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Trypanosoma brucei. gambiense and rhodesiense. Profile. 3 subspecies- brucei, gambiense, rhodesiense Causes trypanosomaiasis (African sleeping sickness) 2 hosts- 1 insect, 1 mammalian Lives in bloodstream Classification: kingdom- Protista
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Trypanosoma brucei gambiense and rhodesiense
Profile • 3 subspecies- brucei, gambiense, rhodesiense • Causes trypanosomaiasis (African sleeping sickness) • 2 hosts- 1 insect, 1 mammalian • Lives in bloodstream • Classification:kingdom- Protista phylum- Euglenozoa class- Kinetoplastea order- Trypanosomatida genus- Trypansoma species- T. brucei
gambiense vs. rhodesiense • Gambiense- causes slow onset chronic trypanosomaiasis, infects only humans (West African Sleeping Sickness) , transmitted human to human via a vector • Rhodesiense- causes fast onset acute trypanosomaiasis, infects animals (East African Sleeping Sickness), able to be transmitted to humans
Incidence Gambiense Rhodesiense
Life Cycle Procyclic cells replicate in fly’s midgut Transform into metacyclic trypomastigotes in salivary gland Transform into epimastigotes, replicate
Life Cycle Metacyclic Trypomastigote Tsetse fly Bloodstream
Life Cycle Bloodstream trypomastigote Binary fission replication in blood Tsetse fly takes blood meal
First Stage of Disease • West (Gambiense)- fever, faint rash • East (Rhodesiense)- possible death without treatment
Second Stage of Disease • West- after months • East- after weeks : • Trypanosomes cross blood-brain barrier, enter central nervous system
Second Stage (con’t) • encephalopathy –brain disease
Second Stage (con’t) • Reduced mental functions • Difficulty in concentration • Eventually enter terminal somnolent state, “Sleeping Sickness”
Death • After considerable loss of weight, most patients die • West- after months, East- after weeks
Treatment for West (Gambiense) • Stage 1 -first line: pentamadine -second line: eflornithine or melarsoprol • Stage 2 -first line: melarsoprol -second line: eflornithine
Treatment for East (Rhodesiense) • Stage 1 -first line: suramin -second line: melarsoprol • Stage 2 -first line: melarsoprol -second line: nifurtimox combined with melarsoprol
Problems with Treatment • Many drugs cause extensive brain damage • Hard to obtain drugs in certain regions of Africa • Treatment, resources scarce in poor areas