COV19 PCR ( 1 )
“At the moment the majority of the current Covid-19 tests that all the reports are coming from are using PCR,” says University of Sussex senior lecturer in microbiology Dr Edward Wright. “They detect the genetic information of the virus, the RNA. That’s only possible if the virus is there and someone is actively infected.”
PCR tests are used to directly detect the presence of an antigen, rather than the presence of the body’s immune response, or antibodies. By detecting viral RNA, which will be present in the body before antibodies form or symptoms of the disease are present, the tests can tell whether or not someone has the virus very early on.
“PCR gives us a good indication of who is infected. They can be isolated and get in contact with people they’ve been in touch with so they can be quarantined too, just in case. That’s the true advantage of the current major diagnostic tests, you can break that transmission chain and get a clearer picture of what’s happening,” says Wright.
By scaling PCR testing to screen vast swathes of nasopharyngeal swab samples from within a population, public health officials can get a clearer picture of the spread of a disease like Covid-19 within a population.