Campaign spokesman Tim Murtaugh has confirmed the news, which was first reported by Politico.
Politico said Stepien received his diagnosis Friday and is experiencing “mild flu-like symptoms.”
Ronna McDaniel, the chairwoman of the Republican National Committee, also announced Friday that she had tested positive, joining Trump, the first lady, top Trump aide Hope Hicks and numerous others.
Stepien, who joined Trump at Tuesday’s first presidential debate, plans to quarantine until he recovers.
Trademark and Copyright 2021 The Associated Press. All rights reserved.