Well, I know someone who had a cut on his knee and accidently kneeled in some chicken poo and got some bacteria in it and almost lost his leg... BUT then I used to walk barefoot everywhere when I was a kid, chicken yard and all, and I aint never had nothin like that happen to me, and one time I literally cut the tip of my toe off on some old tin in the coop itself right under the perches (nasty stuff) and I didnt have anything particularly bad happen to me... Ma was MAD though LOL! I was raised around 'em since I was born and I'm healthy as a horse, I remember gettin in trouble as a boy and sleepin in the coop with the chickens instead of goin in the house and I'm still alive and kickin LOL! So no, I wouldn't worry to much, sometimes weird stuff happens but not often enuff to worry about it.