Evaluation of a novel, rapid antigen detection test for the diagnosis of SARS-CoV-2

Background Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causing coronavirus disease 2019 (COVID-19) is currently finally determined in laboratory settings by real-time reverse-transcription polymerase-chain-reaction (rt-PCR). However, simple testing with immediately available results are crucial to gain control over COVID-19. The aim was to evaluate such a point-of-care antigen rapid test (AG-rt) device in its performance compared to laboratory-based rt-PCR testing in COVID-19 suspected, symptomatic patients. Methods For this prospective study, two specimens each of 541 symptomatic female (54.7%) and male (45.3%) patients aged between 18 and 95 years tested at five emergency departments (ED, n = 296) and four primary healthcare centres (PHC, n = 245), were compared, using AG-rt (positive/negative/invalid) and rt-PCR (positive/negative and cycle threshold, Ct) to diagnose SARS-CoV-2. Diagnostic accuracy, sensitivity, specificity, positive predictive values (PPV), negative predictive value (NPV), and likelihood ratios (LR+/-) of the AG-rt were assessed. Results Differences between ED and PHC were detected regarding gender, age, symptoms, disease prevalence, and diagnostic performance. Overall, 174 (32.2%) were tested positive on AG-rt and 213 (39.4%) on rt-PCR. AG correctly classified 91.7% of all rt-PCR positive cases with a sensitivity of 80.3%, specificity of 99.1%, PPV of 98.3, NPV of 88.6%, LR(+) of 87.8, and LR(-) of 0.20. The highest sensitivities and specificities of AG-rt were detected in PHC (sensitivity: 84.4%, specificity: 100.0%), when using Ct of 30 as cut-off (sensitivity: 92.5%, specificity: 97.8%), and when symptom onset was within the first three days (sensitivity: 82.9%, specificity: 99.6%). Conclusions The highest sensitivity was detected with a high viral load. Our findings suggest that AG-rt are comparable to rt-PCR to diagnose SARS-CoV-2 in COVID-19 suspected symptomatic patients presenting both at emergency departments and primary health care centres.

Download Full-text

Evaluation of a novel, rapid antigen detection test for the diagnosis of SARS-CoV-2

10.1101/2021.04.22.21255637 ◽

2021 ◽

Author(s):

Rainer Thell ◽

Verena Kallab ◽

Wolfgang Weinhappel ◽

Wolfgang Mueckstein ◽

Lukas Heschl ◽

...

Keyword(s):

Health Care ◽

Primary Health Care ◽

Emergency Departments ◽

Rapid Test ◽

Antigen Test ◽

Rt Pcr ◽

Likelihood Ratios ◽

Predictive Values ◽

Cycle Threshold ◽

Primary Health

ABSTRACTBackgroundSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causing coronavirus disease 2019 (COVID-19) is currently finally determined in laboratory settings by real-time reverse-transcription polymerase-chain-reaction (rt-PCR). However, simple testing with immediately available results are crucial to gain control over COVID-19. The aim was to evaluate such a point-of-care antigen rapid test (AG-rt) device in its performance compared to laboratory-based rt-PCR testing in COVID-19 suspected, symptomatic patients.MethodsFor this prospective study, two specimens each of 541 symptomatic female (54.7%) and male (45.3%) patients aged between 18 and 95 years tested at five emergency departments (ED, n=296) and four primary healthcare centres (PHC, n=245), were compared, using AG-rt (positive/negative/invalid) and rt-PCR (positive/negative and cycle threshold, Ct) to diagnose SARS-CoV-2. Diagnostic accuracy, sensitivity, specificity, positive predictive values (PPV), negative predictive value (NPV), and likelihood ratios (LR+/-) of the AG-rt were assessed.ResultsDifferences between ED and PHC were detected regarding gender, age, symptoms, disease prevalence, and diagnostic performance. Overall, 174 (32.2%) were tested positive on AG-rt and 213 (39.4%) on rt-PCR. AG correctly classified 91.7% of all rt-PCR positive cases with a sensitivity of 80.3%, specificity of 99.1%, PPV of 98.3, NPV of 88.6%, LR(+) of 87.8, and LR(-) of 0.20. The highest sensitivities and specificities of AG-rt were detected in PHC (sensitivity: 84.4%, specificity: 100.0%), when using Ct of 30 as cut-off (sensitivity: 92.5%, specificity: 97.8%), and when symptom onset was within the first three days (sensitivity: 82.9%, specificity: 99.6%).ConclusionsThe highest sensitivity was detected with a high viral load. Our findings suggest that AG-rt are comparable to rt-PCR to diagnose SARS-CoV-2 in COVID-19 suspected symptomatic patients presenting both at emergency departments and primary health care centres.SUMMARYThe rapid SARS-Cov-2 antigen test (SARS-CoV-2 Rapid Antigen Test (Roche Diagnostics), was compared in symptomatic patients with PCR testing both in emergency departments and primary health care centres. It showed an overall sensitivity of 80.3% and specificity of 99.1%; these were higher with lower PCR cycle threshold numbers and with a shorter onset of symptoms.

Download Full-text

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

10.1101/2020.10.26.20219600 ◽

2020 ◽

Cited By ~ 11

Author(s):

Andreas K. Lindner ◽

Olga Nikolai ◽

Franka Kausch ◽

Mia Wintel ◽

Franziska Hommes ◽

...

Keyword(s):

Point Of Care ◽

Rapid Test ◽

High Viral Load ◽

Ease Of Use ◽

Healthcare Personnel ◽

Nasopharyngeal Swab ◽

Swab Sample ◽

Rt Pcr ◽

Percent Agreement ◽

Accuracy Study

AbstractBackgroundTwo antigen-detecting rapid diagnostic tests (Ag-RDTs) are now approved through the WHO Emergency Use Listing procedure and can be performed at the point-of-care. However, both tests use nasopharyngeal (NP) swab samples. NP swab samples must be collected by trained healthcare personnel with protective equipment and are frequently perceived as uncomfortable by patients.MethodsThis was a manufacturer-independent, prospective diagnostic accuracy study with comparison of a supervised, self-collected anterior nose (AN) swab sample with a professional-collected NP swab sample, using a WHO-listed SARS-CoV-2 Ag-RDT, STANDARD Q COVID-19 Ag Test (SD Biosensor), which is also being distributed by Roche. The reference standard was RT-PCR from an oro-/nasopharyngeal swab sample. Percent positive and negative agreement as well as sensitivity and specificity were calculated.ResultsAmong the 289 participants, 39 (13.5%) tested positive for SARS-CoV-2 by RT-PCR. The positive percent agreement of the two different sampling techniques for the Ag-RDT was 90.6% (CI 75.8-96.8). The negative percent agreement was 99.2% (CI 97.2-99.8). The Ag-RDT with AN sampling showed a sensitivity of 74.4% (29/39 PCR positives detected; CI 58.9-85.4) and specificity of 99.2% (CI 97.1-99.8) compared to RT-PCR. The sensitivity with NP sampling was 79.5% (31/39 PCR positives detected; CI 64.5-89.2) and specificity was 99.6% (CI 97.8-100). In patients with high viral load (>7.0 log 10 RNA SARS-CoV2/swab), the sensitivity of the Ag-RDT with AN sampling was 96% and 100% with NP sampling.ConclusionSupervised self-sampling from the anterior nose is a reliable alternative to professional nasopharyngeal sampling using a WHO-listed SARS-CoV-2 Ag-RDT. Considering the ease-of-use of Ag-RDTs, self-sampling and potentially patient self-testing at home may be a future use case.

Download Full-text

Utility of the FebriDx point-of-care assay in supporting a triage algorithm for medical admissions with possible COVID-19: an observational cohort study

BMJ Open ◽

10.1136/bmjopen-2021-049179 ◽

2021 ◽

Vol 11 (8) ◽

pp. e049179

Author(s):

Hamish Houston ◽

Gavin Deas ◽

Shivam Naik ◽

Kamal Shah ◽

Shiras Patel ◽

...

Keyword(s):

Point Of Care ◽

Protein A ◽

Medical Patients ◽

Reference Standard ◽

Rt Pcr ◽

Predictive Values ◽

Clinical Criteria ◽

Observational Cohort ◽

Sensitivity Specificity ◽

Triage Algorithm

ObjectiveTo evaluate a triage algorithm used to identify and isolate patients with suspected COVID-19 among medical patients needing admission to hospital using simple clinical criteria and the FebriDx assay.DesignRetrospective observational cohort.SettingLarge acute National Health Service hospital in London, UK.ParticipantsAll medical admissions from the emergency department between 10 August 2020 and 4 November 2020 with a valid SARS-CoV-2 RT-PCR result.InterventionsMedical admissions were triaged as likely, possible or unlikely COVID-19 based on clinical criteria. Patients triaged as possible COVID-19 underwent FebriDx lateral flow assay on capillary blood, and those positive for myxovirus resistance protein A (a host response protein) were managed as likely COVID-19.Primary outcome measuresDiagnostic accuracy (sensitivity, specificity and predictive values) of the algorithm and the FebriDx assay using SARS-CoV-2 RT-PCR from nasopharyngeal swabs as the reference standard.Results4.0% (136) of 3443 medical admissions had RT-PCR confirmed COVID-19. Prevalence of COVID-19 was 46% (80/175) in those triaged as likely, 4.1% (50/1225) in possible and 0.3% (6/2033) in unlikely COVID-19. Using a SARS-CoV-2 RT-PCR reference standard, clinical triage had sensitivity of 96% (95% CI 91% to 98%) and specificity of 61.5% (95% CI 59.8% to 63.1%), while the triage algorithm including FebriDx had sensitivity of 93% (95% CI 87% to 96%) and specificity of 86.4% (95% CI 85.2% to 87.5%). While 2033 patients were deemed not to require isolation using clinical criteria alone, the addition of FebriDx to clinical triage allowed a further 826 patients to be released from isolation, reducing the need for isolation rooms by 9.5 per day, 95% CI 8.9 to 10.2. Ten patients missed by the algorithm had mild or asymptomatic COVID-19.ConclusionsA triage algorithm including the FebriDx assay had good sensitivity and was useful to ‘rule-out’ COVID-19 among medical admissions to hospital.

Download Full-text

Comparison of SARS-COV-2 nasal antigen test to nasopharyngeal RT-PCR in mildly symptomatic patients

10.1101/2020.11.10.20228973 ◽

2020 ◽

Cited By ~ 2

Author(s):

Abdulkarim Abdulrahman ◽

Fathi Mustafa ◽

Abdulla I AlAwadhi ◽

Qadar Alansari ◽

Batool AlAlawi ◽

...

Keyword(s):

Predictive Value ◽

High Specificity ◽

Cost Effective ◽

High Viral Load ◽

Antigen Test ◽

Rt Pcr ◽

Rapid Antigen Detection Test ◽

Specificity And Sensitivity ◽

Medical Teams ◽

Sensitivity Specificity

AbstractIntroductionCOVID 19 has been vastly spreading since December 2019 and the medical teams worldwide are doing their best to limit its spread. In the absence of a vaccine the best way to fight it is by detecting infected cases early and isolate them to prevent its spread. Therefore, a readily available, rapid, and cost-effective test with high specificity and sensitivity for early detection of COVID 19 is required. In this study, we are testing the diagnostic performance of a rapid antigen detection test in mildly symptomatic cases. (RADT).MethodsThe study included 4183 patients who were mildly symptomatic. A nasal sample for the rapid antigen test and a nasopharyngeal sample was taken from each patient. Statistical analysis was conducted to calculate the sensitivity, specificity, positive predictive value, negative predictive value and kappa coefficient of agreement.ResultsThe prevalence of COVID 19 in the study population was 17.5% (733/4183). The calculated sensitivity and specificity were 82.1% and 99.1% respectively. Kappa’s coefficient of agreement between the rapid antigen test and RT-PCR was 0.859 (p < 0.001). A stratified analysis was performed and it showed that the sensitivity of the test improved significantly with lowering the cutoff Ct value to 24.ConclusionThe results of the diagnostic assessment of nasal swabs in the RADT used in our study are promising regarding the potential benefit of using them as a screening tool in mildly symptomatic patients. The diagnostic ability was especially high in cases with high viral load. The rapid antigen test is intended to be used alongside RT-PCR and not replace it. RADT can be of benefit in reducing the use of PCR.

Download Full-text

Concordance between Histology, Immunohistochemistry, and RT-PCR in the Diagnosis of Feline Infectious Peritonitis

Pathogens ◽

10.3390/pathogens9100852 ◽

2020 ◽

Vol 9 (10) ◽

pp. 852

Author(s):

Angelica Stranieri ◽

Donatella Scavone ◽

Saverio Paltrinieri ◽

Alessia Giordano ◽

Federico Bonsembiante ◽

...

Keyword(s):

Accurate Information ◽

Rt Pcr ◽

Likelihood Ratios ◽

Predictive Values ◽

Feline Infectious Peritonitis ◽

Mesenteric Lymph ◽

Polymerase Chain ◽

Sensitivity Specificity ◽

Feline Coronavirus

Histology, immunohistochemistry (IHC), and reverse transcription polymerase chain reaction (RT-PCR) have been used to diagnose feline infectious peritonitis (FIP), but no information regarding the comparison of their diagnostic performances on the same organ is available. The aims of this study were to determine the concordance among these tests and to evaluate which combination of tests and organs can be used in vivo. Histology, IHC, and nested RT-PCR (RT-nPCR) for feline coronavirus (FCoV) were performed on spleen, liver, mesenteric lymph node, kidney, large and small intestine, and lung from 14 FIP and 12 non-FIP cats. Sensitivity, specificity, predictive values, likelihood ratios, and concordance were calculated. IHC and RT-nPCR had the highest concordance in lung and liver, histology and IHC in the other organs. The sensitivity of histology, IHC, and RT-nPCR on the different organs ranged from 41.7 to 76.9%, 46.2 to 76.9%, and 64.3 to 85.7%, respectively, and their specificity ranged from 83.3 to 100.0%, 100% and 83.3 to 100.0%. Therefore, IHC is recommended when histology is consistent with FIP. If RT-nPCR is performed as the first diagnostic approach, results should always be confirmed with IHC. Lung or liver provide accurate information regardless of the method, while IHC is preferred to RT-nPCR to confirm FIP in the kidney or intestine.

Download Full-text

COVID-19 Seroprevalence among Healthcare Workers of a Large COVID-19 Hospital in Rome Reveals Strengths and Limits of Two Different Serological Tests

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18052650 ◽

2021 ◽

Vol 18 (5) ◽

pp. 2650

Author(s):

Giuseppe Vetrugno ◽

Daniele Ignazio La Milia ◽

Floriana D’Ambrosio ◽

Marcello Di Pumpo ◽

Roberta Pastorino ◽

...

Keyword(s):

Blood Test ◽

Healthcare Workers ◽

Point Of Care ◽

Venous Blood ◽

Administrative Staff ◽

Serological Tests ◽

Predictive Values ◽

Work From Home ◽

Significant Difference ◽

Sensitivity Specificity

Healthcare workers are at the forefront against COVID-19, worldwide. Since Fondazione Policlinico Universitario A. Gemelli (FPG) IRCCS was enlisted as a COVID-19 hospital, the healthcare workers deployed to COVID-19 wards were separated from those with limited/no exposure, whereas the administrative staff were designated to work from home. Between 4 June and 3 July 2020, an investigation was conducted to evaluate the seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immunoglobulin (IgG) antibodies among the employees of the FPG using point-of-care (POC) and venous blood tests. Sensitivity, specificity, and predictive values were determined with reverse-transcription polymerase chain reaction on nasal/oropharyngeal swabs as the diagnostic gold standard. The participants enrolled amounted to 4777. Seroprevalence was 3.66% using the POC test and 1.19% using the venous blood test, with a significant difference (p < 0.05). The POC test sensitivity and specificity were, respectively, 63.64% (95% confidence interval (CI): 62.20% to 65.04%) and 96.64% (95% CI: 96.05% to 97.13%), while those of the venous blood test were, respectively, 78.79% (95% CI: 77.58% to 79.94%) and 99.36% (95% CI: 99.07% to 99.55%). Among the low-risk populations, the POC test’s predictive values were 58.33% (positive) and 98.23% (negative), whereas those of the venous blood test were 92.86% (positive) and 98.53% (negative). According to our study, these serological tests cannot be a valid alternative to diagnose COVID-19 infection in progress.

Download Full-text

Investigation of the rapid immunochromatographic test performance in the diagnosis of syphilis; comparison of four serological methods

LaboratoriumsMedizin ◽

10.1515/labmed-2019-0012 ◽

2020 ◽

Vol 0 (0) ◽

Author(s):

Huseyin Agah Terzi ◽

Ozlem Aydemir ◽

Engin Karakece ◽

Huseyin Hatipoglu ◽

Mehmet Olmez ◽

...

Keyword(s):

Test Performance ◽

Gold Standard ◽

Treponema Pallidum ◽

Rapid Test ◽

Immunochromatographic Test ◽

Rapid Plasma Reagin ◽

Serum Samples ◽

Hemagglutination Assay ◽

Predictive Values ◽

Sensitivity Specificity

AbstractObjectivesTo test the performance of the newly available rapid test for syphilis, we compared it with Treponema pallidum hemagglutination assay (TPHA). Additionally, we investigated the performance of rapid plasma reagin (RPR) and chemiluminescence microparticle immunoassays (CMIA) at our laboratory using TPHA as a gold standard.MethodsThe serum samples of 595 patients with the pre-diagnosis of syphilis were studied by four serological methods. The sensitivity, specificity, and predictive values of RPR, CMIA, and syphilis rapid test were assessed by utilizing TPHA as a gold standard for the diagnosis of syphilis.ResultsOf the patients, 6.2% (37/595) had positive RPR, 5.5% (33/595) had positive CMIA, 5.5% (33/595) had a positive rapid immunochromatographic method and 5% (30/595) had positive TPHA. When TPHA results were taken as the reference, the sensitivity of the rapid test for syphilis was 100%, the specificity was 99.5%, PPV was 90.9%, and NPV was 100.0%.ConclusionsIt was observed that the rapid test for syphilis used in the study was quite successful, its cost was appropriate, and the test was very fast and easy to apply. At the same time, the agreement between syphilis rapid test and TPHA was found to be excellent.

Download Full-text

Secondary Analysis of an Electronic Surveillance System Combined with Multi-focal Interventions for Early Detection of Sepsis

Applied Clinical Informatics ◽

10.4338/aci-2016-07-ra-0112 ◽

2017 ◽

Vol 26 (01) ◽

pp. 47-66 ◽

Cited By ~ 7

Author(s):

Bonnie Westra ◽

Sean Landman ◽

Pranjul Yadav ◽

Michael Steinbach

Keyword(s):

Early Detection ◽

Surveillance System ◽

Point Of Care ◽

Management Strategies ◽

Secondary Analysis ◽

Length Of Hospital Stay ◽

Separate Analysis ◽

Electronic Surveillance ◽

Predictive Values ◽

Sensitivity Specificity

SummarySummary: To conduct an independent secondary analysis of a multi-focal intervention for early detection of sepsis that included implementation of change management strategies, electronic surveil-lance for sepsis, and evidence based point of care alerting using the POC AdvisorTM application. Methods: Propensity score matching was used to select subsets of the cohorts with balanced covariates. Bootstrapping was performed to build distributions of the measured difference in rates/ means. The effect of the sepsis intervention was evaluated for all patients, and High and Low Risk subgroups for illness severity. A separate analysis was performed patients on the intervention and non-intervention units (without the electronic surveillance). Sensitivity, specificity, and the positive predictive values were calculated to evaluate the accuracy of the alerting system for detecting sepsis or severe sepsis/ septic shock.Results: There was positive effect on the intervention units with sepsis electronic surveillance with an adjusted mortality rate of –6.6%. Mortality rates for non-intervention units also improved, but at a lower rate of –2.9%. Additional outcomes improved for patients on both intervention and non-intervention units for home discharge (7.5% vs 1.1%), total length of hospital stay (-0.9% vs –0.3%), and 30 day readmissions (-6.6% vs –1.6%). Patients on the intervention units showed better outcomes compared with non-intervention unit patients, and even more so for High Risk patients. The sensitivity was 95.2%, specificity of 82.0% and PPV of 50.6% for the electronic surveillance alerts. Conclusion: There was improvement over time across the hospital for patients on the intervention and non-intervention units with more improvement for sicker patients. Patients on intervention units with electronic surveillance have better outcomes; however, due to differences in exclusion criteria and types of units, further study is needed to draw a direct relationship between the electronic surveillance system and outcomes.

Download Full-text

Value and Diagnostic Efficacy of Fetal Morphology Assessment Using Ultrasound in A Poor-Resource Setting

Diagnostics ◽

10.3390/diagnostics9030109 ◽

2019 ◽

Vol 9 (3) ◽

pp. 109 ◽

Cited By ~ 1

Author(s):

Ukweh ◽

Ugbem ◽

Okeke ◽

Ekpo

Keyword(s):

Predictive Value ◽

Performance Metrics ◽

Area Under The Curve ◽

Youden Index ◽

Likelihood Ratios ◽

Diagnostic Efficacy ◽

Predictive Values ◽

Resource Setting ◽

Post Test ◽

Sensitivity Specificity

Background: Ultrasound is operator-dependent, and its value and efficacy in fetal morphology assessment in a low-resource setting is poorly understood. We assessed the value and efficacy of fetal morphology ultrasound assessment in a Nigerian setting. Materials and Methods: We surveyed fetal morphology ultrasound performed across five facilities and followed-up each fetus to ascertain the outcome. Fetuses were surveyed in the second trimester (18th–22nd weeks) using the International Society of Ultrasound in Obstetrics and Gynecology (ISUOG) guideline. Clinical and surgical reports were used as references to assess the diagnostic efficacy of ultrasound in livebirths, and autopsy reports to confirm anomalies in terminated pregnancies, spontaneous abortions, intrauterine fetal deaths, and still births. We calculated sensitivity, specificity, positive and negative predictive values, Area under the curve (AUC), Youden index, likelihood ratios, and post-test probabilities. Results: In total, 6520 fetuses of women aged 15–46 years (mean = 31.7 years) were surveyed. The overall sensitivity, specificity, and AUC were 77.1 (95% CI: 68–84.6), 99.5 (95% CI: 99.3–99.7), and 88.3 (95% CI: 83.7–92.2), respectively. Other performance metrics were: positive predictive value, 72.4 (95% CI: 64.7–79.0), negative predictive value, 99.6 (95% CI: 99.5–99.7), and Youden index (77.1%). Abnormality prevalence was 1.67% (95% CI: 1.37–2.01), and the positive and negative likelihood ratios were 254 (95% CI: 107.7–221.4) and 0.23 (95% CI: 0.16–0.33), respectively. The post-test probability for positive test was 72% (95% CI: 65–79). Conclusion: Fetal morphology assessment is valuable in a poor economics setting, however, the variation in the diagnostic efficacy across facilities and the limitations associated with the detection of circulatory system anomalies need to be addressed.

Download Full-text

Rapid Diagnosis of SARS-CoV-2 Pneumonia on Lower Respiratory Tract Specimens

10.21203/rs.3.rs-684790/v1 ◽

2021 ◽

Author(s):

Vanessa De Pace ◽

Patrizia Caligiuri ◽

Valentina Ricucci ◽

Nicola Nigro ◽

Barbara Galano ◽

...

Keyword(s):

Intensive Care ◽

Viral Load ◽

Respiratory Tract ◽

Intensive Care Units ◽

Lower Respiratory Tract ◽

Clinical Decision Making ◽

High Viral Load ◽

Rt Pcr ◽

Predictive Values ◽

Rapid Pcr

Abstract Background: The ongoing pandemic of SARS-CoV-2 requires the availability of accurate and rapid diagnostic tests, especially in some clinical settings like emergency and intensive care units. The objective of this study was to evaluate the diagnostic performances of rapid PCR kit Vivalytic SARS-CoV-2 in lower respiratory tract (LRT) specimens.Methods: A consecutive sample of LRT specimens (bronchoalveolar lavage and bronchoaspirates) was collected from Intensive Care Units of San Martino Hospital (Genoa, Italy) between November 2020 and January 2021. All samples were tested in RT-PCR by using Allplex™ SARS-CoV-2 assay (Seegene Inc., South Korea). Based on RT-PCR results, specimens were categorized into negative, positive with high viral load [cycle threshold (Ct) ≤30] and positive with low viral load (Ct of 31–35). A quota 1:1:1 sampling was used to achieve a sample size of 75. Then, all specimens were tested in the rapid PCR assay Vivalytic SARS-CoV-2 (Bosch Healthcare Solutions GmbH, Germany). The diagnostic performance of the rapid PCR against RT-PCR was assessed through calculation of accuracy, Cohen’s κ, sensitivity, specificity and expected positive (PPV) and negative (NPV) predictive values.Results: The overall diagnostic accuracy of the Vivalytic SARS-CoV-2 was 97.3% (95% CI: 90.9–99.3%) with an excellent Cohen’s κ of 0.94 (95% CI: 0.72–1). The sensitivity and specificity were 96% (95% CI: 86.5–98.9%) and 100% (95% CI: 86.7–100%), respectively. Samples with high viral loads had a sensitivity of 100% (Table 1). The distributions of E gene Ct values were similar (Wilcoxon’s test: P=0.070) with medians of 35 (IQR: 25–36) and 35 (IQR: 25–35), respectively (Figure 1). NPV and PPV was 92.6% and 100%, respectively.Conclusions: This study shows Vivalytic SARS-CoV-2 can be used following the sample liquefaction on LRT specimens. It’s a feasible and highly accurate molecular procedure especially in high viral load samples. This assay allows having a result in about 40 min and therefore may accelerate the clinical decision making in urgent/emergency situations.

Download Full-text