Molluscs Intermediate Hosts of Distomes in Some Natural Cattle Water Points in Ngaoundere

Background: Freshwater gastropod molluscs act as indispensable intermediate hosts in the life cycle of many species of distomes of medical and veterinary interest. The aim of this study was to carry out an inventory of molluscs in natural cattle water points and show their contamination and therefore their role as intermediate host.

Material and Methods: Between October to December 2018, a total of 1631 molluscs were collected in five natural cattle water points: Four lakes (Dang, Bini, Djalingo, Calmet) and one river (Mardock). The cattle water points were chosen based on their accessibility and the presence of vegetation around. Molluscs were collected manually by hand from shallow areas or using a rigid fine mesh net for deep areas. Molluscs were then placed in plastic jar and transported to the laboratory where they were identified.

Results: Four species of molluscs belonging to the subclass Pulmonata were identified. These species were Bulinus forskalii (Morelet, 1866), Bulinus globosus (Morelet, 1866), Biomphalaria pfeifferi (Krauss, 1848) and Lymnaea natalensis (Krauss, 1848) with respective numbers of 244 (18%), 796 (58.4%), 293 (21.5%) and 298 (21.9%). Molluscs were not encountered in all the water points. All the four species of molluscs were collected in lake Dang, Bini and Djalingo. Lake Dang showed great specific richness with the presence of four identified molluscs. In lake Bini two species of molluscs were encountered with a high density of B. pfeifferi. The frequency of infestations with Fasciola gigantica and Paramphistomum daubneyi varied in certain localities according to the species of molluscs present in the cattle water points. The majority of molluscs that were subjected to the cercariae emission test showed their infectious nature by emitting cercariae which were larval forms of the distomes.

Conclusion: It is very important to set up a mechanism for controlling molluscs in farming areas because these animals are the main sources parasites dissemination.