Distribution of Cryptosporidium and Cyclospora in the Soil Around the Wells and Springs in Yaounde and Environs: Role of Some Abiotic Factors of the Medium

This study, developed in the Centre Region of Cameroon, made it possible to identify the consequences responsible of soil vulnerability. Chemical and biological analysis of soil samples collected near wells and springs during the short rainy season were carried out. The results show that the pH and electrical conductivity values decrease with the depth respectively 6.11 CU and 127.47 µS/cm at the surface (0cm) followed by 5.52 CU and 69.32 µS/cm at 50 cm depth. The hydraulic conductivity shows that the soil is moderately permeable (10-5m/s). Protozoa oocysts were observed using an Olympus CK2 inverted microscopy at 40X objective using Zinc sulphate flotation and modified Ziehl-Neelsen technique. The distribution of oocysts decreases with depth. At the surface of the soil (0cm) the densities of Cryptosporidium and Cyclospora are respectively 123 oocysts/100g and 50 oocysts/100g. At 25cm depth, the densities of Cryptosporidium and Cyclospora are respectively 36 oocysts /100g and 6 oocysts /100g. At 50cm depth the densities of Cryptosporidium and Cyclospora are respectively 16 oocysts/100g and 3 oocysts/100g. Infiltration of oocysts may be favored by Hydraulic conductivity and obstructed by acidic pH of the soil. The contamination of these different depth layers would be a risk of contamination of groundwater.