Tackling protozoan parasites of cattle in sub-Saharan Africa

More distantly related human-infective kinetoplastids include Trypanosoma cruzi, which causes Chagas disease in South America and over 20 Leishmania species that cause leishmaniasis. Following tick bite, the parasites invade host red blood cells, causing anaemia and fever, and infection can also lead to cerebral babesiosis (B. bovis only) and death of cattle. Efforts to control parasitic disease are hindered by the challenge of implementing vector control strategies across the vast expanses of tsetse and tick-populated land; emerging drug resistance and the prevalence of counterfeit drugs; and a lack of suitable vaccination programmes. Vector control is complex and comes with many limitations, including the following: (i) Tsetse- and tick-infected regions are vast; therefore, traps can only provide a local level of protection, which needs to be ongoing; (ii) ticks and related insects are a valuable source of nutrition to reptiles and birds and so large-scale insecticide use is not feasible; (iii) cattle plunge-dipping into toxic organophosphates or synthetic pyrethroids can cause significant illness to the farmer and the environment and is not a widely available control option; and (iv) the choice of insecticides used are key, due to selective toxicity and resistance [13].