Well, I let my 12 month old touch all the chicks and hens- supervised, of course. And all the other kids hold chicks and chase and catch the bigger pullets. The only thing I am picky about is that they remove their shoes before coming in the house- no exceptions. As for hand washing after holding, honestly, it doesnt happen every time- unless I see visible icky's.
I look at it this way- Thousands of children have grown up on poultry farms for hundreds of years, and still do. The vast majority of them lived to reproduce, mine will too. We try to be clean, and dont take serious risks- but heck, public school has waaaayyyy worse germs floating around in greater quantities than my little flock of chickens. I inspect my flock every few days for illness, (serious inspection, like looking at eyes, ears, feet, and listening to breathing) and check for mites, and bugs on a daily basis. We wash up before meals, but I just dont worry very much about chicken germs. How in the world does one stop a 3 year old from putting his finger in his nose after holding a chicken if you are more than 3 feet away holding another baby?
Guess I'm gonna be in the minority that doesnt worry that much about germs from my chickens.