scholarly journals Clinical Evaluation of a New Antigen-Based COVID-19 Rapid Diagnostic Test from Symptomatic Patients

Diagnostics ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2300
Author(s):  
Saiful Arefeen Sazed ◽  
Mohammad Golam Kibria ◽  
Mohammad Sharif Hossain ◽  
Md Fahad Zamil ◽  
Pranob Chandra Adhikary ◽  
...  
Keyword(s):  
Gold Standard ◽  
Clinical Performance ◽  
Detection System ◽  
Rapid Test ◽  
Test Results ◽  
Rt Pcr ◽  
Test Procedures ◽  
Healthcare Facilities ◽  
The Right ◽  
Current Detection

Accurate diagnosis at the right moment is the prerequisite for treatment of any disease. Failure to correctly diagnose a disease can result in highly detrimental effects, unmistakably a crucial factor during the COVID-19 pandemic. RT-PCR is the gold standard for COVID-19 detection while there are other test procedures available, such as LAMP, X-Ray, and ELISA. However, these tests are expensive, require sophisticated equipment and a highly trained workforce, and multiple hours or even days are often required to obtain the test results. A rapid and cheap detection system can thus render a solution to the screening system on a larger scale and be added as an aid to the current detection processes. Recently, some rapid antigen-based COVID-19 tests devices have been developed and commercialized. In this study, we evaluated the clinical performance of a new rapid detection device (OnSite® COVID-19 Ag Rapid Test by CTK Biotech Inc., Poway, CA, USA) on COVID-19 symptomatic patients (n = 380). The overall sensitivity and specificity were 91.0% (95% CI: 84.8–95.3%) and 99.2% (95% CI: 97.1–99.9), against gold standard RT-PCR. The kit was capable of detecting patients even after 06 days of onset of symptoms and the sensitivity can be maximized to 98% in samples with an average RT-PCR Ct ≤ 26.48, demonstrating a high potential of the kit for clinical diagnosis of symptomatic patients in healthcare facilities.

Accuracy of Computed Tomography for Detection of COVID-19 among Suspected Patients

2021 ◽  
Vol 15 (9) ◽  
pp. 2474-2476
Author(s):  
Maham Munir Awan ◽  
Afshan Noreen ◽  
Farah Kalsoom ◽  
Muhammad Tahir ◽  
Umaima Majeed ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Predictive Value ◽  
Gold Standard ◽  
Radiology Department ◽  
True Positive ◽  
Test Results ◽  
Rt Pcr ◽  
Radiological Society ◽  
Medical University ◽  
Pcr Test

Objective: To determine the accuracy of CT chest in diagnosis of COVID-19 taking RT-PCR-testing as gold standard. Materials and Methods: A total of 150 patients of suspicion of COVID-19 who were referred for CT Chest in Radiology Department of Nishtar Medical University Multan from June-2020 to May-2021 were included. In all patients, two RT-PCR test results were obtained with 7 days of admission in hospital. Presence of any of these positive was labelled as COVID-19 infection. CT chest was performed in all patients within 2 days of admission in hospital using 128 slices CT scan machine. The diagnosis of COVID-19 infection was made according to the recommendations by Radiological Society of North America (RSNA) protocol. Results: Mean age was 51.3±14.7 years. 78 (52%) patients were male and 72 (48%) patients were female. RTPCR test was positive in 89 (59.3%) patients. While the CT chest findings were suggestive of COVID-19 infection in 130 (86.7%) patients. The sensitivity of CT chest was 95.5%, specificity 26.2%, PPV wad 65.4% and NPV was 80.0%. Conclusion: CT chest has a very good sensitivity for detection of COVID-19, it can be used as a rapid diagnostic tool especially in areas of pandemic. However, the specificity of CT chest is low, that can limit its use in low COVID-19 affected areas. Keywords: COVID-19, Computed tomography, False Positive, True Positive, Positive Predictive Value, Negative Predictive Value.

Model Parameter Identification of Tire Dynamic Balance Detection System

2012 ◽  
Vol 157-158 ◽  
pp. 731-736
Author(s):  
Jing Fang Yang ◽  
Xian Ying Feng ◽  
Hong Jun Fu ◽  
Shi Gang Mu
Keyword(s):  
Parameter Identification ◽  
Detection System ◽  
Dynamic Balance ◽  
Signal Amplitude ◽  
Engineering Practice ◽  
Model Parameters ◽  
Test Results ◽  
Process Data ◽  
Validation Experiment ◽  
The Right

Tire dynamic balance detection plays an important part in tire quality detection area. An accurate model structure and precise model parameters are the basis of the right test results. This paper builds a kinetic model based on engineering practice. To acquire parameters presents a method following identification theory. According to the need of actual production, a validation experiment is put forward. In the parameter identification process, data acquisition is completed by the PCI card. For data processing, this paper designs the fitting filter and then it also fetches the signal amplitude and phase with discrete Fourier transform. The results are proven to be right and practicable.

scholarly journals Evaluation of the Cepheid Xpert Xpress SARS-CoV-2 test for bronchoalveolar lavage

2021 ◽  
Author(s):  
Tung Phan ◽  
Ashley Mays ◽  
Melissa McCullough ◽  
Alan Wells
Keyword(s):  
Bronchoalveolar Lavage ◽  
Limit Of Detection ◽  
Clinical Performance ◽  
Rapid Test ◽  
Rt Pcr ◽  
Qualitative Detection ◽  
Upper Respiratory ◽  
Prompt Diagnosis ◽  
Respiratory Specimens ◽  
Rapid Laboratory

Accurate and rapid laboratory tests are essential for the prompt diagnosis of COVID-19, which is important to patients and infection control. The Xpert Xpress SARS-CoV-2 test is a real-time RT-PCR intended for the qualitative detection of nucleic acid from SARS-CoV-2 in upper respiratory specimens. In this study, we assessed the analytical and clinical performance characteristics of this rapid test for SARS-CoV-2 in 60 bronchoalveolar lavage (BAL) specimens. BAL is a specimen type that is not authorized under EUA for the Xpert Xpress SARS-CoV-2 test. The limit of detection of the Xpert Xpress SARS-CoV-2 test was 500 copies/ml. The overall agreement of the Xpert Xpress SARS-CoV-2 test was 100%. The Xpert Xpress SARS-CoV-2 test is sensitive and specific to aid in diagnosis of COVID-19 using bronchoalveolar lavage.

scholarly journals “Evaluation of a COVID-19 IgM and IgG Rapid Test and Assessment of Specific Antibody Response in COVID-19 patients, Tunisia 2020”

2021 ◽  
Author(s):  
letaief hejer ◽  
Sonia Dhaouadi ◽  
Aicha Hechaichi ◽  
Mouna Safer ◽  
Chahida Harizi ◽  
...  
Keyword(s):  
Antibody Response ◽  
Clinical Performance ◽  
Rapid Test ◽  
Antibody Test ◽  
Antibody Responses ◽  
Rt Pcr ◽  
Serological Tests ◽  
Clinical Sensitivity ◽  
Negative Results ◽  
Finger Stick

Abstract Background COVID-19 pandemic is a massive global health emergency. Although RT-PCR is the gold standard for diagnosing suspected cases, there is a need of serological tests to investigate antibody responses. Many serologic immunoassays have been developed to detect antibodies to SARS-CoV2, including rapid tests. This study assessed the clinical performance of the SARS-CoV-2 antibody test (colloidal gold immunochromatography, LEPU TECHNOLOGY) and evaluated the kinetic antibody response in COVID-19 patients.Methods: Samples collected by finger stick; obtained from RT-PCR confirmed cases and samples of negative controls were tested with the IgM/IgG Detection Kit . Results: The kit shows a clinical sensitivity of 65.7 % [59.7%-71.3%] and a specificity of 96.3% [93.0%-98.3%]. The predictive positive value and negative predictive value were respectively 95.2% [91.0%-97.8%] and 71.4% [66.1%-76.2%]. The seroconversion of specific IgM and IgG antibodies were observed as early as the 2nd day after symptom onset.Conclusions: This test is quite useful for assessing previous virus exposure, although negative results may be unreliable during the first weeks after infection. Longitudinal studies on antibody responses during and post infection are needed.

scholarly journals Head-to-head comparison of SARS-CoV-2 antigen-detecting rapid test with professional-collected anterior nasal versus nasopharyngeal swab

2020 ◽  
Author(s):  
Andreas K. Lindner ◽  
Olga Nikolai ◽  
Chiara Rohardt ◽  
Susen Burock ◽  
Claudia Hülso ◽  
...  
Keyword(s):  
Healthcare Professionals ◽  
Rapid Test ◽  
High Viral Load ◽  
Nasopharyngeal Swab ◽  
Rt Pcr ◽  
Test Procedures ◽  
Testing Strategies ◽  
Percent Agreement ◽  
Accuracy Study ◽  
Antigen Testing

AbstractBackgroundNasopharyngeal (NP) swab samples for antigen-detecting rapid diagnostic tests (Ag-RDTs) require qualified healthcare professionals and are frequently perceived as uncomfortable by patients.MethodsWe performed a manufacturer-independent, prospective diagnostic accuracy study, comparing professional-collected anterior nasal (AN) to nasopharyngeal swab, using the test kits of a WHO-listed SARS-CoV-2 Ag-RDT (STANDARD Q COVID-19 Ag Test, SD Biosensor), which is also being distributed by Roche. Individuals with high suspicion for COVID-19 infection were tested. The reference standard was RT-PCR using a combined oro-/nasopharyngeal swab sample. Percent positive and negative agreement, as well as sensitivity and specificity were calculated.ResultsAmong the 179 participants, 41 (22.9%) tested positive for SARS-CoV-2 by RT-PCR. The positive percent agreement of the two different sampling techniques for the Ag-RDT was 93.5% (CI 79.3-98.2). The negative percent agreement was 95.9% (CI 91.4-98.1). The Ag-RDT with AN-sampling showed a sensitivity of 80.5% (33/41 PCR positives detected; CI 66.0-89.8) and specificity of 98.6% (CI 94.9-99.6) compared to RT-PCR. The sensitivity with NP-sampling was 73.2% (30/41 PCR positives detected; CI 58.1-84.3) and specificity was 99.3% (CI 96.0-100). In patients with high viral load (>7.0 log10 RNA SARS-CoV2/swab), the sensitivity of the Ag-RDT with AN-sampling was 100% and 94.7% with NP-sampling.ConclusionThis study demonstrates that sensitivity of a WHO-listed SARS-CoV-2 Ag-RDT using a professional AN-sampling kit is at least equal to that of the NP-sampling kit, although confidence intervals overlap. Of note, differences in the IFUs of the test procedures could have contributed to different sensitivities. AN-sampling can be performed with less training, reduces patient discomfort, and it enables scaling of antigen testing strategies. Additional studies of patient self-sampling should be considered to further facilitate the scaling-up of Ag-RDT testing.

scholarly journals Evaluation of the Panbio™ COVID-19 Ag Rapid Test at an Emergency Room in a Hospital in São Paulo, Brazil

2021 ◽  
Author(s):  
Klinger Soares Faíco-Filho ◽  
Francisco Estivallet Finamor Júnior ◽  
Luiz Vinícius Leão Moreira ◽  
Paulo Ricardo Gessolo Lins ◽  
Alberto Fernando Oliveira Justo ◽  
...  
Keyword(s):  
Emergency Room ◽  
Diagnostic Test ◽  
Gold Standard ◽  
Rapid Test ◽  
Sao Paulo ◽  
Rapid Screening ◽  
São Paulo ◽  
Rt Pcr ◽  
Percent Agreement ◽  
Sensitivity Specificity

Introduction: The performance characteristics of the Panbio™ COVID-19 Ag test were evaluated against RT-PCR – considered the gold-standard for the detection of SARS-CoV-2 – at an emergency room in São Paulo, Brazil. The study aimed to determine the sensitivity, specificity, positive percent agreement (PPA), and negative percent agreement (NPA) as compared to RT-PCR. Methods: Specimens from 127 suspected patients were tested by both the Panbio™ COVID-19 Ag test and by RT-PCR. Results: Evaluation of the agreement between the Panbio™ COVID-19 Ag test and RT-PCR indicated an overall sensitivity of 84% (95%CI, 75-93.8%) and an overall specificity of 98% (95%CI, 96-98.8%). The Panbio™ COVID-19 Ag test showed 97% sensitivity and 99% NPA for subjects with Ct values ≤ 25 (N=37). Conclusion: The Panbio™ COVID-19 Ag test is suitable for use as a diagnostic test for the rapid screening of patients presenting COVID-19 symptoms, or those suspected with being infected, prior to being admitted to hospital.

scholarly journals Portable RT-PCR system: A Rapid and Scalable Diagnostic Tool for COVID-19 Testing

2021 ◽  
Author(s):  
Hosam M Zowawi ◽  
Thamer H Alenazi ◽  
Waleed S AlOmaim ◽  
Ahmad Wazzan ◽  
Abdullah Alsufayan ◽  
...  
Keyword(s):  
Point Of Care ◽  
Rapid Test ◽  
Standard Of Care ◽  
Test Results ◽  
Rt Pcr ◽  
Point Of Care Testing ◽  
System A ◽  
Portable System ◽  
Remote Sites ◽  
User Friendly

Combating the ongoing coronavirus disease 2019 (COVID-19) pandemic demands accurate, rapid, and point-of-care testing with fast results to triage cases for isolation and treatment. The current testing relies on RT-PCR, which is routinely performed in well-equipped laboratories by trained professionals at specific locations. However, during busy periods high numbers of samples queued for testing can delay the test results, impacting upon efforts to reduce the infection risk. Besides, the absence of well-established laboratories at remote sites and low-resourced environments can contribute to a silent spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). These reasons compel the need to accommodate point-of-care testing for COVID-19 that meets the ASSURED criteria (Affordable, Sensitive, Specific, User-friendly, Rapid, robust, Equipment-free, and Deliverable). This study assessed the agreement and accuracy of the portable Biomeme SARS-CoV-2 system against the gold standard tests. Nasopharyngeal and nasal swabs were used. Of the 192 samples tested using the Biomeme SARS-CoV-2 system, the results from 189 samples (98.4%) were in agreement with the reference standard-of-care RT-PCR testing for SARS-CoV-2. The portable system generated simultaneous results for nine samples in 80 mins with high positive and negative percent agreements of 99.0% and 97.8%, respectively. We performed separate testing in a sealed glove box, offering complete biosafety containment. Thus, the Biomeme SARS-CoV-2 system can help decentralize COVID-19 testing and offer rapid test results for patients in remote and low-resourced settings. Single Sentence Summary The Biomeme SARS-CoV-2 system can help decentralize COVID-19 testing and offer rapid test results for patients in remote sites and low-resourced settings.

scholarly journals Performance characteristics of the VIDAS® SARS-COV-2 IgM and IgG serological assays

2020 ◽  
Author(s):  
Nathalie Renard ◽  
Soizic Daniel ◽  
Nadège Cayet ◽  
Matthieu Pecquet ◽  
Frédérique Raymond ◽  
...  
Keyword(s):  
Clinical Performance ◽  
Cross Reactivity ◽  
Epidemiological Surveillance ◽  
Test Results ◽  
Rt Pcr ◽  
Serological Tests ◽  
Clinical Sensitivity ◽  
Healthy Donors ◽  
Coefficients Of Variation ◽  
Respiratory Virus Infection

ABSTRACTThe COVID-19 pandemic, caused by the new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), continues to spread worldwide. Serological testing for SARS-CoV-2-specific antibodies plays an important role in understanding and controlling the pandemics, notably through epidemiological surveillance. Well validated and highly specific SARS-CoV-2 serological assays are urgently needed. We describe here the analytical and clinical performance of VIDAS® SARS-CoV-2 IgM and VIDAS® SARS-CoV-2 IgG, two CE-marked, EUA-authorized, automated, qualitative assays for the detection of SARS-CoV-2-specific IgM and IgG, respectively. Both assays showed high within-run and within-laboratory precision (coefficients of variation < 11.0%) and very low cross-reactivity towards sera of patients with a past common coronavirus or respiratory virus infection. Clinical specificity determined on up to 989 pre-pandemic healthy donors was ≥ 99% with a narrow 95% confidence interval for both IgM and IgG assays. Clinical sensitivity was determined on up to 232 samples from 130 RT-PCR-confirmed SARS-CoV-2 patients. The positive percent agreement (PPA) with SARS-CoV-2 PCR reached 100% at ≥ 16 days (VIDAS® SARS-CoV-2 IgM) and ≥ 32 days (VIDAS® SARS-CoV-2 IgG) of symptom onset. Combined IgM/IgG test results improved the PPA compared to each test alone. SARS-CoV-2 IgG seroconversion followed closely that of SARS-CoV-2 IgM and remained stable over time, while SARS-CoV-2 IgM levels rapidly declined. Interestingly, SARS-CoV-2-specific IgM and IgG responses were significantly higher in COVID-19 hospitalized vs. non-hospitalized patients. Altogether, the VIDAS® SARS-CoV-2 IgM and IgG assays are highly specific and sensitive serological tests suitable for the reliable detection of past acute SARS-CoV-2 infections.

Portable Blood Detection System on the Basis of Dry-Type Chemical Method

2013 ◽  
Vol 321-324 ◽  
pp. 1620-1626
Author(s):  
Xiu Mei Cui ◽  
Feng Chen ◽  
Yao Hua Du ◽  
Chao Li ◽  
Biao Gu ◽  
...  
Keyword(s):  
Digital Signal Processor ◽  
Blood Cells ◽  
Chemical Method ◽  
Detection System ◽  
Correlation Coefficients ◽  
Rapid Test ◽  
Digital Signal ◽  
Test Results ◽  
Relative Standard ◽  
The Stability

This paper presents a portable blood detection system on the basis of dry-type chemical method. Controlled by TM320VC5509A, a high-precision Digital Signal Processor, provided light source by line spot semiconductor laser (LD), converted between light and electricity by photocoupler, the system can fulfill the conventional detection and measurement of blood cells parameters. As for the stability of the system, the test results showed that the relative standard deviation of the parameters of the blood cells were all below 1.7%. The contrast experiment on Sysmex XT-1800i showed that with hematocrit (HCT), hemoglobin (HGB), lymphocytes and moncytes (LM), granulocytes (GRAN), platelets (PLT) and white blood cell (WBC) as contrast items, the correlation coefficients of the system were 0.9910.9720.9520.9860.979 and 0.985 respectively. The volume and time measurements of the system were designed as (25×20×10) cm3and 60s. The system can fulfill some functions such as indicating records, seeking information and deleting. The system will have a wide application prospect in rapid test of blood in field and emergency examination.

Comparison of Two Rapid Test Procedures with the Standard EC Test for Recovery of Fecal Coliform Bacteria from Shellfish-Growing Waters

1978 ◽  
Vol 61 (6) ◽  
pp. 1317-1323 ◽  
Author(s):  
Daniel A Hunt ◽  
Janet Springer
Keyword(s):  
Fecal Coliform ◽  
Rapid Test ◽  
Fecal Coliforms ◽  
Coliform Bacteria ◽  
Test Results ◽  
Test Procedures ◽  
Geographic Variations ◽  
Fecal Coliform Bacteria ◽  
Alternative Test ◽  
And Control

Abstract A study was conducted to compare recovery and enumeration capability of two 24-hr multitube fermentation tests with the standard EC test for fecal coliform levels in shellfish-growing waters. The 2 tests were the A-1 test developed by Andrews and Presnell, specifying 24-hr incubation in A-1 medium at 44.5CC; and a modification of the A-1 test requiring a 3-hr resuscitation at 35°C before incubation at 44.5°C for 21 hr. Fifteen State, Federal, and Provincial laboratories examined 10 routine shellfish-growing area samples per month in parallel by the 3 methods for 1 year. IMViC tests (indole, methyl red, Voges-Proskauer, and citrate) were conducted on all gas-positive tubes. The modified A-1 test recovered higher levels of fecal coliforms than the A-1 test. Although there were seasonal and geographic variations in recovery and enumeration by the modified A-1 test, overall there was good correlation of the modified A-1 test with the EC test. Both the A-1 and modified A-1 tests were more specific for Escherichia coli than the EC test. Results of the study indicate that the 24-hr modified A-1 test can be used as an alternative test for the standard 72-hr EC test as an adjunct to the sanitary survey for the classification and control of shellfish-growing area waters.

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