Is parasitic infection by free-living unicellular eukaryote Naegleria fowleri¹⁾, with fatality rate of 98.5%. It's brain-eating amoeba, attacking nervous system and brain via the nose. N. fowleri could be found in warm, fresh water, like ponds, lakes, rivers, etc. As prevention, children and young adults should use noseclips or avoid warm fresh water (chlorinated swimmings pools or salt water are safe)²⁾.