Democrat Tawnja Zahradka challenges three-term Rep. Tom Emmer in the heavily Republican district.
Emmer says he has not been exposed to the staffers for several weeks.
The congressmen were exposed to COVID-19 on Air Force One.
U.S. Reps. Pete Stauber, Tom Emmer and Jim Hagedorn flew after being exposed to President Trump and others on Air Force One.
The damage is estimated at over $500 million.
A report says it was sent in his capacity as GOP congressional committee chair.