UPDATE: Trump says he's leaving hospital for White House, feels good

In this image from video, President Donald Trump drives past supporters gathered outside Walter Reed National Military Medical Center in Bethesda, Md., Sunday, Oct. 4, 2020. Trump was admitted to the hospital after contracting COVID-19. (AP Photo/Phillip Crowther)
In this image from video, President Donald Trump drives past supporters gathered outside Walter Reed National Military Medical Center in Bethesda, Md., Sunday, Oct. 4, 2020. Trump was admitted to the hospital after contracting COVID-19. (AP Photo/Phillip Crowther)

BETHESDA, Md. (AP) -- President Donald Trump said Monday he's leaving the military hospital where he has been treated for COVID-19 and will continue his recovery at the White House He said he's feeling good and the nation should not be afraid of the virus that has killed more than 209,000 Americans.

Trump's expected return comes as the scale of the outbreak within the White House itself is still being uncovered. Press secretary Kayleigh McEnany announced she had tested positive for the virus Monday morning and was entering quarantine.

"I will be leaving the great Walter Reed Medical Center today at 6:30 P.M.," Trump tweeted. "Feeling really good! Don't be afraid of Covid. ... I feel better than I did 20 years ago!"

He is expected to make the journey aboard the presidential helicopter, Marine One.

It was unclear how long Trump would remain in isolation at the White House. According to the Centers for Disease Control and Prevention, those with mild to moderate symptoms can be contagious for as many -- and should isolate for at least -- 10 days.

On Sunday afternoon, Trump briefly ventured out of the hospital while contagious to salute cheering supporters by motorcade -- an outing that disregarded precautions meant to contain the virus.

White House officials said Trump was anxious to be released after three nights at Walter Reed National Military Medical Center, where doctors revealed on Sunday that his blood oxygen level had dropped suddenly twice in recent days and that they gave him a steroid typically only recommended for the very sick.

Trump "is ready to get back to a normal work schedule" and was optimistic about a Monday release, White House chief of staff Mark Meadows told Fox News. He said a determination would be made after further evaluation by his medical team later Monday.

The president surprised supporters who had gathered outside the hospital, riding by Sunday in a black SUV with the windows rolled up. Secret Service agents inside the vehicle could be seen in masks and other protective gear.

McEnany spoke briefly with reporters Sunday evening without wearing a mask, but said that no members of the White House press corps spent enough time around her to be considered close contacts.

Joe Biden's campaign, meanwhile, said the Democratic presidential nominee again tested negative for coronavirus Sunday. The results came five days after Biden spent more than 90 minutes on the debate stage with Trump. Biden, who has taken a far more cautious approach to in-person events -- and has been mocked repeatedly for it by Trump -- had two negative tests on Friday.

Even before Trump's motorcade outing on Sunday, some Secret Service agents had expressed concern about the lackadaisical attitude toward masks and social distancing inside the White House, but there isn't much they can do, according to agents and officials who spoke to The Associated Press. This close to the election, thousands of agents are engaged on protective duty so they can be subbed out quickly should someone test positive.

According to CDC guidelines, in general, transport and movement of a patient with suspected or confirmed infection of the virus that causes COVID-19 "outside of their room should be limited to medically essential purposes."

In all, nearly 7.4 million people have been infected in the United States, and few have access to the kind of around-the-clock attention and experimental treatments as Trump.

Trump's treatment with the steroid dexamethasone is in addition to the single dose he was given Friday of an experimental drug from Regeneron Pharmaceuticals Inc. that supplies antibodies to help the immune system fight the virus. Trump on Friday also began a five-day course of remdesivir, a Gilead Sciences drug currently used for moderately and severely ill patients. The drugs work in different ways -- the antibodies help the immune system rid the body of virus, and remdesivir curbs the virus' ability to multiply.

The steroid's use has only been proven to help in more serious cases. Among the concerns with earlier use is that steroids tamp down certain immune cells, hindering the body's own ability to fight off infection.

First lady Melania Trump has remained at the White House as she recovers from her own bout with the virus.

This article was updated at 2:10 p.m. Oct. 5, 2020, with new information.