Spreading out the venues means spreading out the transmission. You'll have 20000 people flying from country A to watch a match in country B, then they'll get on

Spreading out the venues means spreading out the transmission. You'll have 20000 people flying from country A to watch a match in country B, then they'll get on another plane together and fly to country C then some will go back home while others fly to country D for the knockouts. A single sick person and it could suddenly be a Europe wide epidemic. Throw in the drinking, the hugging and the tears that these occasions create and it's almost the perfect recipe to spread a virus. A lot could change by June though.