Clinical Validation of GenBody COVID-19 Ag, Nasal and Nasopharyngeal Rapid Antigen Tests for Detection of SARS-CoV-2 in European Adult Population.

Accurate and rapid identification of COVID-19 is critical for effective patient treatment and disease outcomes, as well as the prevention of SARS-CoV-2 transmission. Rapid antigen tests (RATs) for identifying SARS-CoV-2 are simpler, faster and less expensive than molecular assays. Any new product to be considered a medical device is subject to evaluation and data analysis to verify the in vitro diagnostic ability to achieve its intended purpose. Clinical validation of such a test is a prerequisite before clinical application. This study was a clinical validation on adult Europeans of GenBody COVID-19 Ag, nasal and nasopharyngeal RATs. A set of 103 positive and 301 negative from nose and nasopharynx samples confirmed by RT-qPCR were examined. The tests were safe to use and showed 100% specificity in both specimens, and high sensitivity of 94.17% (95%CI 87.75% to 97.83%) and 97.09% (95%CI 91.72% to 99.4%), respectively. The parameters were significantly better for samples with higher virus loads (the highest for CT ≤ 25). The GenBody COVID-19 Ag RATs are inexpensive (compared to RT-qPCR), reliable and rapid with high sensitivity and specificity, making them suitable for diagnosis and timely isolation and treatment of COVID-19 patients, contributing to the better control of virus spread.

Lab-on-PCB-Based Electrical Immunosensing Platform for Point-of-Care Detection of SARS-CoV-2

The present work shows a multiplexed lab-on-printed circuit board (PCB) platform for label-free immunosensing of SARS-CoV-2 nucleocapsid and spike antigens based on electrical impedance measurements. The sensor consists of an interdigitated electrode of soft gold integrated on a PCB with microwells for sample loading. A mercaptoundecanoic acid-protein-G-based site-specific biofunctionalization strategy is employed to efficiently immobilize dual antibodies on the device surface toward the sensitive and rapid antigen test of SARS-CoV-2. Electrical impedance measurements carried out in a point-of-care setting using the PalmSens Sensit Smart system that could detect nucleocapsid and spike proteins with a detection limit of 40 and 20 pg each. Experiments with nasopharyngeal swab samples from N = 5 healthy and N = 14 SARS-CoV-2 positive subjects showed significantly different electrical responses for subjects with high viral load (Ct < 25) compared with healthy subjects and control.

Factors influencing the performance of rapid SARS-CoV-2 antigen tests under field condition.

BACKGROUND: Globally, real-time reverse transcription-polymerase chain reaction (rRT-PCR) is the reference detection technique for SARS-CoV-2, which is expensive, time consuming, and requires trained laboratory personnel. Thus, a cost-effective, rapid antigen test is urgently needed. This study evaluated the performance of the rapid antigen tests (RATs) for SARS-CoV-2 compared with rRT-PCR, considering different influencing factors. METHODS: We enrolled a total of 214 symptomatic individuals with known COVID-19 status using rRT-PCR. We collected and tested paired nasopharyngeal (NP) and nasal swab (NS) specimens (collected from same individual) using rRT-PCR and RATs (InTec and SD Biosensor). We assessed the performance of RATs considering specimen types, viral load, the onset of symptoms, and presenting symptoms. RESULTS: We included 214 paired specimens (112 NP and 100 NS SARS-CoV-2 rRT-PCR positive) to the analysis. For NP specimens, the average sensitivity, specificity, and accuracy of the RATs were 87.5%, 98.6%, and 92.8%, respectively, when compared with rRT-PCR. While for NS, the overall kit performance was slightly lower than that of NP (sensitivity 79.0%, specificity 96.1%, and accuracy 88.3%). We observed a progressive decline in the performance of RATs with increased Ct values (decreased viral load). Moreover, the RAT sensitivity using NP specimens decreased over the time of the onset of symptoms. CONCLUSION: The RATs showed strong performance under field conditions and fulfilled the minimum performance limit for rapid antigen detection kits recommended by World Health Organization. The best performance of the RATs can be achieved within the first week of the onset of symptoms with high viral load.

Diagnostic performance of a SARS-CoV-2 rapid antigen test in a large, Norwegian cohort.

BACKGROUND: Rapid antigen tests (RATs) may be included in national strategies for handling the SARS-CoV-2 pandemic, as they provide test results rapidly, are easily performed outside laboratories, and enable immediate contract tracing. However, before implementation further clinical evaluation of test sensitivity is warranted. OBJECTIVES: To examine the performance of Abbott's Panbio™ COVID-19 Ag Rapid Test Device for SARS-CoV-2 testing in a low to medium prevalence setting in Norway. STUDY DESIGN: A prospective study comparing the results of the Panbio RAT with PCR in 4857 parallel samples collected at a SARS-CoV-2 test station in Oslo, and from COVID-19 outbreaks in six Norwegian municipalities. RESULTS: A total of 4857 cases were included in the study; 3991 and 866 cases from the test station and the outbreak municipalities, respectively. The prevalence at the test station in Oslo was 6.3 %, and the overall sensitivity of the RAT was 74 %. Increased sensitivity was observed in patients who experienced symptoms (79 %) and when considering samples with viral loads above estimated level of infectivity (84 %), while it was lower in asymptomatic persons (55 %). In the outbreak municipalities, the overall prevalence was 6.9 %, and the total sensitivity of the RAT was 70 %. CONCLUSIONS: Our results indicate that the test correctly identified most infectious individuals. Nevertheless, the sensitivity is considerably lower than for PCR, and it is important that the limitations of the test are kept in mind in the follow-up of tested individuals.