The story making the rounds right now is that at least 1 person who attended CPAC (Conservative Political Action Conference), which is a multi-day event and ended on 2/29/20, has been confirmed to have the virus. Ted Cruz placed himself under voluntary quarantine until 14 days from the contact that he had with the individual (his contact was 10 days ago, so he is almost clear). His statement:
According to the WHO: https://www.who.int/news-room/q-a-detail/q-a-coronaviruses
So, it would seem quite plausible that the infected individual (who has not yet been outed, but is apparently a donor) was not a carrier during CPAC and was exposed in early March.
And if you guessed that the Leftists are being their usual, vile selves about the situation, you would be correct.