It seems like 60 outbreaks over 25 years really isn't that many, with 10K illnesses and 0 reported deaths. As a comparison, every year in the US, over 20,000 children are hospitalized due to the flu, and over a hundred die.

I know the denominator is different - most children are exposed to potential flu vectors, while only some visit splash pads - but I think this article mostly sounds scary because poop is gross.