How Long Before I Test Negative For COVID-19

Although most countries do not have mandatory quarantine rules for people who test positive, they recommend isolation until people receive a negative test result, GAVI recently reported.

The time taken to test negative after contracting COVID-19 depends on the severity of the SARS-CoV-2 virus infection and the test itself.

PCR tests that hunt out parts of viral genetic material in our bodies and amplify it so we can detect it are susceptible and can even pick up the presence of a few viral fragments.

Such fragments of viral RNA can sometimes remain in our bodies long after the infection is over and the virus has been cleared from our system.

Furthermore, lateral flow tests that look for viral proteins called antigens are less sensitive and may be less likely to give a positive result several days after the first infection.

If we test positive on a PCR test but negative on an antigen test, then we may not be infectious and have residual virus RNA.

Indeed, as the U.S. Centers for Disease Control and Prevention (CDC) says, many governments regard negative antigen test results as sufficient proof that people are not infectious anymore.

'If you were exposed to COVID-19, you should start taking precautions.'

Under new guidelines from the CDC, people who test positive can stop wearing masks if they test negative on two rapid antigen tests, taken at least 48 hours apart.

Some of these changes in guidance may be more to do with politics and shifting societal sentiments rather than science, suggested researchers in July 2022.

Emily Bruce, a microbiologist and molecular geneticist at the University of Vermont in Burlington, commented on July 22, 2022, "You can have symptoms for longer than you test positive on lateral flow."

"And I think that's because many symptoms are caused by the immune system and not directly by the virus itself."

As of September 18, 2022, the CDC has published an Isolation and Exposure Calculator to determine if you need to isolate or take other steps to prevent spreading the coronavirus.