scholarly journals Rapid, sensitive and specific SARS coronavirus-2 detection: a multi-center comparison between standard qRT-PCR and CRISPR based DETECTR.

2020 ◽  
Author(s):  
Eelke Brandsma ◽  
Han JMP Verhagen ◽  
Thijs J.W. van de Laar ◽  
Eric C.J. Claas ◽  
Marion Cornelissen ◽  
...  
Keyword(s):  
Point Of Care ◽  
Diagnostic Testing ◽  
Added Value ◽  
N Gene ◽  
Analytical Sensitivity ◽  
Qrt Pcr ◽  
Negative Results ◽  
Point Of Care Test ◽  
Ribonucleoprotein Complexes ◽  
Large Patient

Recent advances in CRISPR-based diagnostics suggest that DETECTR, a combination of isothermal reverse transcriptase loop mediated amplification (RT-LAMP) and subsequent Cas12 bystander nuclease activation by amplicon targeting ribonucleoprotein complexes, could be a faster and cheaper alternative to qRT-PCR without sacrificing sensitivity/specificity. Here we compare qRT-PCR with DETECTR to diagnose COVID-19 on 378 patient samples and report a 95% reproducibility. Patient sample dilution assays suggest a higher analytical sensitivity of DETECTR compared to qRT-PCR, however, this was not confirmed in a large patient cohort. The data showed that both techniques are equally sensitive in detecting SARS-CoV-2 providing an added value of DETECTR to the currently used qRT-PCR platforms. For DETECTR, different gRNAs can be used simultaneously to obviate negative results due to mutations in N-gene. Lateral flow strips, suitable as a point of care test (POCT), showed a 100% correlation to the high-throughput DETECTR assay. Importantly, DETECTR was 100% specific for SARS-CoV-2 and did not detect other human coronaviruses. As there is no need for specialized equipment, DETECTR could be rapidly implemented as a complementary technically independent approach to qRT-PCR thereby increasing the testing capacity of medical microbiological laboratories and relieving the existent PCR-platforms for routine non- SARS-CoV-2 diagnostic testing.

scholarly journals Rapid, Sensitive, and Specific Severe Acute Respiratory Syndrome Coronavirus 2 Detection: A Multicenter Comparison Between Standard Quantitative Reverse-Transcriptase Polymerase Chain Reaction and CRISPR-Based DETECTR

2020 ◽  
Author(s):  
Eelke Brandsma ◽  
Han J M P Verhagen ◽  
Thijs J W van de Laar ◽  
Eric C J Claas ◽  
Marion Cornelissen ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Severe Acute Respiratory Syndrome ◽  
Reverse Transcriptase ◽  
N Gene ◽  
Analytical Sensitivity ◽  
Chain Reaction ◽  
Qrt Pcr ◽  
Ribonucleoprotein Complexes ◽  
Large Patient ◽  
Polymerase Chain

Abstract Background Recent advances in CRISPR-based diagnostics suggest that DETECTR, a combination of reverse-transcriptase loop-mediated isothermal amplification (RT-LAMP) and subsequent Cas12 bystander nuclease activation by amplicon-targeting ribonucleoprotein complexes, could be a faster and cheaper alternative to quantitative reverse-transcription polymerase chain reaction (qRT-PCR) without sacrificing sensitivity and/or specificity. Methods In this study, we compare DETECTR with qRT-PCR to diagnose coronavirus disease 2019 on 378 patient samples. Patient sample dilution assays suggest a higher analytical sensitivity of DETECTR compared with qRT-PCR; however, this was not confirmed in this large patient cohort, where we report 95% reproducibility between the 2 tests. Results These data showed that both techniques are equally sensitive in detecting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) providing additional value of DETECTR to the currently used qRT-PCR platforms. For DETECTR, different guide ribonucleic acids can be used simultaneously to obviate negative results due to mutations in N-gene. Lateral flow strips, suitable as a point-of-care test, showed a 100% correlation to the high-throughput DETECTR assay. More importantly, DETECTR was 100% specific for SARS-CoV-2 relative to other human coronaviruses. Conclusions Because there is no need for specialized equipment, DETECTR could be rapidly implemented as a complementary technically independent approach to qRT-PCR thereby increasing the testing capacity of medical microbiological laboratories and relieving the existent PCR platforms for routine non-SARS-CoV-2 diagnostic testing.

scholarly journals Point-of-Care Testing-the Key in the Battle against SARS-CoV-2 Pandemic

Micromachines ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1464
Author(s):  
Florina Silvia Iliescu ◽  
Ana Maria Ionescu ◽  
Larisa Gogianu ◽  
Monica Simion ◽  
Violeta Dediu ◽  
...  
Keyword(s):  
Clinical Decision Making ◽  
Point Of Care ◽  
Low Cost ◽  
Diagnostic Testing ◽  
Clinical Decision ◽  
Rapid Screening ◽  
Diagnostic Tools ◽  
Point Of Care Testing ◽  
Qrt Pcr ◽  
User Friendly

The deleterious effects of the coronavirus disease 2019 (COVID-19) pandemic urged the development of diagnostic tools to manage the spread of disease. Currently, the “gold standard” involves the use of quantitative real-time polymerase chain reaction (qRT-PCR) for SARS-CoV-2 detection. Even though it is sensitive, specific and applicable for large batches of samples, qRT-PCR is labour-intensive, time-consuming, requires trained personnel and is not available in remote settings. This review summarizes and compares the available strategies for COVID-19: serological testing, Point-of-Care Testing, nanotechnology-based approaches and biosensors. Last but not least, we address the advantages and limitations of these methods as well as perspectives in COVID-19 diagnostics. The effort is constantly focused on understanding the quickly changing landscape of available diagnostic testing of COVID-19 at the clinical levels and introducing reliable and rapid screening point of care testing. The last approach is key to aid the clinical decision-making process for infection control, enhancing an appropriate treatment strategy and prompt isolation of asymptomatic/mild cases. As a viable alternative, Point-of-Care Testing (POCT) is typically low-cost and user-friendly, hence harbouring tremendous potential for rapid COVID-19 diagnosis.

Point-Of-Care Clinical Evaluation of the Clungene® SARS-CoV-2 Virus IgG/IgM 15-minute rapid test cassette with the Cobas® Roche RT-PCR platform in patients with or without Covid-19

2021 ◽  
Author(s):  
Fadi Haddad ◽  
Christopher C Lamb ◽  
Ravina Kullar ◽  
George Sakoulas
Keyword(s):  
Symptom Onset ◽  
Serological Test ◽  
Point Of Care ◽  
Diagnostic Testing ◽  
Rapid Test ◽  
Lateral Flow ◽  
Added Value ◽  
Lateral Flow Immunoassay ◽  
Rt Pcr ◽  
Past Infection

Background: Covid-19 remains a pandemic with multiple challenges to confirm patient infectivity: lack of sufficient tests, accurate results, validated quality, and timeliness of results. We hypothesize that a rapid 15-minute Point-Of-Care serological test to evaluate past infection complements diagnostic testing for Covid-19 and significantly enhances testing availability. Method: A three arm observational study at Sharp Healthcare, San Diego, California was conducted using the Clungene® lateral flow immunoassay (LFI) and compared with the Cobas® Roche RT PCR results. Arm 1: Thirty-five (35) subjects with confirmed Covid-19 using RT-PCR were tested twice: prior to 14 days following symptom onset and once between 12 and 70 days. Arm 2: Thirty (30) subjects with confirmed Covid-19 using RT-PCR were tested 12-70 days post symptom onset. Arm 3: Thirty (30) subjects with a negative RT-PCR for Covid-19 were tested 1-10 days following the RT-PCR test date. Results: Specificity of confirmed negative Covid-19 by RT-PCR was 100% (95% CI, 88.4%-100.0%); meaning there was 100% negative positive agreement between the RT-PCR and the Clungene® serological test results. Covid-19 subjects tested prior to day 7 symptom onset were antibody negative. In subjects 7-12 days following symptom onset with a confirmed positive Covid-19 by RT-PCR, the combined sensitivity of IgM and IgG was 58.6% (95% CI, 38.9%-76.5%). In subjects 13-70 days following symptom onset with a confirmed positive Covid-19 by RT-PCR the combined sensitivity of IgM and IgG was 90.5% (95% CI, 80.4%-96.4%). Conclusion: The Clungene® lateral flow immunoassay (LFI) is a useful tool to confirm individuals with an adaptive immune response to SARS-CoV-2 indicating past infection. Providing Point-Of-Care results within 15 minutes without any laboratory instrumentation or specialized software has an added value of increasing test availability to patients who have been symptomatic for more than one week to confirm past infection. Performance characteristics are optimal after 13 days with a sensitivity and specificity of 90% and 100%, respectively.

scholarly journals Diagnostic testing for feline panleukopenia in a shelter setting: a prospective, observational study

2021 ◽  
pp. 1098612X2110053
Author(s):  
Linda S Jacobson ◽  
Kyrsten J Janke ◽  
Jolene Giacinti ◽  
J Scott Weese
Keyword(s):  
Point Of Care ◽  
Diagnostic Testing ◽  
False Negative ◽  
Clinical Signs ◽  
Test Results ◽  
Feline Panleukopenia Virus ◽  
Negative Results ◽  
Copy Numbers ◽  
Rectal Swabs ◽  
Vaccination History

Objectives The aim of this study was to optimize the diagnosis of feline panleukopenia virus (FPV) in a shelter setting by: (1) comparing the results of the canine parvovirus IDEXX SNAP Parvo (SNAP) point-of-care ELISA with a commercial FPV quantitative real-time PCR (qPCR) test; (2) assessing whether vomit and anal/rectal swabs could be used for early diagnosis; and (3) clarifying the interpretation of weak-positive SNAP test results. Methods The study included shelter cats and kittens with incomplete or unknown vaccination history that had clinical signs suspicious for feline panleukopenia and fecal SNAP and PCR tests performed within 24 h of onset. Feces, anal/rectal swabs and vomit were tested using SNAP and PCR, with fecal PCR utilized as the reference standard. Results One hundred and forty-five cats were included. Seventeen were diagnosed with FPV infection and 62 were negative; 66 could not be individually designated because they were co-housed. Sensitivity was as follows: fecal SNAP 55% (n = 102; 95% confidence interval [CI] 32–77); swab SNAP 30% (n = 55; 95% CI 7–65); swab PCR 77% (n = 55; 95% CI 46–95); and vomit PCR 100% (n = 17; 95% CI 16–100). Specificity was high (96–100%) for all sample and test types. For PCR-positive fecal samples, true-positive SNAP tests (including weak positives) had significantly higher DNA viral copy numbers than false-negative SNAP tests ( P = 0.0031). Conclusions and relevance The SNAP ELISA should be viewed as an initial diagnostic test to rule in feline panleukopenia. Positive fecal SNAP test results, including weak positives, are highly likely to be true positives in clinically affected animals. Negative results in clinically affected animals are unreliable and should be followed up with PCR testing.

scholarly journals Dynamic characteristic of SARS-CoV-2 and its antibody detection

2021 ◽  
Vol 7 (4) ◽  
pp. 100-101
Author(s):  
Bahrul Fikri ◽  
◽  
Andi Dwi Bahagia Febriani ◽  
Muhamad Ali ◽  
Nasrum Massi ◽  
...  
Keyword(s):  
Point Of Care ◽  
Diagnostic Testing ◽  
Rapid Test ◽  
Turnaround Time ◽  
Antibody Detection ◽  
Point Of Care Test ◽  
Specimen Collection ◽  
Excess Morbidity ◽  
Sensitivity Specificity ◽  
Testing Solution

To prevent excess morbidity and mortality of Covid-19, a prompt and accurate diagnosis is crucial. Antibody-based rapid diagnostic test (RDT) is a rapid, fairly reliable, and useful diagnostic testing solution for COVID-19. As a point-of-care test with fast turnaround time, the kit permits quick screening in hospitals to avoid the crowding of specimen collection. However, available RDTs kits have different sensitivity, specificity, and accuracy profiles due to antigen and antibody variability because of the sequence mutation of the SARS-CoV-2 gene. Therefore, it is strongly recommended to either re-measure the accuracy of a rapid test before using it in a different country or use tests developed based on local viral characteristics

scholarly journals Is the glass half full? Extraction-free RT-LAMP to detect SARS-CoV-2 is less sensitive but highly specific compared to standard RT-PCR in 101 samples

2020 ◽  
Author(s):  
John J. Schellenberg ◽  
Margaret Ormond ◽  
Yoav Keynan
Keyword(s):  
Point Of Care ◽  
N Gene ◽  
Nasopharyngeal Swab ◽  
Lower Sensitivity ◽  
Rt Pcr ◽  
Public And Private ◽  
Viral Loads ◽  
Negative Results ◽  
Viral Transport Medium ◽  
Point Of Care Tests

AbstractThe current scale of public and private testing cannot be expected to meet the emerging need for higher levels of community-level and repeated screening of asymptomatic Canadians for SARS-CoV-2. Rapid point-of-care techniques are increasingly being deployed to fill the gap in screening levels required to identify undiagnosed individuals with high viral loads. However, rapid, point-of-care tests often have lower sensitivity in practice. Reverse transcription loop-mediated isothermal amplification (RT-LAMP) for SARS-CoV-2 has proven sensitive and specific and provides visual results in minutes. Using a commercially available kit for RT-LAMP and primer set targetting nucleocapsid (N) gene, we tested a blinded set of 101 archived nasopharyngeal (NP) swab samples with known RT-PCR results. RT-LAMP reactions were incubated at 65°C for 30 minutes, using heat-inactivated nasopharyngeal swab sample in viral transport medium, diluted tenfold in water, as input. RT-LAMP agreed with all RT-PCR defined negatives (N=51), and all positives with Ct less than 20 (N=24), 65% of positives with Ct between 20-30 (N=17), and no positives with Ct greater than 30 (N=9). RT-LAMP requires fewer and different core components, so may not compete directly with the mainline testing workflow, preserving precious central laboratory resources and gold standard tests for those with the greatest need. Careful messaging must be provided when using less-sensitive tests, so that people are not falsely reassured by negative results – “glass half empty” – in exchange for reliable detection of those with high levels of virus within an hour, using <$10 worth of chemicals – “glass half full”.

scholarly journals Investigation of a measles outbreak in Zimbabwe, 2010: potential of a point of care test to replace laboratory confirmation of suspected cases

2015 ◽  
Vol 143 (16) ◽  
pp. 3442-3450 ◽  
Author(s):  
A. SHONHAI ◽  
L. WARRENER ◽  
D. MANGWANYA ◽  
R. SLIBINSKAS ◽  
K. BROWN ◽  
...  
Keyword(s):  
Point Of Care ◽  
N Gene ◽  
Predictive Values ◽  
Point Of Care Test ◽  
Measles Outbreak ◽  
Laboratory Confirmation ◽  
High Level ◽  
Sensitivity Specificity ◽  
Level Of Agreement

SUMMARYBlood and oral fluid (OF) samples were collected from 103 suspected measles cases between February and November 2010 during a nationwide measles outbreak in Zimbabwe. Siemens measles IgM enzyme immunoassay (EIA) on serum, Microimmune measles IgM capture EIA on OF, real-time haemagglutinin (H) gene PCR and nested nucleocapsid (N) gene PCR on OF were performed, confirming 75 measles cases. These samples were then used to evaluate a newly developed point of care test (POCT) for measles and determine its potential for identifying measles cases in outbreaks. After performing POCTs on OF samples, nucleic acid was extracted from the used test strips and the measles H and N genes amplified by RT–PCR. The sensitivity, specificity, positive and negative predictive values of the POCT for IgM in OF was 75·0% [95% confidence interval (CI) 63·4–84·5], 96·2% (95% CI 80·4–99·9), 98·2% (95% CI 90·3–100) and 58·1% (95% CI 42·1–73·0), respectively. The N gene sequences showed high level of agreement between original OF and corresponding POCT strips. Measles genotype B3 was identified in all cases. We conclude that the measles POCT has the potential to be used, at the point of contact, in outbreak situations and provide molecular characterization of the virus at a later date.

Rationalization of microscopy in the detection of Neisseria gonorrhoeae in women

2007 ◽  
Vol 18 (10) ◽  
pp. 705-706 ◽  
Author(s):  
K M Forbes ◽  
U Vaze ◽  
H L Wheeler
Keyword(s):  
Neisseria Gonorrhoeae ◽  
Point Of Care ◽  
Added Value ◽  
First Line ◽  
Delayed Treatment ◽  
Point Of Care Test ◽  
First Line Therapy ◽  
Line Therapy ◽  
Medicine Service ◽  
Culture Positive

This study looks at the sensitivity of microscopy in the diagnosis of Neisseria gonorrhoeae (NG), the effect of microscopy on time to treatment of NG and the added value of microscopy in the management of gonorrhoea. Women diagnosed with NG at an inner city genitourinary (GU) medicine clinic between August 2005 and July 2006 were identified and the notes reviewed. There were 103 women who were culture positive for NG. The sensitivity of microscopy was 38%. Microscopy is a point of care test (POCT) and in this group, it facilitated the treatment of 19% ( n=20) of cases of NG infection at the first visit to a GU medicine service. If a POCT is not available, this would result in delayed treatment (32% of patients waited longer than 14 days and 3% did not return for treatment). In total, 29% of women did not return for test of cure, therefore confirming that effective first-line therapy is essential in the treatment of N. gonorrhoeae.

scholarly journals Analytical Performances of the Point-of-Care BIOSYNEX COVID-19 Ag BSS for the Detection of SARS‐CoV‐2 Nucleocapsid Protein in Nasopharyngeal Swabs: A Prospective Field Evaluation During the COVID-19 Third Wave in France

2021 ◽  
Author(s):  
Fréderic Fitoussi ◽  
Serge Tonen-Wolyec ◽  
Natalio Awaida ◽  
Raphael Dupont ◽  
Laurent Belec
Keyword(s):  
Nucleocapsid Protein ◽  
Point Of Care ◽  
Diagnostic Testing ◽  
High Sensitivity ◽  
High Specificity ◽  
Field Evaluation ◽  
N Gene ◽  
Third Wave ◽  
Perfect Agreement ◽  
Viral Excretion

Abstract Background: Evaluating the accuracy and reliability of rapid diagnostic testing kits is crucial for surveillance and diagnosis of SARS-CoV-2 infections in general population. The aim of the study was to assess the analytical performances of the antigen-rapid diagnosis test (Ag-RDT) BIOSYNEX COVID-19 Ag BSS (Biosynex Swiss SA, Freiburg, Switzerland), targeting the SARS-CoV-2 N nucleocapsid protein, for the diagnosis of COVID-19, by reference to real-time RT-PCR (rtRT-PCR).Methods: A total 967 adults living in Paris region were prospectively included during the third wave of the COVID-19 epidemic in France. Paired nasopharyngeal flocked swabs were collected at the same timepoint from persons aged ≥18 years receiving testing for SARS-CoV-2, at two private laboratories.Results: Overall, the Ag-RDT showed high sensitivity, specificity, PPV and NPV of 81.8%, 99.6%, 96.6% and 97.5%, respectively, as well as high or almost perfect agreement (97.0%), reliability assessed by Cohen’s κ coefficient (0.87), and accuracy assessed by Youden’s J index (81.6%) to detect SARS-CoV-2. The analytical performances of the Ag-RDT remained high in the event of significant viral excretion (i.e., N gene Ct values ≤ 33 by reference rtRT-PCR), while the sensitivity of the Ag-RDT dropped to 55.2% with low or very low viral shedding (Ct> 33).Conclusions: The Ag-RDT BIOSYNEX COVID-19 Ag BSS showed high specificity and sufficient sensitivity for the detection of SARS-CoV-2. This test is a promising potential easy diagnostic tool, especially in situations of symptomatic COVID-19 and/or proven contagiousness.

scholarly journals Assessment of the analytical sensitivity of ten lateral flow devices against the SARS-CoV-2 omicron variant

2021 ◽  
Author(s):  
Joshua Deerain ◽  
Julian Druce ◽  
Thomas Tran ◽  
Mitchell Batty ◽  
Yano Yoga ◽  
...  
Keyword(s):  
Public Health ◽  
Point Of Care ◽  
Diagnostic Testing ◽  
Rapid Assessment ◽  
Protein A ◽  
Analytical Sensitivity ◽  
Structural Protein ◽  
Public Health Response ◽  
Recent Emergence ◽  
Antigen Tests

Timely and accurate diagnostic testing is a critical component of the public health response to COVID-19. Antigen tests are used widely in many countries to provide rapid, economical and accessible point-of-care testing (1). The vast majority of antigen tests detect nucleocapsid (N) protein, a structural protein that displays less variation than the spike (S) protein across different SARS-CoV-2 lineages. Although antigen tests are less sensitive than RT-PCR tests, their ability to quickly detect individuals with high viral loads provides clinical and public health utility in many countries, including Australia, where antigen tests have recently been approved for self-testing (2). As new variants arise, including the recent emergence of the SARS-CoV-2 omicron variant, it is essential to rapidly assess the performance of diagnostic assays. Here, in order to assess and compare the ability of antigen tests to detect delta and omicron variants, we performed a rapid assessment of ten commercially available antigen tests.

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