Analytical Performance of the Point-of-care BIOSYNEX COVID-19 Ag BSS for the Detection of SARS‐CoV‐2 Nucleocapsid Protein in Nasopharyngeal Swabs: A Prospective Field Evaluation During the COVID-19 Third Wave in France

Abstract Background: The accuracy and reliability of rapid diagnostic tests are critical for monitoring and diagnosing SARS-CoV-2 infection in the general population. This study aimed to evaluate the analytical performance of the BIOSYNEX COVID-19 Ag BSS (Biosynex Swiss SA, Fribourg, Switzerland) antigen rapid diagnostic test (Ag-RDT), which targets the SARS-CoV-2 N-nucleocapsid protein for the diagnosis of COVID-19. The Ag-RDT was compared with a real-time RT-PCR (rtRT-PCR) gold standard for performance measurement.Methods: Two nasopharyngeal flocked swabs were prospectively collected simultaneously in March and April 2021 from 967 individuals aged ≥18 years tested for SARS-CoV-2 in two private laboratories, Paris, France.Results: Overall, the Ag-RDT demonstrated high sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 81.8%, 99.6%, 96.6%, and 97.5%, respectively, as well as high or near-perfect agreement (97.0%), reliability was assessed using Cohen’s κ-coefficient (0.87), and accuracy was evaluated using Youden index (J) (81.6%) in detecting SARS-CoV-2. The analytical performance of the Ag-RDT remained high when there was significant viral shedding (i.e., N gene Ct values ≤ 33 on reference RT-PCR). The sensitivity was only 55.2% in case of low or very low viral excretion (Ct> 33).Conclusions: The BIOSYNEX COVID-19 Ag BSS Ag-RDT is a promising, potentially simple diagnostic tool, especially in symptomatic COVID -19 or proven infectiousness.

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Analytical performance of the point-of-care BIOSYNEX COVID-19 Ag BSS for the detection of SARS‐CoV‐2 nucleocapsid protein in nasopharyngeal swabs: a prospective field evaluation during the COVID-19 third wave in France

Infection ◽

10.1007/s15010-021-01723-5 ◽

2021 ◽

Author(s):

Frédéric Fitoussi ◽

Serge Tonen-Wolyec ◽

Natalio Awaida ◽

Raphaël Dupont ◽

Laurent Bélec

Keyword(s):

Predictive Value ◽

Nucleocapsid Protein ◽

Point Of Care ◽

High Sensitivity ◽

Field Evaluation ◽

Analytical Performance ◽

N Gene ◽

Youden Index ◽

Rt Pcr ◽

Viral Excretion

Abstract Background The accuracy and reliability of rapid diagnostic tests are critical for monitoring and diagnosing SARS-CoV-2 infection in the general population. This study aimed to evaluate the analytical performance of the BIOSYNEX COVID-19 Ag BSS (Biosynex Swiss SA, Fribourg, Switzerland) antigen rapid diagnostic test (BIOSYNEX Ag-RDT), which targets the SARS-CoV-2 N-nucleocapsid protein for the diagnosis of COVID-19. The Ag-RDT was compared with a real-time RT-PCR (rtRT-PCR) as gold standard for performance measurement. Methods Two nasopharyngeal flocked swabs were prospectively collected simultaneously in March and April 2021 from 967 individuals aged ≥ 18 years tested for SARS-CoV-2 in two private laboratories, Paris, France. Results Overall, the Ag-RDT demonstrated high sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 81.8%, 99.6%, 96.6%, and 97.5%, respectively. The agreement (97.0%), reliability assessed using Cohen’s κ-coefficient (0.87), and accuracy evaluated using Youden index (J) (81.6%) in detecting SARS-CoV-2 were high. The analytical performance of the Ag-RDT remained high when there was significant viral shedding (i.e., N gene Ct values ≤ 33 on reference RT-PCR). The sensitivity was only 55.2% in case of low or very low viral excretion (Ct > 33). Conclusions The BIOSYNEX Ag-RDT is a promising, potentially simple diagnostic tool, especially in symptomatic COVID-19 patients with substantial viral excretion in the nasopharynx.

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Analytical Performances of the Point-of-Care BIOSYNEX COVID-19 Ag BSS for the Detection of SARS‐CoV‐2 Nucleocapsid Protein in Nasopharyngeal Swabs: A Prospective Field Evaluation During the COVID-19 Third Wave in France

10.21203/rs.3.rs-519746/v1 ◽

2021 ◽

Author(s):

Fréderic Fitoussi ◽

Serge Tonen-Wolyec ◽

Natalio Awaida ◽

Raphael Dupont ◽

Laurent Belec

Keyword(s):

Nucleocapsid Protein ◽

Point Of Care ◽

Diagnostic Testing ◽

High Sensitivity ◽

High Specificity ◽

Field Evaluation ◽

N Gene ◽

Third Wave ◽

Perfect Agreement ◽

Viral Excretion

Abstract Background: Evaluating the accuracy and reliability of rapid diagnostic testing kits is crucial for surveillance and diagnosis of SARS-CoV-2 infections in general population. The aim of the study was to assess the analytical performances of the antigen-rapid diagnosis test (Ag-RDT) BIOSYNEX COVID-19 Ag BSS (Biosynex Swiss SA, Freiburg, Switzerland), targeting the SARS-CoV-2 N nucleocapsid protein, for the diagnosis of COVID-19, by reference to real-time RT-PCR (rtRT-PCR).Methods: A total 967 adults living in Paris region were prospectively included during the third wave of the COVID-19 epidemic in France. Paired nasopharyngeal flocked swabs were collected at the same timepoint from persons aged ≥18 years receiving testing for SARS-CoV-2, at two private laboratories.Results: Overall, the Ag-RDT showed high sensitivity, specificity, PPV and NPV of 81.8%, 99.6%, 96.6% and 97.5%, respectively, as well as high or almost perfect agreement (97.0%), reliability assessed by Cohen’s κ coefficient (0.87), and accuracy assessed by Youden’s J index (81.6%) to detect SARS-CoV-2. The analytical performances of the Ag-RDT remained high in the event of significant viral excretion (i.e., N gene Ct values ≤ 33 by reference rtRT-PCR), while the sensitivity of the Ag-RDT dropped to 55.2% with low or very low viral shedding (Ct> 33).Conclusions: The Ag-RDT BIOSYNEX COVID-19 Ag BSS showed high specificity and sufficient sensitivity for the detection of SARS-CoV-2. This test is a promising potential easy diagnostic tool, especially in situations of symptomatic COVID-19 and/or proven contagiousness.

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Clinical Evaluation of a COVID-19 Antibody Lateral Flow Assay using Point of Care Samples

10.1101/2020.12.02.20242750 ◽

2020 ◽

Author(s):

Won Lee ◽

Steven Straube ◽

Ryan Sincic ◽

Jeanne A. Noble ◽

Juan Carlos Montoy ◽

...

Keyword(s):

Predictive Value ◽

Point Of Care ◽

Acute Infection ◽

High Specificity ◽

Lateral Flow ◽

Lateral Flow Immunoassay ◽

Onset Date ◽

Rt Pcr ◽

Serum Samples ◽

Antibody Positivity

ABSTRACTIntroductionThe ongoing SARS-CoV-2 pandemic has spurred the development of numerous point of care (PoC) immunoassays. Assessments of performance of available kits are necessary to determine their clinical utility. Previous studies have mostly performed these assessments in a laboratory setting, which raises concerns of translating findings for PoC use. The aim of this study was to assess the performance of a lateral flow immunoassay for the detection of SARS-CoV-2 antibodies using samples collected at PoC.MethodOne lateral flow immunoassay (Humasis® COVID-19 IgG/IgM) was tested. In total, 50 PCR RT-PCR positive and 52 RT-PCR negative samples were collected at PoC. Fifty serum specimens from Dec 2018 to Feb 2019 were used as controls for specificity. Serum samples collected between Dec 2019 to Feb 2020 were used as additional comparators. Clinical data including symptom onset date was collected from patient history and the medical record.ResultsThe overall sensitivity for the kit was 74% (95% CI: 59.7% -85.4%). The sensitivity for IgM and IgG detection >14 days after date of onset was 88% (95% CI: 68.8% -97.5%) and 84% (95% CI: 63.9% – 95.5%), with a negative predictive value (NPV) of 94% for IgM (95% CI: 83.5% - 98.8%) and 93% for IgG (95% CI: 81.8% - 97.9%). The overall specificity was 94% (95% CI: 83.5% - 98.8%). The Immunoglobulin specific specificity was 94% for IgM (95% CI: 83.5% - 98.8%) and 98% for IgG (95% CI: 89.4% - 100.0%), with a positive predictive value (PPV) of 88% for IgM (95% CI: 68.8% - 97.5%) and 95% for IgG (95% CI: 77.2% - 99.9%) respectively for samples collected from patients >14 days after date of onset. Specimen collected during early phase of COVID-19 pandemic (Dec 2019 to Feb 2020) showed 11.8% antibody positivity, and 11.3% of PCR-negative patients demonstrated antibody positivity.DiscussionHumasis® COVID-19 IgG/IgM LFA demonstrates greater than 90% PPV and NPV for samples collected 14 days after the onset of symptoms using samples collected at PoC. While not practical for the diagnosis of acute infection, the use of the lateral flow assays with high specificity may have utility for determining seroprevalence or seroconversion in longitudinal studies.

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Detecting SARS-CoV-2 at point of care: preliminary data comparing loop-mediated isothermal amplification (LAMP) to polymerase chain reaction (PCR)

BMC Infectious Diseases ◽

10.1186/s12879-020-05484-8 ◽

2020 ◽

Vol 20 (1) ◽

Cited By ~ 2

Author(s):

Marc F. Österdahl ◽

Karla A. Lee ◽

Mary Ni Lochlainn ◽

Stuart Wilson ◽

Sam Douthwaite ◽

...

Keyword(s):

Polymerase Chain Reaction ◽

Reverse Transcription ◽

Predictive Value ◽

Point Of Care ◽

Isothermal Amplification ◽

Service Improvement ◽

Rt Pcr ◽

Chain Reaction ◽

Loop Mediated Isothermal Amplification ◽

Polymerase Chain

Abstract Background A cost effective and efficient diagnostic tool for COVID-19 as near to the point of care (PoC) as possible would be a game changer in the current pandemic. We tested reverse transcription loop mediated isothermal amplification (RT-LAMP), a method which can produce results in under 30 min, alongside standard methods in a real-life clinical setting. Methods This prospective service improvement project piloted an RT-LAMP method on nasal and pharyngeal swabs on 21 residents of a high dependency care home, with two index COVID-19 cases, and compared it to multiplex tandem reverse transcription polymerase chain reaction (RT-PCR). We recorded vital signs of patients to correlate clinical and laboratory information and calculated the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of a single swab using RT-LAMP compared with the current standard, RT-PCR, as per Standards for Reporting Diagnostic Accuracy Studies (STARD) guidelines. Results The novel method accurately detected 8/10 RT-PCR positive cases and identified a further 3 positive cases. Eight further cases were negative using both methods. Using repeated RT-PCR as a “gold standard”, the sensitivity and specificity of a single novel test were 80 and 73% respectively. PPV was 73% and NPV was 83%. Incorporating retesting of low signal RT-LAMP positives improved the specificity to 100%. We also speculate that hypothermia may be a significant early clinical sign of COVID-19. Conclusions RT-LAMP testing for SARS-CoV-2 was found to be promising, fast and to work equivalently to RT-PCR methods. RT-LAMP has the potential to transform COVID-19 detection, bringing rapid and accurate testing to the PoC. RT-LAMP could be deployed in mobile community testing units, care homes and hospitals to detect disease early and prevent spread.

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The Performance of Two Rapid Antigen Tests During Population-Level Screening for SARS-CoV-2 Infection

Frontiers in Medicine ◽

10.3389/fmed.2021.797109 ◽

2021 ◽

Vol 8 ◽

Author(s):

Mohammad Alghounaim ◽

Hamad Bastaki ◽

Farah Bin Essa ◽

Hoda Motlagh ◽

Salman Al-Sabah

Keyword(s):

Positive Predictive Value ◽

Prospective Study ◽

Predictive Value ◽

Point Of Care ◽

Population Level ◽

Lower Sensitivity ◽

Rt Pcr ◽

Antigen Tests ◽

A Prospective Study ◽

Antigen Testing

Background: SARS-CoV-2 antigen assays offer a rapid mean to diagnose and isolate infected individuals. However, their utility in population-level screening is unknown.Objectives: The performance of two antigen tests in detecting SARS-CoV-2 was assessed among individuals randomly selected in the community.Study Design: A prospective study that performed head-to-head comparison of two SARS-CoV-2 antigen assays. Individuals were recruited during community SARS-CoV-2 screening over 10 working days. Demographic and clinical data were collected. Standard Q COVID-19 Ag test, a point-of-care chromatographic assay, was conducted immediately, and then the sample was transported to the virology laboratory to perform PCR and the LIAISON SARS-CoV-2 Ag chemiluminesence immunoassay.Results: respiratory samples from 991 individuals were collected, and 62 were positive by PCR. Inconclusive PCR results were observed in 19 samples and were excluded. The median age of participants was 40.2 years (IQR 32.3–47.8), and 932 (94%) were males. Most (77.4%) of infections were asymptomatic. The sensitivity and the specificity of the LIAISON assay were 43.3% (95%CI 30.6–56.8) and 99.9% (95%CI 99.3–100). The Standard Q assay had lower sensitivity (30.6%, 95%CI 19.6–43.7) but similar specificity (98.8%, 95%CI, 97.8–99.4). Similarly, the LIAISON assay had higher positive predictive value (96.3%, 95%CI 81–99.9% vs. 63.3%, 95%CI, 43.9–80.1%). Both assays performed better in symptomatic patients and among samples with a low-cycle threshold (Ct < 25).Conclusion: In our setting of random community surveillance, rapid antigen testing of nasopharyngeal swabs by either LIAISON SARS-CoV-2 Ag (DiaSorin) or Standard Q COVID-19 Ag (SD Biosensor) was less sensitive to detecting SARS-CoV-2 than the TaqPath COVID-19 RT-PCR.

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Is the glass half full? Extraction-free RT-LAMP to detect SARS-CoV-2 is less sensitive but highly specific compared to standard RT-PCR in 101 samples

10.1101/2020.12.07.20239558 ◽

2020 ◽

Author(s):

John J. Schellenberg ◽

Margaret Ormond ◽

Yoav Keynan

Keyword(s):

Point Of Care ◽

N Gene ◽

Nasopharyngeal Swab ◽

Lower Sensitivity ◽

Rt Pcr ◽

Public And Private ◽

Viral Loads ◽

Negative Results ◽

Viral Transport Medium ◽

Point Of Care Tests

AbstractThe current scale of public and private testing cannot be expected to meet the emerging need for higher levels of community-level and repeated screening of asymptomatic Canadians for SARS-CoV-2. Rapid point-of-care techniques are increasingly being deployed to fill the gap in screening levels required to identify undiagnosed individuals with high viral loads. However, rapid, point-of-care tests often have lower sensitivity in practice. Reverse transcription loop-mediated isothermal amplification (RT-LAMP) for SARS-CoV-2 has proven sensitive and specific and provides visual results in minutes. Using a commercially available kit for RT-LAMP and primer set targetting nucleocapsid (N) gene, we tested a blinded set of 101 archived nasopharyngeal (NP) swab samples with known RT-PCR results. RT-LAMP reactions were incubated at 65°C for 30 minutes, using heat-inactivated nasopharyngeal swab sample in viral transport medium, diluted tenfold in water, as input. RT-LAMP agreed with all RT-PCR defined negatives (N=51), and all positives with Ct less than 20 (N=24), 65% of positives with Ct between 20-30 (N=17), and no positives with Ct greater than 30 (N=9). RT-LAMP requires fewer and different core components, so may not compete directly with the mainline testing workflow, preserving precious central laboratory resources and gold standard tests for those with the greatest need. Careful messaging must be provided when using less-sensitive tests, so that people are not falsely reassured by negative results – “glass half empty” – in exchange for reliable detection of those with high levels of virus within an hour, using <$10 worth of chemicals – “glass half full”.

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The diagnostic performance of deep-learning-based CT severity score to identify COVID-19 pneumonia

British Journal of Radiology ◽

10.1259/bjr.20210759 ◽

2022 ◽

Vol 95 (1129) ◽

Author(s):

Anna Sára Kardos ◽

Judit Simon ◽

Chiara Nardocci ◽

István Viktor Szabó ◽

Norbert Nagy ◽

...

Keyword(s):

Deep Learning ◽

Positive Predictive Value ◽

Predictive Value ◽

Severity Score ◽

Clinical Decision Making ◽

Rapid Diagnosis ◽

Youden Index ◽

Rt Pcr ◽

Data Set ◽

Pcr Test

Objective: To determine the diagnostic accuracy of a deep-learning (DL)-based algorithm using chest computed tomography (CT) scans for the rapid diagnosis of coronavirus disease 2019 (COVID-19), as compared to the reference standard reverse-transcription polymerase chain reaction (RT-PCR) test. Methods: In this retrospective analysis, data of COVID-19 suspected patients who underwent RT-PCR and chest CT examination for the diagnosis of COVID-19 were assessed. By quantifying the affected area of the lung parenchyma, severity score was evaluated for each lobe of the lung with the DL-based algorithm. The diagnosis was based on the total lung severity score ranging from 0 to 25. The data were randomly split into a 40% training set and a 60% test set. Optimal cut-off value was determined using Youden-index method on the training cohort. Results: A total of 1259 patients were enrolled in this study. The prevalence of RT-PCR positivity in the overall investigated period was 51.5%. As compared to RT-PCR, sensitivity, specificity, positive predictive value, negative predictive value and accuracy on the test cohort were 39.0%, 80.2%, 68.0%, 55.0% and 58.9%, respectively. Regarding the whole data set, when adding those with positive RT-PCR test at any time during hospital stay or “COVID-19 without virus detection”, as final diagnosis to the true positive cases, specificity increased from 80.3% to 88.1% and the positive predictive value increased from 68.4% to 81.7%. Conclusion: DL-based CT severity score was found to have a good specificity and positive predictive value, as compared to RT-PCR. This standardized scoring system can aid rapid diagnosis and clinical decision making. Advances in knowledge: DL-based CT severity score can detect COVID-19-related lung alterations even at early stages, when RT-PCR is not yet positive.

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A rapid, high-sensitivity SARS-CoV-2 nucleocapsid immunoassay to aid diagnosis of acute COVID-19 at the point of care

10.1101/2020.12.11.20238410 ◽

2020 ◽

Author(s):

Paul K. Drain ◽

Madhavi Ampajwala ◽

Christopher Chappel ◽

Andre B. Gvozden ◽

Melanie Hoppers ◽

...

Keyword(s):

Real Time ◽

Symptom Onset ◽

Real Time Pcr ◽

Nucleocapsid Protein ◽

Point Of Care ◽

High Sensitivity ◽

Antigen Test ◽

Rt Pcr ◽

Duration Of Symptoms ◽

Microfluidic Immunoassay

AbstractBackgroundThe LumiraDx SARS-CoV-2 antigen test, which uses a high-sensitivity, microfluidic immunoassay to detect the nucleocapsid protein of SARS-CoV-2, was evaluated for diagnosing acute COVID-19 in adults and children across point-of-care settings.MethodsTwo paired anterior nasal swabs or two paired nasopharyngeal swabs were collected from each participant. Swabs were tested by the LumiraDx SARS-CoV-2 antigen test and compared with real-time PCR (rt-PCR; Roche cobas 6800 platform). Positive- and negative predictive values and likelihood ratios were calculated. Results stratified based on gender, age, duration of symptoms, and rt-PCR cycle threshold.ResultsOut of the 512 participants, aged 0-90 years, of this prospective validation study, 414 (81%) were symptomatic for COVID-19 and 123 (24%) swabs were positive for SARS-CoV-2 based on rt-PCR testing. Compared with rt-PCR, the 12-minute swab test had 97.6% sensitivity and 96.6% specificity within 12 days of symptom onset, representing the period of infectivity. All (100%) samples detected within 33 rt-PCR cycles were also identified using the antigen test. Results were consistent across age and gender. Despite being performed by minimally trained healthcare workers, the user error rate of the test system was 1%.ConclusionThe rapid high-sensitivity assay using nasopharyngeal or anterior nasal sampling may offer significant improvements for diagnosing acute SARS-CoV-2 infection in clinic- and community-based settings.SummaryA 12-minute nasal swab test detects 97.6% of COVID-19 infections, compared to gold standard real-time PCR testing, up to 12 days following symptom onset using a microfluidic immunoassay for SARS-CoV-2 nucleocapsid protein.

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Evaluation of production lots of a rapid point-of-care lateral flow serological test intended for identification of IgM and IgG against the N-terminal part of the spike protein (S1) of SARS-CoV-2

10.1101/2020.08.27.20182923 ◽

2020 ◽

Author(s):

Tove Hoffman ◽

Linda Kolstad ◽

Bengt Ronnberg ◽

Ake Lundkvist

Keyword(s):

Predictive Value ◽

Serological Test ◽

Point Of Care ◽

External Validation ◽

Rapid Test ◽

Reference Method ◽

Spike Protein ◽

Index Test ◽

Rt Pcr ◽

Terminal Part

Background and objectives: Several antibody tests are available to detect SARS-CoV-2 specific antibodies, many of which address different antigens. Rapid point-of-care (POC) tests have been doubted due to an eventual risk of production errors, although it is unstudied whether such error would affect test sensitivity and/or specificity. We aimed to evaluate two separate production lots of a commercially available test intended for rapid detection of IgM and IgG against the N-terminal part of the SARS-CoV-2 spike protein (S1). Materials and methods: Serum samples from individuals with confirmed SARS-CoV-2 infection, by RT-PCR and/or serology, and pre-COVID-19 negative control sera gathered from a biobank during 2018 were collected. The presence of anti-S1 IgM/IgG was verified by an in-house Luminex-based serological assay, serving as reference method. The index test was a commercially available rapid POC-test (the COVID-19 IgG/IgM Rapid Test Cassette [Zhejiang Orient Gene Biotech Co Ltd, Huzhou, Zhejiang, China/Healgen Scientific, LLC, U.S.A.]). Results: One hundred samples were verified positive for anti-S1 IgG (median fluorescence intensity (MFI) greater than or equal to 900) and 74 for anti-S1 IgM (MFI greater than or equal to 700), confirmed by RT-PCR (n=90) and/or serology (n=89). None of the negative controls (n=200; MFI <300) had SARS-CoV-2 anti-S1 IgM, while one tested positive for SARS-CoV-2 anti-S1 IgG. For the two lots, the sensitivities of the rapid test were 93.2% (69/74; 95% CI: 85.1% - 97.1%) and 87.8% (65/74; 95% CI: 78.5% - 93.5%) for IgM, respectively 93.0% (93/100; 95% CI: 86.3% - 96.6%) and 100.0% for IgG (100/100; 95% CI: 96.3% - 100.0%). The specificity for both lots was 100% for IgM (200/200; 95% CI: 98.1% - 100%) and 99.5% for IgG (199/200; 95% CI: 97.2% - 99.9%). The positive predictive value was 100% for IgM and 98.9% and 99.0% for IgG. The negative predictive value was 95.7% and 97.6% for IgM, and 96.6% and 100.0% for IgG. Conclusion: The rapid POC-test used in this study is suitable to assess SARS-CoV-2 anti-S1 specific IgM/IgG, as a measure of previous virus exposure on an individual level. While the specificity was not affected by production lot, external validation of separate lots of rapid POC-tests is encouraged to ensure high sensitivity before market introduction.

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A SARS-CoV-2 Coronavirus Nucleocapsid Protein Antigen-Detecting Lateral Flow Assay

10.26434/chemrxiv.12794825 ◽

2020 ◽

Author(s):

Ben D Grant ◽

Caitlin E Anderson ◽

Spencer H Garing ◽

Luis F Alonzo ◽

John R Williford ◽

...

Keyword(s):

Nucleocapsid Protein ◽

Limit Of Detection ◽

Point Of Care ◽

Lateral Flow ◽

Rapid Diagnostics ◽

Rt Pcr ◽

Efficient Detection ◽

Lateral Flow Assays ◽

Optical Reader ◽

Polymerase Chain

Inexpensive, simple, rapid diagnostics are necessary for efficient detection, treatment and mitigation of COVID‑19. Currently, the primary diagnostic tool being utilized is reverse transcription polymerase chain reaction (RT-PCR). RT-PCR delivers results with good sensitivity and excellent specificity, but is expensive, prone to access challenges and is often slowed by transport to centralized testing laboratories. Antigen-based assays are inexpensive and can be rapidly mass-produced and deployed, with lateral flow assays (LFAs) being the most common inexpensive antigen test. To date, few antigen-detecting LFAs for COVID-19 have been commercialized. Herein, we present an open source LFA using commercially available antibodies and materials for the detection of SARS-CoV-2. Using an optical reader with comparable sensitivity to a visual read, the LFA yielded a Limit of Detection (LOD) of 23 TCID50/mL (95% CI of 9.1 to 37 TCID50/mL), equivalent to 1.4x105 copies/mL (95% CI of 5.5x104 to 2.3x105 copies/mL) irradiated virus in pooled nasal matrix. This LOD meets the criteria suggested by WHO for diagnosis of acute SARS-CoV-2 infection in a point of care format. A clinical evaluation and further testing is ongoing.

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