RESUMO
Water samples were collected from five sources related to five residential areas where human populations use them in their daily life and for drinking in El-Ekhewa village. The first and the second were slow running surface water, the third was underground water at shallow depth [5.6 +/- 18 meters], the fourth was chlorinated piped water and the fifth was underground water at depth> [21 +/- 1] meters. The samples were filtered, diluted then concentrated. The thick walled oocysts of Cryptosporidium were identified and counted after specific monoclonal immunofluorescent staining. The density of water contamination by thick walled oocysts per litre was high in surface water of the first [465] and the second [398] sources: Both are frequently in contact with domestic and wild animals. Lesser degrees, although still infective were encountered in underground water at shallow depth [132] and in the piped chlorinated water [85]. Meanwhile, no oocysts were detected in the underground water at depth>20 meters. These findings may indicate that the oocyts are chlorine resistant and the main method for their elimination is effective filteration. Stool from 120 patients with diarrhea and 100 without diarrhea [1-20 ys] from these 5 areas were examined by acid fast trichrome stain of saline Hemo De concentrate to detect intestinal parasites including coccidia and microsporida Bacterial pathogens were sought by standard bacteriologic techniques. Only those with Cryptosporidium as single pathogen were considered. 10.4% of the symptomatic were shedding oocysts in their stools.The correlation between the density of water contamination and the prevalence of cryptosporidiosis among individuals of each area was so significant that it can be concluded that the disease in the present community is water borne. Most of symptomatic cases were encountered at mean age [10.6/-4.2] while the asymptomatic cases were mostly detected at mean age [15 7 +/- 4.4] indicating age related tolerance towards this organism