Towards an integrated fasciolosis control: pinpointing the role of macroinvertebrates and habitat characteristics as drivers of lymnaeid snail abundance in temporary wetlands
摘要
Fasciolosis is a neglected tropical disease causing significant economic losses and public health concerns particularly in Sub-Saharan Africa. Existing control mechanisms are thwarted by limited access to effective diagnostic tools and treatment options as well as high re-infection rates. Biological control of vectors is widely recognised as a potential strategy for neglected tropical diseases (such as malaria and schistosomiasis) management. However, little is known on potential interactions between lymnaeid snails and temporary wetlands invertebrates or habitat characteristics which can be exploited as natural interventions for fasciolosis control. We investigated habitat characteristics and invertebrate communities in 60 temporary wetlands as potential habitats of lymnaeid snails. We then determined significant variables explaining the abundance of lymnaeid snails in temporary wetlands of the Lake Victoria Basin (LVB). Counter-intuitively, of the studied habitat characteristics only openwater proportion and phycocyanin levels had significant effect on lymnaeid snail abundance. Additionally, abundance of fairy shrimps (Streptocephalus spp.), larvae of damselflies (Pseudagrion sp.) and water-veneer moths (Donacaula sp.) significantly affected lymnaeid snail abundance. Increase in phycocyanin (cyanobacteria) levels fostered proliferation of lymnaeid snails. Interaction between damselflies and moth larvae on juvenile lymnaeid snails suggests possible use of the species as biological control. Existing interspecific competition between fairy shrimps and lymnaeid snails can also be exploited. Moreover, limiting algal blooms formation may suppress proliferation of lymnaeid snails. We therefore contend that, an understanding of disease vectors biotic interactions in their habitat is cornerstone in developing complementary strategies for fasciolosis control.