Evaluation of Rapid Antigen Tests Using Nasal Samples to Diagnose SARS-CoV-2 in Symptomatic Patients

Performance of self-performed SARS-CoV-2 rapid antigen test: a systematic review and meta-analysis

Background

The aim of this study was to investigate the accuracy of self-tested SARS-CoV-2 rapid antigen tests.

Methods

Databases of Pubmed, Embase, and Cochrane Library were searched for original studies investigating accuracy of self-tested SARS-CoV-2 rapid antigen tests, with RT-PCR as "gold standard."

Results

Forty-five eligible studies were found after database searching and screening using pre-defined criteria. The accuracy results from 50,897 suspected COVID-19 patients were pooled, and the overall sensitivity, specificity and diagnostic odds ratio were 0.77, 1.00, and 625.95, respectively. Subgroup analysis showed higher sensitivity of rapid antigen tests in subgroups of Abbott Panbio, self-collected nasal swab samples, and use of nasopharyngeal or oropharyngeal swab and lower Ct cutoff value in RT-PCR.

Conclusion

Fully self-performed SARS-CoV-2 rapid antigen tests showed overall high accuracy compared to "gold standard," and are reliable surrogates for the standard test of COVID-19 using nasopharyngeal or oropharyngeal samples and RT-PCR.

The Infectious Diseases Society of America Guidelines on the Diagnosis of COVID-19: Antigen Testing (January 2023)

Immunoassays designed to detect SARS-CoV-2 protein antigens (Ag) are commonly used to diagnose COVID-19. The most widely used tests are lateral flow assays that generate results in approximately 15 minutes for diagnosis at the point-of-care. Higher throughput, laboratory-based SARS-CoV-2 Ag assays have also been developed. The number of commercially available SARS-CoV-2 Ag detection tests has increased rapidly, as has the COVID-19 diagnostic literature. The Infectious Diseases Society of America (IDSA) convened an expert panel to perform a systematic review of the literature and develop best-practice guidance related to SARS-CoV-2 Ag testing. This guideline is an update to the third in a series of frequently updated COVID-19 diagnostic guidelines developed by the IDSA. IDSA's goal was to develop evidence-based recommendations or suggestions that assist clinicians, clinical laboratories, patients, public health authorities, administrators, and policymakers in decisions related to the optimal use of SARS-CoV-2 Ag tests in both medical and nonmedical settings. A multidisciplinary panel of infectious diseases clinicians, clinical microbiologists, and experts in systematic literature review identified and prioritized clinical questions related to the use of SARS-CoV-2 Ag tests. A review of relevant, peer-reviewed published literature was conducted through 1 April 2022. Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology was used to assess the certainty of evidence and make testing recommendations. The panel made 10 diagnostic recommendations that address Ag testing in symptomatic and asymptomatic individuals and assess single versus repeat testing strategies. US Food and Drug Administration (FDA) SARS-CoV-2 Ag tests with Emergency Use Authorization (EUA) have high specificity and low to moderate sensitivity compared with nucleic acid amplification testing (NAAT). Ag test sensitivity is dependent on the presence or absence of symptoms and, in symptomatic patients, on timing of testing after symptom onset. In most cases, positive Ag results can be acted upon without confirmation. Results of point-of-care testing are comparable to those of laboratory-based testing, and observed or unobserved self-collection of specimens for testing yields similar results. Modeling suggests that repeat Ag testing increases sensitivity compared with testing once, but no empirical data were available to inform this question. Based on these observations, rapid RT-PCR or laboratory-based NAAT remain the testing methods of choice for diagnosing SARS-CoV-2 infection. However, when timely molecular testing is not readily available or is logistically infeasible, Ag testing helps identify individuals with SARS-CoV-2 infection. Data were insufficient to make a recommendation about the utility of Ag testing to guide release of patients with COVID-19 from isolation. The overall quality of available evidence supporting use of Ag testing was graded as very low to moderate.

Association of mixed polycyclic aromatic hydrocarbons exposure with oxidative stress in Korean adults

Polycyclic aromatic hydrocarbons (PAHs) are widespread pollutants associated with several adverse health effects and PAH-induced oxidative stress has been proposed as a potential mechanism. This study evaluated the associations of single and multiple PAHs exposure with oxidative stress within the Korean adult population, using serum gamma glutamyltransferase (GGT) as an oxidative stress marker. Data from the Second Korean National Environmental Health Survey (2012-2014) were analyzed. For analysis, 5225 individuals were included. PAH exposure was assessed with four urinary PAH metabolites: 1-hydroxyphenanthrene, 1-hydroxypyrene, 2-hydroxyfluorene, and 2-naphthol. After adjusting for age, sex, body mass index, drinking, passive smoking, and current smoking (model 1), as well as the presence of diabetes and hepatobiliary diseases (model 2), complex samples general linear model regression analyses for each metabolite revealed a significant positive association between Ln(1-hydroxyphenanthrene) and Ln(GGT) (model 1: β = 0.040, p < 0.01 and model 2: β = 0.044, p < 0.05). For the complete dataset (n = 4378), a significant positive association was observed between mixture of four urinary PAH metabolites and serum GGT in both the quantile g-computation and the Bayesian kernel machine regression analysis. Our study provides evidence for the association between mixed PAH exposure and oxidative stress.

Rapid assays of SARS-CoV-2 virus and noble biosensors by nanomaterials

The COVID-19 outbreak caused by SARS-CoV-2 in late 2019 has spread rapidly across the world to form a global epidemic of respiratory infectious diseases. Increased investigations on diagnostic tools are currently implemented to assist rapid identification of the virus because mass and rapid diagnosis might be the best way to prevent the outbreak of the virus. This critical review discusses the detection principles, fabrication techniques, and applications on the rapid detection of SARS-CoV-2 with three categories: rapid nuclear acid augmentation test, rapid immunoassay test and biosensors. Special efforts were put on enhancement of nanomaterials on biosensors for rapid, sensitive, and low-cost diagnostics of SARS-CoV-2 virus. Future developments are suggested regarding potential candidates in hospitals, clinics and laboratories for control and prevention of large-scale epidemic.

Evaluation of a Commercial Point-of-Care RT-LAMP Assay for Rapid Detection of SARS-CoV-2

The goal of this study was to evaluate the performance of a commercial reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay (Detect COVID-19 Test) in the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). A total of 202 human respiratory and viral culture specimens were tested retrospectively. The performance of the Detect COVID-19 Test was comparable to that of commercial real-time polymerase chain reaction assays (sensitivity: 93.42%; specificity: 100%), and better than that of the rapid antigen test (sensitivity: 48.00%; specificity: 100%) for specimens with threshold cycle (Ct) values of less than 30. The Beta, Delta, and Omicron variants of concern were successfully detected. With their simplicity of use and good assay sensitivity, point-of-care RT-LAMP assays may be a viable option for SARS-CoV-2 testing at home, or in regions without sophisticated laboratory facilities.

Nasal swab is a good alternative sample for detecting SARS-CoV-2 with rapid antigen test: A meta-analysis

BACKGROUND

We aim to determine if nasal samples have equivalent detection sensitivity to nasopharyngeal swabs for RAT and evaluate the diagnostic accuracy of nasal swabs with RAT.

METHODS

PubMed and Web of Science were searched for eligible studies published before August 23, 2022. A bivariate random effects model was used to perform the quantitative synthesis.

RESULTS

The pooled sensitivity, pooled specificity, positive likelihood ratio, negative likelihood ratio, and summary AUC on nasal swabs with RAT were 0.81 (95% CI, 0.77-0.85), 1.00 (95% CI: 0.99-1.00), 0.97 (95% CI, 0.95-0.98), 298.91 (95% CI, 144.71-617.42) and 0.19 (95% CI, 0.15-0.23), respectively. WHO required RAT kits to perform with a sensitivity of 0.80 and a specificity of 0.97, nasal swabs (0.81) achieved the required sensitivity while nasopharyngeal swabs (0.75) did not. The symptomatic population yielded higher pooled sensitivity than the asymptomatic population (0.86 versus 0.71), with a pooled sensitivity of 0.90 for five days of symptom onset.

CONCLUSION

Nasal sampling had a great performance and yielded a high sensitivity in detecting SARS-CoV-2 using RAT, we believe that RAT performed with nasal swabs is a good alternative for detecting SARS-CoV-2, especially early in the onset of symptoms.

Evaluation of Four Rapid Antigen Tests for the Detection of SARS-CoV-2 Infection with Nasopharyngeal Swabs

Owing to the high transmissibility of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants, the capacity of testing systems based on the gold standard real-time reverse transcription–polymerase chain reaction (rRT-PCR) is limited. Rapid antigen tests (RATs) can substantially contribute to the prevention of community transmission, but their further assessment is required. Here, using 1503 nasopharyngeal swabs, we compared the diagnostic performance of four RAT kits (Abbott Panbio™ COVID-19 Ag Rapid Test, SD Biosensor Standard™ Q COVID-19 Ag Test, Humasis COVID-19 Ag Test, and SG Medical Acrosis COVID-19 Ag Test) to the cycle threshold (Ct) values obtained from rRT-PCR. The precision values, area under the curve values, SARS-CoV-2 variant detection ability, and non-SARS-CoV-2 specificity of all four kits were similar. An assay using the Acrosis kit had a significantly better positive detection rate with a higher recall value and cut-off value than that using the other three RAT kits. During the current COVID-19 pandemic, the Acrosis kit is an effective tool to prevent the spread of SARS-CoV-2 in communities.

Evaluation of the diagnostic performance of PanbioTM Abbott SARS-CoV-2 rapid antigen test for the detection of COVID-19 from suspects attending ALERT center

BACKGROUND

The emergence and rapid spread of coronavirus disease 2019 (COVID-19), a potentially lethal disease caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), is causing public health issues around the world. In resource-constrained nations, rapid Abbott SARS-CoV-2 antigen test kits are critical for addressing diagnostic gaps in health institutions and community screening. However, there is no evidence or proof of diagnostic performance in Ethiopia. The aim of this study was to compare the performance of PanbioTM Abbott SARS-CoV-2antigen rapid test kit to the gold standard, RT-PCR, in COVID-19 patients with clinical symptoms suggestive of COVID-19.

METHOD

A prospective, cross-sectional study was conducted between November 2021 and April 2022, on 120 suspected patients recruited from outpatient, emergency, and intensive care units in one of the tertiary hospitals in Ethiopia. Nasopharyngeal swabs were collected from suspected cases and were tested using the Abbott SARS-CoV-2 kit, a rapid diagnostic test (RDT) and compared to the reference standard RT-PCR.

RESULT

The sensitivity and specificity of the RDT were 74.2% and 100%, respectively. A total of 62 samples (51.6%) were RT-PCR positive. Of these, 46 were Ag-RDT positive. Sensitivity among symptomatic patients was 79.4% (95% CI 68.3-90). The Abbot RDT and RT-PCR had a Kappa value of agreement of 0.735 (p < 0.001). These values were acceptable when compared to the WHO's suggested thresholds.

CONCLUSION

The finding from this study support the use of the Abbot RDT as a diagnostic tool in COVID-19 suspects, mainly in those with higher viral loads.

Performance and Application Evaluation of SARS-CoV-2 Antigen Assay

Severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) nucleic acid detection is the gold standard for the laboratory diagnosis of coronavirus disease 2019 (COVID‐19). However, this method has high requirements for practitioners' skills and testing sites, so it is not easy to popularize and promote the application in places other than large hospitals. In addition, the detection flux of SARS‐CoV‐2 nucleic acid is small, and the whole detection process takes much time, which cannot meet the actual needs of rapid screening in large quantities. The WHO conditionally approved a batch of SARS‐CoV‐2 antigen reagents for clinical application to alleviate this contradiction. SARS‐CoV‐2 antigen detection offers a trade‐off among clinical performance, speed and accessibility. With the gradual increase in clinical application, the accumulated clinical data show that the sensitivity and specificity of the SARS‐CoV‐2 antigen assay are over 80% and 97%, respectively, which can basically meet the requirements of the WHO. However, the sensitivity of the SARS‐CoV‐2 Antigen Assay among asymptomatic people in low prevalence areas of COVID‐19 cannot meet the standard, leading to a large number of missed diagnoses. In addition, the detection ability of SARS‐CoV‐2 antigen reagent for different SARS‐CoV‐2 mutant strains differs greatly, especially for those escaping the COVID‐19 vaccines. In terms of results interpretation, it is highly reliable to exclude SARS‐CoV‐2 infection based on the high negative predictive value of the SARS‐CoV‐2 antigen assay. However, in the low prevalence environment, the probability of false positives of the SARS‐CoV‐2 antigen assay is high, so the positive results need to be confirmed by the SARS‐CoV‐2 nucleic acid reagent. The SARS‐CoV‐2 antigen assay is only a supplement to SARS‐CoV‐2 nucleic acid detection and can never completely replace it. To date, SARS‐CoV‐2 nucleic acid detection continues to be the standard laboratory method for COVID‐19 diagnosis.