bluuebunny/crossref_metadata_2025_split huggingface dataset:
460. Ceftriaxone vs. Standard of Care for Definitive Treatment of Methicillin-Susceptible Staphylococcus aureus Infections
Authors: Snawerdt Jessica , Withers Sarah , Schrank John 
Published: October 2019

Abstract

Background
β-Lactam antibiotics, specifically nafcillin, oxacillin, and cefazolin, have proven efficacy for methicillin-susceptible Staphylococcus aureus (MSSA) infections. Outpatient antimicrobial therapy (OPAT) with these agents is limited due to side effects and multiple doses required per day. Ceftriaxone, a third-generation cephalosporin, has a favorable profile for OPAT. Limited evidence supporting ceftriaxone therapy for MSSA infections prevents its widespread use.

Methods
A multi-center, retrospective cohort study comparing patients who received cefazolin or nafcillin to patients who received ceftriaxone for treatment of microbiologically proven MSSA infections was conducted from February 2016 to February 2018. The primary outcome of interest was a clinical success, defined as the absence of infection-related readmission, worsening infection, or recurrent infection within 90 days. Secondary outcomes included the rate of adverse reactions, length of stay, and impact of Infectious Diseases (ID) consult.

Results
66 patients treated with ceftriaxone and 156 patients treated with cefazolin or nafcillin were included. Skin and soft tissue and bone and joint were the most common infections in the ceftriaxone group, whereas bacteremia was most common in the nafcillin and cefazolin group. There were significant differences in baseline age (61 years vs. 59 years; P = 0.036) and intravenous drug use (1 patient vs. 25 patients; P = 0.002) between groups. As shown in Table 1, there were significantly lower rates of clinical success with ceftriaxone compared with standard of care as a composite of all infection sites (78.8% vs. 91%; P = 0.012). No statistically significant differences were seen in safety outcomes or ID consultation. Length of stay was significantly longer in the nafcillin and cefazolin group (5.2 days vs. 12.8 days; P ≤ 0.0001).

Conclusion
The results of this study indicate that patients treated with ceftriaxone for MSSA infections had significantly lower rates of clinical success compared with standard of care antibiotics. Nafcillin or cefazolin should remain as first-line agents for treatment of bone and joint infections and skin and soft-tissue infections due to MSSA.

Disclosures
All authors: No reported disclosures.
474. Battling Addiction: Impact of Intravenous Drug Use on Invasive Skin and Soft Tissue Management
Authors: Ivey Alison , Holt Shannon 
Published: October 2019

Abstract

Background
Although skin and soft-tissue infections (SSTIs) remain a common cause of hospitalization for intravenous drug users (IVDU), little has been done to identify whether there should be differences in the SSTI management of IVDU vs. nonusers. The objective of this study was to evaluate the impact of documented intravenous drug abuse on the overall management of invasive SSTIs in hospitalized patients.

Methods
This retrospective cohort study randomly selected 100 IVDU and 100 nonusers (controls) hospitalized for an SSTI over 18 months in a community teaching hospital. Patients eligible for inclusion were 18–60 years old and treated with IV inpatient antibiotics for at least 48 hours. Pregnant women, transfers from an outside hospital, and diabetic foot infections were excluded. The primary endpoint was hospital length of stay (LOS). Secondary endpoints included: percentage prescribed empiric combination antibiotic therapy, percentage prescribed an anti-pseudomonal agent, inpatient and total antibiotic duration of therapy (DOT), 30-day readmission rates, and 30-day emergency department (ED) visit rates.

Results
The study population was predominantly male (66%), Caucasian (72%), and had a mean age of 40 years old (18–59). IVDU were more likely to have complications (18% vs. 6%) and polymicrobial infections (19% vs. 2%), Mean hospital length of stay was 9.0 days for IVDU compared with 4.8 days for controls (P < 0.001). There was no difference in empiric combination therapy (48% vs. 37%; P = 0.115) or empiric exposure to an anti-pseudomonal agent (38% vs. 30%; P = 0.232). Mean duration of inpatient antibiotic DOT was longer in IVDU (7.5 days vs. 4.3 days; P < 0.001), but total antibiotic DOT was similar between groups (16.0 days vs. 13.8 days; P = 0.141). Thirty-day ED visits were higher for IVDU (16% vs. 5%; P = 0.009); however, there was no difference in 30-day readmission (14% vs. 16%; P = 0.692).

Conclusion
Documented IV drug abuse resulted in a significant increase in the length of stay in hospitalized adults with SSTIs requiring IV antibiotics. Exposure to combination therapy and anti-pseudomonal agents did not differ between the groups as would be expected. In the future stewardship initiatives are needed to increase adherence to SSTI guideline recommendations for empiric therapy.

Disclosures
All authors: No reported disclosures.
479. Associated Factors for Extended-Spectrum β-Lactamase Infection Among Patients with Solid or Hematological Malignancy
Authors: Martinez-Valencia Alvaro J , Gomez Martinez Brian J , Montañez Ayala Anita , Garcia Katherine , Sánchez Pedraza Ricardo , Paola Jiménez Cetina Leydy , Cuervo Sonia , César Gómez Rincón Julio 
Published: October 2019

Abstract

Background
Cancer patients are susceptible to infections due to immunodeficiency, frequent invasive interventions-devices, chemotherapy and antibiotics exposure. Infections caused by extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae increase morbidity and mortality. The objective was to identify clinical factors associated with ESBL in infected patients with cancer at the Instituto Nacional de Cancerología.

Methods
A case–control study was conducted from 2013 to 2015. Cases were infected patients with ESBL-producer Enterobacteriaceae. Controls (matched for date and ward) with non-ESBL-producer Enterobacteriaceae were included. Data were extracted from electronic medical records at index culture: clinical and admission data, Charlson index, immunosuppressive, radio and chemotherapy, neutropenia, invasive devices, surgical procedures and antimicrobial therapy. Microorganisms were identified by the automatized system. Conditional logistic regression and backward stepwise was used to identify predictors of ESBL isolation.

Results
A total of 265 patients with ESBL producer Enterobacteriaceae and 445 non-ESBL producers were identified, mean age 59, 61% male, 48% admitted as outpatients, 73% with solid tumors, 38% with Charlson index ≥4. E.coli and Klebsiella spp. represented 90% of microorganisms. Factor associated with ESBL producer Enterobacteriaceae were hospitalization ≥7 days (OR: 1,59; CI 1.11–2,29), hospitalization the previous year (OR: 4.02; CI 2,68–6,02), immunosuppressive therapy (OR: 2.07; CI 1,05–4.05), Β-lactam therapy the last month (OR: 1.54; CI 1.05–2.26), invasive devices (OR: 1.58; CI 1.10–2.27), active neoplasia (OR: 2,22; CI1.05–4.68), neutropenia (OR: 2.03; CI:1.26–3.27) and absence of chemotherapy during last 3 months (OR: 1.91; CI1.29–2.82). Discriminatory capacity was acceptable (AUC: 0.71).

Conclusion
The presence of ESBL-producer Enterobacteriaceae in oncologic patients is associated with health care, hospital admission and length of stay, invasive devices and exposure to antibiotics. The magnitude of associated factors are weak and do not completely allow the identification of cancer patients infected with ESBL-producer Enterobacteriaceae.

Disclosures
All authors: No reported disclosures.
502. Klebsiella variicola Infections in Service Members Who Sustained Trauma in Iraq and Afghanistan
Authors: Kiley John L , Mende Katrin , Beckius Miriam , Kaiser Susan , Carson M Leigh , Lu Dan , Whitman Timothy , Petfield Joseph , Tribble David , Blyth Dana M , Blyth Dana M 
Published: October 2019

Abstract

Background
Recent work has argued that genus Klebsiella is best divided into 3 clades: K. pneumoniae (Kp), K. quasipneumoniae (Kq), and K. variicola (Kv). Kv has drawn attention from reports of higher mortality and virulence. We evaluated a previously defined group of military trauma patients with Klebsiella infections for the presence of Kv, described clinical and isolate characteristics, and compared Kv and Kp groups.

Methods
All initial and serial (≥7 days from prior isolate) infecting Kp isolates (identified by clinical laboratories without the ability to speciate Kq and Kv) were collected from the Trauma Infectious Disease Outcomes Study (6/09–12/14). Additionally, a previously defined group of colonizing isolates linked to the infecting isolates and a selection of random colonizers were included from groin swabs. DNA extraction and PCR targeting Kv per published methods was performed. Antimicrobial susceptibilities were determined using the BD Phoenix Automated Microbiology System and CLSI criteria. Multidrug resistance was defined as either resistance to ≥3 classes of aminoglycosides, β-lactams, carbapenems and/or fluoroquinolones or production of ESBL or KPC.

Results
Of 237 archived Kp isolates (from 122 patients), 10 (4%) were identified as Kv by PCR (from 8 [7%] patients). The Kv sources were 4 from blood (40%), 1 intra-abdominal (10%) and 5 from groin (50%). Six (3%) isolates were identified as Kq (4 from groin and 2 from respiratory specimens). The Kv and Kp patients were all males, with a median age of 25 (IQR 21–46) and 23 (IQR 21–28), length of hospital stay of 24 days (IQR: 5–106) and 53 days (IQR 36–74), and Injury Severity Score of 21 (IQR: 10–50) and 38 (IQR: 30–45), respectively. There were no deaths in the Kv group compared with 4 with Kp. Infecting Kv isolates were more likely to be from blood compared with Kp (80% vs. 17%, P = 0.04). No infecting Kv isolates were multidrug-resistant compared with 70% of infecting Kp isolates (P < 0.01).

Conclusion
Kv represented 4% of the previously identified Kp isolates in this population. Patient characteristics were similar in both groups. While Kv was less resistant than Kp, it was more likely to be associated with invasive disease in this group.

Disclosures
All authors: No reported disclosures.
514. Shedding of Multidrug-Resistant Gram-Negative Bacilli by Colonized Patients during Procedures and Patient Care Activities
Authors: Alhmidi Heba , Cadnum Jennifer , Jencson Annette , Bonomo Robert A , Wilson Brigid , Mayer Jeanmarie , Samore Matthew H , Donskey Curtis 
Published: October 2019

Abstract

Background
Contaminated environmental surfaces contribute to transmission of healthcare-associated pathogens such as multidrug-resistant gram-negative bacilli. We hypothesized that medical procedures and patient care activities facilitate environmental dissemination of multidrug-resistant gram-negative bacilli in hospitalized patients.

Methods
We conducted a cohort study of hospitalized patients in contact precautions for carriage of extended-spectrum β-lactamase (ESBL)-producing or carbapenem-resistant gram-negative bacilli (CR-GNB) to determine the frequency of environmental shedding during procedures and care activities. Perirectal, wound, and skin were cultured for the gram-negative bacilli of interest. Prior to each procedure or activity, surfaces in the room and portable equipment used for procedures were disinfected. After procedures, high-touch surfaces and portable equipment were cultured; negative control cultures were collected after 1 hour in the absence of a procedure.

Results
Of 60 participants, 38 (63%) were in contact precautions for ESBL-producing gram-negative bacilli and 22 (37%) for CR-GNB. Thirty-four (57%) participants had positive perirectal, wound, or skin cultures. Contamination of surfaces with the colonizing multidrug-resistant gram-negative bacilli occurred frequently during procedures and activities such as wound care, assistance with meals, and urinary catheter or colostomy care (11% to 29% of procedures/activities), whereas contamination was rare in the absence of a procedure (1%). Contamination was recovered from 6 of 56 (10%) portable devices used for procedures.

Conclusion
Environmental shedding of multidrug-resistant gram-negative bacilli occurs frequently during medical and non-medical procedures in hospitalized patients. Our results suggest that there is a need for effective strategies to disinfect surfaces and equipment after procedures.

Disclosures
All authors: No reported disclosures.
516. Social Network Analysis to Study MDRO Transmission in VA Community Living Centers and Spinal Cord Injury Units
Authors: Bondar Svetlana , Ewers Tola , Vivo Amanda , Gutkowski Marissa , Evans Charlesnika T , Perencevich Eli N , Crnich Christopher 
Published: October 2019

Abstract

Background
Residents of VA Community Living Centers (CLC) and Spinal Cord Injury units (SCI) are commonly colonized or infected with multidrug-resistant organisms (MDROs). The mechanisms by which MDROs are spread between residents in CLC/SCI settings remain poorly understood. Our objective was to develop methods to better understand how MDROs are spread in VA CLCs/SCIs.

Methods
Preliminary data from two of the four VA medical centers participating in an ongoing study are included in these analyses. A structured sociometric survey was employed to collect data on interactions between residents, staff and environmental surfaces in study units. UCINET was used to construct a sociogram and calculate network characteristics (density, centrality) using responses to the surveys administered in one of the participating facilities.

Results
A total of 136 surveys were completed by 49 staff and 45 residents at the two VA sites. Staff reported more interactions with residents than with other staff. Residents reported more interactions with staff than with other residents, the latter tending to only occur during group activities. Sociograms generated from preliminary surveys collected at one site suggest a four-core-person social network pattern connecting two staff with two specific residents and showed that the dining room was the group setting most frequently visited by residents. Mobile computers, blood pressure cuffs/thermometers and glucometers were the equipment used most heavily during resident care activities (figure). Challenges in identifying contact patterns include recall bias and inability of some residents to identify names of individuals with whom they interacted. Residents were still able to reliably identify staff roles.

Conclusion
This preliminary work shows heterogeneous contact patterns between persons and surfaces in VA CLCs/SCIs. Characterizing this heterogeneity and its influence on MDRO spread via this type of social network analysis is feasible in the VA CLC/SCI setting, albeit with some limitations. Next steps in our studies include adding data from two additional sites and using observation techniques supplemented with microbiological sampling of targeted environmental surfaces to further understand potential transmission patterns.

Disclosures
All authors: No reported disclosures.
526. Significant Reduction of Hospital Onset Carbapenem-Resistant Enterobacteriaceae Utilizing Infection Prevention Strategies: It takes a Village!
Authors: Alexander Kinta , Brown Sean , Lorin Scott , Koll Brian , Mazo Dana , Ehni Jordan , Javaid Waleed 
Published: October 2019

Abstract

Background
Carbapenem-resistant Enterobacteriaceae (CRE) is a Gram-negative bacteria and is considered one of the major challenges in healthcare worldwide. CRE has a high mortality rate, and the majority produce carbapenemase enzymes, which can be easily spread to other bacteria and patients. An inner-city hospital had a substantial decrease in CRE associated infections/colonization after the implementation of a multi-disciplinary process championed by hospital leadership and Infection Prevention (IP).

Methods
A quasi-experimental study of patients with hospital-onset CRE-positive cultures over Thirty-eight months was conducted. The pre-intervention period was from January 2015 to July 2016 and the post intervention period was from August 2016 to February 2018. The intervention comprised of a CRE prevention and control (CPC) bundle. The bundle comprised of hand hygiene, strict contact precautions, appropriate surveillance cultures and the cleaning of a patient’s environment and equipment with bleach. Hospital leadership implemented the CPC bundle during daily huddles with IP and department leaders with real-time identification and resolution of any barriers. The diligence of cleaning and disinfection was monitored using a transparent, easily cleanable and environmentally stable solution that fluoresces when exposed to UV light. The solution was used to mark standardized high touch surfaces and shared equipment in CRE patient rooms prior to terminal cleaning. These surfaces were evaluated with a UV light and used as an opportunity to educate staff on common cleaning oversight.

Results
Prior to implementation of the CPC bundle, there were 24 cases of CRE with a baseline rate of 2.40. After introducing the CPC bundle, there were 8 cases of CRE with a rate of 0.83 (P = 0.006). The CPC bundle was associated with a reduction in CRE cases by 67%.

Conclusion
A hospital-wide approach between multiple departments is critical for the success of CRE prevention and control. This study provides further evidence that a multi-faceted approach to monitoring compliance with the CPC bundle can help reduce the transmission of CRE. This approach can decrease the burden on the healthcare system and improve patient outcomes.

Disclosures
All authors: No reported disclosures.
530. Sequential Screening of High-Risk Patients for Carbapenemase-Producing Enterobacteriaceae Colonization
Authors: Brodkin Elizabeth , Short Katy , Purych Dale 
Published: October 2019

Abstract

Background
Early identification of patients colonized with carbapenemase-producing Enterobacteriaceae (CPE) facilitates the implementation of appropriate infection control measures and reduces nosocomial transmission. Sequential screening for CPE colonization of close contacts of known cases to confirm initial negative results is recommended. Fraser Health (FH) expanded sequential screening to patients with recent exposure to other risk factors following the identification of CPE in patients who initially screened negative.

Methods
FH screens patients for CPE who report healthcare outside of Canada or travel to endemic countries within the previous 12 months. Patients remain on contact precautions and are re-screened 7 and 21 days after the last known exposure date. We reviewed CPE cases with foreign healthcare or travel to endemic countries who screened negative on admission but subsequently screened positive within 30 days. Patients without confirmation of colonization through a rectal screen or possible exposure to a current nosocomial source were excluded. Whole-genome sequencing results were examined to confirm foreign healthcare or travel as the likely source of acquisition. Medical records were reviewed to obtain patient history and clinical details.

Results
Between November 2015 and January 2019, 21 patients had a positive CPE screen within 30 days of a negative screen, with no known CPE exposures during that time. The median time between the last date of known exposure and positive CPE screen was 20 days (range: 7–77 days). Twelve (57%) cases were hospitalized outside of Canada, 8 (38%) reported other foreign healthcare encounters, and 1 (5%) had no reported healthcare outside of Canada but had traveled to an endemic country. Sixteen (71%) cases received antibiotics prior to the positive CPE screen.

Conclusion
Patients with unrecognized CPE colonization are a source for nosocomial transmission. Patients screening negative for CPE with recent exposure to risk factors other than contact with a known case may screen positive at a later date. This may be due to higher colonization levels or antibiotic selection pressures. Consideration should be given to sequential CPE screening of high-risk patients based on the last day of exposure.

Disclosures
All authors: No reported disclosures.
531. Practical and Evidence-Based Considerations for Implementation of Bacterial Whole-Genome Sequencing Within Longitudinal Infection Control Practice
Authors: Chen Donald S , Quinn Moira , Sussner Rita M , Wang Guiqing , Fallon John T , Chanza Melissa , Doty Alan J , Ashworth Judy L , Kelleher Steven W , Holler Devon J , Fortunato-habib Mary M , Loving Joshua , Abdolahi Amir , Carmona Juan J , Gross Brian D 
Published: October 2019

Abstract

Background
Whole-genome sequencing (WGS) of bacteria is becoming a routine tool within microbiology, yet its utility to help guide infection control (IC) practice longitudinally is underexplored. As with any technology adopted in the hospital, the integration of WGS into IC practice must be carefully managed and considered. We qualitatively report an evidence-based implementation workflow that considers WGS to help proactively guide IC professionals during investigation of infectious outbreaks.

Methods
We built upon lessons learned in an ongoing surveillance effort at a tertiary care hospital—utilizing retrospective WGS data within the Philips IntelliSpace Epidemiology system—to understand facilitators and barriers to the use of bacterial WGS longitudinally to inform IC workflow. Our team established a 9-month workgroup to study the practical aspects of implementing WGS in routine IC practice. From expert opinion collected via the workgroup, in addition to evidence from the literature, a workflow guidance document and checklist were codified. New ideas included incorporating education to promote the establishment of an IC triage process.

Results
Facilitators to implementation included ability to display genomic relatedness alongside relevant patient data to enable clinical actionability, ability to pivot time and resources rapidly when infections are a pseudo outbreak (false positive) or missed outbreak (false negative), opportunities for nuanced staff education, and willingness to be a first-of-kind adopter. Barriers were communication of genomic concepts to IC professionals and relevant institutional stakeholders, maintaining sharable notes of active investigations to promote data-sharing practices, and timing and review of relevant interventions into the facility workflow. Strategies to address these issues are considered.

Conclusion
This study provides a novel framework for adaptation of existing IC workflow strategies to leverage the utility of bacterial WGS, and it presents a schema to effectively engage relevant stakeholders, based on an analysis of the unique challenges inherent within IC practice. It also offers an innovative model for the development and implementation of IC workflows to account for, and adapt to, site-specific conditions.

Disclosures
All authors: No reported disclosures.