The search for <i>Cryptosporidium</i>oocysts and <i>Giardia cysts</i>in source water used for purification

Abstract

often fatal disease in immuno-compromised individuals. Both organisms are characterised by the ability to survive in an aquatic
environment with Cryptosporidium having a high tolerance to most of the drinking water disinfectants. The absence of bacteria associated with feacal pollution does not necessarily indicate the absence of Cryptosporidium or Giardia. Being a common cause
of waterborne disease, the requirement for detecting the presence of these organisms in environmental and treated water samples is growing. Although cysts and oocysts can be found in natural waters from any source, the risks of contamination are much greater
in surface waters than in ground waters. A number of waterborne outbreaks of cryptosporidiosis, from potable and recreational water have been recorded. In many cases
these outbreaks have occurred from water that complies to current microbiology standards.

Water SA Vol. 30 (5) 2005: pp.33-36