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Cryptospondium (part 1 of 2) Page 7 of 13 �• �� V ■ Enterocytozoon bieneusi Some of these organisms (e.g., cytomegalovirus and Isopora bell�� have been detected concurrently with Cryptosporidium during bouts of infectious diarrhea.l Summary Cryptosporidium is one of several agents involved in infectious diarrhea and is particularly devastating for immunocompromised individuals who are unable to clear the disease. While the incidence of reported cryptosporidiosis appears to be low, this may be underestimated due to factors such as lack of reporting by doctors and lack of diagnosis. The treatment of cryptosporidiosis has been relatively unsuccessful, aithough there appears to be some promise in use of a hyperimmune bovine colostrum. Water Treatment Occurrence in Water Cryptosporidium is shed from infected individuals in their stools. Concentrations of infective oocysts are very high in the stools with levels on the order of one million oocysts per day being estimated. Cryptosporidium can be transmitted directly from person to person through the fecal-oral route. Cryptosporidium can also find its way into the environment and, hence, into drinking water sources. Detection Because the conventional indicators of microbial water quality (e.g., coliforms and heterotrophic plate counts) do not necessarily correlate with the presence or concentrations of Cryptosporidium and because the minimum infective dose is thought to be very low, detection of low Cryptosporidium concentrations is necessary. To accomplish this, methods have been developed that rely on concentrating large volumes of water (i.e., 100 to 1000 gallons) into a small pellet (ASTM Method P229). The method is detailed in the proposed Information Collection Rule. The basis of the procedure is as follows: ■ Sampling - Water is taken from the source by pumping into a filter housing containing a polypropylene yarn cartridge �Iter.� The volume of water passed through the filter is measured using a water meter. ■ Concentration - After transport to the laboratory, the particles trapped on the filter are eluted using targe volumes of detergent. The eluate is then centrifuged to concentrate and separate out particles denser than the oocysts. ■ Identification - Microscopic examination of the concentrated sample relies on actual measurement of size and the use of fluorescent antibody stains to identify the oocysts. A distinguishing feature of Cryptosporidium is the fold in the oocysts. There are several problems with current detection methods. http://sfwater.org/printContent.cfin/C ID/446/ 10/19/2004