bluuebunny/crossref_metadata_2025_split huggingface dataset:
529. Halting Multi-Modal Transmission of a Novel Carbapenemase-Producing Enterobacteriaceae Outbreak
Authors: Sickbert-Bennett Emily , Schultz Kate , Teal Lisa , DiBiase Lauren , Weber David J 
Published: October 2019

Abstract

Background
In January 2018, the first case of anOXA-48 carbapenem-resistant Klebsiella pneumoniae (OXA-48 CRKP) was identified in a North Carolina hospital in a patient arriving from Eastern Europe. Over the next year across multiple inpatient adult units, 14 patients had clinical isolates and 2 patients had positive rectal surveillance screens for OXA-48 CRKP.

Methods
Investigation activities to characterize the OXA-48 CRKP epidemiology included: >1000 rectal colonization screens of epidemiologically linked patients, chart reviews of infected and colonized patients, hand hygiene and environmental cleaning observations on affected units, environmental sampling to include endoscopes, sinks and toilets, and molecular analyses (pulsed-field gel electrophoresis and whole-genome sequencing).

Results
Molecular analyses confirmed a clonal outbreak. All environmental cultures including endoscope cultures performed were negative for OXA-48 CRKP. All cases were explained by at least one of three mechanisms: (1) time/space overlap on same unit (presumed lack of hand hygiene or contamination of shared patient equipment), (2) patient housed in room where previously infected patient was housed (presumed inadequate terminal disinfection/contaminated environment), or (3) a single upper gastrointestinal endoscope. Interventions included surveillance to identify and isolate colonized patients, discharge room cleaning of OXA-48 CRKP patients enhanced by ultraviolet light disinfection, curtain laundering, and discarding unused patient supplies, and monitoring and feedback for compliance with hand hygiene, cleaning, and use of personal protective equipment. A single endoscope used between multiple OXA-48 CRKP patients with no other known transmission link was quarantined upon identification, sterilized with ethylene oxide, and ultimately placed out of service.

Conclusion
A clonal outbreak of a novel carbapenemase-producing Enterobacteriaceae likely spread via multiple modes of transmission. The investigation was complicated by infrequent identification of colonization among patients epidemiologically linked to known cases. Multiple interventions based on epidemiological links were necessary to halt hospital-wide transmission.

Disclosures
All authors: No reported disclosures.
560. Relating Whole-Genome Sequencing of Methicillin-Resistant Staphylococcus aureus Isolates to Transmission Dynamics and Efficacy of Control Interventions
Authors: Blumberg Seth , Porco Travis , Shopsin Bo , Phillips Michael 
Published: October 2019

Abstract

Background
Methicillin-resistant staphylococcus aureus (MRSA) colonization of hospitalized patients is associated with higher readmission rates and increased morbidity. Depending on the mechanisms of transmission, numerous potential control interventions exist to reduce the burden of disease. However, given the preponderance of asymptomatic colonization, it is challenging to quantify the relative importance of different transmission mechanisms and assess control efficacy. By identifying clusters of transmission, whole-genome sequencing (WGS) provides an opportunity to overcome these challenges.

Methods
We sought to apply cluster analysis techniques to WGS data for MRSA, in order to assess MRSA prevalence, transmissibility, the degree of transmission heterogeneity and the potential effectiveness of control. Our model builds upon previous work that showed a direct relationship between the size distribution of infection clusters, the effective reproduction number (R) and the dispersion parameter (k). To demonstrate its functionality, our model was applied to existing WGS data for MRSA isolates collected during a 12 month period in the East of England (DOI: 10.1126/scitranslmed.aak9745)

Results
The effective reproduction number for the East of England data is 0.29 (95% CI: 0.24–0.36). The dispersion parameter is 0.09 (0.03–0.33) reflecting a high degree of transmission heterogeneity. This implies all transmission is caused by just 12% of the cases. Targeted control of these cases could have decreased overall burden of MRSA colonization by 29% during the time period of the study.

Conclusion
The high degree of transmission heterogeneity seen in MRSA transmission suggests that the risk for infection is variable.This observation motivates the need for more detailed mechanistic modeling of hospital-based MRSA transmission that integrates patients-specific factors, movement data and genome sequencing. Such models could be used to forecast which patients are at greatest risk for either acquiring or transmitting MRSA, thereby improving targeted control.

Disclosures
All authors: No reported disclosures.
565. Implementation of a Staphylococcus aureus Screening and Decolonization Program in a Multisite Urban Healthcare System
Authors: King-Morrieson Tamara , Stachel Anna , Phillips Michael , Aguero-Rosenfeld Maria E , Inglima Kenneth , Hochman Sarah 
Published: October 2019

Abstract

Background
Staphylococcus aureus infection confers high mortality. S. aureus-colonized hospitalized patients are more likely to develop invasive infection and can transmit S. aureus to other patients in the absence of symptoms. Our health system has a baseline S. aureus colonization rate of 21% (MSSA and MRSA combined). To reduce risk of invasive S. aureus infection in our patients, we implemented an inpatient S. aureus screening and decolonization program.

Methods
Interventions include universal S. aureus screening and targeted decolonization for all patients on the Medicine and Pediatrics inpatient services. Adult patients are screened at admission and change in the level of care; pediatric patients are screened weekly. S. aureus screening began incrementally by unit between 2016 and 2017, and extended to transplant units in 2018. All cultures are processed in the hospital microbiology lab for identification of MRSA and MSSA. S. aureus decolonization (mupirocin ointment in nares twice daily, chlorhexidine 2% wipes below the chin daily for 5 days) began in 2017 for patients with a central venous catheter, in intensive care unit or multibedded room. Decolonization was extended to all S. aureus-colonized patients beginning in June 2018, with involvement of a dedicated clinical nurse specialist. We compared compliance with screening and decolonization and the secondary outcome of MRSA bacteremia in the 6 month period before and after the addition of the clinical nurse specialist.

Results
21.5% of screened patients were colonized with S. aureus (82.4% MSSA, 17.6% MRSA). Screening compliance improved from 39.4% of eligible patients (N = 1805) to 52.1% (N = 2024) and decolonization increased from 18.6% of colonized patients to 41.2% comparing January-June 2018 with July-December 2018. The MRSA bacteremia rate fell from 0.2/1,000 patient-days in the first half of 2018 to 0.1/1,000 patient-days in the second half of 2018.

Conclusion
A system-wide program that includes S. aureus screening and decolonization of hospitalized patients found that 21% of patients had S. aureus colonization. Screening and decolonization compliance increased with the introduction of a dedicated clinical nurse specialist, and the MRSA bloodstream infection rate fell.

Disclosures
All authors: No reported disclosures.
570. Impact of Discontinuation of Methicillin-Resistant Staphylococcus aureus Contact Precautions on Bloodstream Infection Rates at an Academic Medical Center
Authors: Navalkele Bhagyashri D , Fletcher Sheila , Truhett Nora , Hester Xiaoming , Martin Sanjosa , Smith Elizabeth , Galloway Regina , Stempak Lisa , Allard Cynthia , Hayes Willis , Parham Jason 
Published: October 2019

Abstract

Background
Contact precautions (CP) in methicillin-resistant Staphylococcus aureus (MRSA) patients along with hand hygiene has been considered a gold standard to prevent transmission. The actual impact of these measures in reducing MRSA infections is still controversial. At our institution, we evaluated the impact of discontinuation of MRSA CP on hospital-onset (HO) and community-onset (CO) MRSA bloodstream (BSI) rates. We also analyzed consequential cost savings.

Methods
The University of Mississippi Medical Center is a 700+ bed academic facility located in Jackson, MS. Patients admitted to any inpatient units with diagnoses or history of MRSA infection or colonization were subjected to CP during their stay. In July 2018, we discontinued MRSA CP across all inpatient units (except neonatal intensive care unit). HO MRSA BSI rate was calculated per National Healthcare Safety Network (NHSN) laboratory-identified event. CO MRSA BSI was reported per NHSN admission prevalence rate. One-way Analysis of Variance (ANOVA) was performed to compare pre-and post-intervention data.

Results
There was a rise in HO MRSA BSI rate after discontinuation of CP (July 2018-March 2019) in comparison to the 9-month pre-intervention period (October 2017-June 2018); however, the difference was not statistically significant (1.79/10,000 patient-days vs. 1.2/10,000 patient-days; P = 0.056). Similarly, CO MRSA BSI prevalence rate did not show a statistically significant difference between pre- and post-intervention period (0.103 vs. 0.08; P = 0.584).The total annualized cost savings on personal protective equipment (PPE) was an estimated $193,398 post-intervention. Hand hygiene (HH) compliance was higher in post-intervention compared with pre-intervention period (83% vs. 78%, P = 0.0007).

Conclusion
At our institute, discontinuation of MRSA CP was associated with an insignificant rise in HO MRSA BSI rates. No impact was observed on CO MRSA BSI prevalence. We had a 34% reduction in PPE expenditure. We observed an increase in HH compliance post-discontinuation of CP, but it did not reduce MRSA BSI rates. Further studies are needed to evaluate the impact of bundling hand hygiene practices with other horizontal strategies (prevention bundles, chlorhexidine bathing, environmental disinfection practices) in prevention of MRSA infections.

Disclosures
All authors: No reported disclosures.
572. Relationship Between Chlorhexidine Gluconate (CHG) Skin Concentrations and Microbial Skin Colonization among Medical Intensive Care Unit (MICU) Patients
Authors: Rhee Yoona , Hayden Mary K , Simms Andrew T , Yelin Rachel D , Lolans Karen , Bell Pamela B , Schoeny Michael , Baker Arthur W , Baker Meghan A , Gohil Shruti K , Rhee Chanu , Talati Naasha J , Warren David K , Welbel Sharon F , Dangana Thelma E , Majalca Thelma , Bravo Heilen , Cass Candice , Nelson Alicia , Tolomeo Pam C , Wolf Robert , Lin Michael Y 
Published: October 2019

Abstract

Background
CHG bathing is used to suppress patients’ microbial skin colonization, in order to prevent infections and transmission of multidrug-resistant organisms. Prior work has suggested that microbial growth is inhibited when CHG skin concentrations exceed threshold levels.

Methods
We conducted 6 single-day surveys from January 2018 to February 2019 in 7 academic hospital MICUs with established CHG patient bathing. Adult patients were eligible to have skin swabbed from adjacent 25 cm2 areas on the neck, axilla, and inguinal region for culture and CHG concentration determination. CHG skin concentrations were measured by a semi-quantitative colorimetric assay. Selective media were used to isolate targeted microorganisms (Table 1). Species were confirmed by matrix-assisted laser desorption ionization time-of-flight mass spectrometry; antibiotic susceptibility was determined by MicroScan (Beckman Coulter). We modeled the relationship between CHG skin concentrations (log2-transformed) and microorganism recovery (yes/no as primary outcome) using multilevel models controlling for clustering of body sites within patients and within ICUs, assessing slope and threshold effects.

Results
We enrolled 736/759 (97%) patients and sampled 2176 skin sites. Gram-positive bacteria were detected most frequently (Table 1). The adjusted odds of identifying gram-positive organisms decreased linearly as CHG skin levels increased (Figure 1a), without evidence of a threshold effect. We also found significant negative linear slopes without evidence of threshold effects for other pathogens tested (Table 2; Figure 1), with the exception of gram-negative bacteria and vancomycin-resistant enterococci. When modeling quantitative culture results (colony-forming units) for gram-positive organisms as a continuous outcome variable, a similar relationship was found.

Conclusion
Higher concentrations of CHG were associated with less frequent recovery of gram-positive bacteria and Candida species on the skin of MICU patients who were bathed routinely with CHG. For microbial inhibition, we did not identify a threshold concentration of CHG on the skin; rather, increasing CHG skin concentrations led to additional gains in inhibition. For infection prevention, aiming for high CHG skin levels may be beneficial.

Disclosures
All authors: No reported disclosures.
573. Enterococcal Bacteremia in a Tertiary Care Center in Mexico: A Retrospective Analysis Focus on Vancomycin-Resistant E. faecium and Ampicillin-Resistant E. faecalis
Authors: Lopez Luis Bruno A , Lambraño-Castillo Darwin , Ortiz-Brizuela Edgar , Ramirez-Fontes Andrea , Estrella Tovar-Calderon Yanet , Javier Leal-Vega Francisco , Bobadilla-Del-Valle Miriam , SIFUENTES-OSORNIO JOSE , Ponce de Leon Alfredo 
Published: October 2019

Abstract

Background
The primary pathogens in genera enterococcus are E. faecalis and E. faecium, increasing acquired resistance to glycopeptides and β lactamic has done the management more challenging. We aimed to describe the risk factors for acquisition of bacteremia for vancomycin-resistant E. faecium (VRE) and ampicillin-resistant E. faecalis (ARE) and the 30-day mortality in comparison to susceptible enterococcal bloodstream infection (BSI)

Methods
From 2007- 2017 medical records of all BSI for E. faecalis and E. faecium were evaluated. Risk factor for acquisition of VRE and ARE as well as the significant variables associated with 30-day mortality for enterococcal BSI were determined by univariate and multivariate analysis. The molecular mechanism of VRE was performed by PCR

Results
There were 192 patients with E. faecium BSI of which 107(56%) patients had VRE BSI with 94% VRE strains expressing vanA gene. The index bacteremic episodes were classified as nosocomial o healthcare associated in 99%, 102(95%) had hospitalization 1 year before and 101(94%) history of use of antibiotics 3 months earlier, the multivariate analysis showed duration of the previous hospitalization >10 days (OR, 80.18; 95% CI, 1.81–634), use of central venous catheter [OR, 11.15; 95% CI, 2.48–50.2), and endotracheal cannula [OR, 17.91; 95% CI, 1.22–262) as significant associated variables. The mortality for VRE was greater than susceptible E. faecium (60% vs. 24%, P < 0.001). The only factors for 30-day mortality for E. faecium BSI in the multivariate analysis was APACHE ll score [OR,1.45; 95% CI, 1.26–1.66) and patients with chemotherapy of cancer. (OR, 3.52; 95% CI, 1.09–11.39). 147 patients had E. faecalis BSI of which 18 (11%) patients had ARE, we did not find relevant clinical differences of ARE in comparison with ampicillin-susceptible E. faecalis, neither in risk factors for acquisition of ARE nor 30-day mortality [7(39%) vs. 38(29%), P = 0.58] in uni and multivariate analysis

Conclusion
Our evaluation showed in a period of 10 years that VRE expressing vanA gene had a strong association with patients with previous nosocomial exposure. Severely ill patients and cancer patients on chemotherapy during the bacteremic episode were the variables more associated with 30-day mortality. ARE is yet of low prevalence and less known, constant surveillance about it is warranted

Disclosures
All authors: No reported disclosures.
576. A Multicenter Epidemiology Study on Risk Factors of Vancomycin-Resistant Enterococcus Infections in China: Results from the China Antimicrobial Surveillance Network (CHINET) in 2016
Authors: Lin Dongfang , Guo Yan , Yang Yang , Zhu Demei , Hu Fupin 
Published: October 2019

Abstract

Background
Bacterial resistance in China had been increasing in prevalence. Vancomycin-resistant enterococcus (VRE) different from other bacteria had lower isolated rate and apparent regional variations. In this study, we identified the characteristics of VRE infections in Chinese patients based on the China Antimicrobial Surveillance Network (CHINET) in 2016.

Methods
This case–control study was conducted in 97 VRE patients and 95 Vancomycin-susceptible Enterococcus (VSE) patients from 20 medical centers. Demographics, disease characteristics, therapeutic measure, as well as laboratory data were obtained from medical records for analysis. Descriptive statistics, simple and multivariate logistic regression were performed to explore the risk factors of VRE infection.

Results
The mean age of patients in the case and control groups was 75.0 years and 65.0 years, respectively. In the case group, 52 patients developed urinary tract infections, accounting for 53.6%, followed by bloodstream infections (19.6%) and abdominal infections (5.2%). And the cases of Enterococcus faecium, Enterococcus faecalis and other enterococci infections were 70 (72.2%), 7 (7.2%), and 20 (20.6%), respectively. Moreover, the proportion of vancomycin usage before infection was 20.6%. The result of resistance analysis showed VRE patients’ other dug resistance rate was higher than VSE ones. Compared with VSE patients, VRE patients had received more urinary intubation, indwelling venous catheter, and dialysis. Additionally, the proportions of combination with stroke (8.3% vs. 2.1%), multiple organ failure (8.3% vs. 3.2%), and other infection (59.8% vs. 40.0%) were higher in the case group. What’s more, 44 (45.4%) VRE patients had been treated in intensive care unit, while 21 (22.1%) cases in the control group. Multivariate logistic regression showed that receiving indwelling venous catheter was independent risk factor for VRE infection (OR=3.342, 95% CI: 1.379~8.099). For prognosis, VRE patients had a lower effective rate (67.4% vs. 83.7%), higher hospital expense (￥94991 vs. ￥38248), and longer hospital stay (26.0 days vs. 21.0 days).

Conclusion
Indwelling venous catheter may increase the VRE infection risk and Linezolid or Fosfomycin could still be used for infection treatment in VRE patients.

Disclosures
All authors: No reported disclosures.
587. Risk Factors for Nosocomial Methicillin-Resistant Staphylococcus aureus (MRSA) Colonization in a Neonatal Intensive Care Unit (NICU): A Case–Control Study
Authors: Balamohan Archana , Beachy Joanna , Kohn Nina , Rubin Lorry G 
Published: October 2019

Abstract

Background
Staphylococcus aureus (SA) is a leading cause of nosocomial infection in NICUs. Colonization is a prerequisite for most SA infections. Previously recognized risk factors for colonization include the length of stay (LOS), multiple gestation, low birth weight, Caesarean delivery and multibed location. The objective of this study was to determine risk factors for MRSA colonization in a Level IV NICU independent of LOS and gestational age (GA) in the context of a circulating MRSA clone.

Methods
Weekly MRSA colonization cultures were performed from April 2017 through March 2018. Case–control study. Cases: Infants with newly acquired MRSA colonization and at least one previous negative culture. Controls: Infants with negative surveillance cultures, matched 1:1 with cases by GA and LOS. Factors compared: (a) neonatal demographics; (b) maternal factors; (c) neonatal factors since admission including antimicrobial therapy; (d) neonatal factors during the week prior to MRSA acquisition, including bed location, number of location changes, presence of central line, respiratory support, NICU census, ATP surface bioburden testing pass rate, MRSA colonization pressure.

Results
50 case infants were matched with controls. Forty-five of the 50 isolates were mupirocin-resistant and related by pulse-field gel electrophoresis On matched univariable analysis, the following were significantly associated with a risk for MRSA acquisition: (1) Bed location in the acute area (P = 0.03), (2) The requirement of any level of respiratory support during the week prior to MRSA detection (P = 0.04), (3) Higher ATP pass rate during the week of and week prior (P = 0.01), (4) Higher MRSA colonization pressure during the prior week (P = 0.002), (5) Not having a hearing test during the time between the previous negative culture and MRSA acquisition (P = 0.01). A multivariable conditional logistic regression model (that excluded ATP pass rate) found that only colonization pressure was associated with acquisition of MRSA colonization.

Conclusion
Independent of LOS and GA, MRSA colonization pressure, ATP pass rate and higher patient acuity, reflected by location within the acute area and requiring respiratory support, are significantly associated with MRSA acquisition in the NICU; only colonization pressure remained associated in a multivariable model.

Disclosures
All authors: No reported disclosures.
592. Assessment of Time Spent in the Room by Nurses and Nursing Assistants on a Pediatric Ward by Patient Isolation Status and Demographics
Authors: Simonsen Kari , High Robin , Fortini Mary , Hegemann Lindsay , Beedle Susan , Phipps Amber 
Published: October 2019

Abstract

Background
Published reports have raised concern that RNs spend less time in hospital rooms of patients requiring isolation precautions. Other patient-related factors including race/ethnicity, primary language, and socio-economic factors reportedly influence the mean time spent in the room by RNs and certified nursing assistants (CNAs). At a children’s hospital the automated hand hygiene monitoring system (AHHMS) has motion sensors that detect patient room entry and exit and sensors that detect hand hygiene events. Time spent in patient rooms by RNs and CNAs was examined using AHHMS data captured for patients on a 24-bed pediatric hospital ward for multiple patient characteristics to evaluate factors influencing the duration of visits.

Methods
RNs and CNAs routinely wore badges with infrared signal technology to monitor hand hygiene compliance, generating time-stamped data for room entries and exits, identified by user job category. Over a 30 day period, April 2016, RN and CNA time in the room was compared by patient characteristics including: length of stay, white yes/no, Hispanic yes/no, interpreter needed yes/no, and isolation status of contact-droplet, contact, or none. Mean minutes spent in the room for RNs and CNAs were evaluated with a random-effects linear model and gamma distribution.

Results
Admissions for 220 patients occurred in the 24 rooms during the evaluation period; 88 RNs and 28 CNAs completed 18,641 time-stamped room entries and exits. The natural log of patient length of stay (hours) was significantly associated with increased RN and CNA minutes spent in the room (P < 0.001). Interpreter required was not associated with time in the room (P = 0.72), nor was race (P = 0.60), nor was Hispanic ethnicity (P = 0.81). There were no significant differences in time spent in the room for contact, contact-droplet, and no isolation (P = 0.92).

Conclusion
Data derived from infrared signal AHHMS badges can provide insight into RN and CNA care patterns. Isolation status and patient demographics were unrelated to mean RN and CNA time in the room. Patient length of stay was the only predictor of increased nursing time spent providing direct patient care. These results contrast with previous reports demonstrating fewer nursing interactions based on patient demographics or isolation.

Disclosures
All authors: No reported disclosures.