bluuebunny/crossref_metadata_2025 huggingface dataset:
1796. Evaluation of Asymptomatic Bacteriuria in Critical Access Hospitals
Authors: Hartlage Whitney , Chan Jeannie D , Martinez-Paz Natalia , Lynch John B , Jain Rupali , Pottinger Paul , Bryson-Cahn Chloe , Castillo Alyssa Y , Castillo Alyssa Y , Kassamali-Escobar Zahra
Published: December 2022

Background

The University of Washington Tele-Antimicrobial Stewardship Program (UW-TASP) provides antimicrobial stewardship education and training to rural and critical access hospitals (CAHs) in the United States through collaborative tele-mentoring. In 2021, UW-TASP implemented a pilot stewardship cohort to reduce antibiotic treatment of asymptomatic bacteriuria (ASB). We sought to quantify the overall prevalence of ASB and proportion treated in participating hospitals.

Methods

Patients undergoing urine testing were identified through local electronic medical records and microbiology data. CAHs adjudicated their own cases and reported demographics, symptoms of urinary tract infection, systemic inflammatory response symptoms (SIRS), location at the time of culture, laboratory results, and antibiotic treatment through a RedCap collection tool. The data form was created and analyzed by UW-TASP faculty. This study was waived by the University of Washington institutional review board.

Results

Nineteen CAHs in 5 states participated in this pilot. Eight submitted urine analysis and culture data for 417 patients. Seventy-seven percent of patients were female and the median age was 70. The emergency department was the most common culture collection location (274/417, 66%), followed by ambulatory care clinics (111/417, 27%), and nursing facilities (13/417, 3%). SIRS criteria and/or organ dysfunction were present in 149/417 patients (36%). Two hundred sixty patients (62%) had a positive culture with Escherichia coli being the most common implicated organism (167/260, 64%). ASB was identified in 69/260 patients (27%), and antibiotics were prescribed for 53/69 (77%) of those with ASB. Oral antibiotics were prescribed for 311 (75%) patients. Of those, 22% were prescribed a fluoroquinolone. Median treatment duration was 7 days (range, 1-14).

Conclusion

Although the prevalence of ASB was only 27% among 417 patients, treatment of ASB was high at 77%. High numbers of culture collections from the emergency department and ambulatory care settings identify these locations as future foci for stewardship interventions in CAHs. Low hanging fruit for intervention include reducing unnecessary fluoroquinolone use and reducing duration of antibiotic therapy.

Disclosures

Chloe Bryson-Cahn, MD, Alaska Airlines: Advisor/Consultant.
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

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

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< 0.001). Figure 2.Median duration of antibiotics pre and post program implementation (p<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

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

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 > 7 days, or > 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 > 7 days and post-discharge LOT > 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 > 7 days decreased from 68% in 2013 to 51% in 2020 (% change: -25%); the proportion with post-discharge LOT > 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

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

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 < 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

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 >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

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

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.
1839. Impact of Hypoalbuminemia on Ceftriaxone Treatment Failure in Patients With Enterobacterales Bacteremia
Authors: Steere Evan , Eubank Taryn , Greenlee Sage , Cooper Megan , Drake Ty C
Published: December 2022

Background

Ceftriaxone (CRO) is a third-generation cephalosporin that is commonly prescribed due to its robust Gram-negative activity and lack of renal dose adjustments. It is also highly protein bound allowing for once daily dosing. In patients with hypoalbuminemia, however, the proportion of free drug is increased thus increasing the rate at which CRO is renally eliminated. This increased clearance could lead to lower serum concentrations and increased risk of treatment failure.

Methods

We performed a retrospective, cohort study to assess the impact of hypoalbuminemia (serum albumin ≤ 2.5 g/dL) on treatment failure among patients with monomicrobial Enterobacterales bacteremia. Adult patients who received > 72 hours of CRO therapy for susceptible Enterobacterales bacteremia between May 1, 2016 and April 30, 2021 were eligible for inclusion. The primary outcome of treatment failure was a composite of inpatient mortality or escalation to an intravenous anti-pseudomonal antibiotic or ertapenem. Secondary outcomes included hospital length of stay, total duration of antibiotic therapy, and time to infection resolution. Baseline characteristics and outcomes were compared using R Studio (Version 4.1.0) in a 1:1 propensity-matched cohort.

Results

After propensity score matching, 142 patients were included in each study group. The most common organisms in our cohort were Escherichia coli (71.5%), Klebsiella pneumoniae (14.1%), and Proteus mirabilis (5.3%). The most frequently implicated source of infection was the urinary tract (71.5%). Interestingly, treatment failure was numerically higher in the hypoalbuminemia group but was not statistically significant (12.0% vs. 7.7%, p = 0.23). All secondary outcomes were similar between groups. Among the subgroup of patients admitted to the ICU at baseline, the difference in treatment failure was even greater between patients with hypoalbuminemia and those without (23.3% vs. 7.5%, P = 0.07).

Conclusion

Hypoalbuminemia did not appear to have a significant impact on clinical outcomes among patients with Enterobacterales bacteremia treated with CRO. However, critically ill patients may be subject to higher incidence of treatment failure in the presence of hypoalbuminemia.

Disclosures

All Authors: No reported disclosures.
2315. Impact of MSSA Surveillance and Decolonization on Invasive Infection in the Neonatal ICU
Authors: Reich Patrick J , Ikpeama Geoffrey , Niesen Angela , Liviskie Caren , McPherson Christopher , Fritz Stephanie A
Published: December 2022

Background

Invasive methicillin-susceptible Staphylococcus aureus (MSSA) infections are an important cause of morbidity and mortality in neonatal intensive care unit (NICU) infants. MSSA colonization (asymptomatic carriage in the nose, skin, or gut) is a risk factor for subsequent invasive infection (e.g., pneumonia, bone infections, bloodstream infections, etc). Active surveillance programs coupled with decolonization measures for MSSA-colonized infants have been associated with decreased invasive MSSA infection rates in the NICU setting.

Methods

In June 2020, an active surveillance program was implemented to detect MSSA nasal colonization for infants admitted to the St. Louis Children’s Hospital NICU, a 140-bed quaternary NICU. MSSA-colonized infants were decolonized with a 7 day course of intranasal mupirocin twice daily plus topical chlorhexidine baths on days 1, 4, and 7 (for infants greater than 30 weeks postmenstrual age). MSSA bloodstream infection (BSI) rates were followed quarterly pre- (September 2018-May 2020) and post- (June 2020-March 2022) implementation of MSSA surveillance and decolonization. Mean MSSA BSI rates pre- and post-implementation were compared via paired T-test. The number of infants treated with mupirocin was calculated pre- and post-implementation.

Results

After implementing MSSA surveillance and decolonization there was no significant change in the mean MSSA BSI rate (Figure): 0.22 per 1000 patient-days pre-implementation, 0.16 per 1000 patient-days post-implementation (p=0.37). Since initiating MSSA decolonization in June 2020, the number of NICU infants exposed to mupirocin increased nearly fourfold: mean 10 infants treated per month pre-implementation, mean 38 infants treated per month post-implementation.

Conclusion

Implementing an MSSA surveillance and decolonization program in the NICU was not associated with a sustained decrease in invasive MSSA infections. However, mupirocin use in the NICU nearly quadrupled following implementation. Additional investigation is warranted to identify potential contributing factors for unchanged invasive MSSA infection rates despite active surveillance and decolonization (e.g., emerging mupirocin resistance).

Disclosures

All Authors: No reported disclosures.
1845. Oritavancin Compared to the Standard-of-Care for the Treatment of Gram-positive Blood Stream Infections
Authors: Moenster Ryan P , Wallace-Lacey Ashleigh , Lorenz Michael , Skouby Danielle , Fong Rebecca , Abdulbasir Anosha , Abner Hartley , Alberts Justin , Doty Johnathan , Tiefenauer Seth , Western Hannah , Linneman Travis W
Published: December 2022

Background

Data is limited comparing oritavancin (ORT) to the standard-of-care (SOC) for the treatment gram-positive blood stream infections (BSI).

Methods

This was a retrospective study of all patients in the Veteran’s Affairs Health Care System treated with at least 1 dose of oritavancin or at least 5 days of vancomycin, daptomycin, ceftaroline, ampicillin, ampicillin-sulbactam, nafcillin, oxacillin, or cefazolin for a documented gram-positive BSI from 1 January 2015 to 30 June 2021. Patients with polymicrobial blood cultures or positive cultures from other sites were included if the organisms were sensitive to the incident antimicrobial; no concomitant antimicrobials could be used once the incident agent was started. Individuals were also excluded if they were diagnosed with endocarditis, had a neutrophil count < 500 cells/mm3, or had a diagnosis of Human Immunodeficiency Virus (HIV) on their problem list.

The primary composite outcome was clinical failure, defined as all-cause mortality within 30-days from the end of therapy, or blood cultures positive for the incident organisms ≥72 hours after administration of the first dose and ≤30 days after the administration of the final dose of the study antimicrobial, or any drug or line-related readmissions within 30-days of hospital discharge. Secondary outcomes included all-cause 30-day readmission and rates of acute kidney injury (AKI).

Results

Two hundred-forty patients were identified for screening with 96 meeting criteria (27 in ORT and 69 in SOC groups). Baseline characteristics were generally balanced between groups except more patients in the ORT group received > 96-hours of treatment before the incident antimicrobial was started (70.3% (19/27) vs. 13.04% (9/69); p<0.001). The pathogen most prevalent was methicillin-susceptible Staphylococcus aureus (MSSA) (ORT 33.3% (9/27) vs. SOC 46.4% (32/69)). Clinical failure occurred in 7.4% (2/27) in the ORT group and 17.4% (12/69) in SOC (p=0.34). No components of the primary outcome were significantly different between groups, but AKI did occur more commonly in the SOC group (27.5% (19/69) vs. 3.7% (1/27); p=0.01).

Conclusion

ORT appears to be a safe and effective option when directly compared to the SOC for non-endocarditis BSIs.

Disclosures

Ryan P. Moenster, Pharm.D., FIDSA, Melinta Therapeutics: Grant/Research Support|Melinta Therapeutics: Honoraria.
1848. Predictors of 6-Month Mortality in Staphylococcus aureus Bacteremia: A Population-Based Study in Olmsted County, Minnesota, from 2006 to 2020
Authors: Hindy Joya-Rita , Quintero-martinez Juan A , Lahr Brian D , DeSimone Daniel C , Baddour Larry M
Published: December 2022

Background

Staphylococcus aureus has high mortality rates, which is influenced by several factors related to the host-pathogen interaction. The current study aims to provide a contemporary evaluation of predictors of 6-month mortality rate in a population-based cohort of incident Staphylococcus aureus bacteremia (SAB) cases.

Methods

Retrospective population-based study of 541 adult residents of Olmsted County, MN with monomicrobial SAB from January 1, 2006 through December 31, 2020. The study’s primary outcome was 6-month mortality rate, and a survival analysis was prepared by the Kaplan-Meier method. Multivariable Cox regression was used to investigate risk factors associated with 6-month mortality.

Results

The median (IQR) age of 541 patients with SAB was 66.8 (54.4-78.5) years and 39.6% were female. The median Charlson Comorbidity Index (CCI) was 2 (1-4). SAB cases were healthcare-associated in 49.2% and 56.2% were methicillin-susceptible. Twenty percent of SAB cases had an unknown infection source and 38.3% had complicated bacteremia. There were 7 relapses within the first 12 weeks of follow-up, corresponding to a cumulative incidence rate of 1.3%. There were no re-infections through the remainder of the 6-month follow-up, although there were 2 recurrences after 7 months. Eighty-nine (16.5%) patients died within 1 month of SAB diagnosis and 144 (26.7%) patients died during the 6-month follow-up period. In a multivariable analysis, older age, elevated CCI, unknown source of SAB, and intensive care unit (ICU) admission were significant predictors of an increased 6-month mortality rate. In contrast, presence of diabetes mellitus was significantly associated with a decreased 6-month mortality rate; also, undergoing infectious diseases consultation was associated with reduced mortality in the first 2 weeks, but not for the remainder of the 6-month follow-up period.

Conclusion

To our knowledge, the current investigation represents the only contemporary population-based study determining significant predictors of mortality in SAB patients, namely, older age, higher CCI, unknown source of SAB, and ICU admission. This study also described one of the lowest 30-day mortality rates reported over the past 2 decades. Figure 1.Survival and reinfection rates of patients with SAB over 6 months.

Abbreviations: SAB, Staphylococcus aureus bacteremia.

Foot notes: The overall survival curve was derived by the Kaplan-Meier estimator, while the curve for reinfection was estimated by the cumulative incidence function taking into account the competing risk of death.

Disclosures

Larry M. Baddour, M.D., Boston Scientific: Advisor/Consultant|Botanix Pharmaceuticals: Advisor/Consultant|Roivant Sciences: Advisor/Consultant|UpToDate, Inc.: Royalty payments - authorship duties.
1853. Relevance of Actinomyces Bacteremia
Authors: Sharma Mamta , Arcobello Jonathan T , Tanveer Farah , Revankar Sanjay , Bhargava Asish
Published: December 2022

Background

Actinomyces species are Gram-positive anaerobic bacilli colonizing the human oropharynx, gastrointestinal tract, and urogenital tract asso­ciated with a wide range of infections. The isolation of Actinomyces spp. from sterile clinical samples is regarded as significant. We reviewed the risk factors, clinical features, and outcomes in patients with Actinomyces bacteremia.

Methods

We conducted a retrospective study of all inpatients with Actinomyces bacteremia from two tertiary care centers from 1/1/06 -9 /26/19 . Data were collected on demographic and clinical characteristics, co-morbidities, primary source of infection, treatment received and duration of therapy and outcomes. True bacteremia was defined as Actinomyces bacteremia with systemic manifestations of infection.

Results

A total of 82 cases of positive blood cultures were identified of which 33 were true bacteremia, based on clinical criteria among 19 females and 14 males ranging from 19-93 years (63.8 ±19.5). Majority of patients were blacks (70%). Clinical risk factors predominantly were diabetes mellitus (21%), chronic renal failure (18%) and active malignancy (12%). Majority of blood cultures were positive within 48 hrs. of admission 84.8%. Skin and soft tissue (27%) was the most common source followed by respiratory (15%), intrabdominal (15%), osteomyelitis (12%), odontogenic (6%), endovascular (6%) genitourinary (3%) and unknown source (16%). In 27 (81%) cases, bacteremia was isolated to species level: A.meyeri 8 (30%), A.odontolyticus 7 (26%), A.israelli 7 (26%), A.turicensis 4 (15%) and A.neuii 1 (4%). The infectious diseases service was consulted in 20 cases of true bacteremia. Duration of antibiotics ranged between 0-84 days (17.6 ±20.7). All-cause mortality during hospitalization was 24% (8).

Conclusion

Not all Actinomyces bacteremia may be relevant and can represent transient bacteremia. Better awareness and involvement of infectious disease service is recommended in understanding of the clinical significance, to ensure appropriate therapy for patients thereby implementing antibiotic stewardship to improve antibiotic use and, patient safety and improve outcomes. Further research will help to identify the true significance of these isolates.

Disclosures

All Authors: No reported disclosures.
1862. Time to Therapeutic Goal is Faster with Continuous Infusion Vancomycin for Methicillin-Resistant Staphylococcus aureus Bloodstream Infections
Authors: Gilliam Diari , Acosta Dominic , Carvour Martha , Walraven Carla
Published: December 2022

Background

Continuous infusion vancomycin (CIV) is an attractive alternative to intermittent infusion vancomycin (IIV) as it may result in more rapid attainment of target serum drug concentrations, provide ease of monitoring, and decreased risk of nephrotoxicity. At our institution CIV has been the preferred infusion method for over 20 years. The purpose of this study was to examine the time to therapeutic goal among patients receiving IIV compared to CIV for methicillin-resistant Staphylococcus aureus (MRSA) bacteremia. Secondary objectives included all-cause readmission, relapse, and mortality 30 days after completion of therapy.

Methods

This was a single-center, retrospective study of patients who received vancomycin for MRSA bacteremia between January 2018 and December 2021. Included patients were ≥ 18 years of age, had ≥ 1 blood culture positive for MRSA, received vancomycin for > 10 days, and had follow-up in the outpatient parenteral antimicrobial therapy clinic. Patients who were pregnant, received vancomycin for ≤ 10 days, or were diagnosed at an outside hospital were excluded. All patients were started on IIV then transitioned to CIV. Patients on IIV with an appropriately drawn trough between 15-20 mcg/mL were considered therapeutic. For patients on CIV, a single random level between 17-25 mcg/mL, corresponding to an AUC/MIC of 400-600 mcg·h/mL, was considered therapeutic.

Results

Sixty-three patients with 65 MRSA bacteremia episodes were included. Significantly fewer patients achieved a therapeutic goal on IIV compared to patients on CIV (52.3% vs. 83.1%, p-value < 0.01). Of the 31 patients who did not reach the IIV trough goal, 87.1% became therapeutic when switched to CIV. Patients on IIV took 3.6 days, on average, to reach the target goal, compared to 1.9 days when patients were switched to CIV (95% confidence interval 0.50 – 2.96, p-value < 0.01). No patients experienced relapse or mortality 30 days after completion of therapy. Six patients (9.2%) were readmitted 30 days after completion of therapy.

Conclusion

CIV enabled patients with MRSA bacteremia to achieve the AUC/MIC goal significantly faster than when receiving IIV. Patients who were unable to achieve a therapeutic goal on IIV became therapeutic once switched to CIV.

Disclosures

Martha Carvour, MD, PhD, The Suga Project/The Suga Project Foundation: I provide consultation and support but do not receive compensation.
1863. Treatment and Outcomes of Cefoxitin-Non-Susceptible Serratia marcescens, Klebsiella aerogenes, Citrobacter freundii, Enterobacter cloacae, and Morganella morganii Bacteremia with Piperacillin/Tazobactam Versus Cefepime or Carbapenem in Immunocompromised Patients
Authors: Lu Brian , Wong Miranda , Diep Calvin , Ha David R , Bounthavong Mark , Banaei Niaz , Deresinski Stan
Published: December 2022

Background

A recent guidance suggested “caution if prescribing piperacillin-tazobactam for serious infections caused by organisms at high risk of significant AmpC production” and that the preferred antibiotic choice should be either cefepime or a carbapenem, despite an admitted lack of definitive evidence. Examination of this question in immunocompromised patients may provide such evidence.

Methods

This was a retrospective, single-center study conducted from January 2016 to December 2021. We included immunocompromised patients aged 18 years or older who had a laboratory confirmed blood culture positive for Enterobacterales showing non-susceptibility to cefoxitin and were definitively treated with piperacillin-tazobactam, cefepime, or a carbapenem. The primary endpoint was a composite of clinical or microbiological failure, which was comprised of in-hospital 30-day mortality, white blood count >12 x 109/L or temperature >38°C on days 5-7, microbiological failure on days 3-5, or microbiological recurrence/relapse on days 5-30.

Results

We identified 81 patients who were included for analysis. Baseline characteristics between arms were similar between groups except for more frequent severe neutropenia (p=0.010) and higher Pitt bacteremia scores (p=0.042) in the cefepime/carbapenem group. Within the piperacillin/tazobactam arm, 17 of 35 (48.6%) had clinical or microbiological failure, compared to 17 of 46 (37.0%) patients in the carbapenem/cefepime arm (p=0.294). Microbiological failure occurred in 4 of 35 (11.4%) patients treated with piperacillin/tazobactam compared to 0 of 46 (0%) patients treated with a carbapenem/cefepime (p=0.019). In multivariate analysis, patients treated with a carbapenem/cefepime had a 69% lower odds of clinical or microbiological failure compared to those treated with piperacillin/tazobactam (OR = 0.31; 95% confidence interval, 0.10-0.98).

Conclusion

In immunocompromised patients with bacteremia due to cefoxitin-non-susceptible Serratia marcescens, Klebsiella aerogenes, Citrobacter freundii, Enterobacter cloacae, or Morganella morganii, definitive treatment with piperacillin/tazobactam was associated with a higher likelihood of microbiological failure compared with treatment with a carbapenem or cefepime.

Disclosures

All Authors: No reported disclosures.
1865. Analysis of National Surveillance Data to Support Case Definition Revisions for Multisystem Inflammatory Syndrome in Children (MIS-C), United States, February 2020–April 2022
Authors: Campbell Angela P , Miller Allison D , Yousaf Anna R , Lee Ellen H , Lim Sarah , Brown Catherine M , Oster Matthew , Abrams Joseph , Lindsey Katherine , Wu Michael J , Cato Shana Godfred , Ermias Belay , Zambrano Laura D , Melgar Michael
Published: December 2022

Background

Classification of MIS-C, COVID-19, and other pediatric inflammatory conditions is challenged by phenotypic overlap and absence of diagnostic laboratory evidence. Due to public health need and based on limited data from early cases, CDC developed a necessarily broad MIS-C surveillance case definition in May 2020. Studies have since shown that some criteria do not distinguish between MIS-C and other conditions and may contribute to misclassification. To inform planned revision to the CDC definition, we evaluated the impact of narrowing these criteria on case inclusion in national MIS-C surveillance.

Methods

Of state and local health-department reported cases meeting the current MIS-C case definition as of 04/14/2022, we describe the proportion that met revised criteria under consideration including fever duration, C-reactive protein (CRP) elevation using a defined cutoff, and organ involvement represented by specific criteria. We also evaluated cases identified using potential combinations of revised criteria.

Results

Of 8,096 MIS-C cases fulfilling the original case definition, 6,332 (78%) had sufficient data for evaluation of criteria. Of these, 96% had fever for ≥2 days and 94% had a CRP ≥ 3.0 mg/dL (Table 1). Cardiac involvement defined by key features of MIS-C was present in 84% of cases (62% if BNP/proBNP elevation was excluded); 43% had shock. Dermatologic, gastrointestinal (GI) and hematologic involvement were present in 75%, 89% and 37% of cases, respectively. Neurologic (excluding headache), renal, and respiratory involvement were present in 16%, 20%, and 63% of cases, respectively. The number of cases with ≥ 2 of cardiac (without BNP/proBNP elevation), shock, dermatologic, GI, or hematologic involvement was 5,733 (91%). SARS-CoV-2 testing results are shown in Table 2.

Conclusion

The CDC MIS-C case definition is intentionally broad. Using national surveillance data, we evaluated case inclusion under narrower criteria, prioritizing features of MIS-C that distinguish it from similar pediatric inflammatory conditions. A surveillance case definition may not capture all cases and is not intended to replace clinical judgment. We plan to assess additional criteria combinations, describe potentially excluded cases, and incorporate findings into a revised definition.

Disclosures

All Authors: No reported disclosures.