by Chuggas
Somebody else did this in an earlier forum. Spoilers for Forsaken cities:[o]Since you move cards from the Infection Discard Pile to the End Game area if the city is forsaken, if you have enough forsaken cities you could get through the entire Infection Deck between Epidemics without even accessing any other way to remove cards from the Infection Deck.[/o]
So yes this is possible, and yes every card in the Infection Discard pile gets reshuffled back into the Infection Deck. You reshuffle the Infection Discard Pile into the Infection Deck either:
a) As part of resolving an Epidemic Card.
b) If the Infection Deck is empty and you need to draw from the Infection Deck.
And minor nitpick about the Cairo recon:
[o]You get the Outrider upgrade when you Recon South America, which lets you Recon with 1 less card. So Cairo can be your 3rd Recon depending on how you are playing. OP may not yet know about the 30 card limit box or the Scientist.[/o]