Community-acquired Staphylococcus aureus skin and soft tissue infection risk assessment using hotspot analysis and risk maps: the case of California emergency departments.

BACKGROUND: Community-acquired Staphylococcus aureus (CA-Sa) skin and soft tissue infections (SSTIs) are historically associated with densely populated urban areas experiencing high poverty rates, intravenous drug use, and homelessness. However, the epidemiology of CA-Sa SSTIs in the United States has been poorly understood since the plateau of the Community-acquired Methicillin-resistant Staphylococcus aureus epidemic in 2010. This study examines the spatial variation of CA-Sa SSTIs in a large, geographically heterogeneous population and identifies neighborhood characteristics associated with increased infection risk. METHODS: Using a unique neighborhood boundary, California Medical Service Study Areas, a hotspot analysis, and estimates of neighborhood infection risk ratios were conducted for all CA-Sa SSTIs presented in non-Federal California emergency departments between 2016 and 2019. A Bayesian Poisson regression model evaluated the association between neighborhood-level infection risk and population structure, neighborhood poverty rates, and being a healthcare shortage area. RESULTS: Emergency departments in more rural and mountainous parts of California experienced a higher burden of CA-Sa SSTIs between 2016 and 2019. Neighborhoods with high infection rates were more likely to have a high percentage of adults living below the federal poverty level and be a designated healthcare shortage area. Measures of population structure were not associated with infection risk in California neighborhoods. CONCLUSIONS: Our results highlight a potential change in the epidemiology of CA-Sa SSTIs in California emergency departments. Future studies should investigate the CA-Sa burden in other geographies to identify whether this shift in epidemiology holds across other states and populations. Further, a more thorough evaluation of potential mechanisms for the clustering of infections seen across California neighborhoods is needed.

Combined Hepatitis B Virus and Hepatocellular Carcinoma Screening Using Point-of-Care Testing and Ultrasound in a Tanzanian Emergency Department.

The WHO aims to detect 90% of global cases of hepatitis B virus (HBV) by 2030. Sub-Saharan Africa carries a disproportionate burden of HBV and hepatocellular carcinoma (HCC). In this study, we sought to assess the utility of a combined HBV and HCC screening program in Tanzania. We conducted a prospective, serial cross-sectional study of patients who participated in a combined HBV and HCC screening program at a regional referral hospital emergency department (ED) in Arusha, Tanzania, between April 19, 2022 and June 3, 2022. All patients completed a study questionnaire and were tested for HBV surface antigen. Patients who were HBV positive were screened for HCC via point-of-care ultrasound (POCUS). The primary outcome was the number of new HBV diagnoses. Data were analyzed with descriptive statistics. A total of 846 patients were tested for HBV (primary ED: 761, clinic referral: 85). The median age of patients was 44 ± 15 years, and 66% were female. Only 15% of patients reported having a primary care doctor. Thirteen percent of patients had been previously vaccinated for HBV. There were 17 new HBV diagnoses (primary ED: 16, clinic referral: 1), which corresponds to a seroprevalence of 2.0% (95% CI: 1.2%, 3.2%). No patients had liver masses detected on POCUS. An ED-based, combined HBV and HCC screening protocol can be feasibly implemented. This study could serve as a model for HBV/HCC screening in regions with high HBV endemicity and low rates of community screening.

A study to assess the impact of the cobas point-of-care RT-PCR assay (SARS-CoV-2 and Influenza A/B) on patient clinical management in the emergency department of the University of California at Davis Medical Center.

BACKGROUND: Rapid detection of SARS-CoV-2 is crucial for reduction of transmission and clinical decision-making. Several rapid (<30 min) molecular point-of-care (POC) tests based on nucleic acid amplification exist for diagnosis of SARS-CoV-2 & Influenza A/B infections. METHODS: This unblinded, pre-post study enrolled consecutive patients with symptoms/signs consistent with SARS-CoV-2 infection presenting to the University of California, Davis emergency department (ED). Outcomes following implementation of the cobas® SARS-CoV-2 & Influenza A/B test for use on the cobas Liat System (intervention: December 2020-May 2021) were compared with previous standard-of-care using centralized laboratory reverse transcriptase polymerase chain reaction (RT-PCR) methods (control: April 2020-October 2020). RESULTS: Electronic health records of 8879 symptomatic patient visits were analyzed, comprising 4339 and 4540 visits and 538 and 638 positive SARS-CoV-2 PCR test results in the control and intervention periods, respectively. Compared with the control period, turnaround time (TAT) was shorter in the intervention period (median 0.98 vs 12.30 h; p < 0.0001). ED length of stay (LOS) was generally longer in the intervention period compared with the control period, but for those SARS-CoV-2-negative who were admitted, ED LOS was shorter (median 12.53 vs 17.93 h; p < 0.0001). The rate of antibiotic prescribing was lower in the intervention than in the control period (42.86% vs 49.16%; p < 0.0001) and antiviral prescribing was higher (7.64% vs 5.49%; p < 0.0001). CONCLUSION: This real-world study confirms faster TAT with a POC RT-PCR method in an emergency care setting and highlights the importance of rapid SARS-CoV-2 detection to aid patient management and inform treatment decisions.

A Bayesian multilevel analysis exploring population-level effects mediating the relationship between area-level poverty and community-acquired Methicillin-resistant Staphylococcus aureus (CA-MRSA) infection across California communities.

Poverty is an often-cited driver of health disparities, and associations between poverty and community-acquired Methicillin-resistant Staphylococcus aureus (CA-MRSA) infection are well documented. However, the pathways through which poverty influences infection have not been thoroughly examined. This project aims to identify mediating variables, or mechanisms, explaining why area-level poverty is associated with CA-MRSA infection in Californians. Bayesian multilevel models accounting for spatial confounding were developed to test whether the association between area-level poverty and CA-MRSA infection is mediated by living in a primary care shortage area (HCSA), living near an adult correctional facility, and residential environmental degradation. The association between area-level poverty and CA-MRSA infection can be partially explained by spatial autocorrelation, living in an HCSA, and environmental degradation in the neighborhood. Combined, the mediators explain approximately 6% of the odds of CA-MRSA infection for individuals living in neighborhoods with high poverty rates and 50% of the statistical association between area-level poverty and CA-MRSA infection. The statistical association between area-level poverty and infection was completely explained by the mediators for individuals living in neighborhoods with low poverty rates.

Rapid identification of sepsis in the emergency department.

Objectives: Recent research has helped define the complex pathways in sepsis, affording new opportunities for advancing diagnostics tests. Given significant advances in the field, a group of academic investigators from emergency medicine, intensive care, pathology, and pharmacology assembled to develop consensus around key gaps and potential future use for emerging rapid host response diagnostics assays in the emergency department (ED) setting. Methods: A modified Delphi study was conducted that included 26 panelists (expert consensus panel) from multiple specialties. A smaller steering committee first defined a list of Delphi statements related to the need for and future potential use of a hypothetical sepsis diagnostic test in the ED. Likert scoring was used to assess panelists agreement or disagreement with statements. Two successive rounds of surveys were conducted and consensus for statements was operationally defined as achieving agreement or disagreement of 75% or greater. Results: Significant gaps were identified related to current tools for assessing risk of sepsis in the ED. Strong consensus indicated the need for a test providing an indication of the severity of dysregulated host immune response, which would be helpful even if it did not identify the specific pathogen. Although there was a relatively high degree of uncertainty regarding which patients would most benefit from the test, the panel agreed that an ideal host response sepsis test should aim to be integrated into ED triage and thus should produce results in less than 30 minutes. The panel also agreed that such a test would be most valuable for improving sepsis outcomes and reducing rates of unnecessary antibiotic use. Conclusion: The expert consensus panel expressed strong consensus regarding gaps in sepsis diagnostics in the ED and the potential for new rapid host response tests to help fill these gaps. These finding provide a baseline framework for assessing key attributes of evolving host response diagnostic tests for sepsis in the ED.

Use of clinical decision support for antibiotic stewardship in the emergency department and outpatient clinics: An interrupted time-series analysis.

Objective: To evaluate the impact of implementing clinical decision support (CDS) tools for outpatient antibiotic prescribing in the emergency department (ED) and clinic settings. Design: We performed a before-and-after, quasi-experimental study that employed an interrupted time-series analysis. Setting: The study institution was a quaternary, academic referral center in Northern California. Participants: We included prescriptions for patients in the ED and 21 primary-care clinics within the same health system. Intervention: We implemented a CDS tool for azithromycin on March 1, 2020, and a CDS tool for fluoroquinolones (FQs; ie, ciprofloxacin, levofloxacin, and moxifloxacin) on November 1, 2020. The CDS added friction to inappropriate ordering workflows while adding health information technology (HIT) features to easily perform recommended actions. The primary outcome was the number of monthly prescriptions for each antibiotic type, by implementation period (before vs after). Results: Immediately after azithromycin-CDS implementation, monthly rates of azithromycin prescribing decreased significantly in both the ED (-24%; 95% CI, -37% to -10%; P < .001) and outpatient clinics (-47%; 95% CI, -56% to -37%; P < .001). In the first month after FQ-CDS implementation in the clinics, there was no significant drop in ciprofloxacin prescriptions; however, there was a significant decrease in ciprofloxacin prescriptions over time (-5% per month; 95% CI, -6% to -3%; P < .001), suggesting a delayed effect of the CDS. Conclusion: Implementing CDS tools was associated with an immediate decrease in azithromycin prescriptions, in both the ED and clinics. CDS may serve as a valuable adjunct to existing antimicrobial stewardship programs.

Risk factors for HIV infection at a large urban emergency department: a cross-sectional study.

OBJECTIVES: In 2019, the US Preventative Services Task Force released updated guidelines recommending HIV screening in all individuals aged 15-64 years and all pregnant females. In the current study, we aimed to identify risk factors for HIV infection in an emergency department (ED) population. METHODS: We performed a cross-sectional study that employed a post hoc risk factor analysis of ED patients ≥18 years who were screened for HIV between 27 November 2018 and 26 November 2019, at a single urban, quaternary referral academic hospital. Patients were screened using HIV antigen/antibody testing and diagnoses were confirmed using HIV-1/HIV-2 antibody testing. The outcome of interest was the number of positive HIV tests. Multiple logistic regression models were used to identify risk factors associated with HIV positivity. RESULTS: 14 335 adult patients were screened for HIV (mean age: 43±14 years; 52% female). HIV seroprevalence was 0.7%. Independent risk factors for HIV positivity included male sex (adjusted OR (aOR) 3.1 (95% CI 1.7 to 5.6)), unhoused status (aOR 2.9 (95% CI 1.7 to 4.9)), history of illicit drug use (aOR 1.8 (95% CI 1.04 to 3.13)) and Medicare insurance status (aOR 2.2 (95% CI 1.1 to 4.4)). CONCLUSIONS: The study ED services a high-risk population with regard to HIV infection. These data support universal screening of ED patients for HIV. Risk factor profiles could improve targeted screening at institutions without universal HIV testing protocols.

Evaluation of pharmacist guided intervention using procalcitonin and respiratory virus testing.

INTRODUCTION: Acute respiratory infections make up a sizable percentage of emergency department (ED) visits and many result in antibiotics being prescribed. Procalcitonin (PCT) has been found to reduce antibiotic use in both outpatient and critical care settings, yet remains underused in the ED. This study aimed to evaluate whether point of care molecular influenza and Respiratory Syncytial Virus (RSV) testing, PCT, and a pharmacist driven educational intervention in aggregate optimizes antibiotic and antiviral prescribing in the ED setting. METHODS: A randomized trial of the Cobas Liat Flu/RSV Assay, procalcitonin, and the use of pharmacist-led education in patients 0-50 years of age being seen in the ED for Influenza Like Illness (ILI) or acute respiratory illness. The study enrolled 200 ED patients between March 2018 and April 2022. RESULTS: There was little difference in antibiotic or antiviral prescribing between the intervention and control groups in this study (39%-32% = 7.0%, 95% CI: -6.2, 20.2, P = 0.30). However, a post-hoc analysis of the use of procalcitonin showed results were used as indicated in the ED (P = 0.001). CONCLUSION: PCT can be used in both adult and pediatric populations to help guide the decision of whether to treat with antibiotics in the ED setting. Pharmacist guided education may not be a driving factor.

Evaluation of an Antimicrobial Stewardship Decision Support for Pediatric Infections.

OBJECTIVES: Clinical decision support (CDS) has promise for the implementation of antimicrobial stewardship programs (ASPs) in the emergency department (ED). We sought to assess the usability of a newly developed automated CDS to improve guideline-adherent antibiotic prescribing for pediatric community-acquired pneumonia (CAP) and urinary tract infection (UTI). METHODS: We conducted comparative usability testing between an automated, prototype CDS-enhanced discharge order set and standard order set, for pediatric CAP and UTI antibiotic prescribing. After an extensive user-centered design process, the prototype CDS was integrated into the electronic health record, used passive activation, and embedded locally adapted prescribing guidelines. Participants were randomized to interact with three simulated ED scenarios of children with CAP or UTI, across both systems. Measures included task completion, decision-making and usability errors, clinical actions (order set use and correct antibiotic selection), as well as objective measures of system usability, utility, and workload using the National Aeronautics and Space Administration Task Load Index (NASA-TLX). The prototype CDS was iteratively refined to optimize usability and workflow. RESULTS: Usability testing in 21 ED clinical providers demonstrated that, compared to the standard order sets, providers preferred the prototype CDS, with improvements in domains such as explanations of suggested antibiotic choices (p < 0.001) and provision of additional resources on antibiotic prescription (p < 0.001). Simulated use of the CDS also led to overall improved guideline-adherent prescribing, with a 31% improvement for CAP. A trend was present toward absolute workload reduction. Using the NASA-TLX, workload scores for the current system were median 26, interquartile ranges (IQR): 11 to 41 versus median 25, and IQR: 10.5 to 39.5 for the CDS system (p = 0.117). CONCLUSION: Our CDS-enhanced discharge order set for ED antibiotic prescribing was strongly preferred by users, improved the accuracy of antibiotic prescribing, and trended toward reduced provider workload. The CDS was optimized for impact on guideline-adherent antibiotic prescribing from the ED and end-user acceptability to support future evaluative trials of ED ASPs.

Assessment of a COVID-19 vaccination protocol for unhoused patients in the emergency department.

BACKGROUND: We aimed to evaluate the feasibility of implementing an emergency department (ED)-based Coronavirus Disease of 2019 (COVID-19) vaccination protocol in a population of unhoused patients. METHODS: On June 10, 2021, a best practice alert (BPA) was implemented that fired when an ED provider opened the charts of unhoused patients and prompted the provider to order COVID-19 vaccination for eligible patients. We downloaded electronic medical record data of patients who received a COVID-19 vaccine in the ED between June 10, 2021 and August 26, 2021. The outcomes of interest were the number of unhoused, and the total number of patients vaccinated for COVID-19 during the study period. Data were described with simple descriptive statistics. RESULTS: There were 25,871 patient encounters in 19,992 unique patients (mean 1.3 visits/patient) in the emergency department during the study period. There were 1,474 (6% of total ED population) visits in 1,085 unique patients who were unhoused (mean 1.4 visits/patient). The BPA fired in 1,046 unhoused patient encounters (71% of PEH encounters) and was accepted in 79 (8%). Forty-three unhoused patients were vaccinated as a result of the BPA (4% of BPA fires) and 18 unhoused patients were vaccinated without BPA prompting. An additional 76 domiciled patients were vaccinated in the ED. CONCLUSIONS: Implementing an ED-based COVID-19 vaccination program is feasible, however, only a small number of patients underwent COVID-19 vaccination. Further studies are needed to explore the utility of using the ED as a setting for COVID-19 vaccination.

Innovations in infectious disease testing: Leveraging COVID-19 pandemic technologies for the future.

Innovations in infectious disease testing have improved our abilities to detect and understand the microbial world. The 2019 novel coronavirus infectious disease (COVID-19) pandemic introduced new innovations including non-prescription "over the counter" infectious disease tests, mass spectrometry-based detection of COVID-19 host response, and the implementation of artificial intelligence (AI) and machine learning (ML) to identify individuals infected by the severe acute respiratory syndrome - coronavirus - 2 (SARS-CoV-2). As the world recovers from the COVID-19 pandemic; these innovative solutions will give rise to a new era of infectious disease tests extending beyond the detection of SARS-CoV-2. To this end, the purpose of this review is to summarize current trends in infectious disease testing and discuss innovative applications specifically in the areas of POC testing, MS, molecular diagnostics, sample types, and AI/ML.

Experience with two antimicrobial prescribing tools in ambulatory care settings.

We compared experiences with The Multifaceted Intervention to Improve Prescribing for Acute Respiratory Infection for Adult and Children in Emergency Department and Urgent Care Settings versus Choosing Wisely to evaluate inappropriate antimicrobial prescribing in ambulatory care. Both identified the same clinics, diagnoses, and antibiotics for high-yield antibiotic stewardship interventions.

Detection of Viral Infection and Bacterial Coinfection and Superinfection in Coronavirus Disease 2019 Patients Presenting to the Emergency Department Using the 29-mRNA Host Response Classifier IMX-BVN-3: A Multicenter Study.

Background: Identification of bacterial coinfection in patients with coronavirus disease 2019 (COVID-19) facilitates appropriate initiation or withholding of antibiotics. The Inflammatix Bacterial Viral Noninfected (IMX-BVN) classifier determines the likelihood of bacterial and viral infections. In a multicenter study, we investigated whether IMX-BVN version 3 (IMX-BVN-3) identifies patients with COVID-19 and bacterial coinfections or superinfections. Methods: Patients with polymerase chain reaction-confirmed COVID-19 were enrolled in Berlin, Germany; Basel, Switzerland; and Cleveland, Ohio upon emergency department or hospital admission. PAXgene Blood RNA was extracted and 29 host mRNAs were quantified. IMX-BVN-3 categorized patients into very unlikely, unlikely, possible, and very likely bacterial and viral interpretation bands. IMX-BVN-3 results were compared with clinically adjudicated infection status. Results: IMX-BVN-3 categorized 102 of 111 (91.9%) COVID-19 patients into very likely or possible, 7 (6.3%) into unlikely, and 2 (1.8%) into very unlikely viral bands. Approximately 94% of patients had IMX-BVN-3 unlikely or very unlikely bacterial results. Among 7 (6.3%) patients with possible (n = 4) or very likely (n = 3) bacterial results, 6 (85.7%) had clinically adjudicated bacterial coinfection or superinfection. Overall, 19 of 111 subjects for whom adjudication was performed had a bacterial infection; 7 of these showed a very likely or likely bacterial result in IMX-BVN-3. Conclusions: IMX-BVN-3 identified COVID-19 patients as virally infected and identified bacterial coinfections and superinfections. Future studies will determine whether a point-of-care version of the classifier may improve the management of COVID-19 patients, including appropriate antibiotic use.

Comparative performance of two automated machine learning platforms for COVID-19 detection by MALDI-TOF-MS.

The 2019 novel coronavirus infectious disease (COVID-19) pandemic has resulted in an unsustainable need for diagnostic tests. Currently, molecular tests are the accepted standard for the detection of SARS-CoV-2. Mass spectrometry (MS) enhanced by machine learning (ML) has recently been postulated to serve as a rapid, high-throughput, and low-cost alternative to molecular methods. Automated ML is a novel approach that could move mass spectrometry techniques beyond the confines of traditional laboratory settings. However, it remains unknown how different automated ML platforms perform for COVID-19 MS analysis. To this end, the goal of our study is to compare algorithms produced by two commercial automated ML platforms (Platforms A and B). Our study consisted of MS data derived from 361 subjects with molecular confirmation of COVID-19 status including SARS-CoV-2 variants. The top optimized ML model with respect to positive percent agreement (PPA) within Platforms A and B exhibited an accuracy of 94.9%, PPA of 100%, negative percent agreement (NPA) of 93%, and an accuracy of 91.8%, PPA of 100%, and NPA of 89%, respectively. These results illustrate the MS method's robustness against SARS-CoV-2 variants and highlight similarities and differences in automated ML platforms in producing optimal predictive algorithms for a given dataset.

Risk factors for hepatitis C virus infection at a large urban emergency department.

In 2020, Centers for Disease Control and Prevention (CDC) released guidelines recommending HCV screening in all adults 18 years and older. In the current study, we aimed to identify risk factors for HCV infection in an ED population. We performed a retrospective analysis of ED patients ≥ 18 years who were screened for HCV between 28 November 2018, and 27 November 2019, at a single urban, quaternary referral academic hospital. An HCV-antibody immunoassay (HCV-Ab) was used for screening; positive results were confirmed by measuring HCV ribonucleic acid (RNA). The outcome of interest was the number of new HCV diagnoses (presence of viremia by HCV RNA testing). Multiple logistic regression models were used to identify risk factors associated with a new HCV diagnosis. 16,722 adult patients were screened for HCV (mean age: 46 ± 15 years; 51% female). HCV seroprevalence was 5%. Independent risk factors for HCV included increasing age [10-year aOR 1.26 (95% CI 1.23, 1.30)], male sex [aOR 1.25 (95% CI 1.03, 1.51)], undomiciled housing status [aOR 2.8 (95% CI 2.3, 3.5)], history of tobacco use [aOR 3.0 (95% CI 2.3, 3.9)], history of illicit drug use [aOR 3.6 (95% CI 2.9, 4.5)], Medicaid insurance status [aOR 4.0 (95% CI 2.9, 5.5)] and Medicare insurance status [aOR 1.6 (95% CI 1.1, 2.2)].The ED services a high-risk population with regards to HCV infection. These data support universal screening of ED patients for HCV. Risk factor profiles could improve targeted screening at institutions without universal testing protocols.

Comparative performance of COVID-19 serology testing.

Background: The 2019 novel coronavirus infectious disease (COVID-19) pandemic resulted in a surge of assays aimed at detecting severe acute respiratory syndrome (SARS) - coronavirus (CoV) - 2 infection and prior exposure. Although both molecular and antigen testing have clearly defined uses, the utility of serology remains uncertain and is presently not recommended for assessing immunity. Methods: We conducted a pragmatic, observational study evaluating four commercially available emergency use authorized laboratory-based COVID-19 serology assays (Assays A-D). Remnant samples from hospitalized, and non-hospitalized SARS-CoV-2 PCR positive patients, as well as vaccinated and unvaccinated individuals were collected and tested. Positive percent agreement (PPA) and negative percent agreement (NPA) were calculated. Antibody concentrations were compared across the platforms and populations. Results: A total of 588 remnant samples derived from 500 patients were tested. PPA at 5-12 weeks post-PCR positive results for Assays A-D was 98.3, 97.4, 99.2, and 95.8% respectively. NPA was 100% across all platforms. Mean antibody concentrations at 2-4 weeks post-PCR positive result were significantly higher in hospitalized versus non-hospitalized patients, respectively, for Assay A (131.8 [101.7] vs. 95.6 [100.3] AU/mL, P < 0.001), B (61.7 [62.4] vs. 38.1 [40.5] AU/mL, P < 0.001), and C (157.6 [105.3] vs. 133.3 [100.7] AU/mL, P < 0.001). For individuals receiving two vaccine doses mean antibody concentrations were respectively 169.6 (104.4), 27.3 (50.8), 189.6 (120.9), 21.19 (13.1) AU/mL for Assays A-D. Conclusions: Overall, PPA and NPA differed across the four assays. Assays A and C produced higher PPA and NPA and detected larger concentrations of antibodies following vaccination.

Universal HIV screening in the emergency department: an interrupted time series analysis.

We performed a calendar-matched, 12-month, before (November 27, 2017 to November 26, 2018) and after (November 27, 2018 to November 26, 2019) study, to assess the utility of an emergency department-based HIV screening program. There were 710 and 14 335 patients screened for HIV during the pre and post-best practice alert (BPA) periods, respectively, representing more than a 20-fold increase in HIV screening following BPA implementation. Total HIV positive tests increased 5-fold following BPA implementation.

Comparing Hepatitis C Virus Screening in Clinics Versus the Emergency Department.

INTRODUCTION: New evidence suggests that emergency department (ED)-based infectious diseases screening programs have utility. We aimed to compare clinic-based and ED-based hepatitis C virus (HCV) screening programs within a single health system, to identify key differences in HCV antibody (Ab) positivity and chronic HCV, as well as population demographics. METHODS: In the clinic-based program, adults in the birth cohort (born 1945-1965) were screened for HCV. In the ED-based program, non-targeted HCV screening of all adults was conducted. We included patients screened between June 2019-June 2020. Patients were screened for anti-HCV Ab, and positive results were followed by HCV viral load (VL) testing. Our primary outcomes were seroprevalence of HCV Ab and HCV VL. RESULTS: There were 1,296 and 12,778 patients screened for HCV in the clinics and the ED, respectively. In the clinic setting, 13 patients (1%) screened positive for HCV Ab and nine (69%) completed VL testing, which was positive in one patient (11%). In the ED, 1,053 patients (8%) screened positive for HCV Ab and 847 (80%) underwent reflex VL testing, which was positive in 381 patients (45%). In an ED birth cohort sub-analysis, Hepatitis C virus Ab seroprevalence was 15% (675/4521). CONCLUSION: In this study of patients in a single healthcare system, ED-based HCV screening was higher yield than clinic-based screening.

The Impact of Point-of-Care Polymerase Chain Reaction Testing on Prescribing Practices in Primary Care for Management of Strep A: A Retrospective Before-After Study.

Background: Rapid antigen detection tests (RADTs) are the standard of care (SOC) for testing in patients with suspected group A β-hemolytic Streptococcus (Strep A) infection. Due to lower sensitivity, guidelines recommend confirmatory microbiological culture following negative RADT results. This process is time-consuming, and adherence is often poor, resulting in high rates of inappropriate antibiotic prescribing. We sought to evaluate the impact of switching from RADTs to point-of-care (POC) polymerase chain reaction (PCR) testing on use of antibiotics in primary care, when used as part of an antibiotic stewardship initiative. Methods: In this retrospective before-after study, electronic medical records of any patients presenting with suspected acute pharyngitis (June 2018-May 2019) across 15 outpatient primary care clinics were evaluated. Strep A was detected using the cobas Strep A assay (cobas Liat system). Results: Analysis of 10 081 eligible patient records showed that POC PCR testing resulted in a 44.1% reduction in antibiotic prescribing for patients with a negative POC PCR test result (10.1% PCR vs 18.0% RADT; P < .0001). Rates of antibiotic prescription varied across clinical sites, ranging between 10.7% and 33.8% and 12.4% and 34.4% during the use of PCR tests and RADTs, respectively. POC PCR had no impact on prescription rates in patients with positive POC test results compared to RADTs (76.2% vs 76.5%, respectively). More than 99% of antibiotics were prescribed during the initial primary care encounter. Conclusions: As part of a broader antibiotic stewardship initiative, implementation of POC PCR as SOC in outpatients with acute pharyngitis symptoms reduced the volume of inappropriate antibiotic prescriptions.