Those super spreaders are crazy, and it’s one of the most odd things about the virus. Many of Europe’s cases started with that guy who went to a ski resort. We’ve had two in GA that they believe are the root of most our state’s cases. We have the NY lawyer, and whoever attended that conference in Boston.
It was the first clue that asymptomatic cases were spreading this thing but some (*cough CDC cough*) refused to accept that.
There were people from Italy at that Biogen conference. They might have been asymptomatic, or they might have just decided to glad hand their colleagues while sick, since they flew across the ocean for that opportunitey.
It's worth noting that two days later there was a party in Princeton and two of the Boston conference attendees went there. They were local (Boston) so were presumably just infected at the Boston conference. One of the two (maybe both) managed to infect 12 out of 48 people in a single evening in New Jersey. My take is the upper respiratory infection (not the one the lower that kills people) happens very quickly and is very prone to spread with a sneeze or cough.
That party probably create a good chunk of the initial spread into central Jersey and eastern PA.