(CNN) — White House chief of staff Mark Meadows has tested positive for coronavirus, according to two officials familiar with the matter, becoming the latest official in President Donald Trump's administration to become infected with the virus after a string of outbreaks in the West Wing.
Two other Trump staffers have also tested positive, officials said, lending further disquiet to an already-tense post-election White House.
Meadows, 61, told people after Tuesday's election that he had contracted Covid, but it wasn't clear when he first tested positive, according to the sources. In the past, he has appeared skeptical of coronavirus mitigation measures and has not often been seen wearing a mask.
He traveled with Trump aboard Air Force One during his final campaign swing on Sunday and Monday, accompanied the President on a visit to his campaign headquarters on Tuesday and attended a White House election night party where he came into close contact with members of the President's family. He was not seen wearing a mask during any of those engagements.
Later this week he has been intensely involved in plotting the President's post-election legal strategy, and has encouraged the President in his false claims that voter fraud could deprive him the presidency.
Meadows was on a conference call with the Trump campaign senior legal team and others on the campaign late this week, according to two sources familiar with the matter. Meadows dialed in while others were in a conference room, according to the sources.
Bloomberg was the first to report about the test.
The development came as White House officials were already contending with the increasing likelihood the President would lose the election to Joe Biden. Earlier in the day, officials described a frenzied atmosphere as the President's future remained in question. The discovery the building's top aide tested positive for coronavirus only added to the consternation.
"As if things weren't bad enough, now this," one official said.
Meadows' positive test comes about a month after Trump's own bout with the disease. Meadows spent three nights at Walter Reed National Medical Center alongside the President as Trump convalesced after experiencing serious symptoms.
At the same time, several other White House staffers tested positive themselves, including many who attended a Rose Garden ceremony for Trump's Supreme Court nominee and the team of aides who helped Trump prepare for his first presidential debate.
Meadows drew criticism from fellow aides for not communicating better about the scale of the outbreak at the White House. While the White House insisted it conducted contact tracing amid the spike in cases, many officials said they felt they had been left on their own to figure out how to proceed.
Meadows has encouraged officials to keep coronavirus cases quiet, hoping to avoid the appearance of widespread contagion inside the executive branch.
But his efforts have mostly fallen short. Last month, senior aides to Vice President Mike Pence revealed they, too, had become infected with coronavirus.
White House officials are now alarmed, given Meadows has been around other staffers while potentially contagious, one aide tells CNN.
One White House official who was around Meadows several times this week said they were not notified that he had tested positive, though staffers are being told that "contact tracing was done."
Meadows has been a leading skeptic inside the White House about the mitigation measures recommended by the coronavirus task force, viewing the panel as largely sidelined.
He acknowledged on CNN last month that the administration strategy is not to "control" the disease.
"We are not going to control the pandemic. We are going to control the fact that we get vaccines, therapeutics and other mitigation areas," Meadows told CNN's Jake Tapper on "State of the Union."
While not many details are known about Meadows' health, he is at increased risk for more severe Covid-19 symptoms based on his age.
The US Centers for Disease Control and Prevention says people in the 50-to-64 age range face four times greater risk of hospitalization and 30 times greater risk of death from Covid-19 than those age 18 to 29.
Men are more likely than women to suffer severe illness or die from coronavirus, according to the CDC.
CNN's Kate Bennett contributed to this report.