INTESTINAL PARASITES (Helminths)
CESTOIDEA Order: Cyclophyllidea

HYMENOLEPIS NANA and H. DIMINUTA

hym1-ic

Hymenolepis nana: Cosmopolitan, H.nana is endemic in both temperate
and tropical regions but most prevalent in conditions of poor sanitation.
Life cycle.

hym2-ic

Hymenolepis nana: eggs are usually spherical, 30-47 µm in diameter
with a hyaline shell and contain a 6-hooked oncosphere.

hym3-ic

Hymenolepis nana egg: detail of one of the two polar thickenings
on the membrane of the onchosphere with filaments extending
into the space around the hexacanth embryo.

hym4-ic	hym4a-ic	hymenLon-ic

Hymenolepis nana: typical egg, measuring between 30 and 47 µm in diameter,
containing an oncosphere with an internal cover with polar thickenings 
and 6 hooks (1.000 X).

hym4b-ic

Hymenolepis nana: typical egg, measuring between 30 and 47 µm in diameter, 
containing an oncosphere with an internal cover with polar thickenings and 6 hooks.

hym5-ic	Hdim_gg-ic	Hdim_gg2-ic	Hdim_gg3-ic

Hymenolepis diminuta: eggs of H.nana must be distinguished from eggs of H.diminuta.
Eggs of H.diminuta are larger (70-85 by 60-80 µm) and lack the polar filaments.
Typical egg, measuring between 70 by 80 µm; spherical form and yellow-transparent cover.
The internal membrane (that surrounds the oncosphere)
has polar salients without filaments and six hooks on its interior.