Hawler Medical University- College of Medicine
Taenia multiceps or T. serialis, a rare cause of
human infection, is acquired by accidental
ingestion of eggs from dog feces.
Canines are the definitive hosts for adult Taenia
multiceps or T. seralis tapeworms; sheep and
other herbivorous animals are intermediate
hosts. Ingestion of material contaminated by dog
feces causes human disease. The larvae invade
and form a cyst (coenurus) in human tissue,
usually in the CNS.
Symptoms require several years to develop and
depend on the organ infected. Involvement of
the brain causes increased intracranial pressure,
seizures, loss of consciousness, and focal
The definitive hosts for Taenia multiceps are members
of the family Canidae (dogs, foxes…) Eggs and gravid
proglottids are shed in feces into the environment ,
where they are ingested by an intermediate
host(rodents, rabbits, horses, cattle, sheep and goats).
Eggs hatch in the intestine, and oncospheres are
released that circulate in blood until they lodge in
suitable organs (including skeletal muscle, eyes, brain
and subcutaneous tissue). After about three months,
oncospheres develop into coenuri.
The definitive host becomes infected by ingesting
the tissue of an infected intermediate host
containing a coenurus containing a coenurus . The
adult cestodes reside in the small intestine of the
definitive host. Humans become infected after the
accidental ingestion of eggs in food and water
contaminated with dog feces . Eggs hatch in the
intestine, and oncospheres are released that
circulate in blood until they lodge in suitable organs
and after about three months develop into coenuri .
Coenuri of T. multiceps are usually found in the eyes
and brain and subcutaneous tissue.
The parasite is not transmissible to man from the
Coenuri in the skin or subcutaneous tissue usually
present as painless nodules. Coenuri in the neck
may affect neck movement and swallowing.
Clinically, coenuri may mimic lymphomas,
lipomas, pseudotumors, or neurofibromas.
Coenuri in the central nervous system may cause
headache, fever and vomiting.. Coenuri in the
eye cause both intraocular and orbital infections,
and patients may present with varying degrees of
visual impairment. If not removed, coenuri in
the eye may cause painful inflammation,
glaucoma and eventually blindness.
Diagnosis is made by the observation of
coenuri in biopsy or autopsy specimens.
Coenuri are usually readily distinguished
from cysticerci by the presence of multiple
protoscoleces, and it is 2 - 5 cm.
Removal of the coenurus effectively treats
intracranial coenurosis in most cases. There
have also been reports of successful removal
of coenuri from patients' eyes, resulting in a
recovery of sight. Coenuri are susceptible to
praziquantel, but caution should be used,
especially in cases of intraocular coenurosis.