When does the Virulent Strain Epidemic effect for Hidden Pocket happen? The way the card is laid out, it would seem that it happens after the three epidemic steps; however, that would negate the effect as there would never be any cards in the discard pile. It could happen before step 1, but that could be pretty nasty and seems to go against the title of the effect, as "hidden pocket" would imply only a small amount of the disease.
When this situation arose in a game, resolving the effect before step 1 would have been pretty bad as there were a lot of cards in the discard pile. We chose to resolve the effect after the Infector phase, since there would only be a few cards in the discard pile, but that seems like a stretch.