WASHINGTON – A growing sense of concern and uncertainty about the reach of the novel coronavirus has begun to take hold in the White House, after an attendee at a recent political conference where President Donald Trump spoke tested positive for covid-19, the disease caused by the virus.

Trump was photographed shaking hands with Matt Schlapp, the chairman of the American Conservative Union who confirmed that he had been in direct contact with the infected man during the Conservative Political Action Conference last month.

The handshake at CPAC put Trump just two degrees of separation away from the virus that he has sought to minimize as it has rocked financial markets and tested his leadership skills. While the White House has maintained that Trump was never in direct contact with the infected person and is not suffering from any symptoms, the potential close call at a political event underscores how the outbreak threatens to upend the president’s routine as he campaigns for reelection.

There is growing tension among Trump administration officials, who now see the rapidly spreading outbreak as an event that could consume the president’s fourth year in office, even as Trump remains reluctant to see much cause for concern, according to White House officials who spoke on the condition of anonymity to describe the internal mood.

“I’m not concerned at all,” Trump said Saturday when asked about the potential threat posed to the White House by the coronavirus.

He also pledged to keep holding “tremendous” political rallies, even as top public health officials within his government have called for millions of Americans to avoid large crowds and major events to reduce the risk of being infected.

White House officials have said they expect the outbreak to spread significantly throughout the country in the coming days, dominating headlines and limiting the president’s ability to maintain his typical routine.

As Trump spent part of the weekend playing golf in West Palm Beach, Florida, top officials met in the Situation Room in what has become a daily briefing and strategy session amid the growing crisis.

The number of confirmed U.S. coronavirus cases has begun to rapidly increase in recent days, surpassing 500. One senior administration official said they expected that number to double by Tuesday. Others said they expected a surge in new cases that could strain the administration’s capabilities.

Concerns for the president’s personal health have also escalated as the death toll from the virus has risen, with most of the victims being senior citizens. Trump’s personal doctor, Sean Conley, now calls into the daily White House meetings on the coronavirus, tracking where new cases are being reported, one official said.

The White House is also being cleaned more regularly, and people with flu-like symptoms are being urged not to come into the complex, with the added warning that they may infect the leader of the free world, officials said. Changes to Trump’s travel schedule are also being contemplated after public health officials warned that elderly Americans should reconsider flying on airplanes and avoid large crowds.

Trump, 73, had no campaign rallies scheduled as of Sunday evening, marking the first time this year that there were no such events on the books.

Repeatedly visiting large crowds at political events could pose risks to the president, said Saskia Popescu, an epidemiologist with Honor Health, a Phoenix hospital system.

“Any time you’re coming into contact with a lot of people and engaging in handshaking and close contact, yes, you are more potentially at risk,” she said.

The White House said Saturday that Trump had not had any contact with the infected person at CPAC, and Trump’s campaign said the president would hold additional rallies when he was ready.

Trump is eager to hold more rallies and has been frustrated that the outbreak has dominated the news cycle, according to senior administration officials. The president has lashed out at Democrats for criticizing his handling of the crisis and repeatedly urged Americans not to be too concerned, while downplaying the seriousness of covid-19.

Schlapp said he had been in touch with administration officials throughout the weekend after learning that coronavirus was present at the conference many of them attended.

“What we’ve ascertained from having literally thousands of interactions with attendees and people associated with the conference and government officials is there is no indication of any sick people or new cases,” he said. “To date, this seems extremely isolated with one sick person.”

Schlapp confirmed that he had personally interacted with the infected man, whose name has not been released, early in the four-day conference. He greeted Trump, Vice President Mike Pence and several other senior administration officials after what he described as a brief interaction with the infected attendee.

Schlapp said he used hand sanitizer regularly during the conference and had not had any symptoms before or after shaking hands with Trump. He said he has been in touch with his own doctor and with the infected patient, who is being quarantined in New Jersey.

Sen. Ted Cruz, R-Texas, said in a statement Sunday that he “briefly interacted” with the infected person while at CPAC and would self-quarantine at his Texas home “out of an abundance of caution.” He said he does not have any symptoms associated with the virus.

The American Conservative Union said in a tweet late Sunday that it was “good advice” for attendees to take their temperatures twice a day and contact the Maryland Department of Health if they develop symptoms.

White House officials said there was not widespread concern among Trump’s aides about the CPAC case. Although many Cabinet officials and White House aides attended the conference, they were shown pictures of the coronavirus patient and none said they recalled interacting with him, officials said.

Several other conferences and events have been canceled for fear that an infected person might attend and spread the virus to others, including high-ranking officials. The American Israel Public Affairs Committee announced that two people from New York who attended the organization’s massive policy conference in Washington last week tested positive for the virus.

Political campaigns are also beginning to reconsider whether to hold major rallies and events.

Josh Michaud, associate director for global health policy at the Kaiser Family Foundation, said all of the candidates running for president need to recognize that local officials may decide at some point that having large crowds gather could fuel the spread of covid-19 in their communities.

“That would certainly be a risk for the campaigns to think about,” he said.

But with the president pushing to stage more political rallies, the Trump administration has struggled to send a consistent message to the public about whether large gatherings are a good idea.

In an interview on CNN on Sunday, Surgeon General Jerome Adams said older Americans and those with underlying health issues should avoid large crowds and think twice about air travel. When asked whether Trump should stop traveling for rallies, Adams said the septuagenarian president was “healthier than what I am.”

Adams, who is more than 25 years younger than Trump, walked back his comments later Sunday.

“Comparisons are always difficult and often fall short of telling the full story,” he wrote on Twitter. “I could have said this better.”

The inconsistent messaging is driven in part by a president who has been reluctant to acknowledge the scope of the crisis facing the country. Some of Trump’s conservative allies have also spent weeks playing down the threat of the outbreak, including many who attended the CPAC event.

Trump’s outgoing acting chief of staff, Mick Mulvaney, used his remarks at the event to urge Americans to turn off the television, arguing that there was too much coverage of the coronavirus. Other CPAC attendees, including Trump’s son Donald Trump Jr., Rep. Matt Gaetz, R-Fla., and media host Sean Hannity, have also mocked the level of concern over the virus. Such comments have faded as the virus has spread to more than 30 states, killing at least 21 people.

Schlapp, who has contacted many CPAC attendees to inform them of potential risks posed by the coronavirus case at the conference, said he wants to move away from the “hot rhetoric” about the outbreak and focus on bipartisan solutions.

“I’m hoping that this is a time when the donkey and the elephant can work together,” he said, referring to the symbols representing Democrats and Republicans.

One of the most difficult questions facing lawmakers and the Trump administration is whether they will be willing to financially support large-scale school or business closures. While these steps could curb the virus’s spread, according to experts, they could lead to major economic and social disruptions. And for Trump, it would mark a sharp departure from how he’s approached the outbreak so far.

Scott Gottlieb, who headed the Food and Drug Administration between May 2017 and April 2019, said on CBS’s “Face the Nation” that policymakers needed to provide generous funding to state and local governments immediately so they could take more drastic measures to limit Americans’ exposure to the disease.

“Well, I think no state and no city wants to be the first to basically shut down their economy,” Gottlieb said, referring to Democratic Washington Gov. Jay Inslee’s reluctance to say whether he’s willing to impose a mandatory quarantine in affected areas such as Seattle. “But that’s what’s going to need to happen. States and cities are going to have to act in the interest of the national interest right now to prevent a broader epidemic.”

Gottlieb, who said that he is “still having discussions with people in the administration,” emphasized that federal officials would have to provide economic incentives to get state and local officials to undertake such measures.