Who's The Culprit?

Last Thursday, as you may recall, I spent the day taking care of my poor, sick little grandson, all runny with goo.

On Saturday, when we went to visit Mr. W's parents at their home in Florida, we discovered that his Dad wasn't feeling well.  He had a sore throat and a cough.

Yesterday, I woke up with a raging sore throat, a cough, and the sniffles.  Hmm ... who was the generous donor of their germs, do you suppose?