President Donald Trump had contact with two Republican congressmen before their announcements Monday that they were entering self-quarantine after learning they had been previously exposed to someone since diagnosed with coronavirus.
Rep. Doug Collins of Georgia shook hands with Trump last Friday when the president traveled to Atlanta to visit the Centers for Disease Control and Prevention, where officials there briefed him on their response to coronavirus.
Rep. Matt Gaetz of Florida flew on Air Force One with Trump on Monday on a flight from Orlando, Fla., to Joint Base Andrews in Maryland.
The New York Times, citing two people with knowledge of the situation, reported that Gaetz learned shortly after the plane was airborne that he, like Collins, had been in contact with a person at the Conservative Political Action Conference in Maryland in late February who since has been diagnosed with coronavirus. Gaetz then sat in a section of the plane by himself, the newspaper reported.
Gaetz publicly revealed he was entering self-quarantining about an hour after he got off the plane with Trump.
Video footage shows Gaetz on the tarmac at Joint Base Andrews stepping backwards and raising his hand as if to keep a man approaching at a distance from him.
The White House said later Monday that Trump had not been tested for coronavirus.
"The President has not received COVID-19 testing because he has neither had prolonged close contact with any known confirmed COVID-19 patients, nor does he have any symptoms," Press Secretary Stephanie Grisham said. "President Trump remains in excellent health, and his physician will continue to closely monitor him."
She added: "Per current CDC guidelines, medical professionals should base testing decisions on patient symptoms and exposure history."
There is no need for Trump to self-quarantine because of his contact with Gaetz and Collins, according to Dr. Ali Khan, a professor in the Department of Epidemiology at the College of Public Health of the University of Nebraska Medical Center.
Khan told CNBC that people need to self-quarantine if they have "direct contact with a confirmed infected person, not contact with a contact."
Both congressmen said they had no symptoms of the virus.
Gaetz has been tested for the virus "and expects results soon," according to his tweets.
Collins did not say if he has been tested.
An aide to Collins told NBC News that in addition to the congressman, two staffers from his office are also self-quarantining.Â
 "This afternoon, I was notified by CPAC that they discovered a photo of myself and the patient who has tested positive for coronavirus," Collins said.
"While I feel completely healthy and I am not experiencing any symptoms, I have decided to self-quarantine at my home for the remainder of the 14-day period out of an abundance of caution," Collins said.
"I will follow the recommendations of the House Physician and my office will provide updates as appropriate."Â
In addition to Collins and Gaetz, two other House members, Reps. Paul Gosar, R-Ariz., and Julia Brownley, D-Calif., have said they entered self-quarantine because of concerns over exposure to coronavirus, as has Sen. Ted Cruz, a Texas Republican.
Gaetz appeared to mock concerns about coronavirus last Wednesday, the day that the House voted to pass an $8.3 billion emergency funding package to combat the spread of the disease.
Gaetz tweeted a picture of himself wearing a biohazard mask while looking at papers.
"Reviewing the coronavirus supplemental appropriation and preparing to go vote," Gaetz tweeted.
In a statement on Monday, Gaetz appeared to reference that prop.
"Congressman Gaetz had expected COVID-19 to impact Congress, given the elevated frequency of travel and human contact, and demonstrated his concern last week on the House Floor," the statement said.
After Trump's visit to CDC last Friday, Collins had said in a statement that, "President Trump, Vice President Pence, and our public health officials are taking bold action to prevent the spread of coronavirus and protect the health and safety of all Americans.
"After our briefing today, I can say with more confidence than ever before that the U.S. has the very best public health officials, and they're doing everything they can to fight coronavirus. I appreciate President Trump and Secretary Azar taking the time to visit Atlanta today, and I'm thankful to Dr. Redfield for providing us with an update. Because of their tireless leadership, our government is more prepared to combat this public health crisis."
- Additional reporting by CNBC's Meg Tirrell