CDC publishes rationale for shorter isolation and quarantine


NEW YORK (AP) – The Centers for Disease Control and Prevention on Tuesday explained the scientific rationale for shortening its COVID-19 isolation and quarantine recommendations, and clarified that the guidelines apply to children as well as adults.

The CDC has also maintained that, for people who catch COVID-19, testing is not necessary to come out of five days of isolation – despite indications from other federal officials that the agency is reconsidering this.

The agency announced the changes last week, cutting isolation time in half for Americans who catch the coronavirus and have no symptoms or only brief illnesses. Isolation should only end if a person has not had a fever for at least 24 hours without using antipyretic drugs and other symptoms go away, the CDC added.

It also reduced the time it takes to quarantine close contacts from 10 days to five days.

CDC officials previously said the changes were in line with evidence that people with coronavirus are most contagious in the two days before and three days after symptoms appear.

Some experts wondered how the new recommendations came about and why they were changed amid a spike in cases largely due to the highly contagious variant of omicron. Some also expressed dismay that the guidelines allow people to leave solitary confinement without getting tested to see if they are still contagious.

On Tuesday, the CDC released documents designed to answer these questions – and more – about the latest recommendations. The new guidelines apply to schoolchildren as well as adults, the CDC said, responding to questions posed by school leaders across the country.

Outlining the scientific basis for the reviews, the agency said more than 100 studies from 17 countries indicate that most transmissions occur at the onset of an infection. The CDC acknowledged that the data came from research done when delta and other pre-omicronic variants caused the most infections. But the agency also pointed to limited early data from the United States and South Korea that suggests the time between exposure and onset of symptoms may be shorter for omicron than for earlier variants.

The CDC also questioned why it didn’t ask for a negative test before people came out of isolation.

On Sunday, Dr Anthony Fauci – the White House’s senior medical adviser – said the CDC was considering including the negative test as part of its guidance.

The agency said lab tests can show positive results long after someone has stopped being contagious, and a negative home test doesn’t necessarily indicate there is no threatens. That is why, the agency said, she recommended that people wear masks everywhere for five days after the isolation is over.

He was offering advice to those who have access to testing and want to get checked out before coming out of isolation.

Dr Eric Topol, director of the Scripps Research Translational Institute, accused the agency of confusing. He agreed that it was appropriate to shorten the isolation time, but only with testing.

“We have to come up with a strategy that limits the isolation time, but we don’t want it to be a strategy that increases the spread of the virus and unintentionally results in the circulation of the virus,” he said.

The CDC also suggests that people exposed to the virus be quarantined for five days, unless they have received boosters or have recently received their first doses of the vaccine. The agency said anyone exposed – regardless of their vaccination status – should be tested five days later, if possible.

The agency also admitted that many people were not following previous recommendations for isolation and quarantine anyway. Research suggests that only 25 to 30 percent of people self-isolate for 10 full days under the old leadership, the CDC said.


Associated Press writer Carla K. Johnson contributed to this report.


The Associated Press’s Department of Health and Science receives support from the Howard Hughes Medical Institute’s Department of Science Education. The AP is solely responsible for all content.

Copyright © 2022. All rights reserved. This website is not intended for users located in the European Economic Area.


Comments are closed.