El test basat en la sang, és capaç de detectar la presència del virus a les 24 hores després de la infecció, abans que les persones mostrin símptomes i diversos dies abans que es consideri capaç de propagar-lo als altres. Detecta el virus uns quatre dies abans que les proves actuals.
Scientists working for the US military have designed a new Covid-19 test that could potentially identify carriers before they become infectious and spread the disease, the Guardian has learned.
In what could be a significant breakthrough, project coordinators hope the blood-based test will be able to detect the virus’s presence as early as 24 hours after infection – before people show symptoms and several days before a carrier is considered capable of spreading it to other people. That is also around four days before current tests can detect the virus.
The test has emerged from a project set up by the US military’s Defense Advanced Research Projects Agency (Darpa) aimed at rapid diagnosis of germ or chemical warfare poisoning. It was hurriedly repurposed when the pandemic broke out and the new test is expected to be put forward for emergency use approval (EUA) by the US Food and Drug Administration (FDA) within a week.
“The concept fills a diagnostic gap worldwide,” the head of Darpa’s biological technologies office, Dr Brad Ringeisen, told the Guardian, since it should also fill in testing gaps at later stages of the infection. If given FDA approval, he said, it had the potential to be “absolutely a gamechanger”
While pre-infectious detection would improve the efficiency of test-and-trace programmes as governments worldwide relax lockdowns, Darpa cautioned that it must wait until after FDA approval is given and the test can be put into practise for evidence of exactly how early it can pick up the virus.
“The goal of research is to develop and validate an early host blood response diagnostic test for Covid,” Prof Stuart Sealfon, who leads the research team at Mount Sinai hospital in New York, said in an email.
He said the testing approach, which looks at the body’s response as it fights Covid-19, should produce earlier results than current nose-swab tests that hunt for the virus itself. “Because the immune response to infection develops immediately after infection, a Covid signature is expected to provide more sensitive Covid infection diagnosis earlier,” he told the Guardian.
The research behind the development of the tests will eventually be made public, with the collaborating teams from medical schools at Mount Sinai, Duke University and Princeton expected to publish online, allowing scientists around the world to trial similar methods.
If EUA is granted, the test should start being rolled out in the US in the second half of May. Approval is not guaranteed, but Darpa scientists are enthusiastic about the potential impact as governments loosen lockdowns amid worries about controlling potential second-wave outbreaks.