Smartphone-assisted point-of-care testing of nucleic acids based on hybridization chain reaction, magnetic beads, and gold nanorods etching

Colorimetric biosensors are simple but effective tools that are gaining popularity due to their ability to provide low-cost, rapid, and accurate detection for viruses like the Novel coronavirus, Influenza A, and Dengue virus, especially in point-of-care testing (POCT) and visual detection. In this study, a smartphone-assisted nucleic acid POCT was built using hybridization chain reaction (HCR), magnetic beads (MBs), and oxidized 3,3′,5,5′-tetramethylbenzidine (TMB2+)-mediated etching of gold nanorods (GNRs). The application of HCR without enzyme isothermal characteristics and MBs with easy separation, can quickly amplify nucleic acid signal and remove other reaction components. The blue shift of longitudinal localized surface plasmon resonance (LSPR) based on GNRs showed significant differences in etching color for different concentrations of target nucleic acid, which convert the signal into a visually semi-quantitative colorimetric result, achieving quantitative analysis with the color recognition software built into smartphones. This strategy, which only takes 40 min to detect and is two-thirds less time than the PCR, was successfully applied for the detection of the Dengue target sequence with a detection limit of 1.25 nM and exhibited excellent specificity for distinguishing single-base mutations, indicating broad application prospects in clinical laboratory diagnosis and enriching the research of nucleic acid POCT.

Acute or chronic? Failing left ventricle in a 34 year old

Submission content Introduction: An unusual case of a very young patient without previously known cardiac disease presenting with severe left ventricular failure, detected by a point of care echocardiogram. Main Body: A 34 year old previously well man was brought to hospital after seeing his general practitioner with one month of progressive shortness of breath on exertion. This began around the time the patient received his second covid-19 vaccination. He was sleeping in a chair as he was unable to lie flat. Abnormal observations led the GP to call an ambulance. In the emergency department, the patient required oxygen 5L/min to maintain SpO2 >94%, but he was not in respiratory distress at rest. Blood pressure was 92/53mmHg, mean 67mmHg. Point of care testing for COVID-19 was negative. He was alert, with warm peripheries. Lactate was 1.0mmol/L and he was producing more than 0.5ml/kg/hr of urine. There was no ankle swelling. ECG showed sinus tachycardia. He underwent CT pulmonary angiography which demonstrated no pulmonary embolus, but there was bilateral pulmonary edema. Troponin was 17ng/l, BNP was 2700pg/ml. Furosemide 40mg was given intravenously by the general medical team. Critical care outreach asked for an urgent intensivist review given the highly unusual diagnosis of pulmonary edema in a man of this age. An immediate FUSIC Heart scan identified a dilated left ventricle with end diastolic diameter 7cm and severe global systolic impairment. The right ventricle was not severely impaired, with TAPSE 18mm. There was no significant pericardial effusion. Multiple B lines and trace pulmonary effusions were identified at the lung bases. The patient was urgently discussed with the regional cardiac unit in case of further deterioration, basic images were shared via a cloud system. A potential diagnosis of vaccination-associated myocarditis was considered,1 but in view of the low troponin, the presentation was felt most likely to represent decompensated chronic dilated cardiomyopathy. The patient disclosed a family history of early cardiac death in males. Aggressive diuresis was commenced. The patient was admitted to a monitored bed given the potential risk of arrhythmia or further haemodynamic deterioration. Advice was given that in the event of worsening hypotension, fluids should not be administered but the cardiac centre should be contacted immediately. Formal echocardiography confirmed the POCUS findings, with ejection fraction <35%. He was initiated on ACE inhibitors and beta adrenergic blockade. His symptoms improved and he was able to return home and to work, and is currently undergoing further investigations to establish the etiology of his condition. Conclusion(s): Early echocardiography provided early evidence of a cardiac cause for the patient's presentation and highlighted the severity of the underlying pathology. This directed early aggressive diuresis and safety-netting by virtue of discussion with a tertiary cardiac centre whilst it was established whether this was an acute or decompensated chronic pathology. Ultrasound findings: PLAX, PSAX and A4Ch views demonstrating a severely dilated (7cm end diastolic diameter) left ventricle with global severe systolic impairment.

Point-of-Care Testing in Primary Care

Point-of-care testing (POCT) in pediatric primary care is essential for clinicians to make a timely and accurate diagnosis. The COVID-19 pandemic has highlighted the importance of timely and accurate testing strategies to correctly identify the etiology of upper and lower respiratory infections. Additionally, pediatric POCT continues to be important in rural and underserved communities where access to hospital laboratories may be less available. This chapter will focus on seven rapid tests: Group A streptococcus (GAS), influenza A & B, SARS-CoV-2 (COVID-19), human immunodeficiency virus (HIV), C-reactive protein (CRP), human chorionic gonadotropin (hCG), and hemoglobin A1c (HbA1c). © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Switzerland AG 2022.

Non-trauma uses of viscoelastic hemostatic assays in critical care: A narrative review and primer for pharmacists

Thromboelastography (TEG) and rotational thromboelastometry (ROTEM) are point-of-care viscoelastic tests of whole blood that provide real-time analyses of coagulation. TEG and ROTEM are often used to guide blood product administration in the trauma and surgical settings. These tests are increasingly being explored for their use in other disease states encountered in critically ill patients and in the management of antithrombotic medications. As the medication experts, pharmacists should be familiar with how to interpret and apply viscoelastic tests to disease state and medication management. The purpose of this narrative review is to provide a primer for pharmacists on viscoelastic tests and their interpretation and to explore non-trauma indications for viscoelastic testing in critical care. Literature evaluating the use of TEG and ROTEM for patients with acute and chronic liver disease, ischemic and hemorrhagic stroke, myocardial infarction, cardiac arrest, coronavirus disease 2019, and extracorporeal membrane oxygenation are described. Current applications of viscoelastic tests by pharmacists and potential future roles of critical care pharmacists in expanding the use of viscoelastic tests are summarized.Copyright © 2023 The Authors. JACCP: Journal of the American College of Clinical Pharmacy published by Wiley Periodicals LLC on behalf of Pharmacotherapy Publications, Inc.

Rapid and Low-Cost Detection of Human Corona Virus Using MEMS ATR-FTIR Spectroscopy

The conventional methods used for the diagnostics of viral infection are either expensive and time-consuming or not accurate enough and dependent on consumable reagents. In the presence of pandemics, a fast and reagent-free solution is needed for mass screening. Recently, the diagnosis of viral infections using infrared spectroscopy has been reported as a fast and low-cost method. In this work a fast and low-cost solution for corona viral detection using infrared spectroscopy based on a compact micro-electro-mechanical systems (MEMS) device and artificial intelligence (AI) suitable for mass deployment is presented. Among the different variants of the corona virus that can infect people, 229E is used in this study due to its low pathogeny. The MEMS ATR-FTIR device employs a 6 reflections ZnSe crystal interface working in the spectral range of 2200-7000 cm-1. The virus was propagated and maintained in a medium for long enough time then cell supernatant was collected and centrifuged. The supernatant was then transferred and titrated using plaque titration assay. Positive virus samples were prepared with a concentration of 105 PFU/mL. Positive and negative control samples were applied on the crystal surface, dried using a heating lamp and the spectrum was captured. Principal component analysis and logistic regression were used as simple AI techniques. A sensitivity of about 90 % and a specificity of about 80 % were obtained demonstrating the potential detection of the virus based on the MEMS FTIR device. © 2023 SPIE.

Smart Nanobiosensing for COVID-19 Diagnosis

Repeated public health menace caused by the pathogenic coronaviruses, including the present COVID-19 caused by the Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2), has had devastating aftereffects, and an intense need for a promising solution has developed. Currently, reverse transcription polymerase chain reaction (RT-PCR) is being extensively utilized for detecting the virus from biological samples. However, it has certain limitations and fails to provide accurate and reliable results. Consequently, simple, portable, and pointof- care testing enabled biosensors have turned up as the most efficient and sustainable diagnostic tool. This review provides a brief introduction about the present global scenario due to the ongoing pandemic and concise information regarding the morphological details of coronaviruses. Thereafter, a summarized data is presented regarding the contemporary biosensing platforms fabricated to specifically identify fatal coronaviruses with particular emphasis towards surface plasmon resonance (SPR)-based biosensor, field-effect transistor (FET)-based biosensor, colorimetric sensors, fluorescence-based sensors, and electrochemical (EC) immunosensors. A comparative analysis of the sensors is also presented along with a few future perspectives that can aid the development of smart and futuristic sensors. This review is expected to provide details to researchers about the ongoing biosensor-related experimentations and encourage them to develop innovative detection devices to manage the current pandemic. © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2023.

Smartphone-based point-of-care testing of the SARS-CoV-2: A systematic review.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus's worldwide pandemic has highlighted the urgent need for reliable, quick, and affordable diagnostic tests for comprehending and controlling the epidemic by tracking the world population. Given how crucial it is to monitor and manage the pandemic, researchers have recently concentrated on creating quick detection techniques. Although PCR is still the preferred clinical diagnostic test, there is a pressing need for substitutes that are sufficiently rapid and cost-effective to provide a diagnosis at the time of use. The creation of a quick and simple POC equipment is necessary for home testing. Our review's goal is to provide an overview of the many methods utilized to identify SARS-CoV 2 in various samples utilizing portable devices, as well as any potential applications for smartphones in epidemiological research and detection. The point of care (POC) employs a range of microfluidic biosensors based on smartphones, including molecular sensors, immunological biosensors, hybrid biosensors, and imaging biosensors. For example, a number of tools have been created for the diagnosis of COVID-19, based on various theories. Integrated portable devices can be created using loop-mediated isothermal amplification, which combines isothermal amplification methods with colorimetric detection. Electrochemical approaches have been regarded as a potential substitute for optical sensing techniques that utilize fluorescence for detection and as being more beneficial to the Minimizing and simplicity of the tools used for detection, together with techniques that can amplify DNA or RNA under constant temperature conditions, without the need for repeated heating and cooling cycles. Many research have used smartphones for virus detection and data visualization, making these techniques more user-friendly and broadly distributed throughout nations. Overall, our research provides a review of different novel, non-invasive, affordable, and efficient methods for identifying COVID-19 contagious infected people and halting the disease's transmission.

Venous blood point-of-care testing (POCT) for paramedics in urgent and emergency care: protocol for a single-site feasibility study (POCTPara).

The COVID-19 pandemic placed the UK healthcare system under unprecedented pressure, and recovery will require whole-system investment in innovative, flexible and pragmatic solutions. Positioned at the heart of the healthcare system, ambulance services have been tasked with addressing avoidable hospital conveyance and reducing unnecessary emergency department and hospital attendances through the delivery of care closer to home. Having begun to implement models of care intended to increase 'see and treat' opportunities through greater numbers of senior clinical decision makers, emphasis has now been placed upon the use of remote clinical diagnostic tools and near-patient or point-of-care testing (POCT) to aid clinical decision making. In terms of POCT of blood samples obtained from patients in the pre-hospital setting, there is a paucity of evidence beyond its utility for measuring lactate and troponin in acute presentations such as sepsis, trauma and myocardial infarction, although potential exists for the analysis of a much wider panel of analytes beyond these isolated biomarkers. In addition, there is a relative dearth of evidence in respect of the practicalities of using POCT analysers in the pre-hospital setting. This single-site feasibility study aims to understand whether it is practical to use POCT for the analysis of patients' blood samples in the urgent and emergency care pre-hospital setting, through descriptive data of POCT application and through qualitative focus group interviews of advanced practitioners (specialist paramedics) to inform the feasibility and design of a larger study. The primary outcome measure is focus group data measuring the experiences and perceived self-reported impact by specialist paramedics. Secondary outcome measures are number and type of cartridges used, number of successful and unsuccessful attempts in using the POCT analyser, length of time on scene, specialist paramedic recruitment and retention, number of patients who receive POCT, descriptive data of safe conveyance, patient demographics and presentations where POCT is applied and data quality. The study results will inform the design of a main trial if indicated.

Recent advancements in critical care: Part I.

Medical colleges are now developing or refurbishing their anaesthesia intensive care units. In most teaching colleges, the residency post includes working in the critical care unit (CCU). Critical care is a rapidly evolving and popular super-speciality for postgraduate students. In some hospitals, anaesthesiologists play a key role in the management of the CCU. As perioperative physicians, all anaesthesiologists should be aware of the recent advancements in diagnostic and monitoring gadgets and investigations in critical care so that they may manage perioperative events effectively. Haemodynamic monitoring gives us warning signs about the change in the internal milieu of the patient. Point-of-care ultrasonography helps in rapid differential diagnosis. Point-of-care diagnostics give us instant bed-side information on the condition of a patient. Biomarkers help in confirming diagnosis, in monitoring, treatment, and providing prognosis. Molecular diagnostics guide anaesthesiologists in providing specific treatment to a causative agent. This article touches upon all of these management strategies in critical care and attempts to put forth the recent advancements in this speciality.

Classification of "Near-patient" and "Point-of-Care" SARS-CoV-2 Nucleic Acid Amplification Test Systems and a first approach to evaluate their analytical independence of operator activities.

BACKGROUND: European legislation defines as "near-patient testing" (NPT) what is popularly and in other legislations specified as "point-of-care testing" (POCT). Systems intended for NPT/POCT use must be characterized by independence from operator activities during the analytic procedure. However, tools for evaluating this are lacking. We hypothesized that the variability of measurement results obtained from identical samples with a larger number of identical devices by different operators, expressed as the method-specific reproducibility of measurement results reported in External Quality Assessment (EQA) schemes, is an indicator for this characteristic. MATERIALS AND METHODS: Legal frameworks in the EU, the USA and Australia were evaluated about their requirements for NPT/POCT. EQA reproducibility of seven SARS-CoV-2-NAAT systems, all but one designated as "POCT", was calculated from variabilities in Ct values obtained from the respective device types in three different EQA schemes for virus genome detection. RESULTS: A matrix for characterizing test systems based on their technical complexity and the required operator competence was derived from requirements of the European In Vitro Diagnostic Regulation (IVDR) 2017/746. Good EQA reproducibility of the measurement results of the test systems investigated implies that different users in different locations have no recognizable influence on their measurement results. CONCLUSION: The fundamental suitability of test systems for NPT/POCT use according to IVDR can be easily verified using the evaluation matrix presented. EQA reproducibility is a specific characteristic indicating independence from operator activities of NPT/POCT assays. EQA reproducibility of other systems than those investigated here remains to be determined.

Laboratory

The laboratory plays an integral part in providing quality, accurate, and reliable services to satisfy clinicians' needs, help improve patient outcomes, and safeguard public health. During a crisis and especially in a pandemic, laboratory may struggle to work on an existing continuity plan, potentially rendering it incapable of providing timely services. This possibility became a reality during the COVID-19 pandemic surge in the Spring of 2020 in New York City, and laboratory experienced a shortage of labor force, necessary tools, personal protective equipment, testing equipment, supplies, and an inability to store bodies in response to mass fatality. The importance of a laboratory response during a crisis, including effective preparation, and the necessity of having a continuity plan were refined. This chapter was developed based on lessons learned during COVID-19 pandemic at the SBH Health System, Bronx, New York, to provide guidelines to better manage a healthcare crisis, including the development of a more effective continuity plan to prevent disruption of laboratory services, enabling laboratory to continue providing accurate, reliable, and quality services to clinicians for timely decision-making in managing patient treatment and resultant fatality management. In addition, this chapter may help minimize and overcome the interruption in laboratory-continued operations if the crisis has already occurred, ensuring that rapid recovery is initiated, and laboratory operations can be resumed within an acceptable period of time to safeguard public health. © SBH Health System 2022.

Point-of-care testing of SARS -CoV-2 and influenza A and B at hospital emergency room during Covid-19 pandemic among patients with acute respiratory diseases

Introduction. The most common causes of acute respiratory diseases (ARD) with significant morbidity and mortality include, for a long time, the influenza virus and, in recent years, also the SARS-Cov-2 virus. Patients with various clinical symptoms are triaged in emergency rooms of hospitals, and therefore their rapid and reliable diagnostics is essential in order to prevent the spread of ARD. Molecular genetic point-of-care testing (POCT) at the point of care represents a significant advance in clinical diagnostics. Materials and methods. Diagnostics of viral agents of ARD took place from December 2021 to February 2022. 1046 nasopharynx swabs samples were collected in the emergency room of I. Internal Clinic of the Faculty of Medicine at Comenius University and the University Hospital in Bratislava. SARSCov-2 and influenza were detected from the same sample using the cobas® SARS-Cov-2 & Influenza A/B test on the cobas® Liat® system. Results. From the total number of biological material collected, the SARS-Cov-2 virus was detected in 135 samples (12.9 %), while the highest incidence of positive samples was in February 2022 - 86 (20.9 % positivity), followed by December 2021 - 31 (23.0 % positivity) and January 2022 - 18 (13.3% positivity). Influenza type A virus was detected in two samples (0.2%) and influenza type B virus was not detected. Conclusion. POCT made it possible to significantly improve the screening of patients and minimize the risk of nosocomial transmission of respiratory infections in the hospital thanks to the rapid and accurate diagnosis of the SARS-CoV-2 virus and influenza A/B (Fig. 3, Ref. 32). Text v PDF www.lekarsky.herba. sk. © 2023, Lekarsky Obzor. All Rights Reserved.

The CRISPR/Cas System: A Customizable Toolbox for Molecular Detection.

Clustered regularly interspaced short palindromic repeats (CRISPR) and their associated proteins (Cas) are promising molecular diagnostic tools for rapidly and precisely elucidating the structure and function of genomes due to their high specificity, programmability, and multi-system compatibility in nucleic acid recognition. Multiple parameters limit the ability of a CRISPR/Cas system to detect DNA or RNA. Consequently, it must be used in conjunction with other nucleic acid amplification techniques or signal detection techniques, and the reaction components and reaction conditions should be modified and optimized to maximize the detection performance of the CRISPR/Cas system against various targets. As the field continues to develop, CRISPR/Cas systems have the potential to become an ultra-sensitive, convenient, and accurate biosensing platform for the detection of specific target sequences. The design of a molecular detection platform employing the CRISPR/Cas system is asserted on three primary strategies: (1) Performance optimization of the CRISPR/Cas system; (2) enhancement of the detection signal and its interpretation; and (3) compatibility with multiple reaction systems. This article focuses on the molecular characteristics and application value of the CRISPR/Cas system and reviews recent research progress and development direction from the perspectives of principle, performance, and method development challenges to provide a theoretical foundation for the development and application of the CRISPR/CAS system in molecular detection technology.

Preparing for the next pandemic: lessons learnt from the implementation of point-of-care SARS-CoV-2 testing in an emergency department.

Point-of-care testing (POCT) provides rapid, accurate results that facilitate diagnosis and patient management. POCT for infectious agents allows timely infection prevention and control interventions and informs decisions around safe patient placement. However, POCT implementation requires careful governance as they are primarily operated by staff with limited prior education on laboratory quality control and assurance processes. Here, we describe our experience implementing SARS-CoV-2 POCT in the emergency department of a large tertiary referral hospital during the COVID-19 pandemic. We describe collaborative governance between pathology and clinical specialities, quality assurance, testing (volume and positivity rates), impact on patient flow and focus on lessons learnt during implementation that should be incorporated into revised pandemic preparedness planning.

A review of current effective COVID-19 testing methods and quality control.

COVID-19 is a highly infectious disease caused by the SARS-CoV-2 virus, which primarily affects the respiratory system and can lead to severe illness. The virus is extremely contagious, early and accurate diagnosis of SARS-CoV-2 is crucial to contain its spread, to provide prompt treatment, and to prevent complications. Currently, the reverse transcriptase polymerase chain reaction (RT-PCR) is considered to be the gold standard for detecting COVID-19 in its early stages. In addition, loop-mediated isothermal amplification (LMAP), clustering rule interval short palindromic repeats (CRISPR), colloidal gold immunochromatographic assay (GICA), computed tomography (CT), and electrochemical sensors are also common tests. However, these different methods vary greatly in terms of their detection efficiency, specificity, accuracy, sensitivity, cost, and throughput. Besides, most of the current detection methods are conducted in central hospitals and laboratories, which is a great challenge for remote and underdeveloped areas. Therefore, it is essential to review the advantages and disadvantages of different COVID-19 detection methods, as well as the technology that can enhance detection efficiency and improve detection quality in greater details.

Recent advances in non-optical microfluidic platforms for bioparticle detection.

The effective analysis of the basic structure and functional information of bioparticles are of great significance for the early diagnosis of diseases. The synergism between microfluidics and particle manipulation/detection technologies offers enhanced system integration capability and test accuracy for the detection of various bioparticles. Most microfluidic detection platforms are based on optical strategies such as fluorescence, absorbance, and image recognition. Although optical microfluidic platforms have proven their capabilities in the practical clinical detection of bioparticles, shortcomings such as expensive components and whole bulky devices have limited their practicality in the development of point-of-care testing (POCT) systems to be used in remote and underdeveloped areas. Therefore, there is an urgent need to develop cost-effective non-optical microfluidic platforms for bioparticle detection that can act as alternatives to optical counterparts. In this review, we first briefly summarise passive and active methods for bioparticle manipulation in microfluidics. Then, we survey the latest progress in non-optical microfluidic strategies based on electrical, magnetic, and acoustic techniques for bioparticle detection. Finally, a perspective is offered, clarifying challenges faced by current non-optical platforms in developing practical POCT devices and clinical applications.

Community pharmacist-provided test and treat programs for acute infectious conditions

Community pharmacists' roles have expanded in recent years to include offering test and treat programs where they perform testing on Clinical Laboratory Improvement Amendment (CLIA)-waived point-of-care testing (POCT) devices to diagnose specific acute infectious conditions, such as influenza and group A streptococcus (GAS) pharyngitis, and then potentially prescribe and dispense appropriate antimicrobials. Availability of these services in pharmacies has several benefits, including increased access to care, decreased overutilization of other health care services, and decreased antimicrobial resistance. States have different requirements for collaborative practice agreements and reimbursement for these clinical services in community pharmacies. Several studies have looked at outcomes related to community pharmacies implementing test and treat programs for influenza and/or GAS. Other studies looked at outcomes related to implementing testing for SARS-CoV-2 and referring for treatment. Most studies described successful implementation and barriers to integration of these programs into pharmacy workflow. Some studies showed that patients want these services to be offered in community pharmacies and are willing to pay for the services. Data show that these services are cost effective compared to physician provider-based treatment. Newer CLIA-waived POCT technology may increase implementation of these services, but studies are needed to evaluate their utility in community pharmacies. Pharmacy schools should implement widespread training on these devices, and research should continue in this area to test the use of newer technology (i.e., multiplexed devices) and their economic impact.Copyright © 2023 Pharmacotherapy Publications, Inc.

Four thermostatic steps: A novel CRISPR-Cas12-based system for the rapid at-home detection of respiratory pathogens.

The outbreak of coronavirus disease 2019 (COVID-19) in 2019 has severely damaged the world's economy and public health and made people pay more attention to respiratory infectious diseases. However, traditional quantitative real-time polymerase chain reaction (qRT-PCR) nucleic acid detection kits require RNA extraction, reverse transcription, and amplification, as well as the support of large-scale equipment to enrich and purify nucleic acids and precise temperature control. Therefore, novel, fast, convenient, sensitive and specific detection methods are urgently being developed and moving to proof of concept test. In this study, we developed a new nucleic acid detection system, referred to as 4 Thermostatic steps (4TS), which innovatively allows all the detection processes to be completed in a constant temperature device, which performs extraction, amplification, cutting of targets, and detection within 40 min. The assay can specifically and sensitively detect five respiratory pathogens, namely SARS-CoV-2, Mycoplasma felis (MF), Chlamydia felis (CF), Feline calicivirus (FCV), and Feline herpes virus (FHV). In addition, a cost-effective and practical small-scale reaction device was designed and developed to maintain stable reaction conditions. The results of the detection of the five viruses show that the sensitivity of the system is greater than 94%, and specificity is 100%. The 4TS system does not require complex equipment, which makes it convenient and fast to operate, and allows immediate testing for suspected infectious agents at home or in small clinics. Therefore, the assay system has diagnostic value and significant potential for further reducing the cost of early screening of infectious diseases and expanding its application. KEY POINTS: • The 4TS system enables the accurate and specific detection of nucleic acid of pathogens at 37 °C in four simple steps, and the whole process only takes 40 min. •A simple alkali solution can be used to extract nucleic acid. • A small portable device simple to operate is developed for home diagnosis and detection of respiratory pathogens.