this is a blood smear, so there are red blood
cells present. First we will look at the African
Trypanosoma. There are African and American
Trypanosomes with very different outcomes.
One of the African Trypanosomaes, Trypanosoma
brucei gambiense. Let’s take a look at the
distribution of this. You can see that these
parasites are found largely in central Western
Africa. Very specific place, nowhere else
on the planet. Trypanosoma brucei gambiense.
The other trypanosome present in Africa is
Trypanosoma brucei rhodesiense. And let's take
a look at the distribution of this parasite.
Look it's very different, that's on the eastern
coast of South Africa, very different from
gambiense. These infections, these parasites,
are spread by the Tsetse fly, the species
glossina, these are very large flies, you
can't tell from this photograph, an inch long,
that can give you quite a nasty bite and deliver
quite a serious disease. Among the African
trypanosomiasis, the animal reservoirs are
different for the East African and the West
African parasites. The reservoirs for the
East African parasites are game animals, like
impalas, like this animal here is an impala,
and other game animals. So these parasites
exist in those reservoirs. The West African
Trypanosoma has as reservoirs either humans
or domestic animals like cattle. So the very
distinct geographic distributions of these
two different African Trypanosomes are a consequence
of the distribution of the animal reservoir.
In both cases they are spread by the same
vector, the tsetse fly.