Giardia and Cryptosporidium species are known to be the most frequently isolated protozoa responsible for a number of episodes of waterborne gastroenteritis. Cysts and/or oocysts of these protozoa have more resistant to routine disinfection (chlorination) than coliform bacteria and this is a potential problem in the water treatment plants.

Between 1997 Agust- 1999 June, 40 raw water samples (480 liters of water for each samples) from the dam lakes of Kağıthane, Büyükçekmece, Ömerli and Elmalı were concentrated of large volumes of water by retention on yarn-wound (Sartofine PP polipropilen cartridges, having 1μm porosity) filtre for Giardia cysts and Cryptosporidium oocysts. Retained particulates were eluted from the filter and reconcentrated by centrifugation. The pelleted cysts and oocysts were separated from other particulate debris by flotation on zinc sulfate solution, and stained with fluorescent antibody (Crypto/Giardia cel IF test, Cellabs) examined under a UV microscope.

No Giardia cysts and Cryptosporidium oocysts were detected in the investigated raw water samples. This is the first parasitological research conveinted to the standarts in the drinking waters foundations in our country and reseach is still on work.