ACORN (A Clinically-Oriented Antimicrobial Resistance Surveillance Network) II: protocol for case based antimicrobial resistance surveillance

Background: Antimicrobial resistance surveillance is essential for empiric antibiotic prescribing, infection prevention and control policies and to drive novel antibiotic discovery. However, most existing surveillance systems are isolate-based without supporting patient-based clinical data, and not widely implemented especially in low- and middle-income countries (LMICs). Methods: A Clinically-Oriented Antimicrobial Resistance Surveillance Network (ACORN) II is a large-scale multicentre protocol which builds on the WHO Global Antimicrobial Resistance and Use Surveillance System to estimate syndromic and pathogen outcomes along with associated health economic costs. ACORN-healthcare associated infection (ACORN-HAI) is an extension study which focuses on healthcare-associated bloodstream infections and ventilator-associated pneumonia. Our main aim is to implement an efficient clinically-oriented antimicrobial resistance surveillance system, which can be incorporated as part of routine workflow in hospitals in LMICs. These surveillance systems include hospitalised patients of any age with clinically compatible acute community-acquired or healthcare-associated bacterial infection syndromes, and who were prescribed parenteral antibiotics. Diagnostic stewardship activities will be implemented to optimise microbiology culture specimen collection practices. Basic patient characteristics, clinician diagnosis, empiric treatment, infection severity and risk factors for HAI are recorded on enrolment and during 28-day follow-up. An R Shiny application can be used offline and online for merging clinical and microbiology data, and generating collated reports to inform local antibiotic stewardship and infection control policies. Discussion: ACORN II is a comprehensive antimicrobial resistance surveillance activity which advocates pragmatic implementation and prioritises improving local diagnostic and antibiotic prescribing practices through patient-centred data collection. These data can be rapidly communicated to local physicians and infection prevention and control teams. Relative ease of data collection promotes sustainability and maximises participation and scalability. With ACORN-HAI as an example, ACORN II has the capacity to accommodate extensions to investigate further specific questions of interest

The Role of Negative Methicillin-Resistant Staphylococcus aureus Nasal Surveillance Swabs in Predicting the Need for Empiric Vancomycin Therapy

Abstract Background The role of MRSA nasal surveillance swabs in guiding decisions about need for subsequent vancomycin therapy is unclear. Our objectives were to (1) determine the likelihood that patients with negative MRSA nasal swabs went on to develop MRSA infections during the same hospitalizations to assess if vancomycin therapy could be avoided once the nasal swab result returns negative, (2) assess days of vancomycin that potentially could be avoided, and (3) identify risk factors for having a negative MRSA nasal swab and developing an MRSA infection during the hospital stay. Methods This retrospective cohort study was conducted at six intensive care units (ICUs) at a tertiary care hospital in Baltimore from December 2013 to June 2015. MRSA nasal swabs are obtained at the time of admission and weekly thereafter for all ICU patients. The negative predictive value (NPV), defined as the ability of a negative MRSA nasal screening test to correctly predict no subsequent MRSA infection during the hospital stay, was calculated, accounting for the 3-day turnaround time of MRSA nasal surveillance swabs. Days of vancomycin therapy started or continued after 3 days from the first negative MRSA nasal swab were determined by chart review. A matched case–control study was performed to identify risk factors for patients with negative MRSA surveillance cultures who subsequently developed MRSA infections. Results Of 11,441 MRSA-nasal swab negative patients, the proportion of subsequent incident MRSA infections was 0.2%. Negative MRSA surveillance swabs had an NPV of 99.4% (95% CI 99.1–99.6%). Among 4,091 MRSA-negative patients receiving vancomycin, vancomycin was started or continued after 3 days since the first MRSA-negative nasal swab in 1,434 patients (35%), translating to 7,377 potentially avoidable vancomycin days. The matched case–control analysis did not identify risk factors associated with subsequent MRSA infection. Conclusion At our institution with robust infection control practices and low nosocomial MRSA transmission rates, patients with negative MRSA nasal swabs have a very low likelihood of subsequent MRSA infection during hospitalizations. MRSA nasal swabs can provide useful information when determining whether to initiate or stop empiric vancomycin. Disclosures All authors: No reported disclosures. </jats:sec

Epidemiology of carbapenem-resistant Enterobacteriaceae: a 5-year experience at a tertiary care hospital

Darunee Chotiprasitsakul,1 Sirawat Srichatrapimuk,2 Suppachok Kirdlarp,1 Alexander D Pyden,3 Pitak Santanirand4 1Division of Infectious Diseases, Department of Medicine, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand; 2Chakri Naruebodindra Medical Institute, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Samutprakan, Thailand; 3Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA; 4Clinical Microbiology Laboratory, Department of Pathology, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand Purpose: The incidence of carbapenem-resistant Enterobacteriaceae (CRE) has been increasing worldwide. Ertapenem resistance is mediated by non-carbapenemase mechanisms, and has less of an effect on susceptibility to imipenem and meropenem. This study aimed to study the epidemiology of CRE, and to compare risk factors and related mortality between non-susceptibility to ertapenem alone Enterobacteriaceae (NSEE), with non-susceptibility to other carbapenems (imipenem, meropenem, or doripenem) Enterobacteriaceae (NSOCE) at a tertiary care hospital in Thailand. Methods: All CRE isolated were identified between December 2011 and December 2016. Quarterly incidence rate was estimated. Hospital-wide carbapenem consumption was calculated as defined daily doses (DDD). Relationships between hospital-wide carbapenem consumption and incidence of CRE were tested. Factors associated with NSEE and NSOCE, and risk factors associated with 14- and 30-day mortality in patients with CRE infection were determined. Results: The quarterly CRE incidence increased significantly from 3.37 per 100,000 patient-days in the last quarter of 2011 to 32.49 per 100,000 patient-days in the last quarter of 2016. (P&nbsp;for trend &lt;0.001). Quarterly hospital-wide carbapenem consumption increased 1.58 DDD per 1,000 patient-days (P for trend=0.004). The Poisson regression showed the expected increase of CRE incidence was 1.02 per 100,000 patient-days for a 1 DDD per 1,000 patient-days increase in carbapenem consumption (P&lt;0.001). There were 40 patients with NSEE and 134 patients with NSOCE in the 5-year study period. The NSEE group had significantly lower carbapenem exposure compared with the NSOCE group (adjusted odds ratio: 0.25; P=0.001). No difference in 14-day and 30-day all-cause mortality between the two groups was observed. Conclusion: The incidence of CRE has risen significantly at our institution. Previous carbapenem use was associated with NSOCE. This hospital-wide carbapenem use was significantly associated with the increasing incidence of CRE. Keywords: CRE, risk factors, incidence, carbapenems, antimicrobial stewardshi