Abstract

Cryptosporidium and Giardia are parasitic protozoa that can be transmitted to man by drinking and recreational water. Depending on the immune state of the infected host, they can cause a selflimiting to severe gastro-enteritis. This report gives a review on the potential for transmission of Cryptosporidium and Giardia by drinking and recreational water, attending data on the occurrence of these parasites in humans and other reservoirs, their persence in sewage and surfase water, removel of the (oo)cysts by water purification processes and waterborne outbreaks. This report also describes the resultsof a preliminary study on the presence of Cryptosporidium and Giardia at Dutch water supplies.