The possibilities are endless! I wonder if any intrepid investigative reporter is looking into local emergency room statistics. . .
There are reports of scabies at Occupy Portland. Maybe the itching and scratching will drive them out of there.
Typhoid is the most likely. Flies land on the human waste and then on the food and away they go.
In AZ, they have another matter. All it would take is for one of them to pick up a dead animal-rabbit, or whatever and they WILL DIE. Anyone from there can tell you what those can carry.