Six White House aides, including Trump’s chief of staff, have the coronavirus.

Mark Meadows, the White House chief of staff, has contracted the coronavirus, as have five other White House aides and a Trump campaign adviser, officials say, raising fears of another outbreak sweeping through the ranks of the nation’s top officials.

A Trump campaign adviser, Nick Trainer, along with four White House officials also tested positive for the virus, people close to the administration told The New York Times on Friday.

The diagnoses came as the pandemic rampaged across the United States, which has recorded an average of more than 100,000 new cases per day over the past week and hit another record on Friday, with more than 132,700 cases in a single day. The country also recorded more than 1,220 deaths.

Mr. Meadows, who abided by President Trump’s efforts to play down the coronavirus throughout the summer, is only the latest in a string of people in the president’s circle to contract the virus in the past seven weeks. Others include Mr. Trump himself and the first lady, Melania Trump, and several aides to the president and Vice President Mike PenceJoseph R. Biden Jr., who was elected the 46th president of the United States on Saturday, made criticism of Mr. Trump’s pandemic response a central feature of his campaign. Since Election Day, Mr. Biden has been briefed on the pandemic by economic and health advisers.

In a brief speech on Friday night, Mr. Biden vowed to control the virus and noted that the Covid-19 death toll in the United States was approaching 240,000.

“That’s 240,000 empty chairs at kitchen tables and dining room tables all across America,” he said. “We’ll never be able to measure all that pain and the loss, the suffering, that so many families have experienced.”