I am probably one of the most germaphobic persons on rabbit talk (most germaphobs are not into farming). I generally avoid touching poop with my bare hands and I will wash/sanitize if I accidentally touch it.
However, even I don't wash my hands after touching the clean fur of rabbits/guinea pigs. If the fur is dirty or if I am treating a sick animal I do wash. I also usually wash before eating. However it is possible that I touched a rabbit, then an hour later, I may eat a potato chip or two without washing my hands first.
It is a tragedy that a young child died. It it is important to teach sanitation to children even though they don't seem to "get it". I remember (from before age 6) I was always putting my fingers and noticing a salty taste of the "dirt" that was on them. To be honest, I am slightly horrified by the memory. Because e. coli was the cause, I would have to imagine that the child got a hold of poop or touched poopy fur. Toddlers don't seam to understand yucky things. I would insist that my child wash after the petting zoo. But as was stated on many of the articles written, only 30% would wash/sanitize afterwards.