Enhancing Resistance to Animal African Trypanosomiasis

Enhancing Resistance to Animal African Trypanosomiasis

Samuel J. Black, Ph.D
UMass Amherst
Wed, 2/15/2017 - 4:00pm

221 Integrated Sciences Building

Abstract: Tsetse flies are endemic to the humid and semi-humid regions of Africa, a landmass of 10 million km2 that encompasses vast swaths of prime agricultural land suited to rain fed agriculture. Tsetse flies feed on mammal blood and transmit African trypanosomes in their saliva. The inoculated flagellated protozoans invade and multiply in the host blood plasma causing animal African trypanosomiasis (AAT), which is endemic throughout the tsetse habitat and fatal in cattle and other livestock species, but tolerated by Cape buffalo and other wildlife species with which African trypanosomes co-evolved and which serve as reservoir hosts. African trypanosomes change their variable surface glycoprotein (VSG) coat infrequently and stochastically, hence as each wave of parasites grows in the blood and is eliminated by the host immune response, new variants remain to seed the next parasitemic wave. In cattle and other trypanosomiasis-susceptible hosts this process results in recurring waves of trypanosomes in the blood, accompanied by recurring waves of co-lateral damage to the host cumulating in wasting and death. Trypanosome antigenic variation has so far prevented the development of an effective vaccine against AAT, which remains a major contributor to food insufficiency in sub-Saharan Africa. Dr. Black has worked on mechanisms of host control of AAT for the last 36 years, many of which were spent in Kenya studying how African Cape buffalo control the disease, and all of which were invested in discovering how to curb the severity of AAT in susceptible hosts. The seminar will review this scientific journey, and report progress towards understanding the mechanism of AAT induced pathogenesis and its control.


Refreshments at 3:45pm