Mick Mulvaney self-quarantines following possible coronavirus exposure

Mick Mulvaney, the outgoing acting White House chief of staff, is under voluntary self-isolation after his niece, who lives with him Washington, D.C., came in contact with one of the Brazilian officials who tested positive for the coronavirus, a senior White House source confirmed.

Mulvaney, currently in his home state of South Carolina, tested negative on Friday and was exhibiting no symptoms, so White House doctors approved his travel plan to fly to the Palmetto State commercially, multiple sources told ABC News.

Maggie Mulvaney interacted with Brazilian press secretary Fabio Wajngarten at President Donald Trump’s Mar-a-Lago resort over a week ago. Wajngarten and other members of the Brazilian delegation who visited the West Palm Beach club have since tested positive for the coronavirus. She's a Republican fundraiser who now works on the Trump campaign's finance team.

Over the weekend, the Trump campaign conducted a deep cleaning of its sprawling D.C.-area offices, in part due to the interaction between the Brazilian officials and Maggie Mulaney. She has been tested for the virus and is awaiting results, and she's maintained a self-quarantine since last week, multiple sources told ABC News.

White House press secretary Stephanie Grisham also is working from home out of an "abundance of caution," a person familiar told ABC News, after she also met with the Brazilian delegation. Grisham said she's "feeling great and looking forward to returning to the White House." It's not clear if she's been tested for the virus.

Republican National Committee Chairwoman Ronna McDaniel, who attended an event with the president at Mar-a-Lago on March 6, was tested after exhibiting a fever and flu-like symptoms. She's self-quarantining while awaiting results, a spokesperson for the RNC said in a statement Saturday.

The president announced he tested negative for the virus on Friday. Vice President Mike Pence has not yet been tested.

Trump's reelection team told staff on Monday night to work from home until the end of March, after initially informing staffers they could return Tuesday after the cleaning, a senior campaign official told ABC News.

The Trump campaign and Republican National Committee have said they're shifting in-person campaign events online because of the outbreak.