This document summarizes key information about Taenia species, including T. saginata, T. solium, T. asiatica, and T. multiceps. It describes the medically important species, diseases they cause, hosts, morphology, life cycles, transmission, diagnosis and treatment. T. saginata and T. solium cause taeniasis in humans. T. solium can also cause cysticercosis, which can lead to seizures. T. saginata uses cattle as an intermediate host while T. solium uses pigs. Diagnosis involves examining stool for eggs or proglottids. Cysticercosis is diagnosed via imaging, biopsy or serology. Treatment

1. Cestodes
Taenia spp
Hawler Medical University
College of Medicine
Prepared by:
Aram Majeed
Ibrahim Hussein

2. Medically important spp. of Taenia.
 T. saginata (beef tapeworm)
 T. solium (pork tapeworm)
Taenia asiatica (Asian tapeworm)
Taenia multiceps

3. Name of diseases caused by each
spp.
Both species T. saginata and T. solium cause of Taeniasis.
Taenia solium pork tapeworm infections can lead
to cysticercosis which is a disease that can cause seizures.

4. Hosts
Species Intermediate host Definitive host
T. saginata cow, cattle human
T. Solium pig, human human
Habitat
Adult worms of both species live in the small intestine (upper jejunum)
of man.

5. Intermediate hosts and definitive hosts
of T. asiatica and T. multiceps
Intermediate hosts …
• T. asiatica : pig.
• T. multiceps : sheep, cattle, horse other herbivores animals
Definitive hosts …..
• T. asiatica : Human
• T. Multiceps : Human, dog, wolf and fox

6. Morphology of Taenia saginata
• T. saginata is a long flattened ribbon-like tapeworm that is
white in color. It is about 6 to 7 milimeters in width.
• The adult T. saginata usually grows to be about 4 to 8
meters in length, with about 1000 segments called
proglottids.
• Unlike the T. solium, the scolex is "unarmed" because it
has 4 suckers but no hooks.

7. Morphological differences
Aspect Taenia saginata Taenia solium
• Adult size Longer (4-8 m) Smaller (4-2 m)
• Scolex 2 mm in diameter with 1 mm in diameter with 4 suckers
4 suckers but no hooklets and hooklets
• Number of segments 1000 – 2000 700 – 1000

8. Taenia scolex
Taenia saginata Taenia solium

9. Taenia Adult worm
Taenia soliumTaenia saginata

10. Taenia solium

11. Taenia saginata

12. Aspect Taenia saginata Taenia solium
Mature segment 2 ovary lobes 3 ovary lobes
Gravid segment 15 - 30 uterine branches 7 -13 uterine branches
Larvae Cysticercus bovis only in cattle, no
scolex no hooklets
Cysticercus cellulosae in pig and
man,scolex with hooklets
Egg in both species are indistinguiable
Morphological differences

13. Taenia mature segment
Taenia soliumTaenia saginata

14. Taenia Gravid Proglotid
Taenia soliumTaenia saginata

15. Egg
• The eggs of Taenia saginata
and T. solium are indistinguishable
morphologically.
• The eggs are spherical, diameter
31 to 43 µm, with a thick radially
striated brown embryophore.
• Inside each is an oncosphere with
6 hooklets.

16. Life cycle of Taenia spp

17. Life cycle of Taenia solium

18. Neurocysticercosis

19. Ophthalmic
Cysticercosis

20. Cysticercosis
in muscles

21. Mode of transmission
Taenia saginata
Man acquires infection by eating raw or undercooked beef
containing encysted larval stage (Cysticercus bovis).

22. Mode of transmission
Taenia solium; man acquires infection by:
1- Eating raw or undercooked pork containing encysted larval stage
(Cysticercus cellulosae).
2- Ingesting the egg with contaminated food or water.
3- A man harbouring adult worms may auto-infect either by unhygienic
personal habits or by reverse peristaltic movements of the intestine
whereby the gravid segments are thrown into the stomach.

23. Infective stage
Taenia saginata Cysticercus bovis
Taenia solium Cysticercus cellulosae and egg
Diagnostic stage
Taenia saginata gravid proglottids and egg
Taenia solium gravid proglottids and egg
T. asiatica …… cysticercus
T. multiceps …. Eggs

24. Pathogenesis
• Usually no symptoms, may cause abdominal discomfort, indigestion,
diarrhea alternating with constipation and loss of appetite.
• Cysticercosis (by cysticercus cullulosae ) may occur in any organ.
• May develop in subcutaneous tissue and form visible nodules or in
brain forming epileptic attacks, and interior vitreous chamber of the
eye.

25. Laboratory diagnosis
1- Stool microscopy; same for both Taenia, by demonstration of eggs or gravid
proglottides in stool by:
A- Direct fecal smear
B- Brine floatation technique
C- Cellophane-tape technique
NOTE; acid fast stain is used to distinguish the eggs, T.saginata is acid
fast positive (red) while T.solium is negative (blue) or by detection of
proglottids & scolex in feces.

26. Laboratory diagnosis cont..
2. Detection of Taenia Ag in faeces; Coproantigen is the most sensitive
method (95% sensitivity and 99% specificity) to detect Taenia specific
Ag in the stool but does not differentiate between species.
3- Molecular diagnosis; Includes DNA probes & PCR

27. Diagnosis of cysticercosis
1- Biopsy of subcutaneous nodule (cysticerci)
2- X-ray (calcified cysticerci), CT scan & MRI for
neurocysticercosis.
3- Histopathological diagnosis (cysticercus in autopsy tissue).
4- Serological tests (IHA, IFA & ELISA anticysticercus Ab).
5- Differential leucocyte count (eosinophilia)

28. Treatment
• Praziquantel and niclosamide single dose of 4 tablets of 500
mg for T. saginata and T. solium.
• Praziquantel high dose over 3-7 days for T. solium.