Some streams in some U.S. national parks advise against submerging your head in the water for the risk of getting brain eating amoebas.
I have only had to take extra precautions in costal areas. When I was a kid, I remember some fairly strict warnings about amoebas in places like Florida and up the East Coast to North Carolina. Honestly, I don’t remember that many details since that was about 35 years ago. (Maybe it’s about water temperature or water chemistry, or something. Dunno.)
Reminiscing aside, all fresh water has risks for one reason or another. If you are ever lost, stranded or even on a super long hike everything becomes exponentially more dangerous anyway. (Small risks become massive risks, basically.)
If there is anything you never fuck around with in the wild, it’s a water source. Not only can it host a ton of things that can kill you or just make you sick, it also attracts other, bigger, critters. Nevermind that we need a fuck ton of water to drink ourselves and need to stay near water sources.
Nature is brutal.
