African Trypanosomiasis Flashcards
What is the vector for Human African Trypanosomiasis?
Tsetse fly
What are the organisms that causes African Trypanosomiasis and which is more common?
Trypanosoma brucei gambiense-98%
Trypanosoma brucei rhodesiense
Which species of tsetse flies transmit gambiense and where are they usually found?
Glossina papalis found in riverine forrest areas
Which species of tsetse flies transmit rhodiesense and where are they found?
Glossina mortisans in savannah woodland areas
Does trypanosoma brucei have an intracellular life cycle?
No
How can human African trypanosomiasis be transmitted?
Tsetse fly bite
Vertical transmission
Needle stick
Raw infected meat
What are the signs and symptoms of early stage African trypanosomiasis and how long does it last ?
Intermittent fevers
Anaemia
Flu like symptoms
Sometimes hepatosplenomegaly
Painless chancre
Winterbottoms sign
Gambiense 3yrs
Rhodesiense weeks to months
Why do you get intermittent fevers in African trypanosomiasis?
Waves in parasitaemia due to variable surface glycoproteins
What are the symptoms of stage 2 African trypanosomiasis?
Meningism Sleep/wake reversal Psychosis Depression Coma
How do you diagnose African trypanosomiasis?
Card agglutination trypanosome test for gambiense
RDTs
Blood film
CSF sample for WCC and parasites
How to treat Trypanosoma brucei gambiense?
Stage 1- pentamidine for 1 week
Stage 2- nifurtimox-eflornithine
How to treat trypanosoma brucei rhodiesense?
Stage 1- IV Suramin
Stage 2- IV melarsoprol
What are the side effects of pentamidine?
Nephrotoxicity
Hypotension
Hypoglycaemia
What are the side effects of suramin?
Fever
Nausea
Anaphylaxis
Proteinuria
What are the side effects of melarsoprol?
Reactive encephalopathy 5% mortality
What’s the follow up for African trypanosomiasis?
Bloods and LP every 6 months for 2 years
What control mechanisms are in place for African trypanosomiasis?
Active surveillance: teams go around the countryside and do mass CATT testing (gambiense)
Vector control: blue flags with insecticide and release sterile males
Free medications negotiated by WHO
How do you identify a tsetse fly?
Folded wings when resting
Hatchet cell on wing
