[Drinking water and parasites]

Entamoeba histolytica, Giardia lamblia, Cryptosporidium parvum, Isospora belli, Balantidium coli, and Microsporidia spp. are cosmopolitan parasites. They often cause diarrheal diseases. The waterborn transmission of all these parasites is possible (41). Surface water supplies used for drinking water are potential sources of contamination. Giardia lamblia and Cryptosporidium spp. have received great attention in industrialized countries during the last years because they are the etiological agents of waterborne diseases. The life cycles of Giardia lamblia and Cryptosporidium are described with a special reference to drinking water technologies aimed at removing these parasites.