ANSWERThere are many protists that can cause diseases in the human body. For example, Plasmodium, they cause malaria, spread by mosquitoes. Trypanosoma, that causes sleeping sickness, transmitted by the tsetse fly. etc.If you're looking for a true or false answer, then the answer is true. SOME GREAT EXAMPLES:Naeglaria Fowleri is nicknamed “The brain-amoeba” and are commonly found in warm, freshwater like lakes, hot springs and rarely, even some unmaintained swimming pools. (mostly found in still waters)It doesn't infect you by drinking but if you jump and got into your nose. That's the only way they can go up and eat your brain. Once it starts eating, it can be fatal, and even cause death. some causes are headaches, etc.