The importance of giardia and cryptosporidium for water industries in european countries

Giardia and Cryptosporidium have been recognised as waterborne pathogens in the USA and England. There have been several documented outbreaks of cryptosporidiosis and giardiasis in the USA and UK. In the year 1994 in the USA the first outbreak of cryptosporidiosis has been documented without apparent water treatment deficiency. In our studies in Germany both parasites were found in surface water, in raw water and in drinking water. Giardia and Cryptosporidium or both were detected in 76% of the raw water samples and in 38% of the drinking water samples. The presence and concentration of parasites in surface (raw) water supplies varies, depending on animal activities, agricultural practices and sewage effluences. Although water treatment technologies are effective to remove Giardia and Cryptosporidium, the results clearly show that Giardia and Cryptosporidium evade the filter harries in the absence of treatment deficiencies and contaminate final water. Current detection methods of Giardia and Cryptosporidium from water give variable results; there is an urgent need l)to standardize the concentration and enumeration methods for these parasites used throughout laboratories in different countries and 2) to give some perspectives to water industries as regard the significance of parasites in their water.