E coli bacteria

li

A couple months ago my niece got this bacteria from drinking raw milk, I read about it and I found out that kids can get this bacteria not just from raw milk but also from any contact with animal/human fecal stuff. Now, my almost 21 months old boy loves to go outside and play, we have a big backyard but we also have six ducks... poop everywhere in the grass!! We stay inside the house for that reason and sometimes we walk to the park (35 minutes walk) Do you think that he will be at big risk of getting this bacteria from the ducks if he's outside for about 30 minutes?

*** I have to say that we drink/drank raw milk but he has never been sick, I actually stop using raw milk after what happened to my niece, my husband grew up drinking raw milk, so when we got married he told me that his mom's milk was better then the one from the store but I didn't know that was raw, I never asked and he never told me until a few months ago.