Despite the symptoms, Mr Trump flew to a rally in Pennsylvania as scheduled that evening, before the White House doctor called Mr Meadows to inform him of the news.
When Mr Meadows passed the news on to Mr Trump, the former president’s response “rhymed with: ‘Oh spit, you’ve gotta be trucking lidding me’,” the chief of staff wrote.
The sample was then re-run, returning a negative result the second time, which indicates an initial false positive. The public were not informed of this initial positive result.
“I didn’t want to take any unnecessary risks,” Mr Meadows writes, “but I also didn’t want to alarm the public if there was nothing to worry about – which according to the new, much more accurate test, there was not.”
On debate day, 29 September, Meadows says, Mr Trump looked slightly better, though he placed “emphasis on the word slightly”.
“His face, for the most part at least, had regained its usual light bronze hue, and the gravel in his voice was gone. But the dark circles under his eyes had deepened. As we walked into the venue around five o’clock in the evening, I could tell that he was moving more slowly than usual. He walked like he was carrying a little extra weight on his back.”
The host, Chris Wallace of Fox News, later said Mr Trump was not tested before the debate because he arrived late. Organisers, Mr Wallace said, relied on an honour system.
Mr Meadows’ memoir, titled All Seasons Press, is due to be published next week.