Trypanosoma brucei

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Trypanosoma brucei

• gambiense and rhodesiense

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Profile

• 3 subspecies- brucei, gambiense, rhodesiense
• Causes trypanosomaiasis (African sleeping
  sickness)
• 2 hosts- 1 insect, 1 mammalian
• Lives in bloodstream
• Classificationkingdom- Protista
• phylum-
  Euglenozoa
• class-
  Kinetoplastea
• order-
  Trypanosomatida
• genus-
  Trypansoma
• species-
  T. brucei

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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

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Incidence
Gambiense
Rhodesiense
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Life Cycle
Procyclic cells replicate in flys midgut
Transform into metacyclic trypomastigotes in
salivary gland
Transform into epimastigotes, replicate
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Life Cycle
Metacyclic Trypomastigote
Tsetse fly
Bloodstream
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Life Cycle
Bloodstream trypomastigote
Binary fission replication in blood
Tsetse fly takes blood meal
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First Stage of Disease

• West (Gambiense)- fever, faint rash
• East (Rhodesiense)- possible death without
  treatment

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Second Stage of Disease

• West- after months
• East- after weeks
• Trypanosomes cross blood-brain barrier, enter
  central nervous system

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Second Stage (cont)

• encephalopathy brain disease

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Second Stage (cont)

• Reduced mental functions
• Difficulty in concentration
• Eventually enter terminal somnolent state,
  Sleeping Sickness

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Death

• After considerable loss of weight, most patients
  die
• West- after months, East- after weeks

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Treatment for West (Gambiense)

• Stage 1
• -first line pentamadine
• -second line eflornithine or
• melarsoprol
• Stage 2
• -first line melarsoprol
• -second line eflornithine

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Treatment for East (Rhodesiense)

• Stage 1
• -first line suramin
• -second line melarsoprol
• Stage 2
• -first line melarsoprol
• -second line nifurtimox combined
• with melarsoprol

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Problems with Treatment

• Many drugs cause extensive brain damage
• Hard to obtain drugs in certain regions of Africa
• Treatment, resources scarce in poor areas