COVID-19 Digital testing Method Can Yield New Information
The nasopharyngeal swab – swab to take the COVID-19 test, is not a pleasant experience. Healthcare employees need to scrape deep in the nasal cavity to get a thorough sample. Restricting the number of tests providers could run, the swab sticks themselves fell in short supply during the early stages of the COVID-19 crisis in the United States.
However, the virus is likewise detectable in saliva and it’s progressively clear from the data. Researchers from the University of Chicago is checking out whether a saliva-based COVID-19 test might be an effective alternative to the nasal swab tests.
The long, thin nasopharyngeal swabs become the key method for testing as COVID-19 is mostly an upper respiratory disease, settling in the nose and sinuses. The collected samples are load into a device that extracts the viral genetic material and then replicates it. They get classified with a light-up tag if there are COVID-19 genes in the mix.
The devices running this test throughout the nation are all based on a particular method called qPCR. However, researchers are likewise evaluating a newer detection system called ddPCR or droplet-digital PCR for testing COVID-19. As per the theory, the droplet-digital PCR for testing COVID-19 could be extra sensitive than qPCR, able to obtain a positive analysis even if the sample contains reduced quantities of the virus. Nishant Agrawal, a UChicago surgeon-scientist and an investigator on the study who has been working on digital PCR and saliva for over a decade said, “Beyond a simple yes or no, it could offer medical professionals with a quantitative measure of just how much virus exists in the sample, “.
Associate Prof. Jeremy Segal, a UChicago pathologist and an investigator on the study, said, “It’s possible that people who have the virus but don’t reveal symptoms, might have a smaller amount of virus that would not turn up on tests”. “If they’re still able to spread out the infection, being able to spot those individuals would certainly be very important. We simply don’t know yet – still there are a lot of unknowns”.
In late March and early April, as the pandemic increase in Illinois, Segal and Assistant Prof. Evgeny Izumchenko, a University of Chicago Medicine geneticist, joined Associate Prof. Savas Tay’s laboratory at the Pritzker School of Molecular Engineering to evaluate ddPCR methods for COVID-19 detection.
Since ddPCR is newer as well as fully automated testing is still being developed, researchers have to carry out the process manually. They decided to attempt utilizing saliva as they were currently using the ddPCR system on nasopharyngeal swabs.
Izumchenko said, “The advantage of it is that it’s much less invasive, and people can collect their own samples – everyone knows exactly how to spit”.
The scientists set up an extra cubicle at UChicago Medicine’s curbside screening for COVID-19 to get patients to volunteer for the trial. The volunteers would get a 2nd nasopharyngeal swab and spit in a tube for the test after UChicago Medicine workers took their samples for the basic nasopharyngeal swab run by the healthcare facility diagnostics laboratory. This way scientists might compare both techniques directly: The medical facility runs the common qPCR test and the investigators run the ddPCR tests on both the nasal swabs as well as saliva samples at Tay’s lab.
The research is ongoing, however, in the test examples collected and examined so far, saliva ddPCR examinations have matched up specifically with the hospital’s outcomes.
The degree of irregularity in the number of viruses identified in COVID-positive patients arriving here for curbside testing actually surprised researchers.
Segal claimed, “The quantity of virus identified amongst these symptomatic people varies by approximately a million-fold”. “There’s a lot we don’t understand about that, in terms of its relationship to what part of the infection cycle the individual remains in, in addition to exactly how it may be impacted by various sampling techniques. However, the variability as well as extreme range provides substantial difficulty from the viewpoint of diagnostics.
He added, “We still don’t know how it belongs to transmissibility or the clinical significance of this high level of irregularity”.
The researchers wish to follow instances gradually and also see if the viral loads correspond to the severity of infection as well as therapy routines, or whether there’s a consistent shape to the amount of virus that patients carry over the course of an infection.
Izumchenko said, “Additionally, there have been some early indicators that from saliva you might get a positive result for a longer period than from the nasopharyngeal swab testing. So When patients are preparing to leave the hospital, we would certainly like to test individuals again to see if they’re still positive”.
All the scientists were happy with the partnership between their laboratories. They intend to continue working together as well as using techniques for troubles past COVID-19, such as HPV or cancer. Izumchenko claimed said, “It actually gave rise to a new center that, under different scenarios, could never have actually happened”.
Author: Sruthi S