What is Hymenolepiasis?
There are two types of tapeworms that causes this disease.
Hymenolepis nana
Hymenolepis dimunata
Hymenolepis is a zoonotic infection, infection happens as a result of humans and rodents ingesting cysticercoid infected arthropods. This worm does not leave the intestine and H. nana can cause both internal and external autoinfection but H. dimunata does not cause autoinfection.
Morphology
Hymenolepis nana
Has a refractile rostellum with a single row of hooks.
Four suckers.
Proglottid are broader than the length.
Hymenolepis dimunata
Has no hooks on the rostellum.
Four suckers.
Cestodes are 15-60mm in length.
Morphology of the Egg
The egg has two membranes, the inner membrane and the outer membrane. There are yolk granules and thread like polar filaments between the two membranes.
The most important point is that both cysticercoid and the adult worm live in the intestine in Hymenolepis dimunata.
