When the bio-terrorist is eliminated from play (via the purple disease being eradicated), should they discard their current hand of infection cards to the infection discard pile?
The rules don't specifically say:
The Bio-Terrorist wins if the players lose and there is at least 1 purple cube on the board. The Bio-Terrorist immediately loses (and is out of the game) if the players eradicate the purple disease.
They are out of the game, but it doesn't say what to do with their cards. Personally, I would just have them discard the cards in their hand, since that should make it easier for the other players (a more diluted infection deck), and that is what normally happens when the Bio-Terrorist is captured.
Capture (special player action) - Place the Bio-Terrorist’s pawn on your role card. The Bio-Terrorist must immediately discard all cards in hand to the Infection Discard Pile (without eﬀect).