DONALD TRUMP’S condition remains clouded by confusion over his treatment for coronavirus disease 2019 (COVID-19), with the president’s effort to show strength contradicted by conflicting accounts from his doctors that raise doubts about how soon he’ll be able return to work and his re-election campaign.

Mr. Trump made a surprise outing from Walter Reed National Military Medical Center on Sunday, waving to supporters gathered outside from his motorcade and saying in a video posted on Twitter that he’s learned a lot about virus. “I get it,” he said.

A member of his medical team, Brian Garibaldi, a pulmonary expert at Johns Hopkins University, said at a briefing on Sunday that the president could be released from the hospital as soon as Monday.

But the White House physician, Sean Conley, disclosed for the first time that he was given supplemental oxygen and has received a medication that’s typically used in more severe COVID-19 patients. That raises questions about the president’s condition as he heads into a phase of the illness where the health of some patients worsens suddenly and dramatically.

The questions about Mr. Trump’s treatment and recovery as well as demands for more complete disclosure about his health come amid the prospect of widening outbreak among White House and campaign staff and Senate Republicans, even as campaign aides predicted the president would soon be back on the campaign trail.

“We have to trust that what they’re telling us about the president’s condition is real,” House Speaker Nancy Pelosi said on CBS’s “Face the Nation,” adding that she’s getting details about Mr. Trump’s health from the press and alleging that Trump is approving the medical team’s public statements.

But Mr. Conley also revealed that Mr. Trump’s blood-oxygen saturation level dropped twice since his diagnosis, and that the president’s medical team decided to administer dexamethasone, a steroid used to treat inflammation in COVID patients. Asked about X-rays and CT scans of the president’s lungs, Mr. Conley said there were “some expected findings” but nothing “of any major clinical concern.”

“The president is not out of the woods,” said William Schaffner, an infectious disease doctor at Vanderbilt University. Mr. Trump’s doctor was “very evasive” in discussing what lung scans had showed, he said. The disease’s effects on patients’ lungs is often worse than is indicated by their outward symptoms. “It is kind of a stealth infection,” Mr. Schaffner added.

Asked why he didn’t disclose during Saturday’s briefing that Mr. Trump had received oxygen despite repeated questions about it, Mr. Conley said, “I was trying to reflect the upbeat attitude” of the team and the president.

“I didn’t want to give any information that might steer the course of illness in another direction, and in doing so, it came off that we were trying to hide something, which wasn’t necessarily true,” Mr. Conley said.

The president first tested positive after he returned from a fundraiser at his New Jersey golf resort on Thursday, White House Press Secretary Kayleigh McEnany told reporters on Sunday evening. Trump made an appearance on Fox News on Thursday night before disclosing on Twitter shortly after midnight on Friday that he had tested positive.

Trump campaign senior aide Jason Miller said on NBC’s “Meet the Press” on Sunday that Trump would soon be “ready to get back to the campaign trail,” and in a separate appearance on ABC’s “This Week,” Miller downplayed a new NBC-Wall Street Journal poll that showing Joe Biden, the Democratic nominee, leading Trump by 14 percentage points. The campaign is optimistic about Trump’s prospects in key battleground states needed to get to 270 electoral votes, he said.

But almost 3.3 million people have already cast ballots for the Nov. 3 election, according to data compiled by University of Florida professor Michael McDonald. David Gergen, a former White House aide to both Democrats and Republicans, said it’s unacceptable that the Americans public doesn’t know the full extent of Trump’s condition.

“The voters should have full information about the outlook for the president’s health before they cast a vote,” Mr. Gergen said on CNN.

Questions have also arisen about whether Trump’s White House and campaign events became super spreader locations for the virus. Hope Hicks, a top aide to the president; his campaign manager, Bill Stepien; his debate coach, former New Jersey Governor Chris Christie; and Republican Senators Thom Tillis of North Carolina, Mike Lee of Utah and Ron Johnson of Wisconsin have tested positive for coronavirus infection.

Scott Gottlieb, a former Food and Drug Administration commissioner, said on CBS it’s “likely” there will be additional COVID-19 cases stemming from the outbreak in the White House and among Republican lawmakers. — Bloomberg