The announcement comes less than 24 hours after Andrew Giuliani reportedly attended a press conference held by his father and others at the Republican National Committee headquarters in Washington, D.C.
"This morning, I tested positive for COVID-19," Andrew Giuliani tweeted. "I am experiencing mild symptoms, and am following all appropriate protocols, including being in quarantine and conducting contact tracing."
According to CNN, Andrew Giuliani works in the White House Office of Public Liaison and was at the Rose Garden event last Friday.
The New York Times reported that Andrew Giuliani was in the room at Thursday's press conference where his father alleged without evidence that there had been a widespread Democratic election conspiracy involving multiple states and suspect voting machines.
Jenna Ellis, one of the other attorneys involved in Thursday's press conference, tweeted Friday afternoon that she and Rudy Giuliani had both tested negative for coronavirus. She added they will "continue to follow the advice and protocols of our doctors."
In recent month, the White House and the Trump administration has been impacted by a number of outbreaks of coronavirus cases. On Thursday night, a Pentagon official installed in a top policy job last week tested positive for COVID-19.
White House chief of staff Mark Meadows tested positive after attending an election night party at the White House. Others who were at the party also tested positive, including White House political director Brian Jack, former White House aide Healy Baumgardner and Trump campaign advisers David Bossie and Corey Lewandowski. Lewandowski said he believed he contracted the virus in Philadelphia while assisting the president’s election challenge there.
Trump himself was treated at Walter Reed National Military Medical Center in October when he contracted the virus. Others in Trump’s orbit who have tested positive include his wife, Melania, his son Barron, press secretary Kayleigh McEnany and advisers Stephen Miller and Hope Hicks.