Enumeration of Cryptosporidium sp. and Giardia sp. (oo)cysts in a tropical eutrophic lake

Enumeration of Cryptosporidium sp. and giardia sp. (oo)cysts in a tropical eutrophic lake is performed. The results reveal an increase in (oo)cysts density from the surface layers to the bottom depth of the lake. There is a considerable decrease in the biodynamics of the resistant forms of these pathogens between the inlet and the outlet of the lake. This suggests the characteristic purification properties of this lentic ecosystems and the application of this mechanism in sedimentary basins of water treatment plants. The accumulation of pathogenic micro-organisms at the bottom layer of the municipal lake exposes the population to an outbreak of giardiasis and/or cryptosporidiosis in cases that the resistant forms of the parasites are released into the entire river basin by floods in the event of heavy rains or anthropogenic activities.