The chicken lice won't spread to humans, they are species specific. You can dust the chickens with sevin dust 5% powder which you can get at home depot or other places like that. It is for gardens and such but works well for the chickens. I just used it and my birds have no more lice. You have to dust twice, do it once then a week or two later because it doesn't kill the lice eggs and you have to get the ones that hatch after. You could also use Diatomaceous Earth which is natural, but it MUST be food grade (not the DE that you get for pools). You can get DE at most local feed stores. You also have to clean and dust with whatever product you get in and around the coop.
Another way that I used once and then decided I was just going to dust was to bathe the chickens in a mixture of salt water, vinegar and dawn dish detergent. I did that and it really worked to kill the lice, but I had to blow dry the birds afterwards because it was cold and that took FOREVER!
Good luck!
