“There’s probably several super spreader events mixed up in this one scenario,” said Susie Welty, a contact tracing expert and technical director of surveillance at the University of California, San Francisco.

Welty said the number of people Trump and Hicks exposed to the virus could have expanded well beyond the circle of close contacts. The pair attended several events over the past week drawing thousands of people. The list includes his top advisers, his campaign donors, his Democratic rival Joe Biden, and scores of his supporters…

Welty said it may have been “inevitable” that Trump and others in his inner circle became infected “because they were relying solely on testing to keep them safe” and shunning other tools – such as masks and distancing – that can prevent infection.

“It’s too late once you test positive,” she said. By that time, “you’ve already been around too many people and spread it to too many people.”