President Donald Trump's coronavirus diagnosis came after a busy week running his administration and campaigning for November's election.
The president announced that he and his wife and his wife, Melania has tested positive for Covid-19, in a tweet sent on Friday at around 01:00 local time (05:00 GMT).
This followed a positive test for his close aide, Hope Hicks, who reportedly started feeling symptoms on Wednesday.
Since the president's diagnosis, several people close to him have tested positive too, including his press secretary.
So far the majority of publicly released results have been negative. However, test accuracy can vary depending on when a sample is taken during the course of the illness. One taken very soon after exposure may not give an accurate result.
The White House says it has begun contact-tracing. Here's a look at some of the people we know Mr Trump has crossed paths with during the last week - starting with an event that is being investigated as a possible "super-spreader":
Saturday, 26 September: The Supreme Court pick
President Trump announced his Supreme Court pick, Judge Amy Coney Barrett, in front of a crowd of about 200 people on the White House lawn.
Judge Coney Barrett said on Friday that she had tested negative. Sources told US media she had the virus earlier this year.
Along with Mr Trump and his wife, at least seven other people who attended the Rose Garden event say they have tested positive - although it's not known where they caught the virus.
They are: White House Press Secretary Kayleigh McEnany; former White House counsellor Kellyanne Conway; Senator Mike Lee of Utah and Senator Thom Tillis of North Carolina, who are both on the judiciary committee; the president of the University of Notre Dame, John Jenkins; and former New Jersey Governor Chris Christie, who said he checked himself into a hospital on Saturday as a precaution.
The White House Correspondents' Association said an unnamed reporter at the event had also tested positive with symptoms.
During the evening, President Trump held a rally at Harrisburg International Airport in Middletown, Pennsylvania.
Since the afternoon's ceremony, Judge Coney Barrett has held meetings with various senators - including Senate Majority Leader Mitch McConnell - ahead of her much-anticipated confirmation hearing, due to take place on 12 October.
Sunday, 27 September: Golf and a veterans' event
The president played golf at his club in Potomac Falls, Virginia, in the morning and led a White House reception for the families of military veterans during the evening.
Monday, 28 September: The Covid briefing
On Monday, President Trump held a news briefing in the White House Rose Garden - giving an update on his administration's coronavirus testing strategy.
It was attended by Vice-President Mike Pence, Health Secretary Alex Azar, Education Secretary Betsy DeVos, and the chief executive of Abbott Laboratories, Robert Ford, among others.
Later, Trump viewed a model of a new pickup truck - being built at a factory in Ohio - on the White House lawn. Representatives from the company, Lordstown Motors, attended, as well as two members of Congress.
The White House regularly tests officials who come in contact with the president. However, US media has noted that mask-wearing and social distancing around him is less common - suggesting that people may be too reliant on the testing system, which is not foolproof.
Tuesday, 29 September: Debate day
The president faced his election rival, Joe Biden, at their first face-to-face debate in Cleveland, Ohio on Tuesday evening.
President Trump flew there on his presidential plane, Air Force One, alongside his wife, adult children and multiple aides. Many were seen not wearing masks when boarding or disembarking.
Also on the plane were: White House Chief of staff Mark Meadows; campaign strategist Jason Miller; policy adviser Stephen Miller; Robert C O'Brien, the national security adviser who tested positive for the virus in July; and Ohio Congressman Jim Jordan.
After landing, the president's campaign manager, Bill Stepien, was spotted getting into a staff van with Ms Hicks, the New York Times reports. Late on Friday, it was announced that Mr Stepien had tested positive for Covid-19 and was experiencing mild flu-like symptoms.
The debate was held at Cleveland Clinic's Health Education Campus, a shared facility with Case Western Reserve University.
The organisers, the Commission on Presidential Debates, brought in numerous Covid-era safety precautions. There were no handshakes between the two candidates and everyone attending - including the 80 or so audience members - was tested before the event and asked to wear masks throughout.
In the run-up, Mr Trump's eldest daughter, Ivanka, posted a picture of herself backstage in a mask, alongside her sister Tiffany, sister-in-law Lara and stepmother Melania.
However, during the event itself, Ivanka Trump and other family members, including siblings Don Jr and Eric, were pictured mask-less. Moderator Chris Wallace has since told Fox News that they were offered masks by event staff but they refused them.
Observers said those on Mr Biden's side of the room kept their masks on.
Mr Trump and Mr Biden kept a distance during the debate, at podiums on opposite sides of the stage.
When the candidates were greeted by the wives on stage afterwards, Jill Biden wore a mask and Melania Trump didn't.
At a separate campaign event in Pennsylvania, Vice-President Mike Pence said he had been in the Oval Office with President Trump earlier that day. It is thought to be their last in-person meeting.
President Trump and much of his entourage flew back to Washington DC on Tuesday night.
Wednesday, 30 September: A fundraiser and a rally
The day after the debate, President Trump was straight back into campaign business, flying to Minnesota. Ms Hicks was among those accompanying him.
At a press conference on Saturday, the president's physician Dr Sean Conley said Mr Trump had been diagnosed 72 hours previously, which would place his diagnosis on Wednesday. But the White House later clarified that he was diagnosed on Thursday.
He attended a closed-door fundraiser at a private home in Minneapolis, and later held a rally at an airport in Duluth, in front of a crowd of thousands. Few wore masks but there was distance between them and the president.
Minnesota Congressman Kurt Daudt tweeted a picture of himself close to Mr Trump, with neither wearing masks.
It was an honor to greet President @realDonaldTrump as he arrived in Minnesota for his latest campaign visit.— Kurt Daudt (@kdaudt) September 30, 2020
The Trump campaign and @mngop have built an unprecedented ground game and Republicans are fired up to win in November! #mnleg #mngop pic.twitter.com/EXQZ6RkAgv
On Wednesday evening, Mr Trump and various aides returned to Washington DC on Air Force One again.
Meanwhile Ms Hicks, who was feeling unwell, was isolated in a separate cabin, according to US media. She reportedly disembarked from the back of the plane, instead of the front alongside the other passengers.
Thursday, 1 October: More fundraising
The following day, Ms Hicks tested positive for coronavirus.
President Trump flew to his Bedminster golf resort in New Jersey for a private fundraiser. Several aides who were in proximity to Ms Hicks scrapped their plans to accompany the president, according to the Associated Press.
Kayleigh McEnany, the White House press secretary, is thought to have been in close contact with Ms Hicks. Ms McEnany held a briefing for reporters at the White House on Thursday, without mentioning her colleague's test and without wearing a mask. She has since said she did not know about the diagnosis.
That night, in pre-taped remarks to the annual Al Smith dinner in New York City - held virtually this year - Mr Trump said that "the end of the pandemic is in sight".
He later announced in an interview on Fox News that he and the first lady were being tested for the virus.
It is not known how many supporters he came into contact with in recent days, he but told Fox presenter Sean Hannity that people were always wanting to get close to him. "They want to hug you, and they want to kiss you," he said.
Friday, 2 October: The announcement
President Trump announced that he and Mrs Trump had tested positive, adding that they will begin the "quarantine and recovery process immediately".
Just before 11:00, his chief of staff, Mark Meadows, told reporters the president has "mild symptoms" but remains in "good spirits".
Mrs Trump tweeted to say she also had mild symptoms.
That day, several other people announce that they've tested positive: Kellyanne Conway, former White House counsellor; Bill Stepien, Mr Trump's campaign manager; Mike Lee, Utah senator; Thom Tillis, a senator for North Carolina; Ronna McDaniel, chairwoman of the Republican National Committee; Rev John Jenkins, president of Notre Dame University; and Senator Ron Johnson, head of the Senate Homeland Security and Governmental Affairs Committee.
Meanwhile Joe Biden, the Democrats' presidential candidate, tests negative, as does: Jill Biden, his wife; Vice President Mike Pence and his wife Karen Pence; Kamala Harris, the Democrats' vice-presidential candidate; Amy Coney Barrett, Supreme Court nominee; Mike Pompeo, secretary of state; Steve Mnuchin, treasury secretary; Alex Azar, secretary of health and human services; William Barr, attorney general; Ivanka Trump and Donald Trump Jr, the president's daughter and son; and Jared Kushner, the president's son-in-law.
Saturday, 3 October
Former New Jersey governor Chris Christie and Nicholas Luna, a White House presidential aide, both test positive.
Sunday, 4 October: Trump greets supporters
Mr Trump waved to well-wishers from behind the glass of a sealed car after tweeting that he would pay a "surprise visit" to "patriots" outside the hospital.
Inside the car, at least two people could be seen wearing protective gear in the front seats, with Mr Trump sat in the back.
There were concerns that the president who wore a mask, may have endangered others inside the car. But White House spokesperson Judd Deere said the trip had been "cleared by the medical team as safe".
Monday 5 October
White House Press Secretary Kayleigh McEnany announces on Twitter that she has tested positive.