Digital Desk: US researchers have created a quick Covid-19 test kit that can identify every SARS-CoV-2 variation currently in existence within hours. The CoVarScan test finds the traces of eight hotspots on the Covid-19-causing SARS-CoV-2 virus.
CoVarScan was put to the
test on samples taken from more than 4,000 patients by researchers at the
University of Texas (UT) Southwestern Medical Center in the US.
The study, which was
just published in the journal Clinical Chemistry, demonstrates that the test
can correctly distinguish between all current SARS-CoV-2 variations and is just
as accurate as existing techniques for diagnosing Covid-19.
According to Jeffrey
SoRelle, an assistant professor at UT Southwestern and the study's principal
author, "with this test, we can find out very rapidly what variants are in
the community and if a new variant is forming."
When dealing with
variants that react differently to medicines, it obviously has ramifications
for specific patients, SoRelle added.
Other Covid-19 assays
are available, however they typically only detect tiny compounds on the surface
of the virus or a piece of the SARS-CoV-2 genetic material, not the variation
itself.
Additionally, many
scientists are concerned that these tests might miss emerging strains or that
they are not reliable in detecting particular variants.
Whole genome sequencing,
which is time-consuming and expensive and relies on advanced tools and analysis
to spell out the whole RNA sequence contained in the viruses, is often required
to identify which form of Covid-19 a patient carries.
CoVarScan focuses on
eight SARS-CoV-2 areas where viral variants frequently diverge.
It analyses the length
of repeating genomic areas that tend to grow and shrink as the virus matures
and finds minor mutations where the sequence of RNA building blocks differs.
The procedure copies and
measures the RNA at these eight sites of interest using polymerase chain
reaction (PCR), a technology used in most pathology labs.
From April 2021 to
February 2022, SoRelle's team gathered approximately 4,000 nasal swab samples
from patients at UT Southwestern that tested positive for Covid-19. These
samples were from both symptomatic and asymptomatic individuals.
When making treatment
decisions for some critically ill Covid-19 patients, the tests were validated
using whole genome sequencing, the industry standard.
CoVarScan showed 96%
sensitivity and 99% specificity when compared to whole genome sequencing.
It recognised and
distinguished the Delta, Mu, Lambda, and Omicron variations of Covid-19, as
well as the BA.2 Omicron strain, which was formerly referred to as
"stealth Omicron" since it was not detected by some tests meant to
solely identify the Omicron strain.
According to a common criticism of this type of test, it must be
adjusted frequently to account for new variants. However, CoVarScan has not
required adjustment in more than a year and is still functioning quite well.
SoRelle has a pending patent application based on this study and
intends to continue developing CoVarScan as a commercial test.
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