Even before Air Force One touched down on July 31, the fallout was apparent: Five Secret Service agents already on the ground had to be replaced after one tested positive for the coronavirus and the others working in proximity were presumed to be infected, according to people familiar with the situation.

The previously unreported episode is one of a series of examples of how Trump’s insistence on traveling and holding campaign-style events amid the pandemic has heightened the risks for the people who safeguard his life, intensifying the strain on the Secret Service.

In the past two months, dozens of Secret Service agents who worked to ensure the security of the president and Vice President Pence at public events have been sickened or sidelined because they were in direct contact with infected people, according to multiple people familiar with the episodes, who spoke on the condition of anonymity to describe the incidents…

“Never before has the Secret Service run up against a president so intent on putting himself first regardless of the costs, including to those around him,” said Ned Price, a national security expert and former CIA analyst.