Labarynthitis
I was having a chat with a doc this afternoon and he mentioned that there is a virus doing the rounds at the moment that triggers labarynthitis. He has seen a number of cases in the past week. The symptoms are sudden bouts of extreme dizziness (vision can be affected). The infection can pass in as little as a matter of hours or in acute cases, the victim can be confined to bed for a few weeks as any movement can cause disorientation, chucking up your breakfast etc.
The good news is that direct human to human communication is unlikely.