Evaluation of four laboratory-based high-throughput SARS-CoV-2 automated antigen tests compared to RT-PCR on nasal and oropharyngeal samples.

BACKGROUND: The demand for RT-PCR testing has been unprecedented during the SARS-CoV-2 pandemic. Fully automated antigen tests (AAT) are less cumbersome than RT-PCR, but data on performance compared to RT-PCR are scarce. METHODS: The study consists of two parts. A retrospective analytical part, comparing the performance of four different AAT on 100 negative and 204 RT-PCR positive deep oropharyngeal samples divided into four groups based on RT-PCR cycle of quantification levels. In the prospective clinical part, 206 individuals positive for and 199 individuals negative for SARS-CoV-2 were sampled from either the anterior nasal cavity (mid-turbinate) or by deep oropharyngeal swabs or both. The performance of AATs was compared to RT-PCR. RESULTS: The overall analytical sensitivity of the AATs differed significantly from 42% (95% CI 35-49) to 60% (95% CI 53-67) with 100% analytical specificity. Clinical sensitivity of the AATs differed significantly from 26% (95% CI 20-32) to 88% (95% CI 84-93) with significant higher sensitivity for mid-turbinate nasal swabs compared to deep oropharyngeal swabs. Clinical specificity varied from 97% to 100%. CONCLUSION: All AATs were highly specific for detection of SARS-CoV-2. Three of the four AATs were significantly more sensitive than the fourth AAT both in terms of analytical and clinical sensitivity. Anatomical test location significantly influenced the clinical sensitivity of AATs.

Peer patient round table: An innovative approach for evaluating clinical performance for nurse practitioner students.

Clinical performance is a crucial part of evaluation in nurse practitioner education and has traditionally been accomplished through faculty site visits. The evolution of distance learning and on-line programs along with the recent COVID-19 pandemic has further complicated completing site visits, requiring innovative strategies. 'The Peer Patient Round Table (PPRT)' was developed as an innovative evaluation method of student performance. It utilizes the standardized patient simulation concept and shared role-play modality via a telehealth platform. During the PPRT evaluation session, students were involved in a shared role-play of three roles; as a patient, a nurse practitioner student, and a preceptor in individual scenarios. A family nurse practitioner program at Radford University, located in Southwest Virginia, incorporated the PPRT method as the alternative student evaluation method starting May 2020 during COVID-19 pandemic for the last two years. After the first year of implementation of the PPRT, students and faculty were surveyed about the effectiveness of PPRT as a clinical evaluation method as well as their satisfaction with the modality. This article discusses the details of the PPRT procedures, PPRT experiences from faculty and students along with lessons learned.

Rapid Antigen Tests during the COVID-19 Era in Korea and Their Implementation as a Detection Tool for Other Infectious Diseases.

Rapid antigen tests (RATs) are diagnostic tools developed to specifically detect a certain protein of infectious agents (viruses, bacteria, or parasites). RATs are easily accessible due to their rapidity and simplicity. During the COVID-19 pandemic, RATs have been widely used in detecting the presence of the specific SARS-CoV-2 antigen in respiratory samples from suspected individuals. Here, the authors review the application of RATs as detection tools for COVID-19, particularly in Korea, as well as for several other infectious diseases. To address these issues, we present general knowledge on the design of RATs that adopt the lateral flow immunoassay for the detection of the analyte (antigen). The authors then discuss the clinical utilization of the authorized RATs amidst the battle against the COVID-19 pandemic in Korea and their role in comparison with other detection methods. We also discuss the implementation of RATs for other, non-COVID-19 infectious diseases, the challenges that may arise during the application, the limitations of RATs as clinical detection tools, as well as the possible problem solving for those challenges to maximize the performance of RATs and avoiding any misinterpretation of the test result.

Can students develop clinical competency in treatment planning remotely through flipped collaborative case discussion?

INTRODUCTION: Effectiveness of flipped learning in clinical education is unknown. This study evaluates the effectiveness of remote case-based learning for teaching clinical treatment planning compared with traditional in-person clinical experience. MATERIALS AND METHODS: Four cases containing medical and dental charts were discussed through flipped learning with faculty panel during the COVID-19 lockdown. Prior to each session, students worked individually or in groups to complete assignments with leading questions. After the final assignment, students completed a survey to rate the learning experience from each case, compare the remote experience with the previous in-person clinical experience and provide suggestions to improve remote clinical instruction in the future. Students' performance measured by the number of case assessments and competencies completed post-lockdown was compared with pre-lockdown and the previous year using odd ratio (OR), Chi-squared test (χ2) and significant level p < .05. RESULTS: A total of 106 students completed the course, and 99 students completed all survey questions. Students reported positive learning experiences (overall mean = 7.84, SD = 1.11). Post-lockdown, statistically significant increase in the proportions of total passed attempts (χ2 p = .002, OR = 2.23), competencies (χ2 p = .028, OR = 2.05) and case assessments (χ2 p = .004, OR = 2.73) was observed between the current class and the previous pre-COVID-19 class (108 students). Post-lockdown, students also passed significantly more attempts (χ2 p < .0001), competencies (χ2 p < .0001) and case assessments (χ2 p = .008) compared with pre-lockdown. CONCLUSIONS: Although a flipped classroom does not replace in-person clinical experience, teaching clinical treatment planning remotely improved students' readiness and clinical performance through collaborative learning, practice and case exposure.

Virus variant-specific clinical performance of SARS coronavirus two rapid antigen tests in point-of-care use, from November 2020 to January 2022.

OBJECTIVES: Antigen rapid diagnostic tests (RDTs) for SARS coronavirus 2 (SARS-CoV-2) are quick, widely available, and inexpensive. Consequently, RDTs have been established as an alternative and additional diagnostic strategy to quantitative reverse transcription polymerase chain reaction (RT-qPCR). However, reliable clinical and large-scale performance data specific to a SARS-CoV-2 virus variant of concern (VOC) are limited, especially for the Omicron VOC. The aim of this study was to compare RDT performance among different VOCs. METHODS: This single-centre prospective performance assessment compared RDTs from three manufacturers (NADAL, Panbio, MEDsan) with RT-qPCR including deduced standardized viral load from oropharyngeal swabs for detection of SARS-CoV-2 in a clinical point-of-care setting from November 2020 to January 2022. RESULTS: Among 35 479 RDT/RT-qPCR tandems taken from 26 940 individuals, 164 of the 426 SARS-CoV-2 positive samples tested true positive with an RDT corresponding to an RDT sensitivity of 38.50% (95% CI, 34.00-43.20%), with an overall specificity of 99.67% (95% CI, 99.60-99.72%). RDT sensitivity depended on viral load, with decreasing sensitivity accompanied by descending viral load. VOC-dependent sensitivity assessment showed a sensitivity of 42.86% (95% CI, 32.82-53.52%) for the wild-type SARS-CoV-2, 43.42% (95% CI, 32.86-54.61%) for the Alpha VOC, 37.67% (95% CI, 30.22-45.75%) for the Delta VOC, and 33.67% (95% CI, 25.09-43.49%) for the Omicron VOC. Sensitivity in samples with high viral loads of ≥106 SARS-CoV-2 RNA copies per mL was significantly lower in the Omicron VOC (50.00%; 95% CI, 36.12-63.88%) than in the wild-type SARS-CoV-2 (79.31%; 95% CI, 61.61-90.15%; p 0.015). DISCUSSION: RDT sensitivity for detection of the Omicron VOC is reduced in individuals infected with a high viral load, which curtails the effectiveness of RDTs. This aspect furthert: limits the use of RDTs, although RDTs are still an irreplaceable diagnostic tool for rapid, economic point-of-care and extensive SARS-CoV-2 screening.

Analytic and Clinical Performance of Major Commercial Severe Acute Respiratory Syndrome Coronavirus 2 Molecular Assays in the United States.

The rapid development of commercially available molecular assays in response to the COVID-19 pandemic has been essential in identifying positive cases and guiding state and national response plans. With over 200 SARS-CoV-2 molecular tests having received emergency use authorization by the US Food and Drug Administration, numerous studies have been conducted to evaluate these methods and compare their analytical and clinical performance. By applying the lessons learned from the rapid development of molecular assays in response to the COVID-19 pandemic, the diagnostic industry will be better prepared to respond to future outbreaks of novel infectious diseases.

Clinical Performance of Three Commercial SARS-CoV-2 Rapid Antigen Tests for Community-Dwelling Individuals in a Tropical Setting.

During the second year of the COVID-19 pandemic, the use of Rapid Diagnosis Antigen Tests (RDAgTs) for SARS-CoV-2 detection has substantially increased as some of the brands available in the market were certified for clinical use by international regulatory agencies. RDAgTs are a fast and cheap tool for SARS-CoV-2 surveillance with great potential to improve testing capacities in middle- and low-income countries compared to the gold standard RT-qPCR. However, as the clinical performance of RDAgTs has been shown to vary greatly between the commercial brands available, evaluation studies are necessary. Moreover, the available evaluation has been done in high-income countries while SARS-CoV-2 transmission is also actively happening in developing countries, many of which are located in tropical latitudes where cross-reactivity with other infectious agents is highly prevalent, which could compromise RDAgT specificity. Moreover, unreported mutations and/or new SARS-CoV-2 variants may compromise RDAgT sensitivity as genomic surveillance is limited in these settings. Here we describe a multicenter and manufacturer-independent evaluation of the clinical performance and analytical sensitivity of three different RDAgTs brands available in South America from three companies, Rapigen (South Korea), SD-Biosensor (South Korea), and Certest (Spain), compared to the gold standard RT-qPCR. A total number of 1,646 nasopharyngeal swabs from community-dwelling individuals were included in the study, and 379 of them were SARS-CoV-2 positive by RT-qPCR. The overall sensitivity for each RDAgT was 79% (IC95%: 72 - 86.2), 64.2% (IC95%: 56.7 - 71.6), and 45.8% (IC95%: 35.8 - 55.8) for SD-Biosensor, Certest, and Rapigen, respectively. The overall specificity for each RDAgT was 100%, 97.7% (IC95%: 96.8 - 98.6), and 100% for SD-Biosensor, Certest, and Rapigen, respectively. However, the limit of detection (LoD) to achieve a sensitivity over 90% was substantially lower for Certest RDAgT (102 copies/uL) compared to SD-Biosensor (103 copies/uL) or Rapigen (106 copies/uL) RDAgTs, considering that the gold standard RT-qPCR method used in this study has a high sensitivity of 97.7% and low LoD of 5 copies/uL. Additionally, the Certest RDAgT also showed an improved sensitivity up to 79.7% (IC95%: 70.2 - 89.2) for symptomatic individuals. Finally, the slight reduction in specificity for Certest RDAgTs was only associated with one of the laboratories performing this study, pointing out the need for locally assessed evaluation for RDAgTs like this one carried out in Ecuador. In conclusion, two of the three the RDAgTs tested in this study are a fast, cheap, and point of care tool for SARS-CoV-2 surveillance and reliable enough to detect SARS-CoV-2 infectious individuals.

Comparison between the analytical sensitivity and clinical performance of two cobas SARS-CoV-2 tests based on high-throughput and point-of-care systems.

Objectives: This study examined analytical sensitivity, specificity, and the clinical performance in detecting SARS-CoV-2 of the Cobas SARS-CoV-2 Test based on the high-throughput Cobas 6800 system and the Cobas SARS-CoV-2 & Flu A/B Test based on the point-of-care cobas Liat system. Methods: The commercial reagents containing SARS-CoV-2 RNA subgenomes were diluted for assessing the sensitivity of the RT-qPCR assay. 385 nasopharyngeal swab specimens taken from contacts of COVID-19 cases were tested for the SARS-CoV-2 detection with both Cobas SARS-CoV-2 Tests. Results: In analytical sensitivity assays, the Cobas SARS-CoV-2 & Flu A/B Test on the Liat system had a lower limit of detection (12.5-25 copies/mL) than the cobas SARS-CoV-2 Test on the cobas 6800 system (25-50 copies/mL). In clinical performance assays, the cobas SARS-CoV-2 Test demonstrated 89.36% (42 out of 47) PPA (positive percent agreement) and 98.82% (334 out of 338) NPA (negative percent agreement) compared to the results of the Cobas SARS-CoV-2 & Flu A/B test. Among five discordant specimens, four had the positive result of the cobas SARS-CoV-2 test, but the negative result of the cobas SARS-CoV-2 & Flu A/B Test. Moreover, these discordant specimens had the Ct values of greater than 33 for the cobas SARS-CoV-2 Test, implying a very small number of virions in the samples. Remarkably, four specimens with a presumptive positive result of the cobas SARS-CoV-2 test had been confirmed by the Cobas SARS-CoV-2 & Flu A/B Test. Next, the scatter plots of the Ct values showed a highly positive correlation between cobas SARS-CoV-2 & Flu A/B Test and the cobas SARS-CoV-2 Test (R-squared value = 0.954-0.962). Conclusions: Both SARS-CoV2 tests of the cobas 6800 and Liat systems produce reliable high throughput and point-of-care assays respectively for the early virus detection and the personal care decision-making during COVID-19 pandemic.

Clinical Validation of the Fully Automated NeuMoDx HPV Assay for Cervical Cancer Screening.

The NeuMoDx HPV assay is a novel fully automated, real-time PCR-based assay for the qualitative detection of high-risk human papillomavirus (HPV) DNA in cervical specimens. The assay specifically identifies HPV16 and HPV18 and concurrently detects 13 other high-risk HPV types at clinically relevant infection levels. Following the international guidelines, the clinical performance of the NeuMoDx HPV assay for cervical intraepithelial neoplasia grade 2 or worse (CIN2+) against the reference standard Hybrid Capture 2, as well as intra- and inter-laboratory reproducibility were assessed on PreservCyt samples. The clinical accuracy of the assay was additionally evaluated against the clinically validated Alinity m HR HPV and COBAS 4800 HPV Test on PreservCyt samples, and against the clinically validated HPV-Risk assay on SurePath samples. The NeuMoDx HPV assay performance for CIN2+ was non-inferior to the reference methods on both sample types (all p < 0.05), and showed excellent intra- and inter-laboratory reproducibility (95.7%; 95% CI: 93.9-97.3; kappa value 0.90 (95% CI: 0.86-0.94); and 94.5%; 95% CI: 92.6-96.2; kappa value 0.87 (95% CI: 0.82-0.92), respectively). In conclusion, the NeuMoDx HPV assay meets international guideline criteria for cross-sectional accuracy and reproducibility, and performs equally well on cervical screening specimens collected in two widely used collection media. The NeuMoDx HPV assay fulfils the requirements to be used for primary cervical screening.

Establishment of an in‐house real‐time RT‐PCR assay for the detection of severe acute respiratory syndrome coronavirus 2 using the first World Health Organization international standard in a resource‐limited country

BackgroundThe COVID‐19 pandemic caused by SARS‐CoV‐2 remains public health burdens and many unresolved issues worldwide. Molecular assays based on real‐time RT‐PCR are critical for the detection of SARS‐CoV‐2 in clinical specimens from patients suspected of COVID‐19.ObjectiveWe aimed to establish and validate an in‐house real‐time RT‐PCR for the detection of SARS‐CoV‐2.MethodologyPrimers and probes sets in our in‐house real‐time RT‐PCR assay were designed in conserved regions of the N and E target genes. Optimized multiplex real‐time RT‐PCR assay was validated using the first WHO International Standard (NIBSC code: 20/146) and evaluated clinical performance.ResultsThe limit of detection validated using the first WHO International Standard was 159 IU/ml for both E and N target genes. The evaluation of clinical performance on 170 clinical samples showed a positive percent agreement of 100% and the negative percent agreement of 99.08% for both target genes. The Kappa value of 0.99 was an excellent agreement, the strong correlation of Ct values observed between two tests with r2 = 0.84 for the E gene and 0.87 for the N gene. Notably, we assessed on 60 paired saliva and nasopharyngeal samples. The overall agreement was 91.66%, and Kappa value of 0.74 showed a high agreement between two types of samples. When using nasopharyngeal swabs as the reference standard, positive percent agreement, and negative percent agreement were 91.83% and 90.90%, respectively.ConclusionIn the present study, we established and validated an in‐house real‐time RT‐PCR for molecular detection of SARS‐CoV‐2 in a resource‐limited country.

Exploring the challenges and ethical requirements of medical sciences education during COVID-19: a qualitative study.

The controversial role of ethics in clinical education and its ability to draw the attention of a large audience is inevitable. The issues and challenges of the COVID-19 pandemic have transformed the clinical education environment. This study was conducted to explore the challenges and ethical requirements of medical sciences education during the COVID-19 pandemic in 2020. The study was qualitative research and the instrument was a semi-structured interview. The participants included faculty members of the basic and clinical Sciences at Iran University of Medical Sciences. After 16 rounds of interviews, theoretical saturation was achieved. Qualitative data were analysed using conventional content analysis, which resulted in 81 preliminary codes and 28 sub-categories. Finally, two themes of "ethical challenges" and "ethical requirements", and 10 categories were achieved. The categories were consisted of "being patient-centred", "social accountability of curriculums", "ethical challenges of the clinical environment", "the poor performance of the clinical faculty members and students", "being justice-centred", "raising awareness", "observing clinical research ethics", "preservation and promotion of mental health", "patient confidentiality", and "respect for individuals". We hope the ethical challenges in medical education that were created due to the emergence of Covid-19 can be reduced and eliminated by defining a framework for ethical requirements.

Comparison of reverse-transcription qPCR and droplet digital PCR for the detection of SARS-CoV-2 in clinical specimens of hospitalized patients.

Accurate detection of severe acute respiratory syndrome coronavirus 2 is not only necessary for viral load monitoring to optimize treatment in hospitalized coronavirus disease 2019 patients, but also critical for deciding whether the patient could be discharged without any risk of viral shedding. Digital droplet PCR (ddPCR) is more sensitive than reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR) and is usually considered the superior choice. In the current study, we compared the clinical performance of RT-qPCR and ddPCR using oropharyngeal swab samples from patients hospitalized in the temporary Huoshenshan Hospital, Wuhan, Hubei, China. Results demonstrated that ddPCR was indeed more sensitive than RT-qPCR. Negative results might be caused by poor sampling technique or recovered patients, as the range of viral load in these patients varied significantly. In addition, both methods were highly correlated in terms of their ability to detect all three target genes as well as the ratio of copies of viral genes to that of the IC gene. Furthermore, our results evidenced that both methods detected the N gene more easily than the ORF gene. Taken together, these findings imply that the use of ddPCR, as an alternative to RT-qPCR, is necessary for the accurate diagnosis of hospitalized coronavirus disease 2019 patients.

Performance of the Sofia SARS-CoV-2 rapid antigen test as frontline test in a university hospital, Germany.

The rapid and reliable detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is of high importance for individual patient care and hospital infection prevention. We aimed to evaluate the performance of the Sofia SARS-CoV-2 antigen rapid diagnostic test (Ag-RDT) in comparison to real-time reverse-transcription polymerase chain reaction (RT-PCR). We conducted a prospective, monocentric cross-sectional study in an emergency department of a German university hospital from November 2020 to March 2021. We tested all samples using both Sofia SARS-CoV-2 Ag-RDT and real-time RT-PCR. A total of 7877 patients were included. Overall sensitivity of the Ag-RDT was 62.9% and specificity was 99.4%. Sensitivity varied across study months, whereas specificity remained high. Sensitivity increased to 94.2% in samples with a cycle threshold (Ct)-value ≤25. The Sofia Ag-RDT proved to be a rapid tool to detect samples with high viral loads (Ct-value ≤25) and might thus help to identify infectious patients.

Exploring the challenges and ethical requirements of medical sciences education during COVID 19: a qualitative stud

The controversial role of ethics in clinical education and its ability to draw the attention of a large audience is inevitable. The issues and challenges of the COVID-19 pandemic have transformed the clinical education environment. This study was conducted to explore the challenges and ethical requirements of medical sciences education during the COVID-19 pandemic in 2020. The study was qualitative research and the instrument was a semi-structured interview. The participants included faculty members of the basic and clinical Sciences at Iran University of Medical Sciences. After 16 rounds of interviews, theoretical saturation was achieved. Qualitative data were analysed using conventional content analysis, which resulted in 81 preliminary codes and 28 sub-categories. Finally, two themes of "ethical challenges" and "ethical requirements", and 10 categories were achieved. The sub-categories were consisted of "being patient-centred", "social accountability of curriculums", "ethical challenges of the clinical environment", "the poor performance of the clinical faculty members and students", "being justice-centred", "raising awareness", "observing clinical research ethics", "preservation and promotion of mental health", "patient confidentiality", and "respect for individuals". We hope the ethical challenges in medical education that were created due to the emergence of Covid-19 can be reduced and eliminated by defining a framework for ethical requirements.

Clinical performance of the Xpert® Xpress Flu/RSV assay for the detection of Influenza A, B, and respiratory syncytial virus on ESwab™ medium

Background : Prior to the SARS-CoV-2 pandemic, the Xpert® Xpress Flu/RSV assay (GXA) was regularly used, while during the pandemic the Xpert® Xpress SARS-CoV-2/Flu/RSV plus assay was developed by Cepheid. In contrast to this new assay, the use of oropharyngeal ESwabs in combination with the Flu/RSV assay is designated as off CE-IVD label use, while these were used frequently in The Netherlands. Aim : To investigate the clinical performance of the GXA using 1,289 ESwab™ oropharyngeal samples for the detection of Influenza A virus, Influenza B virus and respiratory syncytial virus (RSV). Methods : The clinical performance of the GXA was prospectively investigated during the influenza seasons of 2017 and 2018 by testing fresh oropharyngeal samples, collected with ESwab™, contemporaneously with both the GXA and a laboratory developed Flu/RSV real time RT-PCR assay (LDA) (reference method). Results : 1,289 Samples from 1,213 patients (46% men, median age 73 (IQR 62-82)) were tested with both tests. Positive percent agreement (95% CI) was 98% (95%-99%) for Influenza A virus, 92% (88%-95%) for influenza B virus, and 88% (73%-96%) for RSV. Negative percent agreement was ≥ 99% for all three viruses. Ct-values of the GXA were on average higher than the LDA. Conclusion : This study showed a good clinical performance of the GXA in oropharyngeal samples for the detection of Influenza A and B virus. The positive percent agreement of the GXA for the detection of RSV in oropharyngeal samples was somewhat lower and in particular for the detection of RSV-A.

Multicentre Performance Evaluation of the Elecsys Anti-SARS-CoV-2 Immunoassay as an Aid in Determining Previous Exposure to SARS-CoV-2.

INTRODUCTION: We performed a multicentre evaluation of the Elecsys® Anti-SARS-CoV-2 immunoassay (Roche Diagnostics), an assay utilising a recombinant protein representing the nucleocapsid (N) antigen, for the in vitro qualitative detection of antibodies to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). METHODS: Specificity was evaluated using serum/plasma samples from blood donors and routine diagnostic specimens collected before September 2019 (i.e., presumed negative for SARS-CoV-2-specific antibodies); sensitivity was evaluated using samples from patients with polymerase chain reaction (PCR)-confirmed SARS-CoV-2 infection. Point estimates and 95% confidence intervals (CIs) were calculated. Method comparison was performed versus commercially available assays. RESULTS: Overall specificity for the Elecsys Anti-SARS-CoV-2 immunoassay (n = 9575) was 99.85% (95% CI 99.75-99.92): blood donors (n = 6714; 99.82%), routine diagnostic specimens (n = 2861; 99.93%), pregnant women (n = 2256; 99.91%), paediatric samples (n = 205; 100.00%). The Elecsys Anti-SARS-CoV-2 immunoassay demonstrated significantly higher specificity versus LIAISON SARS-CoV-2 S1/S2 IgG (99.71% vs. 98.48%), EUROIMMUN Anti-SARS-CoV-2 IgG (100.00% vs. 94.87%), ADVIA Centaur SARS-CoV-2 Total (100.00% vs. 87.32%) and iFlash SARS-CoV-2 IgM (100.00% vs. 99.58%) assays, and comparable specificity to ARCHITECT SARS-CoV-2 IgG (99.75% vs. 99.65%) and iFlash SARS-CoV-2 IgG (100.00% vs. 100.00%) assays. Overall sensitivity for Elecsys Anti-SARS-CoV-2 immunoassay samples drawn at least 14 days post-PCR confirmation (n = 219) was 93.61% (95% CI 89.51-96.46). No statistically significant differences in sensitivity were observed between the Elecsys Anti-SARS-CoV-2 immunoassay versus EUROIMMUN Anti-SARS-CoV-2 IgG (90.32% vs. 95.16%) and ARCHITECT SARS-CoV-2 IgG (84.81% vs. 87.34%) assays. The Elecsys Anti-SARS-CoV-2 immunoassay showed significantly lower sensitivity versus ADVIA Centaur SARS-CoV-2 Total (85.19% vs. 95.06%) and iFlash SARS-CoV-2 IgG (86.25% vs. 93.75%) assays, but significantly higher sensitivity versus the iFlash SARS-CoV-2 IgM assay (86.25% vs. 33.75%). CONCLUSION: The Elecsys Anti-SARS-CoV-2 immunoassay demonstrated very high specificity and high sensitivity in samples collected at least 14 days post-PCR confirmation of SARS-CoV-2 infection, supporting its use to aid in determination of previous exposure to SARS-CoV-2.

Aspergillus Polymerase Chain Reaction-An Update on Technical Recommendations, Clinical Applications, and Justification for Inclusion in the Second Revision of the EORTC/MSGERC Definitions of Invasive Fungal Disease.

Aspergillus polymerase chain reaction testing of blood and respiratory samples has recently been included in the second revision of the EORTC/MSGERC definitions for classifying invasive fungal disease. This is a result of considerable efforts to standardize methodology, the availability of commercial assays and external quality control programs, and additional clinical validation. This supporting article provides both clinical and technical justifications for its inclusion while also summarizing recent advances and likely future developments in the molecular diagnosis of invasive aspergillosis.

How to choose the right real-time RT-PCR primer sets for the SARS-CoV-2 genome detection?

OBJECTIVES: The SARS-CoV-2 pandemic has created an unprecedented need for rapid large-scale diagnostic testing to prompt clinical and public health interventions. Currently, several quantitative reverse-transcription polymerase chain reaction (RT-qPCR) assays recommended by the World Health Organization are being used by clinical and public health laboratories and typically target regions of the RNA-dependent RNA polymerase (RdRp), envelope (E) and nucleocapsid (N) coding region. However, it is currently unclear if results from different tests are comparable. This study aimed to clarify the clinical performances of the primer/probe sets designed by US CDC and Charité/Berlin to help clinical laboratories in assay selection for SARS-CoV-2 routine detection. METHODS: We compared the clinical performances of the recommended primer/probe sets using one hundred nasopharyngeal swab specimens from patients who were clinically diagnosed with COVID-19. An additional 30 "pre-intervention screening" samples from patients who were not suspected of COVID-19 were also included in this study. We also performed sequence alignment between 31064 European SARS-CoV-2 and variants of concern genomes and the recommended primer/probe sets. RESULTS: The present study demonstrates substantial differences in SARS-CoV-2 RNA detection sensitivity among the primer/probe sets recommended by the World Health Organization especially for low-level viral loads. The alignment of thousands of SARS-CoV-2 sequences reveals that the genetic diversity remains relatively low at the primer/probe binding sites. However, multiple nucleotide mismatches might contribute to false negatives. CONCLUSION: An understanding of the limitations depending on the targeted genes and primer/probe sets may influence the selection of molecular detection assays by clinical laboratories.

COVID-19 Point-of-Care Diagnostics That Satisfy Global Target Product Profiles.

COVID-19 pandemic will continue to pose a major public health threat until vaccination-mediated herd immunity is achieved. Most projections predict vaccines will reach a large subset of the population late in 2021 or early 2022. In the meantime, countries are exploring options to remove strict lockdown measures and allow society and the economy to return to normal function. One possibility is to expand on existing COVID-19 testing strategies by including large-scale rapid point-of-care diagnostic tests (POCTs). Currently, there is significant variability in performance and features of available POCTs, making selection and procurement of an appropriate test for specific use case difficult. In this review, we have used the World Health Organization's (WHO) recently published target product profiles (TPPs) for specific use cases of COVID-19 diagnostic tests to screen for top-performing POCTs on the market. Several POCTs, based on clinical sensitivity/specificity, the limit of detection, and time to results, which meet WHO TPP criteria for direct detection of SARS-CoV-2 (acute infection) or indirect diagnosis of past infection (host antibodies), are highlighted here.