Unnamed officials told The Washington Post that those with flu symptoms were being warned that they could cause President Donald Trump to catch the virus should they fail to keep away from the White House as more than 500 cases of infection were recorded across the United States.

President Trump’s personal doctor Sean Conley is also attending select White House meetings on coronavirus and COVID-19, according to the Post, which noted that he was attending the briefings to keep tabs on newly reported cases of infection.

The newspaper further reported that the White House was considering making changes to the commander-in-chief’s travel schedule following a top health expert’s warning that elderly and ill Americans should avoid large crowds as well as getting aboard airplanes and cruise ships.

Newsweek has contacted the White House for comment and will update this article with any response.

At the time of writing, the president’s public schedule shows that he is due to fly from Florida to Washington D.C. later today.

The Washington Post’s reporting on White House measures taken to prevent COVID-19 spreading in the building came after two Republican congressmen announced they were self-isolating following brief interactions with a Conservative Political Action Conference (CPAC) attendee who tested positive for the new virus.

Sen. Ted Cruz (R-TX) and Rep. Paul Gosar (R-AZ) both shook hands with the individual at the conservative gathering held in late February, but neither congressman has exhibited symptoms of the virus.

In a statement released on Sunday, Sen. Cruz said: “I’m not experiencing any symptoms, and I feel fine and healthy. Given that the interaction was 10 days ago, that the average incubation period is 5-6 days, that the interaction was for less than a minute, and that I have no current symptoms, the medical authorities have advised me that the odds of transmission from the other individual to me were extremely low.”

But he later added that he would be self-isolating “out of an abundance of caution” despite not meeting Centers for Disease Control and Prevention (CDC) criteria for quarantine.

“I have decided to remain at my home in Texas this week, until a full 14 days have passed since the CPAC interaction,” he added.

In a statement posted on social media last night, Rep. Gosar said he would be under self-quarantine, along with three of his staffers, after having contact with the individual.

“We are all asymptomatic and feel great,” the congressman said. “But we are being proactive and cautious.”

The latest CPAC conference was also attended by President Trump, Vice President Mike Pence, Secretary of State Mike Pompeo and other administration officials.

Trump did not have direct contact with the infected attendee, but was pictured shaking hands with American Conservative Union chair Matt Schlapp at the conference. The ACU leader told Fox News on Sunday that he had “incidental” contact with the COVID-19 patient.

The White House released a statement, published by Politico on Saturday, saying that there was “no indication” the president or vice president were in close proximity to the infected person while at CPAC.

A statement released by the ACU on Sunday encouraged the conference’s attendees to watch out for “unusual symptoms” and check their temperatures twice a day.

“We continue to remain in close contact with the infected individual and he continues to be doing better,” the group added. “Also, at this point, no other CPAC attendee, participant or staff has tested positive for coronavirus.”

The number of COVID-19 cases in the United States escalated over the weekend, with more than 500 reported as of 7:45 a.m. ET today. At the time of writing, 22 people in America had died as a result of contracting the virus.

Confirmed cases of COVID-19 worldwide surpassed 111,000 this morning according to the Johns Hopkins tracker. A total of 3,892 deaths had been reported, compared to 62,373 cases of total recovery.