COVID-19 Ag Rapid Test Device Research Articles

Non-SARS-CoV-2 respiratory viral detection and whole genome sequencing from COVID-19 rapid antigen test devices: a laboratory evaluation study

There has been high uptake of rapid antigen test device use for point-of-care COVID-19 diagnosis. Individuals who are symptomatic but test negative on COVID-19 rapid antigen test devices might have a different respiratory viral infection. We aimed to detect and sequence non-SARS-CoV-2 respiratory viruses from rapid antigen test devices, which could assist in the characterisation and surveillance of circulating respiratory viruses in the community. We applied archival clinical nose and throat swabs collected between Jan 1, 2015, and Dec 31, 2022, that previously tested positive for a common respiratory virus (adenovirus, influenza, metapneumovirus, parainfluenza, rhinovirus, respiratory syncytial virus [RSV], or seasonal coronavirus; 132 swabs and 140 viral targets) on PCR to two commercially available COVID-19 rapid antigen test devices, the Panbio COVID-19 Ag Rapid Test Device and Roche SARS-CoV-2 Antigen Self-Test. In addition, we collected 31 COVID-19 rapid antigen test devices used to test patients who were symptomatic at The Royal Melbourne Hospital emergency department in Melbourne, Australia. We extracted total nucleic acid from the device paper test strips and assessed viral recovery using multiplex real-time PCR (rtPCR) and capture-based whole genome sequencing. Sequence and genome data were analysed through custom computational pipelines, including subtyping. Of the 140 respiratory viral targets from archival samples, 89 (64%) and 88 (63%) were positive on rtPCR for the relevant taxa following extraction from Panbio or Roche rapid antigen test devices, respectively. Recovery was variable across taxa: we detected influenza A in nine of 18 samples from Panbio and seven of 18 from Roche devices; parainfluenza in 11 of 20 samples from Panbio and 12 of 20 from Roche devices; human metapneumovirus in 11 of 16 from Panbio and 14 of 16 from Roche devices; seasonal coronavirus in eight of 19 from Panbio and two of19from Roche devices; rhinovirus in 24 of 28 from Panbio and 27 of 28 from Roche devices; influenza B in fourof 15 in both devices; and RSV in 16 of 18 in both devices. Of the 31 COVID-19 devices collected from The Royal Melbourne Hospital emergency department, 11 tested positive for a respiratory virus on rtPCR, including one device positive for influenza A virus, one positive for RSV, four positive for rhinovirus, and five positive for SARS-CoV-2. Sequences of target respiratory viruses from archival samples were detected in 55 (98·2%) of 56samples from Panbio and 48 (85·7%) of 56 from Roche rapid antigen test devices. 98 (87·5%) of 112 viral genomes were completely assembled from these data, enabling subtyping for RSV and influenza viruses. All 11samples collected from the emergency department had viral sequences detected, with near-complete genomes assembled for influenza A and RSV. Non-SARS-CoV-2 respiratory viruses can be detected and sequenced from COVID-19 rapid antigen devices. Recovery of near full-length viral sequences from these devices provides a valuable opportunity to expand genomic surveillance programmes for public health monitoring of circulating respiratory viruses. Australian Government Medical Research Future Fund and Australian National Health and Medical Research Council.

Rapid antigen test as a screening tool for SARS-CoV-2 infection: Head-to-head comparison with qRT-PCR in Ethiopia

ObjectiveThis study aimed to determine the diagnostic accuracy of the antigen rapid diagnostic test (Ag-RDT) as a screening tool for SARS-CoV-2 infection compared to Quantitative reverse transcription polymerase chain reaction (qRT-PCR). MethodsThis study was conducted at six referral hospitals in Oromia Region, Ethiopia. One thousand seven hundred twenty-one patients who visited the hospitals for various medical conditions were tested with qRT-PCR and/or Ag-RDTs. Qualitative detection of SARS-CoV-2 antigen was performed using the Panbio™ COVID-19 Ag rapid test device. ResultsCompared with qRT-PCR, Ag-RDTs had a sensitivity of 33.3 % (95%CI: 30.9%–35.9 %) and a specificity of 99.3 % (95%CI: 98.8%–99.7 %) to detect active SARS-CoV-2 infection. The area under the receiver operator curve was 0.67 (95%CI: 0.63–0.69). The sensitivity of Ag-RDTs appeared high in patients with shortness of breath (73.3 %) and those presenting with all three symptoms – fever, cough, and dyspnea (71.4 %). In all instances, specificity was more than 98 %. The Ag-RDT positivity rate also correlated well with viral load: 51.7 % in cases with cycle threshold (Ct) < 25 (high viral load) and only 3.4 % when Ct > 25 (low viral load). ConclusionAlthough Ag-RDT for diagnosing SARS-CoV-2 is a good option as a point-of-care screening tool, it has a low sensitivity to detect active infections. Using Panbio™ COVID-19 Ag Rapid test for diagnostic and treatment decisions may lead to a false negative, resulting in patient misdiagnosis, ultimately contributing to disease spread and poor patient outcome.

COVID-19 self-testing using antigen rapid diagnostic tests: Feasibility evaluation among health-care workers and general population in Malawi.

COVID-19 testing is critical for identifying cases to prevent transmission. COVID-19 self-testing has the potential to increase diagnostic testing capacity and to expand access to hard-to-reach areas in low-and-middle-income countries. We investigated the feasibility and acceptability of COVID-19 self-sampling and self-testing using SARS-CoV-2 Antigen-Rapid Diagnostic Tests (Ag-RDTs). From July 2021 to February 2022, we conducted a mixed-methods cross-sectional study examining self-sampling and self-testing using Standard Q and Panbio COVID-19 Ag Rapid Test Device in Urban and rural Blantyre, Malawi. Health care workers and adults (18y+) in the general population were non-randomly sampled. Overall, 1,330 participants were enrolled of whom 674 (56.0%) were female and 656 (54.0%) were male with 664 for self-sampling and 666 for self-testing. Mean age was 30.7y (standard deviation [SD] 9.6). Self-sampling usability threshold for Standard Q was 273/333 (82.0%: 95% CI 77.4% to 86.0%) and 261/331 (78.8%: 95% CI 74.1% to 83.1%) for Panbio. Self-testing threshold was 276/335 (82.4%: 95% CI 77.9% to 86.3%) and 300/332 (90.4%: 95% CI 86.7% to 93.3%) for Standard Q and Panbio, respectively. Agreement between self-sample results and professional test results was 325/325 (100%) and 322/322 (100%) for Standard Q and Panbio, respectively. For self-testing, agreement was 332/333 (99.7%: 95% CI 98.3 to 100%) for Standard Q and 330/330 (100%: 95% CI 99.8 to 100%) for Panbio. Odds of achieving self-sampling threshold increased if the participant was recruited from an urban site (odds ratio [OR] 2.15 95% CI 1.44 to 3.23, P < .01. Compared to participants with primary school education those with secondary and tertiary achieved higher self-testing threshold OR 1.88 (95% CI 1.17 to 3.01), P = .01 and 4.05 (95% CI 1.20 to13.63), P = .02, respectively. One of the first studies to demonstrate high feasibility and acceptability of self-testing using SARS-CoV-2 Ag-RDTs among general and health-care worker populations in low- and middle-income countries potentially supporting large scale-up. Further research is warranted to provide optimal delivery strategies of self-testing.

Field evaluations of four SARS-CoV-2 rapid antigen tests during SARS-CoV-2 Delta variant wave in South Africa

BackgroundRapid antigen tests detecting SARS-CoV-2 were shown to be a useful tool in managing the COVID-19 pandemic. Here, we report on the results of a prospective diagnostic accuracy study of four SARS-CoV-2 rapid antigen tests in a South African setting.MethodsRapid antigen test evaluations were performed through drive-through testing centres in Durban, South Africa, from July to December 2021. Two evaluation studies were performed: nasal Panbio COVID-19 Ag Rapid Test Device (Abbott) was evaluated in parallel with the nasopharyngeal Espline SARS-CoV-2 Ag test (Fujirebio), followed by the evaluation of nasal RightSign COVID-19 Antigen Rapid test Cassette (Hangzhou Biotest Biotech) in parallel with the nasopharyngeal STANDARD Q COVID-19 Ag test (SD Biosensor). The Abbott RealTime SARS-CoV-2 assay was used as a reference test.ResultsEvaluation of Panbio and Espline Ag tests was performed on 494 samples (31% positivity), while the evaluation of Standard Q and RightTest Ag tests was performed on 539 samples (13.17% positivity). The overall sensitivity for all four tests ranged between 60 and 72% with excellent specificity values (> 98%). Sensitivity increased to > 80% in all tests in samples with cycle number value < 20. All four tests performed best in samples from patients presenting within the first week of symptom onset.ConclusionsAll four evaluated tests detected a majority of the cases within the first week of symptom onset with high viral load.

PREVALENCE OF COVID-19 INFECTION AMONG OUTPATIENTS ATTENDING A NIGERIAN TERTIARY HOSPITAL

Introduction: Three years after its declaration as a pandemic, countries and regions are still gathering data on the epidemiology of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) infection. Following the relaxation of many restrictions earlier imposed to curb spread and the observation of some sort of seasonal surge in infection rates, it is still not clear whether the disease should remain a pandemic. Methods: This descriptive cross-sectional study was conducted at a Nigerian tertiary hospital. Ninety-two adult male and female patients presenting with common symptoms associated with COVID-19 disease were enrolled at the Outpatient Department of the facility. Ethical approval was duly sought and obtained from The Ethics and Health Research Committee of the hospital. Informed consent was obtained from each study participant. The COVID-19 testing was determined using Panbio COVID-19 Ag Rapid Test Device from Abbott (United States). Results are presented as numbers and frequencies. Results: Among outpatients presenting with symptoms such as fever and midnight sweats, body aches and pain, difficulty in breathing as well as cough and catarrh, the prevalence of COVID-19 was observed to be 15.2%. On the knowledge of the respondents regarding COVID-19, majority (80.6%) had a prior knowledge while 19.4% lacked knowledge of COVID-19. Conclusion: This study observed 15.2% prevalence for COVID-19 infection among outpatients in a Nigerian tertiary hospital. There still exists persons (19.4%) who lack knowledge of the disease.

Comparison of COVID-19 Rapid Antigen Test Results with PCR Reactive/ Non-Reactive Cases

Objective: To evaluate the analytical accuracy of the COVID-19 Ag Rapid Test Device by Abbott PanbioTM using RT-PCR as the reference assay and to detect any false-positive/negative reactions to assess the specificity of this analytical procedure.&#x0D; Study Design: Cross-Sectional analytical study.&#x0D; Place and Duration of Study: Department of Chemical Pathology, Chughtai Institute of Pathology, Lahore Pakistan, from Feb to May 2021.&#x0D; Methodology: This study was comprised of a total of 105 samples. The result of these nasopharyngeal specimens was already established by Reverse-Transcriptase Polymerase Chain Reaction (RT-PCR). Then the same (nasopharyngeal) specimens were analysed on Rapid Antigen Detection Test Device.&#x0D; Results: Out of 105 specimens, we got 88(83%) PCR positive samples and 17(16%) PCR negative, which, when compared with the Abbott PanbioTM Rapid Antigen Test Device, showed 60(57%) positive and 45(42.8%) negative samples having a sensitivity of 75(86%) (CI 67.04%-83.32%) and specificity of 100%(80.49-100%). The accuracy of the test was found to be 78(95%). This assay was found convenient and more appropriate for outdoor settings.Keywords: COVID-19, RT-PCR, Rapid antigen test, Specificity, Sensitivity.

Analytical sensitivity of six lateral flow antigen test kits for variant strains of SARS-CoV-2

IntroductionThe lateral flow antigen test is a useful tool for rapid diagnosis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. The analytical sensitivity of six lateral flow antigen test kits was compared. MethodsThe limit of detection (LoD) and time to positive results were evaluated for six lateral flow tests including ImmunoArrow®, ESPLINE® SARS-CoV-2, QuickNavi™ COVID19 Ag, ImmunoAce® SARS-CoV-2, Panbio™ COVID-19 Ag Rapid Test Device, and SARS-CoV-2 Rapid Antigen Test using the heat-inactivated virus. The LoD of ImmunoArrow® against the Omicron variants was compared with that against the wild-type using recombinant proteins. ResultsImmunoArrow® and ESPLINE® showed the lowest LoD. The time to positive results of all tests except for ESPLINE® was within 200 s in the evaluation at high dose of antigens (2.5 × 105 TCID50/mL) and 500 s in the evaluation at low dose of antigens (2.5 × 104 TCID50/mL). The LoD of ImmunoArrow® against the Omicron variants was the same concentration against the wild-type antigen. ConclusionsImmunoArrow® detected SARS-CoV-2 antigens including the Omicron variants with good sensitivity among the six lateral flow antigen tests. These finding support that it can support the rapid diagnosis of COVID-19 with the good sensitivity.

Efficacy Of PanbioTM Covid-19 Ag Rapid Test In Sars-Cov-2 Detection: Comparison With RT-PCR Test.

Evidence on performance of Rapid Antigen Detection Tests to recognize SARS-CoV-2 symptomatic patients in our context is limited. This study was aimed to evaluate Panbio™ COVID-19 Ag Rapid Test Device (Abbott Diagnostics, Jena, Germany) in identifying SARS-CoV-2 infection in comparison with RT-PCR test. This cross-sectional validation study was carried out at Margalla Hospital, Taxila from October, 2020 to March, 2021. Three hundred and eighty-two participants of both gender and all ages, symptomatic for 3-4 days were included in this study. For each participant, two nasopharyngeal swabs were collected by trained lab technicians according to SOPs, one for Rapid Antigen Test and other for RT-PCR.Covid-19 antibodies were checked 4-6 weeks after symptoms among 77 randomly selected participants to further evaluate the performance of Rapid Antigen Test. Data was analyzed using SPSS-26. The mean age of the participants was 43.1 years (SD=15.9). More than half of participants were males (n=213%=55.8) and 169 (44.2%) were females. Sensitivity of Rapid Antigen Test was calculated to be 94.3%, whereas the specificity was 39.7%. Out of 34 RT-PCR negatives that were initially detected positive on Rapid Antigen Test, 33 demonstrated presence of COVID-19 antibodies. Panbio™ COVID-19 Ag Rapid Test was found to have 93.4% overall sensitivity and relatively low overall specificity (37.9%). Rapid antigen testing using Panbio™ COVID-19 Ag Rapid Test Device can be effectively used to scale up mass testing to interrupt transmissibility of COVID-19 infection by generating quick result.

Accuracy of Rapid Antigen Detection Test Device (COVID-19 Ag Rapid Test Device) in Diagnosis of Acute COVID-19 Infections

Objective: To evaluate the accuracy of the COVID-19 Ag Rapid test device for detection of SARS-CoV-2 with Reverse Transcriptase Polymerase Chain Reaction as the gold standard.&#x0D; Study Design: Cross-sectional study.&#x0D; Place and Duration of Study: Department of Virology, Armed Forces Institute of Pathology, Rawalpindi, in the month of Sept 2020.&#x0D; Methodology: A total of 106 patients suspected of COVID-19 were tested, including 63 patients admitted to the COVID-19 ward of Pak Emirates Military Hospital and 43 from the emergency department of Combined Military Hospital, Rawalpindi Pakistan respectively. The samples were transported to the Virology department and subjected to Polymerase Chain Reaction and Antigen testing. In addition, the diagnostic accuracy of the COVID-19 Ag Rapid test device was compared to Reverse Transcriptase Polymerase Chain Reaction for detection of SARS-CoV-2 infection.&#x0D; Results: Out of 106 nasopharyngeal swab samples tested, 48 (45.2%) samples were positive by Rapid test device and Reversed Transcriptase Polymerase Chain Reaction, and 52 (49.0%) samples tested negative by both methods. Inconsistent results (False Negative) were obtained in 6 (5.6%) samples. COVID-19 Ag Rapid test device has detected the maximum number of cases, 41 (85.4%), during the first week of illness. Its sensitivity decreases as the duration of infection progress.&#x0D; Conclusion: The overall sensitivity of the Rapid test device is much less than the Polymerase chain reaction due to potential false negative results. However, it can be helpful in the early isolation of cases in an outbreak in a closed community and for case management in peripheral setups....

Clinical Evaluation of Severe Acute Respiratory Syndrome Coronavirus 2 Rapid Antigen Tests During the Omicron Wave in South Africa.

We evaluated the performance of nasal and nasopharyngeal Standard Q COVID-19 [coronavirus disease 2019] Ag tests (SD Biosensor) and the Panbio COVID-19 Ag Rapid Test Device (nasal; Abbott) against the Abbott RealTime severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) assay during the Omicron (clades 21M, 21K, and 21L) wave in South Africa. Overall, all evaluated tests performed well, with high sensitivity (range, 77.78%–81.42%) and excellent specificity values (>99%). The sensitivity of rapid antigen tests increased above 90% in samples with cycle threshold <20, and all 3 tests performed best within the first week after symptom onset.

Investigating the Sensitivity of Nasal or Throat Swabs: Combination of Both Swabs Increases the Sensitivity of SARS-CoV-2 Rapid Antigen Tests.

ABSTRACTThe COVID-19 pandemic has been hallmarked by several waves of variants of concern (VoCs), each with novel challenges. Currently, the highly transmissible Omicron VoC is predominant worldwide, and sore throat is common, among other cold-like symptoms. Anecdotes on social media have suggested that sampling one’s throat can increase the sensitivity for Omicron detection by antigen-based rapid testing devices (Ag-RDTs). This work aimed to improve the local testing strategy and determine whether the sensitivity of Ag-RDTs designed for nasal sampling is altered with the use of self-administered throat swabs in self-perceived asymptomatic individuals. This investigation used a common Ag-RDT (i.e., Abbott Panbio COVID-19 Ag rapid test device) to compare three sampling sites: nasal swab, throat swab, and combined nasal/throat. All Ag-RDT results were confirmed with molecular testing from residual test buffer. Compared to reverse transcriptase PCR (RT-PCR), samples from nasal or throat swabs each detected 64.5% of SARS-CoV-2 cases; however, combining the contributions of each swab increased the positive percent agreement (PPA) with RT-PCR to 88.7%. This trend was also evident with the Rapid Response Ag-RDT (BTNX), which uses more flexible swabs than does the Panbio. When nasal swab collection was compared to paired sampling of the nose/throat using a single swab with the Panbio Ag-RDT, the PPAs were 68.4% and 81.6%, respectively. No false-positive results were observed with nasal, throat, or combined nasal/throat sampling. Self-administered throat and nasal/throat swabs both had >90% acceptability. These findings support the use of self-collected combined nasal/throat sampling for Ag-RDT-based SARS-CoV-2 detection in self-perceived asymptomatic individuals.IMPORTANCE This quality project demonstrates that combining the results of nasal and throat swabs or using a combined single swab of the throat and nares resulted in increased detection of SARS-CoV-2 using a rapid antigen test, in an asymptomatic population. Importantly, no false positives were detected, and over 90% of people were willing to perform the combination swab. These types of projects are instrumental in informing local practices to improve testing strategies. These data support the option of using a combined nasal/throat swab in our local setting to enhance the detection of Omicron.

N-antigenemia detection by a rapid lateral flow test predicts 90-day mortality in COVID-19: A prospective cohort study

ObjectivesTo evaluate if the detection of N antigen of SARS-CoV-2 in plasma by a rapid lateral flow test predicts 90-day mortality in COVID-19 patients hospitalized at the wards. MethodsThe presence of N-antigenemia was evaluated in the first 36 hours after hospitalization in 600 unvaccinated COVID-19 patients, by using the Panbio COVID-19 Ag Rapid Test Device from Abbott (Abbott Laboratories Inc., Chicago, IL, USA). The impact of N-antigenemia on 90-day mortality was assessed by multivariable Cox regression analysis. ResultsPrevalence of N-antigenemia at hospitalization was higher in nonsurvivors (69% (82/118) vs. 52% (250/482); p < 0.001). The patients with N-antigenemia showed more frequently RNAemia (45.7% (148/324) vs. 19.8% (51/257); p < 0.001), absence of anti-SARS-CoV-2 N antibodies (80.7% (264/327) vs. 26.6% (69/259); p < 0.001) and absence of S1 antibodies (73.4% (240/327) vs. 23.6% (61/259); p < 0.001). The patients with antigenemia showed more frequently acute respiratory distress syndrome (30.1% (100/332) vs. 18.7% (50/268); p = 0.001) and nosocomial infections (13.6% (45/331) vs. 7.9% (21/267); p = 0.026). N-antigenemia was a risk factor for increased 90-day mortality in the multivariable analysis (HR, 1.99 (95% CI,1.09–3.61), whereas the presence of anti-SARS-CoV-2 N-antibodies represented a protective factor (HR, 0.47 (95% CI, 0.26–0.85). DiscussionThe presence of N-antigenemia or the absence of anti-SARS-CoV-2 N-antibodies after hospitalization is associated to increased 90-day mortality in unvaccinated COVID-19 patients. Detection of N-antigenemia by using lateral flow tests is a quick, widely available tool that could contribute to early identify those COVID-19 patients at risk of deterioration.

Different performance of three point-of-care SARS-CoV-2 antigen detection devices in symptomatic patients and close asymptomatic contacts: a real-life study

ObjectivesPCR on nasopharyngeal exudates, the cornerstone of the detection of SARS-CoV-2, is time-consuming and commonly unavailable at primary health care centres. Detection of viral nucleocapsid antigens using lateral flow point-of-care tests is helpful for the early triage of patients who attend health care facilities. MethodsThis was a prospective study carried out in clinically suspected cases and close asymptomatic contacts who attended a primary care centre (Madrid, Spain) for SARS-CoV-2 detection. Patients were divided into three 300-patient cohorts (n = 200 symptomatic cases and n = 100 close asymptomatic contacts per cohort). Three antigen detection tests (SGTI-Flex COVID-19 Ag, Panbio COVID-19 Ag Rapid Test Device, and GSD NovaGen SARS-CoV-2 Ag Rapid Test) were used and compared. Paired nasopharyngeal exudates were obtained, one swab for PCR and the other for antigen detection. Each antigen detection test was evaluated on one cohort. ResultsAll tests showed invariably 100% specificity. Sensitivity was 68.9% (95% CI: 55.7–80; SGTI-Flex), 71.1% (95% CI: 55.6–83.6; Panbio), and 84.6% (95% CI: 72–93.1; NovaGen) in clinically suspected patients and 84.6% (95% CI: 54.5–98.1), 33.3% (95% CI: 11.8–61.6), and 55.6% (95% CI: 30.7–78.4) in close asymptomatic contacts, respectively. Sensitivity was systematically higher in samples yielding positive PCR results with Ct ≤ 20. DiscussionWe found considerable test-to-test antigen detection variations among patients with clinical suspicion of COVID-19 and close asymptomatic contacts. Negative antigen results, regardless of the test used, should be confirmed by PCR.

Rapid antigen tests for positive Covid-19 confirmation in the laboratory setting

Introduction: Pooling patient samples for PCR testing increases throughput and has become standard practice during the COVID-19 pandemic. Accurate, rapid and cost-effective methods to determine the actual positive sample from a pooled well are needed. Aims: To determine the utility of rapid antigen tests for discerning the positive COVID-19 sample from pooled test results that are positive. Methods: 15 known positive and negative Covid-19 samples were tested using the Abbott Panbio COVID-19 Ag Rapid test device with a modified method suitable for use in the laboratory. Briefly, 150 μL of reaction buffer was mixed with 150 μL of patient sample from liquid swabs and the result was read at 15 minutes. Discussion: The performance of rapid antigen kits in this study were consistent with results using the standard method with direct inoculation of swabs.1 Samples yielding a Ct value below 25 were detected successfully, and those above that threshold failed. Thus for pooled positive results with a Ct value below 25, the current method can be used to discern the positive sample in that pool. This method would also lower the cost of further testing on pooled samples and expedite determination of the positive sample. Data collection is ongoing to further assess. Reference 1. Dinnes J, Deeks JJ, Berhane S, et al. Rapid, point-of-care antigen and molecular-based tests for diagnosis of SARS-CoV-2 infection. Cochrane Database Syst Rev 2021; 3: CD013705.

Performance Validation of COVID-19 Self-Conduct Buccal and Nasal Swabs RTK-Antigen Diagnostic Kit.

The antigen rapid diagnostic test (Ag-RDT) is an immunodiagnostic test that detects the presence of viral proteins (antigens) expressed by the COVID-19 virus in a sample from a patient’s respiratory tract. This study focused on evaluating the performance of self-conduct buccal and nasal swabs RTK-antigen test compared to nasopharyngeal swab RTK-based COVID-19 diagnostic assays, Panbio™ COVID-19 Ag Rapid Test Device (Nasopharyngeal) (Abbott Rapid Diagnostics Jena GmbH, Jena, Germany) used in hospitals for first-line screening. The sensitivity and specificity of the paired RTK-Ag test in detecting the an-tigen were calculated at 96.4% and 100%, respectively. Fisher exact tests showed the association between nasopharyngeal swabs RTK-Ag assay and buccal-nasal swabs RTK-Ag from ProdetectTM is significant (p-values < 0.001). The result showed that a self-conducted buccal and nasal RTK-antigen rapid test by the patients is comparable to the results obtained from a rapid test device conducted by trained medical personnel using a nasopharyngeal swab.

Evaluation of a rapid antigen detection test (Panbio™ COVID-19 Ag Rapid Test Device) as a point-of-care diagnostic tool for COVID-19 in a pediatric emergency department.

We evaluated the Panbio™ COVID‐19 Ag Rapid Test Device as a point‐of‐care diagnostic tool for COVID‐19 in 357 patients at a pediatric emergency department. Thirty‐four patients tested positive by reverse transcription polymerase chain reaction, of which 24 were positive by the antigen assay. The sensitivity and specificity of the assay were 70.5% and 100%, respectively.

EVALUATION OF THREE COVID-19 ANTIGEN ASSAY VERSUS PCR DETECTION IN ROUTINE PRACTICE

According to WHO, molecular testing is the "Gold Standard" for the diagnosis of SARS-CoV-2 infection. However, these tests have some limitations in practice (well trained staff, specific equipment requirements, organization of area and time frame for reporting results). Thus, rapid antigen test (RAT) for the detection of one or several SARS-CoV-2 antigens have emerged. We evaluated the analytical performance of 3 RAT used in our laboratory : FREND® Ag COVID-19 (NanoEntek) (FA), STANDARD Q COVID-19 Ag (SD Biosensor) (BA), PANBIO™ COVID-19 Ag RAPID TEST DEVICE (Abbott) (PA) in comparaison to rRT-PCR results. Our study indicates that PA and SA antigen tests have a very good sensitivity to identify infected patients with COVID-19 specifically between in the 0-5 days time-window post onset of symptoms. Nevertheless, one out of three antigen tests (FA) showed very poor clinical performance.

Diagnostic accuracy of two commercial SARS-CoV-2 antigen-detecting rapid tests at the point of care in community-based testing centers.

ObjectivesDetermine the diagnostic accuracy of two antigen-detecting rapid diagnostic tests (Ag-RDT) for SARS-CoV-2 at the point of care and define individuals’ characteristics providing best performance.MethodsWe performed a prospective, single-center, point of care validation of two Ag-RDT in comparison to RT-PCR on nasopharyngeal swabs.ResultsBetween October 9th and 23rd, 2020, 1064 participants were enrolled. The PanbioTM Covid-19 Ag Rapid Test device (Abbott) was validated in 535 participants, with 106 positive Ag-RDT results out of 124 positive RT-PCR individuals, yielding a sensitivity of 85.5% (95% CI: 78.0–91.2). Specificity was 100.0% (95% CI: 99.1–100) in 411 RT-PCR negative individuals. The Standard Q Ag-RDT (SD Biosensor, Roche) was validated in 529 participants, with 170 positive Ag-RDT results out of 191 positive RT-PCR individuals, yielding a sensitivity of 89.0% (95%CI: 83.7–93.1). One false positive result was obtained in 338 RT-PCR negative individuals, yielding a specificity of 99.7% (95%CI: 98.4–100). For individuals presenting with fever 1–5 days post symptom onset, combined Ag-RDT sensitivity was above 95%. Lower sensitivity of 88.2% was seen on the same day of symptom development (day 0).ConclusionsWe provide an independent validation of two widely available commercial Ag-RDTs, both meeting WHO criteria of ≥80% sensitivity and ≥97% specificity. Although less sensitive than RT-PCR, these assays could be beneficial due to their rapid results, ease of use, and independence from existing laboratory structures. Testing criteria focusing on patients with typical symptoms in their early symptomatic period onset could further increase diagnostic value.

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

BackgroundRapid 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.ObjectivesTo 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 designA 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.ResultsA 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 %.ConclusionsOur 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.

Diagnostic performance of CerTest and Panbio antigen rapid diagnostic tests to diagnose SARS-CoV-2 infection.

ObjectivesAntigen rapid diagnostic tests (Ag-RDT) have been developed as reliable tools to control the SARS-CoV-2 pandemic. The objective of our study was to evaluate the diagnostic performance of two Ag-RDTs.MethodsWe evaluated CerTest SARS-CoV-2 Ag One Step Card Test and Panbio COVID-19 Ag Rapid Test Device Ag-RDTs. We included 320 nasopharyngeal samples: 150 PCR negative samples to assess the specificity and 170 PCR positive samples to evaluate the sensitivity. We also evaluated their sensitivity according to cycle threshold (Ct) values and the time from the onset of symptoms. Tests were compared using the McNemar’s test and agreement was evaluated using the kappa score (k).ResultsBoth Ag-RDTs showed a specificity of 100 %. Overall sensitivity was 53.5 % for CerTest and 60.0 % for Panbio. For samples with 25, sensitivity was 94.0 % for CerTest and 96.4 % for Panbio (p = 0.500). Regarding samples with Ct>25, sensitivity was 14.0 % for CerTest and 24.4 % for Panbio (p = 0.004). Sensitivity for samples within the first 5 days after the onset of symptoms were 84.8 % for CerTest and 91.3 % for Panbio (p = 0.250) and notably decreased for samples taken after the fifth day. Both Ag-RDTs showed an excellent agreement between them (agreement = 96.7 %, k = 0.920). Agreement with PCR was also excellent for high viral load samples (Ct<25) for CerTest (98.0 %, k = 0.954) and Panbio (98.8 %, k = 0.973).ConclusionsCerTest SARS-CoV-2 and Panbio COVID-19 Ag showed excellent performance and agreement results for samples with high viral loads (Ct 25) or samples taken within the first 5 days after the onset of symptoms.