You all three should report it to the health department, they track outbreaks of food poisoning. This enables them to trace sources of contaminated food (in case whole lots of food need to be recalled, such as ground beef, unpastuerized juice, etc.). I'm not sure if you would report it to the department in your hometown or in the city where you landed, but calling your local dept., they should be able to tell you what action to take.

Also, once you get an authority involved, it will help you to recoup some sort of compensation for your illness from AA (I would think they should throw some miles your way at the very least, even though the caterer would be more liable).

Good luck!