Several members of Congress have closed their Washington offices or gone into self-quarantine following positive diagnoses of the virus among staff members. Reps. Mario Diaz-Balart (R-Fla.) and Ben McAdams (D-Utah) were the first two members to test positive, on Wednesday.

Several members of the president’s immediate circle were potentially exposed to the virus last week at Trump’s Mar-a-Lago resort, where the White House hosted a delegation from Brazil, including President Jair Bolsonaro. Bolsonaro tested negative for the virus, but some of his aides have since tested positive — including one who was seated with Trump at a dinner at the resort.

The White House has also been shifting more of its work online to limit person-to-person contact, and many staffers have opted to work from home. Temperature checks are now in place for all those coming in contact with Trump and Pence, and several programs and tours have been canceled.

“In order to keep the entire White House complex safe and healthy, beginning Monday morning, temperature checks will be conducted on everyone who enters campus,” deputy White House press secretary Judd Deere said last week. “As was announced over the weekend, additional temperature checks will be conducted on individuals who are in close contact with the president and vice president throughout the day.”