Diagnosis and main types of coronavirus in humans: a narrative review / Uma análise dos principais diagnósticos de Sars-cov-2 disponíveis no Brasil: uma revisão de literatura / Diagnóstico y principales tipos de coronavirus en humanos: una revisión narrativa

Introdução: Com a emergência do SARS-CoV-2 foi disponibilizado uma grande quantidade de ferramentas de diagnóstico. Neste contexto, a falta de vacina, de tratamento e o grande número de casos graves e morte, possibilitou a aprovação emergencial de diversos testes, que ainda necessitam de estudos populacionais para seu registro definitivo. Objetivo: Realizar uma revisão de literatura para avaliar as metodologias de diagnóstico disponíveis no Brasil, de acordo com a realidade local de saúde, explorando o momento epidemiológico a complexidade do teste e a finalidade da sua aplicação. Metodologia: Trata-se de um estudo bibliográfico, descritivo do tipo revisão de literatura. Foram utilizadas as seguintes bases de dados científicos para buscas: PUBMED, MEDLINE, LILACS E COCHRANE LIBRARY, através de descritores selecionados na plataforma DECS. Resultados: O cenário de diversos ensaios, baseados em diferentes metodologias, como os testes baseados em RNA viral, em detecção de antígenos virais ou de anticorpos, associados ao conhecimento da história natural do vírus, possibilita uma análise crítica do melhor diagnóstico de acordo com a clínica do paciente, os epidemiológicos, o objetivo do diagnóstico e a acurácia do ensaio. Atualmente, há mudança no padrão imunológico da população e a descrição de tipos e subtipos de SARS-CoV-2 com mudanças gênicas, que podem levar a mudanças na acurácia diagnóstica ou a re-emergência em surtos de doença grave. Conclusão: Ainda é incerto o caminho evolutivo da história natural da Covid-19 e os ensaios diagnósticos estão em diferentes estágios de desenvolvimento, validação e produção e cada tipo de teste tem suas próprias vantagens e desvantagens distintas inerentes a plataforma tecnológica de origem e uma combinação de tipos de testes usados em momentos diferentes pode ser útil para a condução clínica dos pacientes e no controle da pandemia por SARS-CoV-2.

Introduction: With the emergence of SARS-CoV-2, a large number of diagnostic tools were made available. In this context, the lack of vaccine, treatment and the large number of severe cases and death, allowed the emergency approval of several tests, which still require population studies for their definitive registration. Objective: To carry out a literature review to evaluate the diagnostic methodologies available in Brazil, according to the local health reality, exploring the epidemiological moment, the complexity of the test and the purpose of its application. Methodology: This is a bibliographic, descriptive study of the literature review type. The following scientific databases were used for searches: PUBMED, MEDLINE, LILACS AND COCHRANE LIBRARY, through selected descriptors on the DECS platform. Results: The scenario of several tests, based on different methodologies, such as tests based on viral RNA, on detection of viral antigens or antibodies, associated with knowledge of the natural history of the virus, allows a critical analysis of the best diagnosis according to the patient's clinical, epidemiological, diagnostic objective and assay accuracy. Currently, there is a change in the immune pattern of the population and the description of types and subtypes of SARS-CoV-2 with genetic changes, which can lead to changes in diagnostic accuracy or the re-emergence in outbreaks of severe disease. Conclusion: The evolutionary path of the natural history of Covid-19 is still uncertain and diagnostic assays are at different stages of development, validation and production and each type of test has its own distinct advantages and disadvantages inherent in the technology platform of origin and a combination of types of tests used at different times can be useful for the clinical management of patients and in the control of the SARS-CoV-2 pandemic.

Introducción: Con la aparición del SARS-CoV-2, se dispuso de un gran número de herramientas diagnósticas. En este contexto, la falta de vacuna, tratamiento y el gran número de casos graves y muerte, permitieron la aprobación de urgencia de varias pruebas, que aún requieren estudios poblacionales para su registro definitivo. Objetivo: Realizar una revisión bibliográfica para evaluar las metodologías diagnósticas disponibles en Brasil, de acuerdo con la realidad sanitaria local, explorando el momento epidemiológico, la complejidad de la prueba y la finalidad de su aplicación. Metodología: Se trata de un estudio bibliográfico, descriptivo, del tipo revisión de literatura. Para las búsquedas se utilizaron las siguientes bases de datos científicas PUBMED, MEDLINE, LILACS Y COCHRANE LIBRARY, a través de descriptores seleccionados en la plataforma DECS. Resultados: El escenario de varias pruebas, basadas en diferentes metodologías, como pruebas basadas en el ARN viral, en la detección de antígenos virales o anticuerpos, asociado al conocimiento de la historia natural del virus, permite un análisis crítico del mejor diagnóstico de acuerdo con la clínica del paciente, epidemiológica, objetivo diagnóstico y precisión de la prueba. Actualmente, hay un cambio en el patrón inmunológico de la población y la descripción de tipos y subtipos de SARS-CoV-2 con cambios genéticos, que pueden conducir a cambios en la precisión diagnóstica o la reaparición en brotes de enfermedad grave. Conclusiones: El camino evolutivo de la historia natural del Covid-19 es aún incierto y los ensayos de diagnóstico se encuentran en diferentes etapas de desarrollo, validación y producción y cada tipo de prueba tiene sus propias ventajas y desventajas distintas inherentes a la plataforma tecnológica de origen y una combinación de tipos de pruebas utilizadas en diferentes momentos puede ser útil para el manejo clínico de los pacientes y en el control de la pandemia de SARS- CoV-2.

Agreement between diagnostic methods for SARS-CoV-2 infection in children seen at the Emergency Department of a children's hospital / Concordancia entre métodos diagnósticos de infección por SARS-CoV-2 en niños asistidos en el departamento de urgencias de un hospital pediátrico

Introducción. Los inmunoensayos de detección rápida de antígenos (TRA) del SARS-CoV-2, son considerados adecuados para el diagnóstico en el punto de atención. El objetivo fue conocer la concordancia entre la reacción en cadena de la polimerasa en tiempo real con transcriptasa inversa (RT-qPCR, por su sigla en inglés) y los TRA en población pediátrica. Población y métodos. Se reclutaron todos los pacientes entre 1 mes y 17 años 11 meses de edad atendidos en la Unidad Febril de Urgencia de un hospital pediátrico entre el 11 de junio y el 3 de octubre de 2021. Se utilizó el TRA Panbio COVID-19 Ag® (Abbott Diagnostic) y, comométodo de referencia, la RT-qPCR (según el protocolo de los Centros para el Control y la Prevención de Enfermedades). Resultados. Se incluyeron 6491 pacientes. La prevalencia de COVID-19 fue del 2,8 %. El92,1 % de los sujetos presentaron síntomas. La sensibilidad, la especificidad y el índice kappa de concordancia para el TRA fueron del 71,0 %, 99,9 % y 0,813, respectivamente. El índice kappa yla sensibilidad del TRA fueron significativamentemayores en el grupo de 13 a 17 años (0,89 y 82,4 %,respectivamente) cuando se los comparó con los grupos de 0 a 5 y de 6 a 12 años. Esto podría deberse a la menor carga viral observada en los pacientes menores de 12 años. Conclusión. Si bien los TRA permiten acortar el tiempo de obtención de los resultados y mejorar la estrategia de aislamiento de pacientes con COVID-19, la sensibilidad en niños menores de 12 años o asintomáticos no se encontraría dentro de los rangos recomendados, sobre todo enperíodos de baja prevalencia de la enfermedad.

Introduction. Rapid antigen tests (RAgTs) for SARS-CoV-2 are considered adequate for diagnosis at the point of care. Our objective was to establish the agreement between reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and RAgTs in the pediatric population. Population and methods. All patients aged 1 month to 17 years and 11 months seen at the Emergency Fever Unit of a children's hospital between 6-11-2021 and 10-3-2021 were recruited. The Panbio COVID-19 Ag® test (Abbott Diagnostic) was compared to the reference method RT-qPCR (as per the protocol suggested by the United States Centers for Disease Control and Prevention). Results. A total of 6491 patients were included. The prevalence of COVID-19 was 2.8%. Symptoms were observed in 92.1%. Sensitivity, specificity, and the kappa index of agreement for the RAgT were 71.0%, 99.9%, and 0.813, respectively. The kappa index and the RAgT sensitivity were significantly higher in the group aged 13­17 years (0.89 and 82.4%, respectively) compared to the groups aged 0­5 and 6­12 years. This may be due to the lower viral load observed in patients younger than 12 years. Conclusion. Although RAgTs shorten the time to result and improve the isolation strategy for COVID-19 patients, their sensitivity in children younger than 12 years or asymptomatic children is not within the recommended ranges, especially during periods of low disease prevalence.

Evaluation of Temporary COVID-19 Testing Sites at Brussels Airport, Belgium: Users' Comfort and Privacy

This paper explored the temporary facilities created during the pandemic for use as COVID-19 test centers at Zaventem Airport, the main airport for the city of Brussels, Belgium. The possibilities of modular construction technology and the impact of the building envelope on users' perception of indoor space comfort and privacy were closely observed. The three main problem statements were as follows: (1) the COVID-19 crisis indirectly influenced the creation of temporary modular buildings with glass envelopes;(2) the modular envelope is adaptable to the existing context;and (3) the envelope meets the needs of the users. This study's objectives were to identify the critical factors for users' well-being in temporary modular buildings, and to conduct factor comparisons among different users and between different building-enclosure systems. The study data were collected through a subjective assessment using a SWOT analysis and a survey questionnaire. The glass facade affected the users' acceptance levels of comfort and privacy. The main results show that the users were satisfied with the level of comfort and dissatisfied with the level of privacy. This information can be used to identify areas for improvement and provide useful feedback to designers and engineers about specific design features and operating strategies for temporary modular emergency healthcare buildings.

Compliance with COVID-19 prevention guidelines: Active vs. passive risk takers

In 2020, most countries around the world adopted various measures aimed at combating the coronavirus (i.e., COVID-19), or reducing risky behavior which may spread the virus. In the current study (N = 215), we examined compliance with COVID-19 prevention guidelines using a risk-taking perspective, differentiating active from passive risk taking. In the corona context active risk taking involves actions that may cause disease contraction, such as shaking hands, while passive risk taking involves the acceptance of risk brought on by inaction, as in not using an alco-gel disinfectant. We found that personal tendencies for passive and active risk taking predicted passive and active corona related risk taking, respectively. Furthermore, compliance with COVID-19 prevention measures was also related to differences in self-control, with low Initiation self-control predicting passive corona risk taking and low levels of Inhibition self-control predicting active corona risk taking. Thus, while not complying with Covid-19 prevention measures put people at risk, differentiating between active and passive risks is helpful for accurate prediction of each type of risk behavior. (PsycInfo Database Record (c) 2023 APA, all rights reserved)

Rational thinking style, rejection of coronavirus (COVID-19) conspiracy theories/theorists, and compliance with mandated requirements: Direct and indirect relationships in a nationally representative sample of adults from the United Kingdom

Faced with the threat posed by the COVID-19 pandemic, many nations have mandated sets of requirements, such as social-distancing measures. However, compliance with such measures is likely to be shaped by a range of factors. Here, we proposed and tested a mediation model in which rejection of COVID-19 conspiracy theories and/or theorists mediates the relationship between rational thinking style and compliance with mandated requirements. An online, nationally representative sample of the adult population in the United Kingdom (N = 520) completed a previously validated measure of rational thinking style, as well as novel measures of rejection of COVID-19 conspiracy theories/theorists and compliance with mandated requirements. Intercorrelations between scores on all three measures were significant and positive. Mediation analysis indicated that rational thinking style and rejection of COVID-19 conspiracy theories/theorists, respectively, were directly associated with compliance, and that the mediated association was also significant. These results may have implications for practical policy aimed at promoting greater compliance with mandated requirements, including social distancing. (PsycInfo Database Record (c) 2023 APA, all rights reserved)

Covid-19 detection using Cough Sound with Neural Networks

COVID-19 has already had a significant influence on our everyday lives and with the influx of patients infected with the newer emerging variants there arises a need for a quick, accurate, and remote mode of identification. Cough sounds can play a vital role in the identification of COVID-19 in individuals. They can be used as an important factor to determine if the person is infected by COVID-19 or not, even with the prior existence of a respiratory ailment. Hence, we focused on providing a widely accessible and scalable solution through the method of a real-time mode of detection of the 'COVID cough' via a machine learning model trained 'COVID cough' recorded dataset. Based on the input, the person is provided with the diagnosis after being assessed by the model. © 2022 IEEE.

Clinical Evaluation of BioFire COVID-19 Test, BioFire Respiratory Panel 2.1, and Cepheid Xpert Xpress SARS-CoV-2 Assays for Sample-to-Answer Detection of SARS-CoV-2.

Background: Due to the extreme infectivity of SARS-CoV-2, sample-to-answer SARS-CoV-2 reverse transcription (RT) polymerase chain reaction (PCR) assays are urgently needed in order to facilitate infectious disease surveillance and control. The purpose of this study was to evaluate three sample-to-answer SARS-CoV-2 RT-PCR assays­BioFire COVID-19 Test, BioFire RP 2.1, and Cepheid Xpert Xpress SARS-CoV-2­using clinical samples. Methods: A total of 77 leftover nasopharyngeal swab (NP) swabs (36 positives and 41 negatives) confirmed by reference SARS-CoV-2 RT real-time (q) PCR assay were collected. The clinical sample concordance, as specified by their respective emergency use authorizations (EUAs), in comparison to the reference SARS-CoV-2 RT-qPCR assay, was assessed. Results: The results showed that all three sample-to-answer SARS-CoV-2 RT-PCR assays provided perfectly concordant results consistent with the reference SARS-CoV-2 RT-qPCR assay. The BioFire COVID-19 Test exhibited the best turnaround time (TAT) compared to the other assays, regardless of the test results, using one-way analysis of variance followed by Scheffe's post hoc test (p < 0.001). The Xpert Xpress SARS-CoV-2 showed a shorter average TAT (mean ± standard deviation, 49.9 ± 3.1 min) in the positive samples compared to that (55.7 ± 2.5 min) of the negative samples. Conclusions: Our evaluation demonstrates that the BioFire COVID-19 Test, BioFire RP 2.1, and Cepheid Xpert Xpress SARS-CoV-2 assays compare favorably to the reference SARS-CoV-2 RT-qPCR assay, along with a 100% concordance in assay results for clinical samples and an acceptable analytical performance at their guaranteed limits of detection. The addition of a widely used simultaneous sample-to-answer SARS-CoV-2 RT-PCR assay will contribute to the number of medical laboratories able to test for COVID-19.

Designing a RFID/IoT prototype for improving COVID19 test centers daily operations

In this research paper, we propose a hybrid agent-based and discrete-event simulation model coupled with a RFID/IoT infrastructure for improving COVID19 test centers located in Montreal region. This study is important, since defining an optimal capacity for healthcare operations is always a challenge, especially in a pandemic mode. Indeed, in such situations, all managers are more concerned by the effectiveness of daily operations regardless their efficiency. Even though, this can be meaningful and largely acceptable, it could lead to critical situations depending on how the current situation may evolve. To improve the performance of COVID19 test centers, it requires a good understanding of logistics flows and a visibility on daily patient inflows and different resource utilization. We propose a RFID/IoT infrastructure that captures test centers real time data and make them available to be used by our hybrid simulation model. The model uses real time data to continuously adjust test centers capacity. This study is part of a bigger project conducted in Montreal region where we design and develop Digital Twins modules to assist different healthcare units such as emergency departments, COVID19 vaccination centers as well as COVID19 test centers. © 2021 The Authors.

Evaluation of self-administered antigen testing in a college setting.

BACKGROUND: The objective of our investigation was to better understand barriers to implementation of self-administered antigen screening testing for SARS-CoV-2 at institutions of higher education (IHE). METHODS: Using the Quidel QuickVue At-Home COVID-19 Test, 1347 IHE students and staff were asked to test twice weekly for seven weeks. We assessed seroconversion using baseline and endline serum specimens. Online surveys assessed acceptability. RESULTS: Participants reported 9971 self-administered antigen test results. Among participants who were not antibody positive at baseline, the median number of tests reported was eight. Among 324 participants seronegative at baseline, with endline antibody results and ≥ 1 self-administered antigen test results, there were five COVID-19 infections; only one was detected by self-administered antigen test (sensitivity = 20%). Acceptability of self-administered antigen tests was high. CONCLUSIONS: Twice-weekly serial self-administered antigen testing in a low prevalence period had low utility in this investigation. Issues of testing fatigue will be important to address in future testing strategies.

A Special Case of Acute Myocarditis with Left Ventricular Thrombus

Introduction. Acute myocarditis is a potential life-threatening disease and left ventricular thrombus could be a complication. Nowadays, myocarditis has been observed after SARS-CoV-2 vaccination. We report the case of a young adult female with left ventricular thrombus secondary to COVID19 mRNA vaccine-related acute myocarditis. Case report A 33-year-old afro-descendant female was admitted to the ED with dyspnea, heart-pounding and chest pain. The EKG showed sinus tachycardia with diffuse changes in repolarization. The lab tests showed: TnHS 8437 ng/mL, C-reactive protein 3,8 mg/dL, normal white blood cell count, NTproBNP 3800 pg/mL, GOT 171 UI/l, GPT 57 UI/l. She received the first dose of mRNA SARS-CoV-2 vaccine 21 days earlier. The PCR swab test for SARS-CoV-2 was negative. Clinical examination revealed HR 110 bpm, BP 105/75 mmHg, normal lung sounds, tachycardic heart sounds. Transthoracic echocardiogram showed EF 25%, massive apical adherent thrombus and mild diffuse pericardial effusion. Serological analysis for viral and bacterial infection were negative. Coronary angiography, cardiac- MRI, myocardial biopsy were not performed because of patient refuse and claustrophobia. LMWH 8000 UI bid, Ibuprofen 600 mg tid and Colchicine 0,5 mg/die were administered. The patient was discharged after 14 days with no symptoms, no residual thrombus and total EF recovery. The alleged adverse event was reported to the National Pharmacovigilance Network. Conclusions Myocarditis is a potential consequence of both COVID-19 and its mRNA vaccines. Post-vaccine myocarditis is usually self-limiting with a low rate of consequences.

Agreement between diagnostic methods for SARS-CoV-2 infection in children seen at the Emergency Department of a children's hospital. / Concordancia entre métodos diagnósticos de infección por SARS-CoV-2 en niños asistidos en el departamento de urgencias de un hospital pediátrico.

INTRODUCTION: Rapid antigen tests (RAgTs) for SARS-CoV-2 are considered adequate for diagnosis at the point of care. Our objective was to establish the agreement between reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and RAgTs in the pediatric population. POPULATION AND METHODS: All patients aged 1 month to 17 years and 11 months seen at the Emergency Fever Unit of a children's hospital between 6-11-2021 and 10-3-2021 were recruited. The Panbio COVID-19 Ag® test (Abbott Diagnostic) was compared to the reference method RT-qPCR (as per the protocol suggested by the United States Centers for Disease Control and Prevention). RESULTS: A total of 6491 patients were included. The prevalence of COVID-19 was 2.8%. Symptoms were observed in 92.1%. Sensitivity, specificity, and the kappa index of agreement for the RAgT were 71.0%, 99.9%, and 0.813, respectively. The kappa index and the RAgT sensitivity were significantly higher in the group aged 13-17 years (0.89 and 82.4%, respectively) compared to the groups aged 0-5 and 6-12 years. This may be due to the lower viral load observed in patients younger than 12 years. CONCLUSIONS: Although RAgTs shorten the time to result and improve the isolation strategy for COVID-19 patients, their sensitivity in children younger than 12 years or asymptomatic children is not within the recommended ranges, especially during periods of low disease prevalence.

Introducción. Los inmunoensayos de detección rápida de antígenos (TRA) del SARS-CoV-2, son considerados adecuados para el diagnóstico en el punto de atención. El objetivo fue conocer la concordancia entre la reacción en cadena de la polimerasa en tiempo real con transcriptasa inversa (RT-qPCR, por su sigla en inglés) y los TRA en población pediátrica. Población y métodos. Se reclutaron todos los pacientes entre 1 mes y 17 años 11 meses de edad atendidos en la Unidad Febril de Urgencia de un hospital pediátrico entre el 11 de junio y el 3 de octubre de 2021. Se utilizó el TRA Panbio COVID-19 Ag® (Abbott Diagnostic) y, como método de referencia, la RT-qPCR (según el protocolo de los Centros para el Control y la Prevención de Enfermedades). Resultados. Se incluyeron 6491 pacientes. La prevalencia de COVID-19 fue del 2,8 %. El 92,1 % de los sujetos presentaron síntomas. La sensibilidad, la especificidad y el índice kappa de concordancia para el TRA fueron del 71,0 %, 99,9 % y 0,813, respectivamente. El índice kappa y la sensibilidad del TRA fueron significativamente mayores en el grupo de 13 a 17 años (0,89 y 82,4 %, respectivamente) cuando se los comparó con los grupos de 0 a 5 y de 6 a 12 años. Esto podría deberse a la menor carga viral observada en los pacientes menores de 12 años. Conclusión. Si bien los TRA permiten acortar el tiempo de obtención de los resultados y mejorar la estrategia de aislamiento de pacientes con COVID-19, la sensibilidad en niños menores de 12 años o asintomáticos no se encontraría dentro de los rangos recomendados, sobre todo en períodos de baja prevalencia de la enfermedad.

COVID-19 test-kit trade and trade policy: Implications for developing countries.

At the centre of the multi-dimensional impact of the COVID-19 pandemic, the shortage of medical supplies in countries with weaker healthcare systems significantly reduced the effectiveness of national and international public health interventions. Using a database of test-kit trade flows and barriers, we estimate the price responsiveness of test-kit demand in a global sample of countries. These estimates allow us to investigate the degree to which import tariffs by leading producers could result in a disruption in global supply chains, price increases, and welfare loss. Simulation experiments indicate that the combination of rising demand for test kits and import dependence magnifies the impact of trade barriers on consumer welfare and this impact is more profound for developing countries.

COVID-19 Test Before Tokyo2020 Paralympic Games: An Implemented Protocol to Protect Paralympic Athletes.

OBJECTIVES: The COVID-19 pandemic represents a difficult challenge for the whole of humanity. Sports, in which contact between athletes is essential, became impossible to practice without the risk of viral spread. Athletes of the national teams are a particular subgroup of the population for whom there is an important need for protection and the implementation of targeted preventive measures. The present report describes the protocol that was developed to answer the urgent protection need for athletes during COVID-19 pandemic. The protocol aimed at demonstrating the feasibility of a rigid prevention intervention to prevent outbreaks and infections in terms of COVID-19 as well as in other potential future pandemics from pathogens with similar path of transmission. METHODS: The study was conducted in rowing para-thletes training of the Paralympic Games in Tokyo2020. It was designed to create an anti-COVID-19 "protection bubble" with the aim to isolate para-athletes and their technical support team during pre-Olympic retreats. The "bubble" development relied on a carefully conducted protocol of repeated antigen and molecular COVID-19 tests on nasal and oropharyngeal fluids among all participants carried out before, during and at the end of each retreat. RESULTS: During the 10 months of protocol implementation there were no COVID-19 outbreaks among the para-athletes and technical personnel during the retreats. In total, 552 PCR tests and 298 antigen-based tests were performed for an average number of 42 test per athlete. The number of retreat participants was larger (n = 23) in the beginning of the year due to the Paralympic selection rounds and smaller at the end of the study period (n = 12). CONCLUSION: The protocol has indicated that it is possible to implement an anti-COVID-19 protection protocol where athletes and technical staff can train and compete in safe conditions. The study showed that it is feasible to implement a rigid prevention protocol for athletes and technical staff based on repeated COVID-19 antigenic and molecular tests for a long period of training with excellent participation and compliance.

Managing COVID-19 Test Certificates Using Blockchain Platform

In early 2020, World Health Organization (WHO) declared that the world is facing the COVID-19 pandemic. This pandemic is caused by the emergence of a new type of coronavirus which spreads very quickly. Because of this pandemic, the government has issued health protocols that use a lot of COVID-19 tests. However, cases of forgery of test certificates often occur in paper-based test certificate. To overcome this problem, we propose a COVID-19 test certificate management system using blockchain technology. By using blockchain technology, the system can be used by multiple entities, even though the entities that use it do not have trust relationship beforehand. This is possible because blockchain is a technology that uses a decentralized network that can store its data with a secure consensus mechanism. The system built using the Ethereum platform, which is a public non-permissioned blockchain that supports decentralized application development through smart contracts that executed via EVM (Ethereum Virtual Machine). The system has been developed using 3-layers architecture, which contains network, software, and application layer. The evaluation shows that the system successfully fulfills the COVID-19 test certificate management requirement. The system can be used for tester registration, and create, revoke, display certificates. Furthermore, by using encryption and digital signature mechanism, the system can protect patient privacy and data integrity. The system has also succeeded in fulfilling the availability and security requirements. However, due to the nature of Ethereum consensus mechanism, the system has much lower response time, compared to the centralized counterpart. © 2021 IEEE.

A fast and cheap in-house magnetic bead RNA extraction method for COVID-19 diagnosis.

COVID-19 has posed a worldwide public health challenge affecting millions of people in different countries. Rapid and efficient detection of SARS-CoV-2 is essential for pandemic control. Reverse Transcription quantitative PCR (RT-qPCR) of nasopharyngeal swabs is the gold standard method for the virus detection, but the high demand for tests has substantially increased the costs and reduced the availability of reagents, including genetic material purification kits. Thus, the present study aimed to compare two bead-based RNA extraction methods (an in-house and a commercial kit) from nasopharyngeal swabs and RT-qPCR detection of SARS-CoV-2. Twenty-five positive and five negative nasopharyngeal swab samples were subjected to extraction of nucleic acids using both methods in an automated platform. Both protocols revealed a high correlation between Cycle Quantifications (Cqs) (r = 0.99, p < 0.0001). In addition, the in-house kit was 89.5 % cheaper when compared to the mean cost of commercial RNA extraction kits. The results show that the in-house protocol is an affordable and reliable option for RNA extraction for SARS-CoV-2 detection from nasopharyngeal swabs.

COVID-19 screening in a Portuguese pediatric population.

OBJECTIVE: To assess the characteristics of suspected coronavirus disease 19 (COVID-19) and the rate of confirmed COVID-19 in a pediatric population at the beginning of the pandemic in Portugal. STUDY DESIGN: Suspected COVID-19 pediatric cases that were tested in a Portuguese hospital between March 17 and April 2 2020 were included in this descriptive retrospective study. The analyzed data included socio-demographic parameters, characteristics of the household, underlying medical conditions and symptoms. RESULTS: Ninety-four patients were included and all of them were symptomatic and treated without hospitalization. The most common symptoms were cough (80%;n=75), rhinorrhea (72%;n=68) and fever (60%;n=56). There was only one positive for SARS-CoV-2 in a five-year-old child with mild illness without epidemiologic linkage. CONCLUSION: This study showed a low rate of confirmed COVID-19 in children. The causes for this low rate can be multifactorial and illustrates how differently this virus spreads in the pediatric population.

Modeling a deep transfer learning framework for the classification of COVID-19 radiology dataset.

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-Coronavirus-2 or SARS-CoV-2), which came into existence in 2019, is a viral pandemic that caused coronavirus disease 2019 (COVID-19) illnesses and death. Research showed that relentless efforts had been made to improve key performance indicators for detection, isolation, and early treatment. This paper used Deep Transfer Learning Model (DTL) for the classification of a real-life COVID-19 dataset of chest X-ray images in both binary (COVID-19 or Normal) and three-class (COVID-19, Viral-Pneumonia or Normal) classification scenarios. Four experiments were performed where fine-tuned VGG-16 and VGG-19 Convolutional Neural Networks (CNNs) with DTL were trained on both binary and three-class datasets that contain X-ray images. The system was trained with an X-ray image dataset for the detection of COVID-19. The fine-tuned VGG-16 and VGG-19 DTL were modelled by employing a batch size of 10 in 40 epochs, Adam optimizer for weight updates, and categorical cross-entropy loss function. The results showed that the fine-tuned VGG-16 and VGG-19 models produced an accuracy of 99.23% and 98.00%, respectively, in the binary task. In contrast, in the multiclass (three-class) task, the fine-tuned VGG-16 and VGG-19 DTL models produced an accuracy of 93.85% and 92.92%, respectively. Moreover, the fine-tuned VGG-16 and VGG-19 models have MCC of 0.98 and 0.96 respectively in the binary classification, and 0.91 and 0.89 for multiclass classification. These results showed strong positive correlations between the models' predictions and the true labels. In the two classification tasks (binary and three-class), it was observed that the fine-tuned VGG-16 DTL model had stronger positive correlations in the MCC metric than the fine-tuned VGG-19 DTL model. The VGG-16 DTL model has a Kappa value of 0.98 as against 0.96 for the VGG-19 DTL model in the binary classification task, while in the three-class classification problem, the VGG-16 DTL model has a Kappa value of 0.91 as against 0.89 for the VGG-19 DTL model. This result is in agreement with the trend observed in the MCC metric. Hence, it was discovered that the VGG-16 based DTL model classified COVID-19 better than the VGG-19 based DTL model. Using the best performing fine-tuned VGG-16 DTL model, tests were carried out on 470 unlabeled image dataset, which was not used in the model training and validation processes. The test accuracy obtained for the model was 98%. The proposed models provided accurate diagnostics for both the binary and multiclass classifications, outperforming other existing models in the literature in terms of accuracy, as shown in this work.

[The contribution of teleconsultation and isolation of symptomatic cases in control of the COVID-19 outbreak a military base]. / Apport de la téléconsultation et de l'isolement des cas symptomatiques dans la maîtrise de l'épidémie COVID-19 au sein d'une base militaire.

BACKGROUND: The first wave of COVID-19 swept over France during the first quarter of 2020, leading to saturation of the health care system. We wished to study, in a French military medical unit assisting one of the country's largest armed forces populations, the impact of teleconsultation and the systematic isolation of all possible, probable and confirmed cases of COVID-19. METHODS: This is a retrospective study carried out from March 9 to May 31, 2020 on the basis of our activity register. The variables collected included type of medical consultation procedure, occupational status, classification of cases and date of onset of first symptoms. We have paralleled our activity with that of SOS Médecins and the emergency departments of the Île-de-France region. RESULTS/DISCUSSION: During this period, 1719 episodes of care (teleconsultations or physical consultations) were recorded, of which 91% (n=1561) were linked to COVID-19. We identified 598 "suspected" (possible and probable) and confirmed cases. "Isolated" teleconsultations (not followed by a face-to-face medical consultation, sample taking or necessitating the dispatch of prompt assistance) represented 86% of episodes of care (n=1482). Comparison of our activity and the number of new cases with the databases of SOS Médecins and the Île-de-France emergency services suggests that our isolation strategy was timely and effective. CONCLUSION: The contribution of teleconsultation was substantial and reassuring. Teleconsultation makes it possible to absorb a large volume of patients, is easy to implement, and entails no nosocomial risk. Isolation of infected patients should be a priority during an outbreak. Once it has become a priority to rapidly bring an epidemic under control, this attitude must be extended to all symptomatic patients.

Pretravel consultation on COVID-19 testing before international travel: lessons learnt from the Thai Travel Clinic, Bangkok, Thailand.

The demand for COVID-19 testing has been on the rise after many countries have eased travel restrictions for essential travel to aid their economy. Thus, we discuss our lessons learnt of the crucial points that need to be considered by the clinicians when dealing with individuals seeking COVID-19 testing before international travel.

COVID-19 screening in a Portuguese pediatric population.

OBJECTIVE: To assess the characteristics of suspected coronavirus disease 19 (COVID-19) and the rate of confirmed COVID-19 in a pediatric population at the beginning of the pandemic in Portugal. STUDY DESIGN: Suspected COVID-19 pediatric cases that were tested in a Portuguese hospital between March 17 and April 2 2020 were included in this descriptive retrospective study. The analyzed data included socio-demographic parameters, characteristics of the household, underlying medical conditions and symptoms. RESULTS: Ninety-four patients were included and all of them were symptomatic and treated without hospitalization. The most common symptoms were cough (80%;n=75), rhinorrhea (72%;n=68) and fever (60%;n=56). There was only one positive for SARS-CoV-2 in a five-year-old child with mild illness without epidemiologic linkage. CONCLUSION: This study showed a low rate of confirmed COVID-19 in children. The causes for this low rate can be multifactorial and illustrates how differently this virus spreads in the pediatric population.