1/26/2016 Protozoan Diseases of the Nervous African Trypanosomiasis System African sleeping sickness -500,000 infected in Africa Learning Objective -100,000 new cases each year Trypanosoma brucei gambiense Identify the causative agent,vector, -Humans are the only reservoir symptoms,and treatment for African -97%of the cases trypanosomiasis and amebic T.b.rhodesiense meningoencephalitis -Reservoir in livestock and wild animals Transmitted by the tsetse fly -Distributed in west and central Africa Coma and death occur without treatment Cycle of African trypanosomiasis African Trypanosomiasis (间 Parasite evades antibodies through t&doe日 06018 antigenic variation -Difficult for vaccine development Treated with eflornithine:crosses Tsetse fly- the blood-brain barrier:blocks an (e) enzyme necessary for the parasite Prevention:elimination of tsetse fly vectors Tent-like,insecticide treated traps (b) Interval of years -Release of sterile male tsetse flies (weak flyer) -Eliminated tsetse fly on Zanzibar island CNS damage 1/26/2016 11 Protozoan Diseases of the Nervous System L gj earning Objective Identify the causative agent, vector, symptoms, and treatment for African trypanosomiasis and amebic mg p eningoencephalitis African Trypanosomiasis • African sleeping sickness – 500,000 infected in Africa – 100,000 new cases each year • Trypanosoma brucei gambiense – Humans are the only reservoir – 97% of the cases • T. b. rhodesiense – Reservoir in livestock and wild animals • Transmitted by the tsetse fly – Distributed in west and central Africa • Few early symptoms, followed by fever, headache, and deterioration of the CNS • Coma and death occur without treatment African Trypanosomiasis • Parasite evades antibodies through antigenic variation – Difficult for vaccine development • Treated with eflornithine: crosses the blood–brain barrier; blocks an enzyme necessary for the parasite • Prevention: elimination of tsetse fly vectors – Tent-like, insecticide treated traps – Release of sterile male tsetse flies (weak flyer) – Eliminated tsetse fly on Zanzibar island