FILE - In this Sept. 16, 2020 file photo, Senate Homeland Security and Governmental Affairs Committee Chairman Sen. Ron Johnson, R-Wis., speaks during the committee's business meeting where it will consider new subpoenas in the "Crossfire Hurricane"/Burisma investigation on Capitol Hill in Washington. Johnson says he tested positive for the coronarivus. Johnson’s office announced the diagnosis in a statement Saturday, Oct. 3. (AP Photo/Manuel Balce Ceneta, File)

MADISON, Wis. (AP) — Wisconsin Sen. Ron Johnson said Saturday that he tested positive for the coronarivus.

Johnson’s office announced the diagnosis in a statement Saturday morning. He’s the third Republican senator to report a positive test this week, joining Utah Sen. Mike Lee and North Carolina Sen. Thom Tillis and adding to tension in Washington since President Donald Trump announced his positive test Friday.

Johnson, a second-term Republican, reported being exposed to someone with COVID-19 last month and quarantined for 14 days without developing symptoms. He said he tested negative twice during that time. He returned to Washington on Tuesday and said he was exposed soon after that to someone else who tested positive. Johnson said he was tested Friday after learning of the exposure and tested positive.

Johnson told The Associated Press by phone on Saturday that he returned from Washington on Thursday and was quarantining at home in Oshkosh. He said he felt fine, with no symptoms. He said he decided to get a test after finding out about Lee caught the disease and was shocked it came back positive.

Asked whether his exposure may have come from other senators, Johnson said, “Possibly. ... Nobody knows. I was around all my colleagues.”

Johnson's spokesman, Ben Voelkel, said the senator was still in Wisconsin during quarantine and did not attend last Saturday's Rose Garden event in which Trump announced Amy Coney Barrett as his Supreme Court nominee. Several people who attended the event, including Lee, Tillis and former White House counselor Kellyanne Conway, announced positive tests this week.

Johnson said he learned of his positive result while driving home after speaking Friday evening at a Republican dinner in suburban Milwaukee. He said he wore a mask at the event except for when he delivered his speech. He also said he didn't shake hands or pose for photographs and left immediately afterward.

“I let people know why,” he said. “I'm not taking photographs, I'm not socializing, I'm not a prima donna, I need to stay healthy so I can provide a vote to confirm Amy Barrett."

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