaboration of multidisciplinary providers who participated in the national Value in Inpatient Pediatrics (VIP) program. One aim of this project is to evaluate baseline and improve antibiotic duration for CAP and UTI.

Methods
This is a retrospective/prospective chart review study that compares baseline and post-intervention duration of antibiotic prescribing for UTI and CAP cases from July 2019-December 2021 based on data collected through the VIP program. Figure 1 describes the timeline of events and results. Patients included were identified by diagnosis code for CAP and UTI. Each case was randomized for inclusion and manually reviewed to ensure it met the diagnosis clinical definition. Cases with underlying chronic medical conditions were excluded from this analysis. Duration of antibiotics prescribed was compared for each group using Wilcoxon rank-sum testing. Figure 1.Timeline of guideline implementation and evaluation

Results
Among the 351 patients included, 163 had a diagnosis of CAP (98 pre-, 65 post- implementation); 188 with UTI (121 pre-, 67 post- implementation). Post Implementation, there was a significant decrease in median duration of antibiotic prescribing from 10 to 7 days in both groups (p&lt; 0.001). Figure 2.Median duration of antibiotics pre and post program implementation (p&lt;0.001)

Conclusion
Institutional implementation of guidelines is an important step in local AMS. Guideline implementation alone is not enough to ensure practice change and going beyond the CDC core elements has become important. In our case, participation in a national project with local multidisciplinary involvement was successful in improving duration of therapy for CAP and UTI not previously achieved by the local guidelines. Changes were made to the electronic medical record in the ED to ensure sustainability of this change.

Disclosures
All Authors: No reported disclosures.
1805. Safety Outcomes Following Beta-Lactam use in Patients with a Documented Beta-Lactam Allergy
Authors: Rampersad Daniel , Maxwell Tyler , Moy Stanley 
Published: December 2022

Abstract

Background
Management of bacterial infections typically consist of beta-lactam antibiotics. Individuals with histories of beta-lactam allergy are more likely to receive alternative broad-spectrum antibiotics which may be less efficacious or lead to increased adverse events. Patients can be prescribed full doses of structurally non-related beta-lactam antibiotics due to the low similarity of side chains between these medications and penicillin, and the low incidence of penicillin allergies being true allergies. Nevertheless, there is a lack of data regarding safety outcomes in patients who are treated with a beta lactam with a documented allergy.

Methods
This was a single-center retrospective observational study of patients with a documented beta-lactam allergy who received at least one dose of any beta-lactam antimicrobial excluding aztreonam from SUNY Downstate Health Sciences University between January 2015 – October 2021. Electronic medical records were reviewed for relevant study data. The primary outcome was the incidence of allergic reaction on full dose beta lactam with a documented allergy in the medical record.

Results
Baseline characteristics are summarized in Table 1.
Two patients experienced a suspected allergic reaction while on beta-lactam therapy. Anaphylaxis was not reported and pharmacologic rescue agents were not required for each case. The antimicrobial agent was changed after the reaction was noted in both cases.

Conclusion
Patients who were administered beta-lactam antimicrobials with beta-lactam allergy had low rates of allergic reaction. The rate of allergic reactions observed is similar to the incidence of allergy in patients without documented allergies reported in the literature. Administration of beta-lactams with dissimilar side chains such as beta-lactam beta-lactamase inhibitors and third and fourth generation cephalosporins were safely administered to patients with a documented allergy.

Disclosures
All Authors: No reported disclosures.
1810. Trends in the Length of Antibiotic Therapy Among Hospitalized Adults with Uncomplicated Community-Acquired Pneumonia, 2013-2020
Authors: Kazakova Sophia V , Natalie McCarthy , Baggs James , Attell Brandon , Kabbani Sarah , Yi Sarah H , Neuhauser Melinda M , Hatfield Kelly M , Reddy Sujan , Hicks Lauri A 
Published: December 2022

Abstract

Background
The 2014 United States National Strategy aimed to reduce inappropriate inpatient antibiotic use by 20% for monitored conditions by 2020. The Hospital Core Elements of Antibiotic Stewardship highlight opportunities to improve treatment of common infections, including optimizing length of therapy (LOT) for community-acquired pneumonia (CAP). A minimum of 5 days of antibiotic therapy for patients with uncomplicated CAP is recommended, with &gt; 7 days, or &gt; 3 days after clinical improvement, rarely necessary. In this study, we evaluated annual trends in LOT from 2013-2020.

Methods
We conducted a retrospective cohort study using IBM MarketScan® database to evaluate LOT annual trends among adults 18-64 years in the United States hospitalized with uncomplicated CAP from 2013-2020. We included patients with a primary diagnosis of bacterial or unspecified pneumonia using International Classification of Diseases 9th and 10th revision codes, length of stay (LOS) of 2-10 days, discharged home with self-care, and not re-hospitalized in the 3 days following discharge. Discharge home was used as a surrogate for clinical improvement. We obtained inpatient LOS and post-discharge LOT data from MarketScan. We estimated annual inpatient LOT based on LOS from the Premier Healthcare Database (PHD). Total LOT was calculated by summing predicted inpatient LOT (from PHD) and actual post-discharge LOT (from MarketScan). Proportion of total LOT &gt; 7 days and post-discharge LOT &gt; 3 days were considered indicators of likely excessive LOT.

Results
There were 44,976 uncomplicated CAP hospitalizations among patients 18–64 years in MarketScan, 2013-2020. Patients had a median age of 54 years, median LOS of 3 days, were more likely to be female (56%) and in the South region (49%). The median LOT decreased from 9.6 days in 2013 to 8.6 days in 2020. The proportion of patients with total LOT &gt; 7 days decreased from 68% in 2013 to 51% in 2020 (% change: -25%); the proportion with post-discharge LOT &gt; 3 days decreased from 73% in 2013 to 63% in 2020 (% change: -14%; Figure 1).

Conclusion
The proportion of CAP patients with likely excessive LOT decreased by 25% from 2013-2020, surpassing the 2020 goal. Antibiotic stewardship programs should continue to pursue interventions to reduce excessive length of therapy for common infections.

Disclosures
All Authors: No reported disclosures.
1813. A Population-Based Multi-Year Assessment of the Incidence of High Inoculum Cefazolin (CZ) Resistance Amongst Methicillin-Susceptible Staphylococcus aureus (MSSA) Causing Bloodstream Infections (BSIs) over time in Calgary, Canada
Authors: Du Kristine , Waddell Barbara Jean M , Ligier Chloe , Svishchuk Julianna , Kipp Alexander , Lam John , Robinson Stephen , Somayaji Ranjani , Conly John M , Gregson Daniel , Parkins Michael 
Published: December 2022

Abstract

Background
Cefazolin (CZ) is a 1st-line therapy for methicillin-susceptible Staphylococcus aureus (MSSA) infections due to its tolerability, lower toxicity, and convenient dosing. However, some strains exhibit reduced susceptibility to CZ when present in high inoculum. Treatment failure and worsened outcomes are documented in BSI cohorts treated with CZ when infections are caused by strains demonstrating this inoculum effect (IE) (Miller, 2018). The objective of our study was to investigate the incidence of MSSA strains demonstrating IE over time across a general population, free of referral bias.

Methods
All initial isolates of first episodes of MSSA BSI from persons in Calgary, Canada were analyzed during 2012-14 and 2019. CZ minimum inhibitory concentration (MIC) was determined at standard (SI: 5x105 CFU/mL) and high inocula (HI: 5x107 CFU/mL) using the broth microdilution method at 24 hours as per 2009 CLSI criteria. Isolates were defined as having the CZ IE if they had a ≥ 4-fold difference between MIC at SI and HI. Isolates were defined as having a pronounced IE (pIE), if they were susceptible at SI but resistant at HI with an MIC ≥ 32µg/mL. Population density of Calgary was obtained from census data. Annual incidence rates (IR) were calculated by dividing the number of IE and pIE by the mid-year population data, and IR ratios (IRR) were calculated for IE and pIE by comparing 2019 to 2012 rates.

Results
During the years of study, 1040 individuals experienced at least one episode of MSSA BSI. The mean incidence rates of IE and pIE were 6.50 and 0.98 per 100,000 person-years, respectively. Comparing 2019 to 2012, rates of IE decreased significantly with an IRR of 0.67 (95% CI 0.47 – 0.95) but rates of pIE were not significantly different (IRR 1.24; 95% CI 0.43 – 3.86).
Incidence rates of IE and pIE in Calgary, Canada in 2012-14 and 2019.
MSSA BSIs in Calgary, Canada over the years are shown alongside corresponding rates of IE and pIE. The population density was used to find rates for IE/pIE per 100,000 person-years.

Conclusion
Population-based studies on MSSA BSI with the IE and pIE phenotype are lacking. Herein, we observed that while the incidence of MSSA with pIE has not changed, those occurring with the IE have decreased. Further studies on the clinical implications of pIE are needed.

Disclosures
All Authors: No reported disclosures.
1814. Acute Q fever: A 2-year Experience at a Tertiary-Care Center
Authors: Zein Said El , Saleh Omar M Abu 
Published: December 2022

Abstract

Background
Diagnosing acute Q fever is challenging partly due to the non-specific and self-limited course of illness in the majority of cases. It is important to identify and treat patients who are at increased risk for progression to persistent disease to prevent future complications. We describe the demographics, clinical presentation, and treatment of patients diagnosed with acute Q fever at our institution.

Methods
We identified all patients diagnosed with acute Q fever between December 2019 and March 2022. Patients 18 years or older who had a Q fever anti-phase II IgM ≥ 1:50 and anti-phase II IgG ≥ 200 were included. Patient with an anti-phase II IgG &lt; 200 were included if they had a fourfold rise in titers at follow-up within 3-6 weeks.

Results
Overall, 13 cases of acute Q fever were identified. Ages ranged between 32 and 68 years and 85% were men. The majority resided in the Midwest. A non-specific febrile illness was the most common presentation (11/13) (Table 1). Duration of symptoms predominantly ranged between 10 to 20 days. Elevated liver enzymes were noted in 7/13. Three had detectable Coxiella DNA in the blood during the acute phase using cell free DNA next generation sequencing but not using Coxiella PCR. Eleven patients had an exposure history. Overall, 6 patients received doxycycline monotherapy for a median of 14 days, while 7, who had risk factors for progression to chronic disease, received doxycycline and hydroxychloroquine for a median of 15 months. Among patients who followed-up, only one was restarted on therapy due to recurrence of symptoms. None of the patients developed infective endocarditis.

Conclusion
Acute Q fever is more frequently recognized, partly, because of increased awareness among physicians, however also possibly due to the increasing prevalence of the infection. In a cohort of 49 patients with Q fever at our institution between 2012 and 2018, 20 had acute Q fever, compared to 13 patients in this cohort. The infection predominantly affects men and the majority have an identifiable exposure history. Elevated CRP, abnormal liver enzymes, and detectable antiphospholipid antibodies were prevalent in our cohort. Patient with risk factors for progression into chronic disease were often placed on a longer course of a combination therapy in attempt to prevent chronic focal infections.

Disclosures
All Authors: No reported disclosures.
1830. Epidemiology of Recurrent Bacterial Bloodstream Infections in the US Military Health System
Authors: Vostal Alexander C , Grance Melissa , Powers John H , Carson Leigh , Chukwuma Uzo , Lanteri Charlotte , Seliga Nicholas , Poitras Beth , Parmelee Edward , Mende Katrin 
Published: December 2022

Abstract

Background
The epidemiology of recurrent bacterial bloodstream infections (rBSI) has not been fully characterized. Evaluating rBSI represents opportunities to inform morbidity risk factors and prevention strategies. We describe the clinical and microbiological features of rBSI in the US Military Health System (MHS) in a prospective cohort study, including retired and active-duty US uniformed service members and their beneficiaries.

Methods
We collected data for rBSI episodes from MHS beneficiaries (Jan 2010 – Dec 2019). A rBSI is defined as growth of the same bacterial pathogen in blood culture &gt;14 days after the index or previous episode. Demographics and comorbidities were collected prior to the index BSI. Microbiological data were obtained from the Navy and Marine Corps Public Health Center. Descriptive statistics are presented.

Results
A total of 12,749 beneficiaries were diagnosed with a BSI attributed to 1 of the 15 most common bacterial pathogens associated with BSI in the MHS, with 646 (5.1%) experiencing a rBSI. Escherichia coli had the largest proportion among all patients with rBSI (31% of 646); however, Enterococcus spp. accounted for the highest proportion of rBSI within a given pathogen subgroup (7.4% of 1,154 Enterococcus BSI; Table). Pseudomonas aeruginosa BSI had the shortest average time to recurrence (119 days), and Acinetobacter spp. had the highest frequency of BSI recurrences per patient (mean of 3). Male sex (59.9%) and age ≥65 years (52.9%) were most common among the rBSI patients. The updated Charlson Comorbidity index score preceding the index BSI was a median of 5.0, and chronic pulmonary disease (57.3%) and diabetes (56.6%) contributed the largest proportion of common comorbidities. A total of 88 (13%) rBSI patients had their index BSI while hospitalized following trauma where S. aureus was the most common (37.5%) bacterial pathogen.

Conclusion
Overall, the proportion of rBSI (5.1%) in our cohort of MHS beneficiaries was generally lower than that previously reported in the literature. Individuals with rBSI had a substantial burden of comorbid disease with 13% having trauma precede the index BSI. Identifying risk factors for recurrence may improve management strategies of primary BSI and may reduce morbidity of subsequent BSI.

Disclosures
John H. Powers, III, MD, Arrevus: Advisor/Consultant|Eicos: Advisor/Consultant|Evofem: Advisor/Consultant|Eyecheck: Advisor/Consultant|Gilead: Advisor/Consultant|GlaxoSmithKline: Advisor/Consultant|OPKO: Advisor/Consultant|Resolve: Advisor/Consultant|Romark: Advisor/Consultant|SpineBioPharma: Advisor/Consultant|UTIlity: Advisor/Consultant|Vir: Advisor/Consultant.
1832. Epidemiology, risk factors for mortality and resistance associated with Stenotrophomonas maltophilia bacteremia at a tertiary care hospital in Korea over 7 years
Authors: Sim Yong Ki , Lee Jeong Eun , Lee Shinwon , Lee Soon Ok , Hee Lee Sun 
Published: December 2022

Abstract

Background
Stenotrophomonas maltophilia (SM) is an important emerging nosocomial pathogen. This study aimed to describe the epidemiological, clinical, and microbiological charateristics of SM bacteremia at a tertiary care hospital in Korea over 7 years.

Methods
A retrospective study was conducted at a 1150-bed tertiary care hospital in Busan, South Korea. Data were collected between January, 2013 and November, 2019.

Results
A total of 79 bacteremia patients (median age: 61 years; 62% males) were reviewed; 38 (48.1%) were in 2013-2016 and 41 (51.9%) were in 2017-2019. The overall SM bacteremia-related 30-days mortality was 31.6%. Susceptibility to levofloxacin, sulfamethoxazole-trimethoprim (SMX/TMP) and minocycline were 87.3%, 92.4% and 100%, respectively. The most common clinical syndrome was central line-associated bloodstream infection (n=37, 46.8%). The others were intra-abdominal infection (n=18, 22.8%), skin and soft tissue infection (n=5, 6.3%) and pneumonia (n=5, 6.3%). In 50.6%, SM was the only pathogen of bacteremia, whereas in 49.4%, more than one causative organisms were isolated. Acinetobacter baumanii (in 8 cases) was the most frequent co-isolated pathogen, followed by Enterococcus faecium (in 6 cases), Pseudomonas aeruginosa (in 5 cases), Staphylococcus epidermidis (in 5 cases), Enterococcus gallinarum (in 3 cases) and Klebsiella pneumoniae (in 3 cases). Age (OR, 6.60; 95% Cl, 1.59-27.41; P = 0.009), inappropriate antimicrobial treatment (OR, 3.47; 95% Cl, 1.14-10.56; P = 0.029), and levofloxacin-resistant strains (OR, 7.86; 95% Cl, 1.20-51.41; P = 0.031) were independent risk factors for SM bacteremia-related 30-days mortality in multivariate analysis.

Conclusion
SM bacteremia has a high early mortality rate. In our study, old age, inappropriate antimicrobial treatment and levofloxacin-resistant strains were significant independent risk factors for early mortality in SM bacteremia patients. Early diagnosis and immediate use of appropriate antibiotics are recommended to improve mortality of SM bacteremia.

Disclosures
All Authors: No reported disclosures.
1837. Genotypic and Phenotypic Diversity of Contemporaneous Carbapenem Resistant Klebsiella pneumoniae from Blood Cultures of Individual Patients
Authors: Fleres Giuseppe , Cheng Shaoji , Chen Liang , Liu Guojun , Hao Binghua , Newbrough Anthony , Shields Ryan K , Kreiswirth Barry N , Nguyen Minh-Hong , Clancy Cornelius J 
Published: December 2022

Abstract

Background
The longstanding paradigm is that almost all bloodstream infections (BSIs) stem from a single, clonal organism. We hypothesized that carbapenem resistant K. pneumoniae (CRKP) from individual patients (pts) with BSIs are genetically diverse and manifest phenotypic differences that are not typically recognized by the clinical microbiology laboratory at time of diagnosis.

Methods
We streaked blood culture (BC) broth from 6 pts with CRKP BSI onto blood agar plates, and randomly picked 9 colonies (strains) for HiSeq (Illumina) whole genome sequence. Single BSI isolates recovered by the clinical micro lab from individual pts underwent short- and long-read MinION (ONT) sequencing.

Results
2 pts were infected with clade 1 (B, G), and 4 with clade 2 (A, D, F, J) ST258 KPC-producing KP. Strains from individual pts clustered by cgSNP phylogeny (Fig. 1A-B). BC bottles from each pt harbored genetically heterogenous KP populations, with strains differing from each other by cgSNPs (Fig. 1B), presence/absence of specific antibiotic resistance genes (Fig. 1A), mutations of capsular genes (Fig 2) and at other loci involved in host interactions, and/or loss of plasmids or plasmid-borne genes (Fig. 1A). Differences in capsular gene composition were observed in KL107 capsule type strains from pts A, D and J (Fig. 2). Pangenome analyses showed accessory gene composition diversity among strains from all pts (Fig. 3). Intra-pt genetically diverse strains exhibited differences in antibiotic resistance (Fig. 4), viscosity and mucosity, capsular content, and resistance to serum and macrophage killing. Various strains from pts A and J differed in ability to cause target organ infections or mortality in a mouse model of intravenous disseminated infection (Fig. 5).

Conclusion
We identified genotypic and phenotypic variant strains of ST258 KP from BSIs of individual patients that were not recognized at time of diagnosis. Our data suggest a new, population-based paradigm for BSIs by CRKP. The findings potentially have profound implications for medical, microbiology laboratory and infection prevention practices, and for understanding emergence of antibiotic resistance and pathogenesis.

Disclosures
Cornelius J. Clancy, MD, receives research funding paid to his institution from Astellas and Merck: Grant/Research Support|serves as an advisory Board member for Astellas, Cidara, and Scynexis, served on the advisory board for Merck, Qpex Biopharma, and Shionogi: Advisor/Consultant|Venatorx and Needham & Associates: Advisor/Consultant.