Point-of-care Testing Research Articles

N-Doped Porous Carbon Synergistic Freezing-Induced DNA with Catalyzed Hairpin Assembly Enables Electrochemical One-Pot Detection of Pathogen in Food Samples.

A DNA electrochemical interface biosensor based on screen-printed carbon electrodes (SPCEs) holds promise for point-of-care testing (POCT) detection of pathogens in food safety. Nevertheless, SPCE commonly has a rough surface and suffers from a relatively low electron transfer rate, disorder of DNA capture probes (CPs), and the steric hindrance effect of target nucleic acid binding. These issues lead to a low sensitivity. Herein, a simple and rapid electrochemical biosensor based on N-doped porous carbon (NPC)-modified SPCE and freezing-directed DNA combined with catalyzed hairpin assembly (CHA) was constructed for the one-pot detection of pathogens in food samples without time-consuming growth cultures. The biosensor was constructed by SPCE modified with NPC for enhanced electrochemical properties, and the DNA CP designed for CHA was stably fixed on the electrode for a high hybridization efficiency. Moreover, the signals amplified by CHA enable the selective and sensitive detection of pathogens without washing steps. This one-pot method is simple and sensitive with a wide detection linear range of 101 to 107 CFU/mL and limit of detection of 5 CFU/mL for Escherichia coli and shows specificity against other coexisting pathogens. The whole detection of pathogens in complex samples is performed only within 60 min from sample-to-answer, which has great potential for POCT of pathogens in food safety.

A sample-to-answer digital microfluidic multiplexed PCR system for syndromic pathogen detection in respiratory tract infection.

Timely identification of infectious pathogens is crucial for the accurate diagnosis, management, and treatment of syndromic respiratory diseases. Nevertheless, the implementation of rapid, precise, and automated point-of-care testing (POCT) remains a significant challenge. This study introduces an advanced digital microfluidic (DMF) POCT testing system designed for the rapid molecular syndromic testing of multiple respiratory pathogens from a single untreated sample. The system seamlessly integrates magnetic beads-based nucleic acid extraction, PCR amplification, and real-time fluorescence analysis in an automatic run, facilitating sample-to-answer detection within 80 min. It accommodates various sample types, including nasopharyngeal swabs, oropharyngeal swabs, bronchoalveolar lavage fluid, and sputum. A facile sample loading method has been developed to reduce hands-on time to less than 1 min. The system exhibits high sensitivity (200-628 copies per mL) for 15 pathogens and has the capacity for up to 32 multiplexed tests per run. Validation with 255 clinical samples confirms its high sensitivity and specificity. The DMF-based system significantly reduces manual labour, enhances rapid POCT for respiratory infections, and, with optimized manufacturing processes, lowers costs for large-scale production. The system can be applied and improve clinical management near the patients as well as in resource-limited settings.

Continuous Glucose Monitoring in Hospitalized Adults With Diabetic Ketoacidosis: A Prospective Open-Label Pilot Study.

Continuous glucose monitoring (CGM) devices are increasingly used in critical and non-critical care hospital units. The efficacy of CGM in assessing glucose control in adults with diabetic ketoacidosis (DKA) is unknown. This single-center pilot study compared glycemic control by real-time CGM (Dexcom G6), capillary point-of-care (POC), and basic metabolic panel (BMP) during intravenous (IV) insulin treatment and after the resolution of DKA. We compared the mean absolute relative difference (MARD), median absolute relative difference (ARD) glucose values, and Diabetes Technology Society (DTS) Error Grid analyses. We recruited 52 patients (49 ± 19 years, admission glucose: 503 ± 239.4 mg/dL) with type 1 diabetes (n = 24) and type 2 diabetes (n = 28). Compared with POC testing, the MARD was 17.4% ± 13.2%, and the median ARD was 14.2% (interquartile range [IQR]: 6.4, 28) during the initial IV insulin period and 19.8% ± 18.7% and 14.3% (7, 26.2) after DKA resolution. The DTS Error Grid analysis showed that 100% of values during the IV insulin treatment and 95% after the DKA resolution were in zones A+B. Compared with BMP glucose values, the MARD and median ARD were 18.5% ± 19.1% and 12.2% (5.4, 23.8) during the IV insulin treatment and 22.5% ± 24.7% and 15.1% (6.6, 27.6) after DKA resolution. This is the first report on the use of real-time CGM in adults with DKA. Our study indicates that CGM technology is a reliable tool for hospital use during acute insulin treatment and after the resolution of DKA. Future multicentre randomized studies are needed to determine the benefits of real-time CGM in facilitating diabetes care in hospitalized patients with hyperglycemic crises.

An Attomolar-Level Optical Device for Monitoring Receptor–Analyte Interactions Without Functionalization Steps: A Case Study of Cytokine Detection

A plastic optical fiber (POF)-based device for biosensing strategies has been developed to monitor several protein–protein interactions at ultra-low concentrations without functionalization processes, exploiting plasmonic phenomena. In this work, novel tests were applied to different kinds of analyte–receptor interactions, such as interleukins, where the bioreceptor’s (protein antibody) molecular weight is roughly ten times that of the analyte (protein interleukin), while intracellular bioreceptors and small molecules at low molecular weight interactions have already been demonstrated via the same point-of-care test (POCT). The POCT was implemented by a white light source and a spectrometer connected via two POF-based chips connected in series: an innovative microcuvette chip and a D-shaped POF surface plasmon resonance (SPR) probe. In particular, the POF microcuvette chip was achieved by drilling three micro holes in the core of a modified POF. Instead of performing a functionalization step, the micro holes were filled with a specific receptor solution for the analyte (one microliter at the femtomolar level), which selectively captured the target (e.g., cytokine) when the samples were dropped over the filled micro holes (twenty microliters at the attomolar level). Three interleukins, IL-1β, IL-17A, and IL-18, were detected in the attomolar concentrations range by monitoring the resonance wavelength shift over time due to the cytokine/antibody (protein–protein) interaction. The POF-based device was proven to be effective for detecting several interleukins at the attomolar level in a few minutes and without functionalization processes.

Partially purified Strongyloides ratti antigen improved the diagnostic performance of strongyloidiasis by enzyme-linked immunosorbent assay (ELISA) and immunochromatographic test (ICT).

Strongyloides stercoralis infection is a neglected tropical disease with a global distribution. Serodiagnosis is a sensitive method, but improving its performance and simplifying into a point-of-care test (POCT) are needed. This study aimed to improve the diagnostic performance of serological tests using partially purified Strongyloides ratti antigen in an enzyme-linked immunosorbent assay (ELISA) and an immunochromatographic test (ICT). Crude S. ratti antigen was purified by an IgG affinity column to partition the antigen into flow-through, washing fraction (WF), and elution fractions. Optimized ELISA and ICT using crude and antigen fractions were used to analyze sera from three groups of subjects. Group 1 comprised subjects with proven strongyloidiasis, Group 2 were subjects with other parasitic infections, and Group 3 were negative parasitic infections. The diagnostic performance and Kappa agreement of the serological tests were analyzed and compared, using larvae detection as the reference test (fecal examination). The results showed that the WF was the most efficient antigen in terms of sensitivity and specificity, as determined by the ELISA and ICT. Kappa's agreement between fecal examination and WF-ELISA was moderate (Kappa = 0.52), and WF-ICT was almost perfect (Kappa = 0.94). The WF antigen reduced cross-reactivity to other parasitic infections, that is, Opisthorchis viverrini, Taenia spp., and hookworms, compared to crude S. ratti antigen when assessed by ELISA and ICT. We concluded that the WF of purified S. ratti improved the ELISA and ICT diagnostic performance, and the latter assay format could be used as a POCT for screening and controlling strongyloidiasis.IMPORTANCEThis study aimed to improve the serological diagnosis of strongyloidiasis, a disease caused by infection with the intestinal nematode Strongyloides stercoralis, by evaluating the impact of Strongyloides ratti antigen purification using an IgG affinity column for detecting parasite-specific IgG in serum via enzyme-linked immunosorbent assay (ELISA) and immunochromatographic test (ICT) formats. Compared to crude S. ratti antigen, the washing fraction (WF) of the purified antigen demonstrated significantly improved sensitivity and specificity in both ELISA and ICT, achieving strong diagnostic concordance with the gold-standard fecal examination. Furthermore, the WF antigen fraction exhibited reduced cross-reactivity with coinfections caused by the liver fluke (Opisthorchis viverrini), tapeworms (Taenia spp.), and hookworms. These findings underscore antigen purification as a promising strategy to enhance the accuracy of strongyloidiasis serodiagnosis.

Point-of-care tests in the emergency medical services: a scoping review

BackgroundThis scoping review aimed to summarize existing research on point-of-care tests (POCTs) within emergency medical services (EMS). There is a lack of comprehensive reviews covering the breadth and scope of application of POCTs in EMS despite growing interest and potential benefits in this setting. A review of the research will inform how we target future research efforts to support effective implementation and avoid duplication.MethodsWe searched three databases to April 2023 using comprehensive terms for POCTs. One author screened titles and abstracts, full-text papers and extracted data with a second author checking the data. A scoping review framework was used to categorise studies according to demographics, study design, medical conditions, biomarkers and test devices.ResultsWe found 141 papers that included 158 reports of 9 study designs, 155 reports of 40 combinations of biomarker and condition and 161 reports of 41 test-devices. The majority of research was done in the UK (19%), US (17%), and the Netherlands (16%), mostly in land-based EMS (82%). Most frequently assessed were troponin for acute coronary syndromes (26%), lactate for sepsis (14%) or lactate for trauma/critical illness (13%). The majority of research designs investigated the accuracy of the tests (43%). Few studies were of a design to inform guidelines to change patient pathways and the associated outcomes, including, randomised controlled trials (RCTs) (4%), non-randomised studies able to assess causality (6%), economic analyses (1%) or qualitative work on acceptability (3%). In those few cases where RCTs were done there were long delays between initial test-accuracy research and publication of the first RCT, for example 11 years delay for troponin for acute coronary syndromes.ConclusionsWe identified a thriving base of research on POCT in the EMS, however most studies established the diagnostic accuracy of the tests with few RCTs, economic analyses or qualitative research on acceptability. The time-lag from diagnostic accuracy to developing an RCT is considerable. Investment in funding and infrastructure is needed to support the research pathway for potential POCTs beyond diagnostic accuracy to designs able to assess clinical effectiveness, acceptability and economic effectiveness.

Operational Feasibility of Point-of-Care Testing for Sickle Cell Disease in Resource-Limited Settings of Tribal Sub-Plan Region of India

Background: Sickle cell disease (SCD) individuals in India are mostly identified when they become symptomatic. To provide a timely diagnosis of SCD to participants, healthcare workers should be competent in using the point-of-care test (POCT). In this study, we aimed to evaluate the competence of healthcare workers to screen infants and adult populations through POCT. Methodology: This study was conducted in pilot mode over 8 months from April to November 2023. A random sampling method was used to select ten auxiliary nursing midwives (ANMs), ten lab technicians (LTs), and five medical officers (MOs). Each selected ANM and LT was supposed to conduct ten tests and MOs to conduct five tests. The POCT used to diagnose sickle cell disease was HemoTypeSC. Results: Among the healthcare workers who participated in the study, 67% belonged to the scheduled tribes. When the ANM and LT competencies were compared for the pre-analytical phase (phase I), ANMs were more competent than the LTs. ANMs were more adept at handling people, whereas the LTs were more competent in conducting the test procedures. When the comparison was made for the analytical phase (phase II), both the ANMs and LTs were found to be equally competent. ANMs followed the standard operating procedure (SOP) more precisely than MOs and LTs. In the post-analytical phase, LTs were found to be more competent than ANMs. The approach used in this study with sub-centers and primary health centers (PHCs) appears to have encouraged the feasibility of the screening program. Conclusions: The results of this study conclude that the healthcare workers in the region are competent to perform the POCT for the diagnosis of sickle cell disease. The POCT may be introduced in the program for the diagnosis of SCD.

From Conventional Detection to Point-of-care Tests (POCT) Method for Pediatric Respiratory Infections Diagnosis: A Systematic Review

Bacterial respiratory infections pose significant health risks to children, particularly infants susceptible to upper respiratory tract infections (URTIs). The COVID-19 pandemic has further exacerbated the prevalence of these infections, with pathogens such as Mycoplasma pneumoniae, Streptococcus pneumoniae, Legionella pneumophila, Staphylococcus aureus, Haemophilus influenzae, and Klebsiella species commonly implicated in pediatric cases. The critical need for accurate and timely detection of these bacterial agents has highlighted the importance of advanced diagnostic techniques, including multiplex real-time PCR, in clinical practice. Multiplex real-time polymerase chain reaction (PCR) offers several advantages, including rapid results, high sensitivity, and specificity. By accelerating the diagnostic process, this approach enables early intervention and targeted treatment, ultimately improving patient outcomes. In addition to PCR technologies, rapid and point-of-care testing (POCT) play a crucial role in the prompt diagnosis of bacterial respiratory infections. These tests are designed to be user-friendly, sensitive, and deliver quick results, making them particularly valuable in urgent clinical settings. POCT tests are often categorized into two main groups: those aimed at determining the cause of infection and those focused on confirming the presence of specific pathogens. By utilizing POCT, healthcare providers can make rapid and informed treatment decisions, leading to more effective management of bacterial respiratory infections in children. As the medical community continues to explore innovative diagnostic approaches, the integration of molecular and rapid testing methods offers significant promise in the realm of bacterial respiratory infections. By adopting these cutting-edge technologies, healthcare professionals can enhance their ability to accurately diagnose these infections, tailor treatment strategies, and ultimately improve patient care.

Use of continuous glucose monitoring and point-of-care glucose testing in hospitalized patients with diabetes mellitus in non-intensive care unit settings: A systematic review and meta-analysis of randomized controlled trials.

The benefits of using continuous glucose monitoring (CGM) in hospitalized patients with diabetes remain uncertain. Point-of-care (POC) glucose testing is the standard of care in this setting. We compared the effect of adding CGM to POC testing versus POC testing alone on glycemic outcomes in this population. We have searched the Cochrane Library, Embase, and MEDLINE databases and relevant conferences up to May 2024. We have included six randomized controlled trials (n=979 patients) comparing CGM plus POC testing to POC testing alone in non-pregnant, non-critically ill hospitalized adults with diabetes. The addition of CGM improved time in range (mean difference [MD]+7.24%; 95% confidence interval [CI]: +5.06, +9.42; P<0.00001; I2=35%), reduced time below range<70mg/dL (MD: -1.23%; 95%CI: -2.27, -0.18; P=0.02; I2=64%) and<54mg/dL (MD: -0.95%; 95%CI: -1.19, -0.70; P<0.00001; I2=0%), and time above range>250mg/dL (MD: -3.70%; 95%CI: -6.10, -1.29; P=0.003; I2=39%) compared to POC testing alone. We observed no statistically significant differences in glycemic variability or insulin doses. In non-critically ill, hospitalized adults with diabetes, the addition of CGM to POC testing for insulin dosing resulted in superior glycemic control and reduction of hypoglycemia compared to POC testing alone.

Entropy driven-based catalytic biosensors for bioanalysis: From construction to application-A review.

The rapid advancement of precision medicine and the continuous emergence of novel pathogens have presented new challenges for biosensors, necessitating higher requirements. Target amplification technology serves as the core component in biosensor construction. Enzyme-based amplification methods are often sensitive and selective but involve relatively complex operational steps, whereas enzyme-free amplification methods offer simplicity but frequently fail to meet both sensitivity and selectivity simultaneously. Existing research has confirmed that entropy-driven catalyst (EDC) biosensors not only fulfills the demands for sensitivity and selectivity concurrently but also offers ease of operation and flexibility in construction. In this review, we summarize the key advantages of EDC, explore how to construct DNA nanomachines based on these advantages to achieve intracellular detection and simultaneous detection of multiple targets, as well as point-of-care testing (POCT) to address practical issues in clinical diagnosis and treatment. We also anticipate potential challenges, propose corresponding solutions, and outline future development directions for EDC-based biosensors in practical clinical applications. We firmly believe that EDC sensors will emerge as a crucial branch within the realm of biosensor development.

Theta-Alpha Variability on EEG Is Associated With Acute Brain Injury in Children and Young Adults With Liver Failure.

Patients with liver failure experience long hospitalizations and acute neurologic complications. Encephalopathy limits the bedside examination, rendering presenting signs of acute brain injury less specific. Seizures are common. Brain MRI is the gold standard for detecting acute brain injury, but intensive medical needs may preclude immediate transfer for imaging. EEG is a bedside test applied in cases of seizure or encephalopathy. We hypothesized that EEG variables can predict MRI signs of acute brain injury in children hospitalized with liver failure. In this retrospective cohort analysis, records were collected for patients admitted to a MedStar hospital between 2014 and 2022 with ICD-9/10 codes related to liver failure, who underwent brain MRI and EEG testing during the same admission. Exclusion criteria included age older than 24 years and >7 days elapsing between EEG and MRI testing. Clinical data of interest from chart review, reinterpreted MRI scans, reinterpreted EEG tracings, and quantitative EEG variables were compiled into a database. Quantitative EEG variables were processed using MNE-Python. Of 746 records screened, 52 patients met inclusion criteria comprising 63 EEG-MRI pairs. Univariate analysis of all quantitative EEG variables of interest showed depressed theta-alpha variability (TAV) when paired MRI involved abnormal restricted diffusivity in cortical or deep gray matter structures (TAV 0.705, SD 0.310; p < 0.001) compared with MRI with no abnormal restricted diffusivity (TAV 0.895, SD 0.095). Multilinear regression analysis including potential confounders demonstrated independent association of depressed TAV with this MRI finding, with an odds ratio of 4.0317 (95% CI 1.3868-11.7165; AUROC 0.83). Depressed TAV on EEG is associated with increased odds of abnormal restricted diffusivity in gray matter on brain MRI in children and young adults hospitalized with liver failure. This MRI finding is seen in scenarios where changes to medical management are time-sensitive (i.e., acute stroke and PRES) or where prognostic discussion may be influenced by MRI findings (hypoxic-ischemic injury). TAV thus has a potential role as an automated, bedside decision support tool for clinicians deciding on the urgency of brain MRI in critically ill patients.

Revolutionizing emergency care: the transformative role of point of care testing (POCT) in modern medicine

Point of Care Testing (POCT) has revolutionized emergency medicine by providing rapid diagnostic results, enhancing patient care, and improving clinical outcomes. This review explores the impact of POCT on emergency settings, particularly focusing on turnaround time (TAT), patient outcomes, and specific applications such as acute coronary syndrome (ACS). While the utility of POCT is evident in certain clinical scenarios, its broader implementation poses challenges, including cost, analytical performance, and integration with traditional laboratory workflows. Future perspectives emphasize the potential of molecular POCT advancements to further streamline emergency care.

Budget impact analyses of hemoglobin A1c and lipid panel point-of-care testing with Afinion™ 2 in Canada and Italy.

Aim: Screening and monitoring of diabetes or dyslipidemia frequently involves a multi-step process requiring patients to obtain test requisitions from their primary care physician (PCP), followed by a laboratory visit and re-consultation. Point-of-care testing (POCT) for hemoglobin A1c (HbA1c) and lipid panel can streamline the patient care pathway. This study assessed the budget impact of introducing Afinion™ 2 POCT (Abbott Rapid Diagnostics) from the Canadian and Italian societal perspectives. Methods: Budget impact models were developed for Canada and Italy over a 5-year time horizon (2025 to 2029). The analyses considered the screening and monitoring of diabetes or dyslipidemia for patients utilizing the public healthcare system and attending primary care, and included direct costs (testing, consultations) and indirect costs (productivity loss, transportation) based on published sources. The budget impact (BI) was calculated by comparing scenarios with and without POCT. All costs were adjusted to Canadian dollars ($) or 2024 Euros (€). Scenario analyses were conducted to explore the impact of alternative assumptions. Results: The 5-year cumulative BI was -$758,006,692 (-$50,709,964 direct, -$707,296,728 indirect) for HbA1c POCT and -$726,452,755 ($2,684,011 direct, -$729,136,766 indirect) for lipid panel POCT in Canada and -€1,380,658,764 (-€6,391,954 direct, -€1,374,266,809 indirect) for HbA1c POCT and -€851,792,115 (€55,962,879 direct, -€907,754,993 indirect) for lipid panel POCT in Italy. In both countries, cost savings for both the healthcare payer and patients were observed for HbA1c POCT, while costs savings were derived from patient indirect costs for lipid panel POCT. The analyses estimated that 1,558,062 and 1,501,260 PCP consultations in Canada, 4,962,338 and 1,951,026 PCP consultations in Italy were avoided with implementation of POCT for HbA1c and lipid panel, respectively. Scenario analyses demonstrated potential further cost savings with implementation of POCT in pharmacies. Conclusion: This study demonstrates that the adoption of Afinion 2 POCT for HbA1c and lipid panel can provide efficiencies to different types of healthcare systems through reducing PCP consultations, saving time and money for patients and providing cost savings for payers.

P-342. Outcomes of Human Metapneumovirus in Nursing Home Residents: A Matched Analysis

Abstract Background Identified in 2001, human Metapneumovirus (hMPV) is a Paramyxoviridae with bimodal age distribution - affecting children and older people. In older people, clinically severe hMPV may be associated with respiratory symptoms resulting in hospitalization and/or death. The purpose of this study was to compare hospitalization and death in older nursing home residents with hMPV or influenza. Methods Using the electronic medical records of VA Community Living Centers (CLC) during the epidemiology years of Sept 1, 2017 to August 31, 2023, we identified CLC residents who tested positive for hMPV or influenza. We collected information on demographics and comorbidities, as well as clinical testing. We developed a propensity matched cohort of hMPV and influenza positive CLC residents and used proportional hazards models to determine the hazard ratio (HR) for hospitalization, death or either during the 90 days after positive test among hMPV- and influenza-positive residents. Results During the study period, we identified 135 hMPV infections and 1170 influenza. Most hMPV included influenza testing and there were no co-infections. Both populations were older (hMPV 76.1 (10.6) vs. influenza 74.2 (10.9) years, SMD=0.18) and predominantly male (hMPV 96.7% vs. influenza 96.3%, SMD=0.02). The hMPV cohort had more pulmonary disease (42.2% vs 30.9%, SMD=0.25) and dementia (55.6% vs. 42.3%, SMD=0.26) compared to influenza cohort. The propensity matching identified 130 hMPV and 601 influenza residents that were well matched. proportional hazard model on the propensity matched cohort found equivocal hazard for hospitalization (adjusted HR 0.91 (0.55, 1.50)), death (adjusted HR 1.03 (0.61, 1.75)), and the combined outcome (adjusted HR 0.92 (0.61, 1.33)). Conclusion When hMPV develops in nursing home residents, the outcomes of hospitalization and death are comparable to influenza. Increased awareness of hMPV and appropriate point of care testing are needed to accurately detect hMPV and implement infection control measures. Additional studies are needed to better understand epidemiology, prevention, and treatment of hMPV in especially high-risk nursing home residents. Funded by Icosavax, a member of the AstraZeneca Group Disclosures Yasin Abul, MD, Moderna: Grant/Research Support|Moderna, Abt, CDC: Grant/Research Support Kevin McConeghy, Pharm.D., Genentech: Grant/Research Support|GlaxoSmithKline: Grant/Research Support|Moderna: Grant/Research Support|Sanofi-Pasteur: Grant/Research Support|Seqirus: Grant/Research Support Stefan Gravenstein, MD, MPH, CDC: Advisor/Consultant|CDC: Grant/Research Support|Genentech: Advisor/Consultant|Genentech: Grant/Research Support|Genentech: Honoraria|GlaxoSmithKline: Advisor/Consultant|GlaxoSmithKline: Grant/Research Support|GlaxoSmithKline: Honoraria|Janssen: Advisor/Consultant|Janssen: Grant/Research Support|Janssen: Honoraria|Moderna: Advisor/Consultant|Moderna: Grant/Research Support|Moderna: Honoraria|NIH: Grant/Research Support|Pfizer: Advisor/Consultant|Pfizer: Grant/Research Support|Pfizer: Honoraria|Sanofi: Advisor/Consultant|Sanofi: Grant/Research Support|Sanofi: Honoraria|Seqirus: Advisor/Consultant James L. Rudolph, MD, Icosavax / AstraZeneca: Grant/Research Support

Overview of dengue diagnostic limitations and potential strategies for improvement.

Dengue is a viral infection caused by any one of the four related dengue virus (DENV) serotypes, 1-4. DENV is a single-stranded RNA virus belonging to the genus Flavivirus. Dengue can cause a range of symptoms, from mild to severe life-threatening illness. Currently, treatment for DENV is limited to supportive care, with better outcomes achieved through early diagnosis. The WHO has suggested that dengue mortality can be reduced to nearly zero by implementing appropriate clinical management strategies, such as early laboratory diagnosis. This calls for diagnostic approaches that combine high sensitivity and specificity, while also being suitable for point-of-care testing (POCT) in remote locations with minimal staff training and low testing costs. In this paper, we outline the limitations of existing confirmatory dengue diagnostic methods, such as ELISA and RT-PCR, which are time-consuming, expensive, and require skilled personnel. We also highlight alternative strategies toovercome these challenges. Additionally, the paper emphasizes the growing clinical demand for diagnosing severe dengue to reduce the risk of death, which must be addressed by next-generation dengue diagnostic approaches. We propose the adoption of alternative strategies, such as fluorescence immunoassay (FIA) and chemiluminescence immunoassay (CLIA), which have the potential to overcome the limitations of existing dengue diagnostic methods. Improvements in dengue diagnosis, with a specific focus on identifying severe dengue in POCT setting, can help achieve the goal of zero deaths from dengue.

Ultrasensitive and selective impedance paper-based analytical device through Dual-C imprinted sensor for determination of carcinoembryonic antigen and C-reactive protein.

Carcinoembryonic antigen (CEA) and C-reactive protein (CRP) are biomacromolecules known as cancer and inflammatory markers. Thus, they play a crucial role in early cancer diagnosis, post-treatment recurrence detection, and tumor risk assessment. This paper describes the development of an ultrasensitive and selective imprinted paper-based analytical device (PAD) as impedance sensor for determination of CEA and CRP in serum samples for point-of-care testing (POCT). They combine a core comprising of silica nanospheres decorated with silver nanoparticles (SiO2@AgNPs) coated with molecularly imprinted polymers (MIPs) for CEA and CRP as shells. CEA-MIP and CRP-MIP were successful coated on the core via self-assembly of N-acetyl-L-cysteine (NAC) followed by building up recognition sites in iminodiacetic acid/ethylene glycol dimethacrylate (IDA/EGDMA) polymer. We constructed a selective and compact imprinted PAD based on a SiO2@AgNPs@MIP-CEA- and SiO2@AgNPs@MIP-CRP-modified graphene electrode, a so-called Dual-C sensor. The resulting twin voltammetric cells to detect CEA and CRP use foldable hydrophobic back-up sheets acting as reservoirs. The advantages of this approach include straightforward manufacturing with highly reproducibility, quick assembly, and good physical durability. The Dual-C sensor revealed excellent linear dynamic ranges of 0.0001 to 10 ng mL-1 for both CEA and CRP, which covers on the concentration ranges of clinical interest for both analytes. Furthermore, the system shows high accuracy and precision, with no evidence of interference from serum samples.

P-1462. Utilization of a Point-of-Care Hepatitis C Test to Treat in People Experiencing Homelessness with Street Medicine Outreach

Abstract Background Persons experiencing homelessness (PEH) have disproportionately higher rates of untreated chronic hepatitis C virus (HCV) than the public. Improved community funding and resources are needed to expand HCV rapid point-of-care (POC), confirmatory testing, treatment and follow-up. Given that PEH face competing priorities (unstable housing, food access, addiction, other infections), it is our role as clinicians to reduce barriers to HCV treatment, understand hesitancies for deferring treatment, and design programs to improve accessibility. This is the pilot project of a Street Medicine (SM) based initiative to use POC testing for HCV amongst PEH with linkage of care to a federally qualified health clinic (FQHC). Hepatitis C Screening and Treatment Protocol HCV- Hepatitis C Virus POC- Point of Care CHASS- Community Health and Social Services HbsAg- Hepatitis B Surface Antigen CBC- Complete Blood Count CMP- Complete Metabolic Panel Methods SM provides medical care to PEH outside of a hospital setting. Medical students and residents were recruited to form a HCV outreach team at Henry Ford Hospital and trained in HCV testing via OraQuick rapid antibody (Ab) test. During SM outreach, PEH were provided education on HCV and offered POC testing with a $10.00 grocery gift card. If a patient was identified as HCV Ab positive they were provided free transportation to a FQHC for confirmatory testing. If diagnosis was confirmed, they were evaluated for eligibility for simplified HCV treatment, check-ins to assess adherence and sustained virologic response (Figure 1). Results From February-April 2024, 103 PEH were tested using POC HCV testing on SM runs, with 4 positive results. 3 of 4 patients were confirmed for CHASS clinic appointments. 1 patient presented to clinic follow-up but deferred confirmatory testing bloodwork, demonstrating challenges in arranging for HCV clinic follow-up care. Conclusion Previous studies have shown that lack of insurance, prior authorization and referral process, active injection drug use or alcohol use, lack of knowledge of HCV treatment, and limited healthcare workforce and infrastructure have all contributed to the low treatment rate in the homeless. Using trusted community organizations with SM, this initiative aims to reduce testing and transportation barriers in order to eliminate HCV in PEH. Larger numbers of positive patients are needed to best assess the feasibility of the program, and if providing all testing and treatment at the point of care is needed to improve compliance. Disclosures Marcus Zervos, MD, Johnson and johnson: Grant/Research Support|Moderna: Grant/Research Support Seema Joshi, MD, AbbVie: Grant/Research Support

P-485. Enhancing Adolescent Human Immunodeficiency Virus (HIV) Screening : A Quality Improvement Approach with Point-of-Care Testing

Abstract Background Pediatricians play a key role in preventing Human Immunodeficiency Virus (HIV) by offering routine HIV testing. While there has been great progress in treatment for patients with HIV/AIDS, many adolescents still believe they are not at risk for HIV and have never been tested. Recent studies have shown that almost half of adolescents who have HIV are undiagnosed. A key barrier to screening adolescents for HIV during clinic well child visits includes patient follow through with HIV screening lab work. Traditionally, this requires a visit to the lab, serum draw, followed by waiting hours to days for a result. We sought to eliminate this barrier by implementing a point of care (POC) HIV oral swab during adolescent well child visits with anticipation of increasing overall HIV screening rates. Plan Do-Study-Act Cycle Multiple PDSA cycles were implemented throughout the project to ensure continued improvement and integration of HIV screening during clinic visits. This was the an example of the main overarching PDSA cycle driving quality improvement. Methods Adolescents ages 15-18 presenting for well-child check who had not yet tested for HIV were eligible. Interventions included creating educational curriculum for physicians regarding HIV screening guidelines, generating mulit-lingual resources for families about the importance of HIV screening, and utilizing a multidisciplinary team to implement testing into clinic workflow. The primary outcome measure was the monthly percentage of adolescents ages 15-18 who were screened for HIV via the POC swab during their WCC. Multiple “Plan-Do-Study-Act cycles” were implemented to reinforce change. Proportion of Adolescents tested for HIV Red arrow indicated when POC HIV swabs became available for use in clinic Results We found a statistically significant difference between the proportion of patients screened for HIV before and after the availability of POC HIV swab with p&amp;lt; 0.001. Prior to implementation, the year-to-date percentage of those screened among eligible patients from January 2023 to July 2023 was 29% (80/276). Within eight months of implementation of the HIV POC swab from August 2023 to March 2024 the percentage of adolescents screened increased to 47 % (155/331). Conclusion Improving HIV screening among adolescents is feasible and effective through the use of point of care rapid antibody testing. This type of testing is painless, can be quickly performed during clinic visits, and improves patient confidentiality as results are available at time of visit instead of traditionally waiting for the results by phone or email. Medicaid covers POC testing for HIV so this form of testing could be used in many clinics. Disclosures All Authors: No reported disclosures

P-2331. A Pilot Study to Establish a Nursing Home Syndromic Surveillance Network

Abstract Background Local viral surveillance data available from the CDC for nursing home (NH) staff to assess risk for acute respiratory infections (ARI) lags the occurrence of infections by ≥2 weeks. Also, the CDC report represents a minority of NHs nationally. We evaluated a pragmatic approach to expand and improve respiratory virus testing in NHs. Methods We evaluated the implementation of a CLIA-waived point of care (POC) multiplex assay to assess symptomatic viral ARI as part of routine care in a NH network of typically-sized facilities (∼100 beds). The device automatically generated real time reports for participating NHs. We tested a framework for data collection and reporting to describe the natural history of ARI and expand our understanding of the burden of these infections in NHs through facility surveys. The CLIA-waived Cepheid GeneXpert Xpress device was chosen for 4 pathogen testing due to its 1) timely result reporting (e.g., less than 30 minutes) for immediately actionable results, 2) ability to use a nasal swab, a process familiar to key NH staff, 3) ability to allocate data fields on the touch screen for the entry of patient symptoms at the time of testing, for syndromic surveillance, and 4) automatic upload of de-identified data to the cloud providing the ability to report anonymized results to a network dashboard while retaining facility site location. Data collected between November 2023 and April 2024 are presented. Results We enrolled 22 NHs in 4 of 10 HHS reporting regions, and placed a Cepheid GeneXpert Xpress device in each, with results reporting in real time to a central database. A high proportion of tested specimens (38%) confirmed viral infection (Table 1). We found the barriers to setting up the network included unfamiliarity with the technology, identifying space to place the device, staff training, getting the device network access, addressing cybersecurity concerns, ensuring symptom entry by NH staff, and NH staff turnover. According to facility surveys, the NH staff universally liked that access to the device produced immediate, actionable, and highly sensitive and specific results for RSV, SARS-CoV-2, and influenza A and B. Conclusion CLIA-waived viral ARI POC testing can be implemented in NHs and identified SARS-CoV-2, influenza, or RSV in about 30% of all samples. Disclosures H. Edward Davidson, PharmD, MPH, GSK: Grant/Research Support|Moderna: Grant/Research Support Lisa Han, MPH, GSK: Grant/Research Support|Moderna: Grant/Research Support Kevin McConeghy, Pharm.D., Genentech: Grant/Research Support|GlaxoSmithKline: Grant/Research Support|Moderna: Grant/Research Support|Sanofi-Pasteur: Grant/Research Support|Seqirus: Grant/Research Support Yasin Abul, MD, Moderna: Grant/Research Support|Moderna, Abt, CDC: Grant/Research Support Ivis Perez, MPH, LPN, Moderna: Grant/Research Support David Canaday, MD, Moderna: Grant/Research Support|Pfizer: Grant/Research Support Stefan Gravenstein, MD, MPH, CDC: Advisor/Consultant|CDC: Grant/Research Support|Genentech: Advisor/Consultant|Genentech: Grant/Research Support|Genentech: Honoraria|GlaxoSmithKline: Advisor/Consultant|GlaxoSmithKline: Grant/Research Support|GlaxoSmithKline: Honoraria|Janssen: Advisor/Consultant|Janssen: Grant/Research Support|Janssen: Honoraria|Moderna: Advisor/Consultant|Moderna: Grant/Research Support|Moderna: Honoraria|NIH: Grant/Research Support|Pfizer: Advisor/Consultant|Pfizer: Grant/Research Support|Pfizer: Honoraria|Sanofi: Advisor/Consultant|Sanofi: Grant/Research Support|Sanofi: Honoraria|Seqirus: Advisor/Consultant

Screening for sickle cell disease by point-of-care tests in Italy: pilot study on 1000 at risk children

Sickle cell disease (SCD) is a global health problem causing premature deaths and preventable severe chronic complications. A priority goal to improve outcomes both in the short and long term is the screening for early diagnosis and access to specialized care. In Italy, as in other countries, no systematic national screening program is available. A regional pilot project was developed with the aim to screen 1000 children at risk of SCD in Italy. Primary care paediatricians received point-of-care tests (POCTs) to detect abnormal haemoglobin (Hb) to be offered to children regularly followed at their own clinics. Children positive to the POCT were referred to the regional paediatric specialized centre for diagnosis confirmation and follow up. Among 1000 at risk children screened, 85 (8,5%) tested positive for an abnormal Hb. HbS trait was reported in 69 (7%) children, HbC trait in 13 (1,3%) and SCD was diagnosed in 3 (0,3% overall; 0,56% in African background) children. African family background was the most affected by sickle mutations and all children with SCD had African ancestry. Only 56/259 (22%) primary care paediatricians invited but 20/21 (95%) reception centres adhered to the pilot screening project.Conclusions: A screening program for SCD performed by the primary care paediatricians is feasible and relatively easy to organize. SCD affects mainly children with African family background and the scarce adherence of primary care paediatricians, in contrast to the high adhesion of charitable institutions, outlines the need for a mandatory screening for SCD, and improved awareness among health care providers.What is Known:• Sickle Cell Disease (SCD) is a serious global health problem that requires management in specialized centres from the first months of life.• In the absence of neonatal screening for SCD, primary health care settings represent a feasible and costeffective approach for early disease detection.What is New:• In Italy, screening for SCD performed by primary care pediatricians detected a hemoglobin variant in 8.5% children, with a disease prevalence of 0.3% in the whole population and 0.56% in children with African family background.• The poor adherence of paediatricians to the voluntary screening for SCD highlights the need for legislative interventions and training activities to ensure early diagnosis and rapid access to care for all children affected by SCD.