President Donald Trump, Vice President Mike Pence and other administration officials attended the conference, though the ACU says the attendee did not come into contact with the president or vice president, nor did they attend events in the main hall.
The ACU said the Trump administration "is aware of the situation."
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"The exposure occurred previous to the conference. A New Jersey hospital tested the person, and CDC confirmed the positive result," ACU said in a statement. "The individual is under the care of medical professionals in the state of New Jersey, and has been quarantined."
The ACU noted that it has been in contact with the state of Maryland's health department and would follow guidance from health experts.
"Our children, spouses, extended family, and friends attended CPAC. During this time, we need to remain calm, listen to our health care professionals, and support each other. We send this message in that spirit," ACU said in a statement.
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