To be honest, I always get a bit irritated when people try to tell me that chickens will be the death of me. The only way that I would contract a chicken-borne disease is if I practiced really REALLY bad sanitation habits. Habits like never washing my hands after I touch them, drinking their uncooked blood (yes some people do this, it's how Avian Flu started), not cleaning thier coop often enough, etc.
People are so suprised when they get lazy with any kind of animal, and contract a disease. It's not the animal's fault if someone decides to skip precautions like wearing protective gear when cleaning, and not cleaning often enough. Disease and parasites are opportunistic... so don't give them the opportunity.
Case and point, Avian Flu exists here in Idaho because some yokel thought "hey, you know what would be cool to have? Alligators!", and didn't take any precautions whatsoever. The alligators were carrying Avian Flu from Florida mosquitos, and when the local mosquitos bit them, tada, the virus spread. Poor standards and poor practices will get you with ANY animal that you keep, not just chickens.
So.... can you get diseases from your chickens? Yep, you absolutely can. But it'll be your fault, not the fault of your birds.