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1.
Talanta ; 222: 121534, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33167242

RESUMO

As COVID-19 has reached pandemic status and the number of cases continues to grow, widespread availability of diagnostic testing is critical in helping identify and control the emergence of this rapidly spreading and serious illness. However, a lacking in making a quick reaction to the threat and starting early development of diagnostic sensing tools has had an important impact globally. In this regard, here we will review critically the current developed diagnostic tools in response to the COVID-19 pandemic and compare the different types through the discussion of their pros and cons such as nucleic acid detection tests (including PCR and CRISPR), antibody and protein-based diagnosis tests. In addition, potential technologies that are under development such as on-site diagnosis platforms, lateral flow, and portable PCR units are discussed. Data collection and epidemiological analysis could also be an interesting factor to incorporate with the emerging technologies especially with the wide access to smartphones. Lastly, a SWOT analysis and perspectives on how the development of novel sensory platforms should be treated by the different decision-makers are analyzed.


Assuntos
Técnicas de Laboratório Clínico/métodos , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/epidemiologia , Pandemias , Pneumonia Viral/diagnóstico , Pneumonia Viral/epidemiologia , Técnicas de Laboratório Clínico/instrumentação , Humanos , Testes Imediatos , Kit de Reagentes para Diagnóstico
2.
PLoS One ; 15(11): e0241959, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33166373

RESUMO

The coronavirus disease 2019 (Covid-19) pandemic, caused by SARS-CoV-2, has resulted in a global testing supply shortage. In response, pooled testing has emerged as a promising strategy that can immediately increase testing capacity. In pooled sample testing, multiple samples are combined (or pooled) together and tested as a single unit. If the pool is positive, the individual samples can then be individually tested to identify the positive case(s). Here, we provide support for the adoption of sample pooling with the point-of-care Cepheid Xpert® Xpress SARS-CoV-2 molecular assay. Corroborating previous findings, the limit of detection of this assay was comparable to laboratory-developed reverse-transcription quantitative PCR SARS-CoV-2 tests, with observed detection below 100 copies/mL. The Xpert® Xpress assay detected SARS-CoV-2 after samples with minimum viral loads of 461 copies/mL were pooled in groups of six. Based on these data, we recommend the adoption of pooled testing with the Xpert® Xpress SARS-CoV-2 assay where warranted based on public health needs. The suggested number of samples per pool, or the pooling depth, is unique for each point-of-care testing site and can be determined by the positive test rates. To statistically determine appropriate pooling depth, we have calculated the pooling efficiency for numerous combinations of pool sizes and test rates. This information is included as a supplemental dataset that we encourage public health authorities to use as a guide to make recommendations that will maximize testing capacity and resource conservation.


Assuntos
Betacoronavirus/genética , Infecções por Coronavirus/diagnóstico , Pneumonia Viral/diagnóstico , RNA Viral/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Betacoronavirus/isolamento & purificação , Infecções por Coronavirus/virologia , Humanos , Pandemias , Pneumonia Viral/virologia , Testes Imediatos , RNA Viral/genética , Kit de Reagentes para Diagnóstico , Manejo de Espécimes , Carga Viral
3.
BMJ ; 371: m4262, 2020 11 11.
Artigo em Inglês | MEDLINE | ID: mdl-33177070

RESUMO

OBJECTIVE: To assess the accuracy of the AbC-19 Rapid Test lateral flow immunoassay for the detection of previous severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. DESIGN: Test accuracy study. SETTING: Laboratory based evaluation. PARTICIPANTS: 2847 key workers (healthcare staff, fire and rescue officers, and police officers) in England in June 2020 (268 with a previous polymerase chain reaction (PCR) positive result (median 63 days previously), 2579 with unknown previous infection status); and 1995 pre-pandemic blood donors. MAIN OUTCOME MEASURES: AbC-19 sensitivity and specificity, estimated using known negative (pre-pandemic) and known positive (PCR confirmed) samples as reference standards and secondly using the Roche Elecsys anti-nucleoprotein assay, a highly sensitive laboratory immunoassay, as a reference standard in samples from key workers. RESULTS: Test result bands were often weak, with positive/negative discordance by three trained laboratory staff for 3.9% of devices. Using consensus readings, for known positive and negative samples sensitivity was 92.5% (95% confidence interval 88.8% to 95.1%) and specificity was 97.9% (97.2% to 98.4%). Using an immunoassay reference standard, sensitivity was 94.2% (90.7% to 96.5%) among PCR confirmed cases but 84.7% (80.6% to 88.1%) among other people with antibodies. This is consistent with AbC-19 being more sensitive when antibody concentrations are higher, as people with PCR confirmation tended to have more severe disease whereas only 62% (218/354) of seropositive participants had had symptoms. If 1 million key workers were tested with AbC-19 and 10% had actually been previously infected, 84 700 true positive and 18 900 false positive results would be projected. The probability that a positive result was correct would be 81.7% (76.8% to 85.8%). CONCLUSIONS: AbC-19 sensitivity was lower among unselected populations than among PCR confirmed cases of SARS-CoV-2, highlighting the scope for overestimation of assay performance in studies involving only PCR confirmed cases, owing to "spectrum bias." Assuming that 10% of the tested population have had SARS-CoV-2 infection, around one in five key workers testing positive with AbC-19 would be false positives. STUDY REGISTRATION: ISRCTN 56609224.


Assuntos
Técnicas de Laboratório Clínico/normas , Infecções por Coronavirus/diagnóstico , Imunoensaio/normas , Pneumonia Viral/diagnóstico , Betacoronavirus , Feminino , Bombeiros , Pessoal de Saúde , Humanos , Masculino , Pandemias , Polícia , Valor Preditivo dos Testes , Kit de Reagentes para Diagnóstico/normas , Sensibilidade e Especificidade , Reino Unido
4.
PLoS Biol ; 18(10): e3000896, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-33006983

RESUMO

The ongoing COVID-19 pandemic has created an unprecedented need for rapid diagnostic testing. The World Health Organization (WHO) recommends a standard assay that includes an RNA extraction step from a nasopharyngeal (NP) swab followed by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) to detect the purified SARS-CoV-2 RNA. The current global shortage of RNA extraction kits has caused a severe bottleneck to COVID-19 testing. The goal of this study was to determine whether SARS-CoV-2 RNA could be detected from NP samples via a direct RT-qPCR assay that omits the RNA extraction step altogether. The direct RT-qPCR approach correctly identified 92% of a reference set of blinded NP samples (n = 155) demonstrated to be positive for SARS-CoV-2 RNA by traditional clinical diagnostic RT-qPCR that included an RNA extraction. Importantly, the direct method had sufficient sensitivity to reliably detect those patients with viral loads that correlate with the presence of infectious virus. Thus, this strategy has the potential to ease supply choke points to substantially expand COVID-19 testing and screening capacity and should be applicable throughout the world.


Assuntos
Betacoronavirus/genética , Técnicas de Laboratório Clínico/métodos , Infecções por Coronavirus/diagnóstico , Pneumonia Viral/diagnóstico , RNA Viral/genética , Kit de Reagentes para Diagnóstico/normas , Reação em Cadeia da Polimerase Via Transcriptase Reversa/normas , Betacoronavirus/patogenicidade , Técnicas de Laboratório Clínico/normas , Infecções por Coronavirus/virologia , Primers do DNA/normas , Humanos , Nasofaringe/virologia , Pandemias , Pneumonia Viral/virologia , Sensibilidade e Especificidade , Estados Unidos , Carga Viral
5.
PLoS Biol ; 18(10): e3000867, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-33027248

RESUMO

The current quantitative reverse transcription PCR (RT-qPCR) assay recommended for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) testing in the United States requires analysis of 3 genomic targets per sample: 2 viral and 1 host. To simplify testing and reduce the volume of required reagents, we devised a multiplex RT-qPCR assay to detect SARS-CoV-2 in a single reaction. We used existing N1, N2, and RP primer and probe sets by the Centers for Disease Control and Prevention, but substituted fluorophores to allow multiplexing of the assay. The cycle threshold (Ct) values of our multiplex RT-qPCR were comparable to those obtained by the single assay adapted for research purposes. Low copy numbers (≥500 copies/reaction) of SARS-CoV-2 RNA were consistently detected by the multiplex RT-qPCR. Our novel multiplex RT-qPCR improves upon current single diagnostics by saving reagents, costs, time, and labor.


Assuntos
Betacoronavirus/genética , Técnicas de Laboratório Clínico/métodos , Infecções por Coronavirus/diagnóstico , Reação em Cadeia da Polimerase Multiplex/normas , Pneumonia Viral/diagnóstico , RNA Viral/genética , Kit de Reagentes para Diagnóstico/normas , Reação em Cadeia da Polimerase Via Transcriptase Reversa/normas , Betacoronavirus/patogenicidade , Estudos de Casos e Controles , Técnicas de Laboratório Clínico/normas , Infecções por Coronavirus/virologia , Primers do DNA/normas , Células HEK293 , Humanos , Limite de Detecção , Nasofaringe/virologia , Pandemias , Pneumonia Viral/virologia , Estados Unidos
6.
PLoS One ; 15(10): e0241332, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33112931

RESUMO

In this work we present a three-stage Machine Learning strategy to country-level risk classification based on countries that are reporting COVID-19 information. A K% binning discretisation (K = 25) is used to create four risk groups of countries based on the risk of transmission (coronavirus cases per million population), risk of mortality (coronavirus deaths per million population), and risk of inability to test (coronavirus tests per million population). The four risk groups produced by K% binning are labelled as 'low', 'medium-low', 'medium-high', and 'high'. Coronavirus-related data are then removed and the attributes for prediction of the three types of risk are given as the geopolitical and demographic data describing each country. Thus, the calculation of class label is based on coronavirus data but the input attributes are country-level information regardless of coronavirus data. The three four-class classification problems are then explored and benchmarked through leave-one-country-out cross validation to find the strongest model, producing a Stack of Gradient Boosting and Decision Tree algorithms for risk of transmission, a Stack of Support Vector Machine and Extra Trees for risk of mortality, and a Gradient Boosting algorithm for the risk of inability to test. It is noted that high risk for inability to test is often coupled with low risks for transmission and mortality, therefore the risk of inability to test should be interpreted first, before consideration is given to the predicted transmission and mortality risks. Finally, the approach is applied to more recent risk levels to data from September 2020 and weaker results are noted due to the growth of international collaboration detracting useful knowledge from country-level attributes which suggests that similar machine learning approaches are more useful prior to situations later unfolding.


Assuntos
Betacoronavirus , Infecções por Coronavirus/epidemiologia , Planejamento em Desastres , Aprendizado de Máquina , Modelos Teóricos , Pandemias , Pneumonia Viral/epidemiologia , Medição de Risco/métodos , Algoritmos , Classificação , Técnicas de Laboratório Clínico , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/mortalidade , Infecções por Coronavirus/transmissão , Árvores de Decisões , Previsões , Saúde Global , Humanos , Cooperação Internacional , Pneumonia Viral/diagnóstico , Pneumonia Viral/mortalidade , Pneumonia Viral/transmissão , Kit de Reagentes para Diagnóstico/provisão & distribução , Máquina de Vetores de Suporte
9.
Sci Rep ; 10(1): 16608, 2020 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-33024174

RESUMO

The technique RT-qPCR for viral RNA detection is the current worldwide strategy used for early detection of the novel coronavirus SARS-CoV-2. RNA extraction is a key pre-analytical step in RT-qPCR, often achieved using commercial kits. However, the magnitude of the COVID-19 pandemic is causing disruptions to the global supply chains used by many diagnostic laboratories to procure the commercial kits required for RNA extraction. Shortage in these essential reagents is even more acute in developing countries with no means to produce kits locally. We sought to find an alternative procedure to replace commercial kits using common reagents found in molecular biology laboratories. Here we report a method for RNA extraction that takes about 40 min to complete ten samples, and is not more laborious than current commercial RNA extraction kits. We demonstrate that this method can be used to process nasopharyngeal swab samples and yields RT-qPCR results comparable to those obtained with commercial kits. Most importantly, this procedure can be easily implemented in any molecular diagnostic laboratory. Frequent testing is crucial for individual patient management as well as for public health decision making in this pandemic. Implementation of this method could maintain crucial testing going despite commercial kit shortages.


Assuntos
Betacoronavirus/genética , Infecções por Coronavirus/diagnóstico , Pneumonia Viral/diagnóstico , RNA Viral/genética , RNA Viral/isolamento & purificação , Reação em Cadeia da Polimerase em Tempo Real , Infecções por Coronavirus/virologia , Testes Diagnósticos de Rotina , Temperatura Alta , Humanos , Concentração de Íons de Hidrogênio , Indicadores e Reagentes , Pandemias , Pneumonia Viral/virologia , Kit de Reagentes para Diagnóstico/provisão & distribução
11.
PLoS One ; 15(10): e0240779, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33057446

RESUMO

The practicability of a prototype capillary whole-blood IgG-IgM COVID-19 self-test (Exacto® COVID-19 self-test, Biosynex Swiss SA, Freiburg, Switzerland) as a serological screening tool for SARS-CoV-2 infection adapted to the general public was evaluated in a cross-sectional, general adult population study performed between April and May 2020 in Strasbourg, France, consisting of face-to-face, paper-based, semi-structured, and self-administrated questionnaires. Practicability was defined as the correct use of the self-test and the correct interpretation of the result. The correct use of self-test was conditioned by the presence of the control band after 15-min of migration. The correct interpretation of the tests was defined by the percent agreement between the tests results read and interpret by the participants compared to the expected results coded by the numbers and verified by trained observers. A total of 167 participants (52.7% female; median age, 35.8 years; 82% with post-graduate level) were enrolled, including 83 and 84 for usability and test results interpretation substudies, respectively. All participants (100%; 95% CI: 95.6-100) correctly used the self-test. However, 12 (14.5%; 95% CI: 8.5-23.6) asked for verbal help. The percent agreement between the tests results read and interpret by the participants compared to the expected results was 98.5% (95% CI: 96.5-99.4). However, misinterpretation occurred in only 2.3% of positive and 1.2% of invalid test results. Finally, all (100%) participants found that performing the COVID-19 self-test was easy; and 98.8% found the interpretation of the self-test results easy. Taken together, these pilot observations demonstrated for the first-time, high practicability and satisfaction of COVID-19 self-testing for serological IgG and IgM immune status, indicating its potential for use by the general public to complete the arsenal of available SARS-CoV-2 serological assays in the urgent context of the COVID-19 epidemic.


Assuntos
Técnicas de Laboratório Clínico/métodos , Infecções por Coronavirus/diagnóstico , Pneumonia Viral/diagnóstico , Kit de Reagentes para Diagnóstico/normas , Adulto , Técnicas de Laboratório Clínico/normas , Infecções por Coronavirus/sangue , Feminino , Humanos , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Masculino , Programas de Rastreamento/métodos , Programas de Rastreamento/normas , Pandemias , Pneumonia Viral/sangue , Testes Imediatos , Autoadministração , Sensibilidade e Especificidade
12.
Biomed Eng Online ; 19(1): 75, 2020 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-33008462

RESUMO

BACKGROUND: The world is facing an unprecedented outbreak affecting all aspects of human lives which is caused by the COVID-19 pandemic. Due to the virus novelty, healthcare systems are challenged by a high rate of patients and the shortage of medical products. To address an increased need for essential medical products, national authorities, worldwide, made various legislative concessions. This has led to essential medical products being produced by automotive, textile and other companies from various industries and approved under the emergency use authorizations or legal concessions of national regulatory bodies. This paper presents a narrative commentary of the available documentation on emergency use authorizations and legal concessions for medical products during COVID-19 pandemic. METHODOLOGY: The basis for narrative commentary includes scientific articles published in Web of Science, Scopus, PubMed and Embase databases, official publications of international organizations: Food and Drug Agency (FDA), World Health Organisation (WHO), World Bank and United Nations (UN), and national regulatory agency reports in native languages (English, German, Bosnian, and Croatian) published from November 1, 2019 to May 1, 2020. This paper focuses on three types of essential medical products: mechanical ventilators, personal protective equipment (PPE) and diagnostic tests. Evidence-informed commentary of available data and potential identified risks of emergency use authorizations and legal concessions is presented. DISCUSSION: It is recognized that now more than ever, raising global awareness and knowledge about the importance of respecting the essential requirements is needed to guarantee the appropriate quality, performance and safety of medical products, especially during outbreak situation, such as the COVID-19 pandemic. Emergency use authorizations for production, import and approval of medical products should be strictly specified and clearly targeted from case to case and should not be general or universal for all medical products, because all of them are associated with different risk level. CONCLUSION: Presented considerations and experiences should be taken as a guide for all possible future outbreak situations to prevent improvised reactions of national regulatory bodies.


Assuntos
Betacoronavirus , Comércio/legislação & jurisprudência , Infecções por Coronavirus , Licenciamento/legislação & jurisprudência , Indústria Manufatureira/legislação & jurisprudência , Pandemias , Equipamento de Proteção Individual/provisão & distribução , Pneumonia Viral , Kit de Reagentes para Diagnóstico/provisão & distribução , Ventiladores Mecânicos/provisão & distribução , Técnicas de Laboratório Clínico/normas , Infecções por Coronavirus/diagnóstico , Falha de Equipamento , União Europeia , Saúde Global , Humanos , Equipamento de Proteção Individual/normas , Kit de Reagentes para Diagnóstico/normas , Medição de Risco , Estados Unidos , United States Food and Drug Administration , Ventiladores Mecânicos/normas
13.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 6131-6134, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33019370

RESUMO

Point-of-care diagnostic devices aid in the early and rapid detection of immunological markers leading to better medical outcomes. Lateral flow immunoassays (LFIA) are fast assays that provide both qualitative and semi-quantitative results on site. Sample preparation for LFIA tests is usually done manually with multiple mixing steps and is prone to errors. The iQuant Auto is an entirely automated system that can handle sample preparation, effective transfer to lateral flow test membrane, and subsequent result estimation. The system uses a pneumatic system for fluid handling and sample preparation, and an image-based fluorescence reader for reaction visualization. The device works with test specific milli-fluidic lateral flow kit called iQPrep Kit, which has integrated reagent storage areas and valves for fluid control. The test kit can be manufactured using standard manufacturing techniques and can be produced at scale cheaply. The iQPrep Kit can be modified to test for various markers like HbA1c, Vitamin D, and TSH, while the hardware for sample preparation and the fluorescence reader remains the same. The device has a minimalist and intelligible graphical interface aiding smooth operation by less skilled people at resource-limited settings. Standard reference cartridges of different volume ratios were used to validate the functionality of the instrument. The intra- instrument coefficient of variation (CoV) of the mobile kit reader was found to be less than 0.62%. The positional accuracy of the system to ensure precise kit engagement with the other auxiliary systems was checked, and the CoV was 0.16%. The fluid handling capabilities were tested, and it was found that an average fluid loss of 10 µl results due to the liquid adherence to fluid channel walls and valve interfaces. The iQuant Auto is an easily operable, total analysis system for immunodiagnostics.


Assuntos
Imunoensaio , Testes Imunológicos , Sistemas Automatizados de Assistência Junto ao Leito , Biomarcadores , Humanos , Tempo de Protrombina , Kit de Reagentes para Diagnóstico
15.
PLoS One ; 15(9): e0237694, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32941461

RESUMO

BACKGROUND: The SARS-CoV-2 (Severe Acute Respiratory Syndrome CoronaVirus 2) is responsible for the infectious respiratory disease called COVID-19 (COronaVIrus Disease 2019). In response to the growing COVID-19 pandemic, point-of-care (POC) tests have been developed to detect specific antibodies, IgG and IgM, to SARS-CoV-2 virus in human whole blood. We conducted a prospective observational study to evaluate the performance of two POC tests, COVID-PRESTO® and COVID-DUO®, compared to the gold standard, RT-PCR (real-time reverse transcriptase polymerase chain reaction). METHODS: RT-PCR testing of SARS-Cov-2 was performed from nasopharyngeal swab specimens collected in adult patients visiting the infectious disease department at the hospital (Orléans, France). Capillary whole blood (CWB) samples from the fingertip taken at different time points after onset of the disease were tested with POC tests. The specificity and sensitivity of the rapid test kits compared to test of reference (RT-PCR) were calculated. RESULTS: Among 381 patients with symptoms of COVID-19 who went to the hospital for a diagnostic, 143 patients were RT-PCR negative. Results of test with POC tests were all negative for these patients, indicating a specificity of 100% for both POC tests. In the RT-PCR positive subgroup (n = 238), 133 patients were tested with COVID-PRESTO® and 129 patients were tested with COVID-DUO® (24 patients tested with both). The further the onset of symptoms was from the date of collection, the greater the sensitivity. The sensitivity of COVID-PRESTO® test ranged from 10.00% for patients having experienced their 1st symptoms from 0 to 5 days ago to 100% in patients where symptoms had occurred more than 15 days before the date of tests. For COVID-DUO® test, the sensitivity ranged from 35.71% [0-5 days] to 100% (> 15 days). CONCLUSION: COVID-PRESTO® and DUO® POC tests turned out to be very specific (none false positive) and to be sensitive enough after 15 days from onset of symptom. These easy to use IgG/IgM combined test kits are the first ones allowing a screening with CWB sample, by typing from a finger prick. These rapid tests are particularly interesting for screening in low resource settings.


Assuntos
Anticorpos Antivirais/sangue , Betacoronavirus/imunologia , Técnicas de Laboratório Clínico/métodos , Infecções por Coronavirus/diagnóstico , Imunoensaio/métodos , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Pneumonia Viral/diagnóstico , Kit de Reagentes para Diagnóstico , Adulto , Idoso , Especificidade de Anticorpos , Betacoronavirus/genética , Betacoronavirus/isolamento & purificação , Capilares , Infecções por Coronavirus/sangue , Dedos/irrigação sanguínea , Humanos , Pessoa de Meia-Idade , Nasofaringe/virologia , Pandemias , Pneumonia Viral/sangue , Testes Imediatos , Estudos Prospectivos , Reação em Cadeia da Polimerase em Tempo Real , Sensibilidade e Especificidade , Adulto Jovem
16.
J Virol Methods ; 285: 113970, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32920028

RESUMO

The global COVID-19 pandemic has led to the rapid development of tests for detection of SARS-CoV-2. Studies are required to assess the relative performance of different assays. Here, we compared the performance of two commercial assays, the cobas® SARS-CoV-2 (Roche Diagnostics) and Xpert® Xpress SARS-CoV-2 (Cepheid®) tests, and a laboratory developed RT-PCR test adapted for use on the Hologic® Panther Fusion® (Hologic®) instrument as well as Bio-Rad and QIAGEN real-time PCR detection systems. Performance characteristics for each test were determined by testing clinical specimens and reference material. All assays detect the pan-Sarbecovirus E (envelope structural protein) gene plus a SARS-CoV-2-specific target. The limit of detection for the E gene target varied from ∼2 copies/reaction to >30 copies/reaction. Due to assay-specific differences in sample processing and nucleic acid extraction, the overall analytical sensitivity ranged from 24 copies/mL specimen to 574 copies/mL specimen. Despite these differences, there was 100 % agreement between the commercial and laboratory developed tests. No false-negative or false-positive SARS-CoV-2 results were observed and there was no cross-reactivity with common respiratory viruses, including endemic coronaviruses.


Assuntos
Betacoronavirus , Técnicas de Laboratório Clínico , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/virologia , Técnicas de Diagnóstico Molecular , Pneumonia Viral/diagnóstico , Pneumonia Viral/virologia , Kit de Reagentes para Diagnóstico , Betacoronavirus/genética , Betacoronavirus/imunologia , Técnicas de Laboratório Clínico/métodos , Técnicas de Laboratório Clínico/normas , Humanos , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Diagnóstico Molecular/normas , Pandemias , Kit de Reagentes para Diagnóstico/normas , Sensibilidade e Especificidade
17.
PLoS One ; 15(9): e0239146, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32976521

RESUMO

The first objective of this study was to determine the GenoType NTM-DR assay performance for subspecies identification in Mycobacterium abscessus complex isolates. The second objective was to evaluate the GenoType NTM-DR assay ability to detect clarithromycin and amikacin resistance in M. abscessus complex isolates compared with drug susceptibility testing (DST) and PCR sequencing of the erm(41), rrl and rrs genes. The concordance between the GenoType NTM-DR and MLST results concerning subspecies identification was 100%. The wild type and mutated alleles of the rrl and rrs genes were detected by the GenoType NTM-DR assay and PCR sequencing with 100% (115/115) agreement. Similarly, 100% concordance between GenoType NTM-DR and DST was observed for clarithromycin and amikacin testing. Sensitivity for the detection of clarithromycin and amikacin resistance was 100%. The GenoType NTM-DR assay provides a robust and complementary tool to the gold standard methods (MLST and broth microdilution) for subspecies identification and drug resistance detection.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana/genética , Técnicas de Genotipagem/instrumentação , Testes de Sensibilidade Microbiana/instrumentação , Mycobacterium abscessus/genética , Kit de Reagentes para Diagnóstico , Amicacina/farmacologia , Amicacina/uso terapêutico , Antibacterianos/uso terapêutico , Claritromicina/farmacologia , Claritromicina/uso terapêutico , Análise Mutacional de DNA/instrumentação , DNA Bacteriano/genética , DNA Bacteriano/isolamento & purificação , Genes Bacterianos/genética , Humanos , Tipagem de Sequências Multilocus , Mutação , Infecções por Mycobacterium não Tuberculosas/tratamento farmacológico , Infecções por Mycobacterium não Tuberculosas/microbiologia , Mycobacterium abscessus/isolamento & purificação , Reação em Cadeia da Polimerase
18.
J Clin Virol ; 131: 104609, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32866811

RESUMO

INTRODUCTION: IgG immunoassays have been developed and used widely for clinical samples and serosurveys for SARS-CoV2, with most detecting antibodies against the spike/receptor-binding-domain or nucleocapsid. Limited information is available on comparative evaluation of IgG immunoassays against a clinical reference standard, i.e., RT-PCR positivity with >20 days of illness. This study addresses the need for comparing clinical performance of IgG immunoassays with respect to this alternate reference standard. METHODS: We compared the performance of three immunoassays, an in-house RBD assay, and two commercial assays, the Diasorin LIAISON SARS-CoV-2 S1/S1 IgG CLIA which detects antibodies against S1/S2 domains of the Spike protein and the Zydus Kavach assay based on inactivated virus using a well-characterized panel of sera. 379 sera and plasma samples from RTPCR positive individuals >20 days of illness in symptomatic or RT-PCR positivity in asymptomatic individuals and 184 samples collected prior to 2019 were used for assay evaluation. RESULTS: The sensitivity of the assays were 84.7 (95 %CI 80.6-88.1), 82.6 (95 %CI 78.3-86.2) and 75.7 (95 %CI 71.0-79.9) respectively for RBD, LIAISON and Kavach. Kavach and the in-house RBD ELISA showed a specificity of 99.5 % and 100 %, respectively. The RBD and LIAISON (S1/S2) assays showed high agreement (94.7 %; 95 %CI: 92.0, 96.6) and were able to correctly identify more positive sera/plasma than Kavach. CONCLUSION: Independent comparisons support the evaluation of performance characteristics of immunoassays. All three assays are suitable for serosurveillance studies, but in low prevalence sites, estimation of exposure may require adjustment based on our findings.


Assuntos
Anticorpos Antivirais/sangue , Técnicas de Laboratório Clínico/métodos , Infecções por Coronavirus/imunologia , Imunoensaio/métodos , Imunoglobulina G/sangue , Pneumonia Viral/imunologia , Automação Laboratorial , Betacoronavirus , Infecções por Coronavirus/diagnóstico , Humanos , Índia , Estudos Longitudinais , Medições Luminescentes , Pandemias , Estudos Prospectivos , Kit de Reagentes para Diagnóstico , Sensibilidade e Especificidade
19.
Expert Rev Mol Diagn ; 20(9): 971-983, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32896179

RESUMO

INTRODUCTION: The starting months of 2020 witnessed a global pandemic of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) infection. The first case of Coronavirus Disease 2019 (COVID-19) was reported in December, 2019 in Wuhan, China and millions of cases and thousands of deaths were reported within five months. Currently, reverse transcription-polymerase chain reaction (RT-PCR) and computed tomography (CT) scanning are clinically prescribed for COVID-19 detection across the globe. AREAS COVERED: This systematic review is focused on currently used diagnostic methods for COVID-19 detection and their future prospects. Online searches on Google Scholar, PubMed and online resources were conducted on the period of year 2017 to mid-2020. Studies investigating laboratory examinations, radiographical analysis, and potential sensors for COVID-19 detection were included. Along with this, the current status of commercially available kits for SARS-CoV-2 coronavirus detection is discussed. EXPERT OPINION: The search has identified the potential applications of nucleic acid technology, diagnostics radiology examinations, and in-vitro diagnostic kits in detection of COVID-19 infections. Despite having their own limitations of each technology, the emerging diagnostic technologies for COVID-19 detection along with undergoing clinical trials are summarized suggesting more collaborations and funding are required for fast track clinical trials.


Assuntos
Betacoronavirus/genética , Técnicas de Laboratório Clínico , Infecções por Coronavirus/diagnóstico , Pneumonia Viral/diagnóstico , Técnicas Biossensoriais , Sistemas CRISPR-Cas , Infecções por Coronavirus/diagnóstico por imagem , Prova Pericial , Humanos , Pandemias , Kit de Reagentes para Diagnóstico , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Tomografia Computadorizada por Raios X/métodos , Ultrassonografia/métodos
20.
PLoS One ; 15(8): e0236228, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32866177

RESUMO

INTRODUCTION: Nucleosomes consist of small fragments of DNA wrapped around a histone octamer core. Diseases such as cancer or inflammation lead to cell death, which causes fragmentation and release of nucleosomes into the blood. The Nu.Q™ technology measures circulating nucleosome levels and exploits the different compositions of cancer derived nucleosomes in blood to detect and identify cancer even at early stages. The objectives of this study are to identify the optimal sample type for the Nu.Q™ H3.1 assay and to determine if it can accurately detect nucleosomes in the blood of healthy canines as well as those with cancer. MATERIALS AND METHODS: Blood samples from healthy canine volunteers as well as dogs newly diagnosed with lymphoma were used. The blood was processed at a variety of times under a variety of conditions to determine the most reliable sample type and conditions, and to develop an appropriate processing strategy to ensure reliably accurate results. RESULTS: Nucleosomes could be detected using a variety of sample collection and processing protocols. Nucleosome signals were highest in EDTA plasma and serum samples and most consistent in plasma. Samples should be processed within an hour of collection. Experiments showed that samples were able to withstand several freeze thaw cycles. Processing time and tcollection tube type did affect nucleosome detection levels. Finally, significantly elevated concentrations of nucleosomes were seen in a small cohort of dogs that had been newly diagnosed with lymphoma. CONCLUSIONS: When samples are collected and processed appropriately, the Nu.Q™ platform can reliably detect nucleosomes in the plasma of dogs. Further testing is underway to validate and optimize the Nu.Q™ platform for veterinary use.


Assuntos
Linfoma/diagnóstico , Linfoma/veterinária , Nucleossomos , Kit de Reagentes para Diagnóstico/veterinária , Animais , Cães , Ensaio de Imunoadsorção Enzimática/instrumentação , Ensaio de Imunoadsorção Enzimática/métodos , Estudos de Viabilidade , Feminino , Linfoma/sangue , Masculino , Reprodutibilidade dos Testes
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