US move to shorten Covid-19 isolation baffles medical experts

US Centres for Disease Control and Prevention facing pressure from public and private sectors to reduce risk of severe understaffing

The US Centres for Disease Control and Prevention's announcement to shorten the Covid-19 isolation time has baffled experts as the country sees another spike in cases. Reuters

US health officials’ decision to shorten the recommended Covid-19 isolation and quarantine period from 10 days to five is drawing criticism from some medical experts and could create more confusion and fear among Americans.

To the dismay of some authorities, the new guidelines allow people to leave isolation without being tested.

The guidance has raised questions about how it was crafted and why it was changed now in the middle of another wintertime spike in cases, this one driven largely by the Omicron variant.

Monday’s action by the US Centres for Disease Control and Prevention cut in half the recommended isolation time for Americans infected with the coronavirus but have no symptoms. The CDC similarly shortened the amount of time people who have come into close contact with an infected person need to quarantine.

The CDC has been under pressure from the public and the private sector, including Delta Air Lines, to explore ways to shorten the isolation time and reduce the risk of severe staffing shortages amid the Omicron surge. Thousands of airline flights have been cancelled over the past few days in a mess blamed on Omicron.

US CDC officials said the guidance is in keeping with growing evidence that people with the virus are most infectious in the first few days.

But some experts have questioned the new CDC guidelines.

“It’s frankly reckless to proceed like this,” said Dr Eric Topol, founder and director of the Scripps Research Translational Institute.

Louis Mansky, director of the Institute for Molecular Virology at the University of Minnesota, said the CDC probably did not include exit testing in its guidelines for logistical reasons: there is a run on Covid-19 rapid tests amid the spike in cases and the busy holiday travel season. In many places, at-home tests are difficult or impossible to find.

The US airline industry applauded the CDC move.

But the head of a flight attendants union criticised the change, saying it could lead businesses to pressure sick employees to come back before they are well.

If that happens, “we will make clear it is an unsafe work environment, which will cause a much greater disruption than any ‘staffing shortages,’” said Sara Nelson, president of the Association of Flight Attendants-CWA International.

Qamara Edwards, director of business and events for Sojourn Philly, which owns four restaurants in Philadelphia, said about 15 per cent of its employees are out sick with Covid-19, and staffing is tight.

The CDC changes are “great for businesses, they do allow people to return to work sooner than they’ve expected”, Ms Edwards said, though she understands why workers might be resistant and worried about their safety.

But Dana Martin, a Philadelphia teacher and educational consultant, said: “The looser Covid guidelines make me nervous. I’m more hesitant to participate in holiday activities because of the Omicron variant and the seemingly more lax protocols.’’

Marshall Hatch, senior pastor of New Mount Pilgrim Church on Chicago’s West Side, said he is bracing for some confusion in his congregation. The church has been a strong advocate for testing, vaccinations and booster shots.

“Either we’re in a surge that we need to take very seriously or are we winding down the pandemic and that’s why we’re shortening the isolation and quarantine times,” he said on Tuesday. “They might want to give us a little more information to go with.”

CDC revises Omicron cases projection

The Omicron variant was estimated to be 58.6 per cent of the coronavirus variants circulating in the US as of December 25, data from the CDC showed on Tuesday.

The agency also revised the Omicron proportion of cases for the week ending December 18 to 22 per cent from 73 per cent, citing additional data and the rapid spread of the variant that in part caused the discrepancy.

“We had more data come in from that time frame and there was a reduced proportion of Omicron,” a CDC representative said.

“It’s important to note that we’re still seeing a steady increase in the proportion of Omicron.”

The Delta variant, which had been the dominant strain in the past few months, accounted for 41.1 per cent of all US Covid-19 cases as of December 25, the public health agency's data showed.

The agency said the data includes modelled projection that may differ from weighted estimates generated at later dates.