President didn't disclose 1st positive test, sources say

The president had already tested positive Thursday when he appeared on Fox News.

ByMatt Zarrell, Jon Haworth, Ivan Pereira, and Marc Nathanson
Last Updated: October 5, 2020, 7:58 AM EDT

President Donald Trump's condition is continuing to improve as he fights a coronavirus infection, doctors say, and he may be able to leave Walter Reed Medical Center as early as Monday -- even as details emerge that the president allegedly initially tested positive for COVID-19 earlier than he acknowledged.

Doctors also reported that Trump, over the course of exhibiting coronavirus symptoms, had earlier experienced two episodes of "transient drops" in his oxygen saturation.

Yet the president was feeling well enough Sunday evening to briefly leave Walter Reed for a surprise drive-by, waving to supporters outside the hospital.

Meanwhile, numerous questions remain about how many people at the highest levels of government had been exposed to the virus after a week of events involving the president where social distancing and mask-wearing were lax in the White House and elsewhere.

Sunday's headlines:

Here is how the news developed on Sunday. All times Eastern.
Oct 04, 2020, 2:27 PM EDT

More on steroid treatment given to Trump

Doctors treating President Trump announced that he has been given the steroid Dexamethasone to combat symptoms of the coronavirus.

Dexamethasone, a steroid treatment, is seeing positive results in some patients.

A study in the United kingdom in June found that dexamethasone increased survival in severely ill COVID-19 patients who needed help breathing.

Trump's condition is improving, doctors say, but he did have two episodes where his oxygen levels dropped.

Prescribing dexamethasone for President Trump may be appropriate considering he received oxygen at some point during his illness.

"It's a borderline indication within the physicians prerogative," said Dr. William Schaffner, professor of preventative medicine in the Department of Health Policy as well as professor of medicine in the Division of Infectious Diseases at Vanderbilt University School of Medicine in Nashville, Tennessee.

Although the U.K. study appeared promising, dexamethasone only was demonstrated to help patients who have severe COVID-19 and need help breathing, through ventilation or oxygen assistance. The steroid treatment has not been proven to help people with a more mild COVID-19 illness, which accounts for most cases.

In fact, it may not be safe to use in patients with mild illness. In the U.K. study, dexamethasone "non-significantly increases death if used in milder patients with COVID-19," said Dr. Todd Ellerin, director of Infectious Diseases at South Shore Health. He warned that for patients with milder COVID-19 illness "the risks of the medication likely outweigh the benefits."

-ABC News' Sony Salzman contributed to this report

Oct 04, 2020, 1:50 PM EDT

Masks mandatory at White House for NSC staff

White House national security adviser Robert O'Brien while speaking to reporters at the White House on Sunday announced that mask wearing is now mandatory for National Security Council staff.

"We made mask wearing mandatory for National Security Council staff," O'Brien said.

Mask wearing was previously voluntary.

-ABC News' Elizabeth K. Thomas

Oct 04, 2020, 1:40 PM EDT

Pence, wife negative for COVID-19

Vice President Mike Pence and second lady Karen Pence again have been tested Sunday for the coronavirus and received negative test results, a White House official told ABC News.

President Donald Trump and Vice President Mike Pence arrive in the Rose Garden to speak on Covid-19 testing at the White House in Washington, D.C., Sept. 28, 2020.
Mandel Ngan/AFP via Getty Images, FILE

This is the third day since President Donald Trump's coronavirus diagnosis that they have received a negative test result.

-ABC News' Elizabeth K. Thomas

Oct 04, 2020, 1:33 PM EDT

Pelosi has not been updated on Trump's condition

House Speaker Nancy Pelosi, D-Calif., in an appearance on CBS's "Face the Nation" on Sunday, said she still hasn't heard from the president's team regarding his condition or any continuity of government matters.

"We're getting our information the way everyone else is: in the media. But in terms of the succession, that's an ongoing process. Sadly, at this time, it comes to the forefront," she said.

House Speaker Nancy Pelosi participates in a news conference at the U.S. Capitol in Washington, Oct. 1, 2020.
Erin Scott/Reuters

Amid calls to improve the testing system available to lawmakers and Capitol Hill denizens after this week, Pelosi said she has confidence in the recommendations of the Office of the Attending Physician of Congress -- noting that the sheer number of people working on the Hill (approximately 20,000 employees of all kinds) would pose a challenge for testing.

"There could be some sampling. Let’s depend on science on how deal with it," she said.

-ABC News' Benjamin Siegel