By ANNE FLAHERTY and JOSH MARGOLIN, ABC News

(WASHINGTON) — Americans who celebrated Thanksgiving with other people outside their household should assume they are infectious and a “dangerous to others,” the White House Coronavirus Task Force is warning in a startling new report obtained by ABC News.

Delivered Nov. 29 to the nation’s governors, but not released publicly, President Donald Trump’s top pandemic advisers said it’s up to state and local public health officials to alert the public as COVID-19 cases hit an all-time high.

The task force advises older Americans should be warned to stay away from indoor public spaces and to have groceries and medications delivered.

“It must be made clear that if you are over 65 or have significant health conditions, you should not enter any indoor public spaces where anyone is unmasked due to the immediate risk to your health.”

It tells young people to assume they are spreading the virus and putting other people at risk.

“If you are under 40, you need to assume you became infected during the Thanksgiving period if you gathered beyond your immediate household,” the task force wrote in a sweeping 413-page assessment of the pandemic.

“Most likely, you will not have symptoms; however, you are dangerous to others and you must isolate away from anyone at increased risk for severe disease and get tested immediately,” the group added.

The dire warnings come as cases continue to top 180,000 per day and COVID-19 patients crowd local hospitals. The numbers have alarmed public health experts who compare case numbers in early summer to 25,000 new cases per day.

While Americans have been urged to stay home for the holidays and cancel in-person gatherings, it’s likely many didn’t listen. While air travel was down about half of what it was in previous years, authorities reported checking millions of Americans through airports Thanksgiving weekend.

The White House itself has shirked public health warnings in favor of hosting its own indoor holiday gatherings.

“We are in a very dangerous place due to the current, extremely high COVID baseline and limited hospital capacity; a further post-Thanksgiving surge will compromise COVID patient care, as well as medical care overall,” the White House task force stated.

The task force, which includes Drs. Deborah Birx and Anthony Fauci, was convened by Trump earlier this year but is no longer in the public eye and has not briefed the public on the pandemic in months.

The group, however, issues weekly lengthy reports to the nation’s governors that tailor recommendations by state and analyzes local trends. The idea is that local leaders review these reports and make recommendations on testing and other public health measures like mask mandates.

In the Nov. 29 update, the report notably tells every state: “The COVID risk to all Americans is at a historic high.”

It also takes a swipe at governors and other local leaders who have played down the seriousness of the epidemic.

“If state and local policies to not reflect the seriousness of the current situation, all public health officials must alert the state population directly,” it states.

The report also calls for more widespread testing of people without symptoms but says that has to be combined with changing behavior.

Among the recommendations for states: “Ensure every American understands the clear risks of ANY family or friend interactions outside of their immediate household indoors without masks.”

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