The US government was facing chaos on Saturday night after Covid-19 swept through the White House and the Senate halted legislative work for two weeks.
The decision to partially shut down the senate came after three Republican senators tested positive.
At the White House the focus turned to a possible "super-spreading" event, the Rose Garden ceremony on Sept 26 to announce the nomination of judge Amy Coney Barrett for the Supreme Court.
Anthony Scaramucci, the president's former communications director, said: "This is a wake-up call for the president and staff. You are going to come to a situation where the West Wing and the members of Congress are going to have more Covid-19 than the entire country of New Zealand due to this laxity."
Among the latest to announce being infected were Bill Stepien, Donald Trump's campaign manager, and Chris Christie, the former New Jersey governor. Mr Scaramucci added: "It's sad for me because a lot of these people are my friends. Hope [Hicks] is my friend. I wish her well. But it's also sad for the country because we put the country now in this dilemma where we've politicised the science, politicised the masks, politicised the health and wellbeing of the people in the country."
It came as reports suggest virus cases have risen in 33 US states since late August and more than a dozen states have seen an increase in sufferers taken to hospital over the last several days.
On Friday, Mr Trump was one of around 40,000 Americans who tested positive that day.
Eight months after the virus first reached the US, experts said there were worrying signs about what would happen through the autumn. The NFL postponed its first game because of a worsening outbreak among the Tennessee Titans team. Some hospitals in Wisconsin have run low on space as it reported a record daily death toll. And economists said it could take until late 2023 for the job market to fully recover.
Dr Reed Tuckson, board chairman of the Health Policy Alliance in Washington, said: "Every single American must double down on their vigilance. If we don't, then we are being foolhardy and irresponsible. The statistics are so mind-boggling, they make us numb to the reality of just how painful, unacceptable and absurd this is."
Iowa reported more than 1,000 new cases for the third consecutive day on Friday, and South Dakota health officials reported record highs in deaths and cases.
Dr William Schaffner, an infectious diseases expert at Vanderbilt University, said Mr Trump's diagnosis "reinforces the notion we need a national policy and we need everyone to participate in the basic preventions". The decision to postpone legislative work in the senate came after Ron Johnson, the Republican senator who heads the powerful homeland security and governmental affairs committee, tested positive.
His spokesman said Mr Johnson "feels healthy and is not experiencing symptoms" but will stay in isolation until he is cleared by a doctor.
The spokesman did not identify the infected person Mr Johnson came in contact with recently.
Two other Republican senators on the judiciary committee - Mike Lee from Utah and Thom Tillis from North Carolina - had already tested positive.
Mitch McConnell, the Republican Senate leader, said: "Previously-scheduled floor activity will be rescheduled until after Oct 19. The important work of the senate's committees can and will continue as each committee sees fit."
On Capitol Hill, testing and tracing had been offered, but was not required, for anyone who thought they may have been exposed to the virus.
Democrats in the Senate accused the White House of having been "cavalier" and said the Trump administration's approach to the virus "must not be allowed to adversely affect this branch of government".
In the House of Representatives, Republican leader Steny Hoyer said he had spoken with Nancy Pelosi, the Democrat Speaker, about increasing testing or making it mandatory.
Mr Hoyer said: "We haven't made a decision on that. In light of that we need to consult with our medical people."
The dilemma facing Congress remains similar to what confronts schools, churches, workplaces and the White House as the virus rampages across the US. Nationally and on Capitol Hill, there are no comprehensive plans requiring testing or wearing masks.
For months, leaders in Congress have resisted increasing the voluntary testing system, or accepting tests from the White House, saying supplies should go to front-line workers and the rest of America. The Capitol has been closed to visitors since March, and most offices and committee hearings are at least partially conducted virtually.
Patrick Maloney, a Democrat congressman, said: "I think it's time my colleagues who are denying the science to stop their flat-Earth nonsense and protect themselves and others."
Chris Murphy, another Democrat congressman, said: "Everyone in the Capitol complex needs to be tested. Every Republican senator or staff member who was in close contact with Trump needs to quarantine. No business should proceed in the Senate until we understand the scope of this crisis."
Meanwhile, Mr Trump's diagnosis sparked an explosion of rumours, misinformation and conspiracy theories on social media.
Facebook said it immediately began monitoring misinformation around the president's diagnosis and had started applying fact checks to some false posts.
Authorities in the city of Cleveland, Ohio, where the president and Joe Biden had held their televised debate on Tuesday, said they were aware of 11 Covid cases reported of people involved in the "pre-debate planning and set-up" and the "majority were among out-of- state residents".
They added: "At this time, though that could change, no city residents appear to have contracted the virus as a result of this event.
"Based on what we know about the virus and the safety measures we had in place, we believe there is low risk of exposure to our guests."
Emilia Strong Sykes, the leader of the Democrats in the Ohio House of Representatives, who was at the debate, went into self-isolation after Mr Trump's positive test, and criticised his entourage for not wearing masks.
Mr Christie checked himself into hospital on Saturday night after discussing his situation with doctors.
He tweeted: "While I am feeling good and only have mild symptoms, due to my history of asthma we decided this is an important precautionary measure."
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