safety of drinking water concept

naegleria fowleri parasite protozoan 3d illustration brain braineaiting amoeba amoebeasis naegleriasis water encephalitis primary amoebic meningoencephalitis meningitis science medicine medical scientific research pathology pathogen microbe microorganism protozoal infection infectious parasitic ill disease illness ritual nasal rinsing tap contaminated flagellated entamoeba histolytica acanthamoeba ameba world day contamination virus white background