"With colder weather, more time spent indoors, the ongoing USA holiday season, and silent spread of disease, with approximately 50% of transmission from asymptomatic persons, the United States has entered a phase of high-level transmission where a multipronged approach to implementing all evidence-based public health strategies at both the individual and community levels is essential", the report said.
The CDC recommends that those following the new quarantine time periods check with their local health department to ensure that the local authorities have not issued different guidance. That could also mean multiple shorter periods of contact with a positive case.
"If you don't get tested, it's safest to stay home for 10 days".
For now, Canada is maintaining its 14-day quarantine. This recommendation reflects the virus' ability to incubate for a longer period before symptoms arise. "If you do travel, get tested 1-3 days before travel and 3-5 after, and minimize any movement between times".
Reducing the quarantine period from 14 to 10 days comes with a "residual risk" the person leaving early could transmit to someone else at between one to 12 per cent, according to CDC calculations.
The revised quarantine guidance says people who have been in contact with someone infected with the virus can resume normal activity after 10 days, or seven days if they receive a negative test result.
Smith said the CDC is permitting a negative result from either a molecular (PCR) or antigen rapid test. He said the agency still recommends 14 days, but is now offering two "acceptable alternative quarantine periods".
The CDC on Wednesday presented findings with options to reduce the required number of quarantine days for individuals with known exposure to a confirmed COVID-19 case, according to a news release.
The revision marks a significant change from the CDC's recommendations since the start of the pandemic earlier this year.
The head of the CDC, Dr. Robert Redfield, shared with CNN Health that these next three months will be the most hard time in public health that the country has seen. "I actually believe they're going to be the most hard in the public health history of this nation, largely because of the stress that's going to be put on our health-care system".
For the upcoming holiday season, the CDC is recommending people stay home - just as it did before the Thanksgiving holiday.