New Antigen Tests15 May 2020 01:29
“New antigen test
A Belgian biotech company called Coris BioConcept has created a new point-of-care test by repurposing a test originally developed to detect the closely related coronavirus SARS-CoV, which causes the respiratory infection SARS.
Called “COVID-19 Ag Respi-Strip,” the test is only commercially available to healthcare services. It is not for sale to the general public.
Like a home pregnancy test, it is a “lateral flow test,” comprising a reagent strip enclosed in plastic casing. If the test is positive, a colored band appears at a marked test line.
Researchers gauged the sensitivity and specificity of the new test against the gold-standard laboratory test for SARS-CoV-2, which uses the highly sensitive polymerase chain reaction to detect genetic material of the virus.
In a study paper published in Frontiers in Medicine, the researchers explain that they tested 328 nasopharyngeal swab samples from people with symptoms of SARS-CoV-2 infection.
Their results showed an overall sensitivity of 57.6%, which means that, on average, the test will identify around 6 out of every 10 people who have the infection.
Put another way, around 4 in 10 people with the infection would receive a negative test result.
However, among the subset of samples containing a high viral load — taken from the patients with the most contagious infections — this test will detect 7 out of 10 cases.
The test had an overall “specificity” of 99.5%, meaning that almost all of the samples that tested positive were from patients who had the infection. In other words, there were very few false positives.
Importantly, when the researchers tested samples containing other pathogens, including those that cause pneumonia, the common cold, and influenza, none tested positive.
As expected, samples containing SARS-CoV tested positive, but those that contained other coronaviruses tested negative.”
https://www.medicalnewstoday.com/articles/covid-19-antigen-test-could-give-quick-results-but-is-not-foolproof#New-antigen-test
https://www.corisbio.com/Products/Human-Field/Covid-19.php