Another of US President Donald Trump's top aides has tested positive for the coronavirus, as the cluster of infections connected to the White House continues to grow.
Stephen Miller, a senior policy adviser to the president, announced his diagnosis in a statement today
"Over the last five days I have been working remotely and self-isolating, testing negative every day through yesterday," he said.
"Today I tested positive for Covid-19 and am in quarantine."
His diagnosis brings the number of infections linked to Trump to well over 20. The list now includes:
• First Lady Melania Trump
• Trump campaign manager Bill Stepien
• Press secretary Kayleigh McEnany
• Former White House adviser Kellyanne Conway
• Communications adviser Hope Hicks
• Republican National Committee chairwoman Ronna McDaniel
• Former New Jersey governor Chris Christie
• Senator Mike Lee
• Senator Thom Tillis
• Senator Ron Johnson
• Pastor Greg Laurie
• Notre Dame President John Jenkins
• Three deputy press secretaries
• Three White House reporters
• Two housekeeping staff from the White House residence
• The president's bodyman, Nick Luna
• Two military aides to Trump, including his valet.
Many of those people were at a suspected "superspreader" event in the White House's Rose Garden last month, where Trump announced he was nominating Judge Amy Coney Barrett to replace Justice Ruth Bader Ginsburg on the Supreme Court.
The event involved no social distancing, and guests were told they could remove their face coverings after they tested negative on their way in.
But as Miller's diagnosis shows, a negative test is not definitive proof that someone is free of the virus, particularly when they have only recently been exposed to infection.
That is because of the coronavirus's incubation period.
As Dr Alan Wells from the University of Pittsburgh Medical Centre told The Associated Press on Tuesday, a negative test less than seven days after exposure is "a very, very poor indicator of whether you have the virus on board".
"That is why, if you have had a credible exposure, you should wear a mask and you should self-quarantine," Wells said.
A negative test is more likely to be accurate between seven and 10 days after exposure.
To Miller's credit, he did self-quarantine, which means he is relatively unlikely to have spread the virus to anyone else.
Kayleigh McEnany, who announced her diagnosis yesterday, did not take that step even though she had been in close contact with Hope Hicks, who was the first White House staffer to test positive.
The press secretary continued to go to work, citing the negative test result she was returning each day. And she held press gaggles with reporters on both Friday and Sunday without wearing a mask.
That was in keeping with McEnany's broader practice of going maskless during official White House media briefings throughout the pandemic.
Speaking to Fox Business on Wednesday, McEnany denied the Rose Garden ceremony was necessarily a superspreader event.
"There's no way to say where this originated," McEnany said.
"Certainly several people who tested positive were at that event, but many of these individuals interact on a daily basis, certainly when it comes to White House staff."
Then there is the behaviour of Donald Trump himself.
After returning to the White House from his stint at Walter Reed Medical Center yesterday, the first thing Trump did was remove his face mask, even though there were staffers in the near vicinity.
He filmed a video message on the White House balcony, then walked inside, still maskless and still infectious.