for the rest of your days.
Alright let's move from the roundworms into
the flatworms, Schistosomiasis. These are
helminths again; of course they are worms,
non-segmented flatworms, also known as trematodes.
Here in this photograph is Schistosoma mansoni.
There is actually an adult male and a female
in this picture. Can you see them? Probably
not, you might see the head of the female
just sticking out, she is located in a groove
along the length of the male worm. They are
mating. This is how they mate. This is how
they mate inside of you and the female will
then shed eggs which go on to spread to others.
So the two worms find each other, they come
together, the female fits into this groove,
they mate and they produce eggs, that's Schistosoma
mansoni. Here is another just schistosome,
Schistosoma hematobium, these are the cyst
forms in a tissue. This is Schistosoma japonicum.
This is the cercarial form. We will talk about
what this is in a moment. And another cyst
form of Schistosoma mekongi. So all of these
different species of schistosomes can cause
the same type of schistosomiasis. Now remember
again, these are worms, trematodes in particular,
non-segmented flatworms. These different schistosome
species are located in different parts of
the world, depending on a snail. The intermediate
host for schistosomiasis, schistosomes is
the snail of different kinds and in this snail,
it goes through a certain morphological transformation,
it doesn't complete the whole lifecycle, that's
why it's an intermediate host. Globally there
are somewhere between 200 and 300 million