US promotes 'serial testing' for Covid-19 with streamlined approval

The US government issued simplified rules for developers of coronavirus tests to promote serial screening, a process in which the same individual is tested multiple times within a few days, the Food and Drug Administration (FDA) said.

"Today, we are providing information for test developers about a streamlined path to emergency use authorization," the FDA said in a press release on Tuesday. "This [path] applies to developers of molecular and antigen tests, for use in serial testing programs, as well as at-home tests for use in a serial manner outside of a testing program."

Serial testing is used to detect asymptomatic coronavirus infections that fail to show up in a single test, the release said. The release noted that the US Centers for Disease Control and Prevention (CDC) recommends serial testing once a week, in addition to other coronavirus mitigation measures such as wearing facemasks and social distancing.

The FDA said that a test that performs well detecting the virus in symptomatic patients, when combined with serial testing, can likely mitigate the risk of false results in asymptomatic individuals.

Studies show that up to half of the people who test positive never develop symptoms, prompting concerns that asymptomatic spreaders provide a major source of coronavirus infections.