Trypanosoma congolense is a parasite that infects several mammals, particularly cattle, in Central Africa and is the major cause of animal african trypanosomiasis (AAT). AAT is a severe disease that strongly contributes to poverty in Africa due to impairment of agriculture and livestock production. Direct losses from animal death are in the range of £0.7 billion annually, whereas indirect losses can reach as much as £4 billion a year.

Here is a video from wikipedia showing the amazing parasites and their very characteristic movement due to the absence of a free flagellum.