Evaluation of performance of two SARS-CoV-2 Rapid whole-blood finger-stick IgM-IgG Combined Antibody Tests

Abstract

Background The SARS-CoV-2 virus is responsible for the infectious respiratory disease called COVID-19 (COronaVIrus Disease). In response to the growing COVID-19 pandemic, Rapid Diagnostic Tests (RDTs) have been developed to detect specific antibodies, IgG and IgM, to SARS-CoV-2 virus in human whole blood. We conducted a real-life study to evaluate the performance of two RDTs, COVID-PRESTO and COVID-DUO, compared to the gold standard, RT-PCR. Methods RT-PCR testing of SARS-Cov-2 was performed from nasopharyngeal swab specimens collected in adult patients visiting the infectious disease department at the hospital (Orleans, France). Fingertip whole blood samples taken at different time points after onset of the disease were tested with RDTs. The specificity and sensitivity of the rapid test kits compared to test of reference (RT-PCR) were calculated. Results Among 381 patients with symptoms of COVID-19 who went to the hospital for a diagnostic, 143 patients were RT-PCR negative. Results of test with RDTs were all negative for these patients, indicating a specificity of 100% for both RDTs. In the RT-PCR positive subgroup (n=238), 133 patients were tested with COVID-PRESTO and 129 patients were tested with COVID-DUO (24 patients tested with both). The further the onset of symptoms was from the date of collection, the greater the sensitivity. The sensitivity of COVID-PRESTO test ranged from 10.00% for patients having experienced their 1st symptoms from 0 to 5 days ago to 100% in patients where symptoms had occurred more than 15 days before the date of tests. For COVID-DUO test, the sensitivity ranged from 35.71% [0-5 days] to 100% (> 15 days). Conclusion COVID-PRESTO and DUO RDTs turned out to be very specific (none false positive) and to be sensitive enough after 15 days from onset of symptom. These easy to use IgG/IgM combined test kits are the first ones allowing a screening with capillary blood sample, by typing from a finger prick. These rapid tests are particularly interesting for screening in low resource settings.

Evaluation of the practicability of a finger-stick whole-blood SARS-Cov-2 self-test adapted for the general population

“…COVID-PRESTO ® has recently been evaluated for performance and showed sensitivity ranging from 69% for patients with symptoms that occurred from 11 to 15 days before the date of test to 100% in patients who experienced first symptoms more than 15 days before the test [ 13 ]. However, for the test to be approved as a self-test, a practicability study was needed in order to assess the feasibility of the test for use by untrained individuals with different education levels.…”

“…test [13]. However, for the test to be approved as a self-test, a practicability study was needed in order to assess the feasibility of the test for use by untrained individuals with different education levels.…”

Evaluation of the Practicability of a Finger-Stick Whole-Blood SARS-Cov-2 Self-Test Adapted for the General Population

“…COVID-PRESTO ® has recently been evaluated for performance and showed a sensitivity ranging from 69% for patients with symptoms that occurred from 11 to 15 days before the date of test and 100% in patients who experienced first symptoms more than 15 days before the test. These results are currently being reviewed for publication [2]. However, for it to be approved as a self-test, a practicability study was needed in order to assess the feasibility of the test by untrained individuals with different education levels.…”

“…The AAZ COVID-PRESTO ® is a Rapid Diagnostic Tests (RDTs), easy-to-use device based on lateral flow chromatographic immunoassay from a single drop of blood (Figure 1). It has been evaluated in terms of sensitivity and specificity and showed good results that have been submitted for publication and currently under review [2]. Those results were obtained in a controlled setting where the test was performed by trained professionals.…”

Science's Response to CoVID‐19

“…These can be detected by a range of methods including ELISA, immunofluorescence, and immunochromatographic assays. Numerous tests (probing for IgGs binding to either the N or S‐proteins) have been given approval for use by the FDA; [183] other tests for IgM are available and several tests assay for both IgM [184] and IgG [185] . Although outputs are varied, these tests do seem to be rapid, accurate and sensitive [186] .…”