Pandemic: The Board Game

This achievement requires curing all four diseases on the second-highest difficulty setting.

I went with a three-person team consisting of the Scientist, the Researcher, and the Quarantine Specialist. The Scientist only needs four cards (instead of five) of the same color to cure a disease. The Researcher can give any of her cards to any other character sharing the same space. Use the Researcher to feed cards to the Scientist so the Scientist can cure diseases. You can use these two to keep nearby areas in check, but be sure to keep them in or within a turn of Atlanta and each other.

The Quarantine Specialist has the ability to stop a disease from increasing in or spreading to the city that she's located in as well as any adjacent cities (meaning there is a white line between them). Move the Quarantine Specialist around to cities in danger of having an outbreak, heal if needed to get them out of danger. Remember you can save moves and turns by using the cards she's holding to make a direct line to the city on the card.

Concentrate especially on areas where you have clusters of cities in danger of outbreaking (meaning they have three cubes of the same color) because if any one of them hits four, it'll start a chain reaction of outbreaks and may cause you to lose the game. Also concentrate on colors in danger of running out. If you run out of a particular color block, you lose.

You might have to play a couple of times. I failed a few times but eventually got the achievement.

What I Found Doesn't Work:

I tried using the Medic instead of the Quarantine Specialist, but found it didn't prevent the outbreak cascade problem as he can only go so far and heal only at most two cities at a time. I also tried the Dispatcher instead of the Quarantine Specialist, but ran into the same problem.

Lastly, I've seen guides recommending just a team of the Scientist and the Researcher, but I found that allows things to spiral out of control given the high number of epidemic cards, the apparent lack of event cards to keep things in check (at least I never saw any event cards), and the fact that this team works best when you keep them together in Atlanta. I failed multiple times trying this team.