A virologist explains why COVID-19 coronavirus isn’t really dangerously lingering on surfaces for weeks ForbesFrontlines
The test in these studies uses a very well-established technique called quantitative reverse-transcription polymerase chain reaction, or qRT-PCR. This test demonstrates whether a person is infected or not by detecting the presence and relative quantity of viral RNA. Basically, “Is the virus in your system?” So what you might think about qRT-PCR tests is that measurements of how much viral RNA is detected corresponds directly to how infectious a person is.
Here’s the thing. RNA viruses, like the one that causes COVID-19, make a lot of mistakes when replicating their genomes, and sometimes these mistakes result in viral genomes containing fatal mistakes, or mutations, that render a critical viral gene non-functional – meaning they won’t infect people who come into contact with them. But when you run a qRT-PCR test, those viral genes with mistakes are indistinguishable from the ones that aren’t.
Virologists use other tests to detect infectious viruses – the ones we need to worry about actually making people sick. The most classical of these, plaque assays and 50% tissue culture infectious dose assays, are based on the ability of viruses to kill infected cells in culture. These methods are much better for assessing how much potentially transmissible virus would be “shed” from recovered patients or in the environment. Paul J.
So why don’t we use these tests all the time? The problem with them is that they are also more time-consuming to perform and require specialized biocontainment. So they’re not practical for performing clinical diagnostic testing or broad surveillance. qRT-PCR can be performed in hours in standard laboratory conditions , while plaque and TCID50 assays for SARS-CoV-2 take several days and must be performed in BSL-3 containment.
Going forward, testing for infectious virus using plaque and TCID50 assays will be essential for accurately determining how long recovered patients remain a transmission risk. Undoubtedly, those studies are in progress by virologists around the world using samples from both patients and animal models that are actively under development.
France Dernières Nouvelles, France Actualités
Similar News:Vous pouvez également lire des articles d'actualité similaires à celui-ci que nous avons collectés auprès d'autres sources d'information.
Smoking weed and coronavirus: Even occasional use raises risk of Covid-19 complicationsYou may think that an occasional hit of weed during the coronavirus pandemic isn't an issue, but even that could make it more difficult for doctors to diagnose you with Covid-19. And more frequent use puts you at risk for severe complications.
Lire la suite »
Why Coronavirus Antibody Testing Is the Next Big Step in the Fight Against COVID-19A Coronavirus Antibody Test Is the Next Step in Fighting COVID-19, Experts Say
Lire la suite »
Fact checking Trump’s claim about virus testing and anti-malaria medicineNBC News’ Jane Timm fact checks President Trump’s claim that coronavirus testing in the U.S. is the “best,” as well as his recommendation of anti-malaria medication for COVID-19.
Lire la suite »
Your coronavirus questions, answered: How can I disinfect a face mask? Should I wear gloves?How COVID-19 is transmitted, microwaving face masks, gloves and more: USA TODAY is answering your specific questions about the coronavirus.
Lire la suite »
Tarana Burke, founder of #MeToo movement, details partner's 'scary' coronavirus battle'The reason why I’m sharing is because I’ve read so much information, but the most informative has been first person accounts of folks with it,' Tarana Burke said.
Lire la suite »
The meaning behind your strange coronavirus dreamsWhat's the meaning of those bizarre coronavirus dreams plaguing you during the Covid-19 pandemic? Here's what experts think.
Lire la suite »