Taenia solium vs. Taenia saginata 

Taeniasis is the parasitic infection of humans caused by adult tapeworm species; i.e. Taenia saginata (beef tapeworm)Taenia solium (pork tapeworm), or Taenia asiatica (Asian tapeworm). T. solium and T. saginata have a worldwide distribution but the incidence is higher in developing countries whereas  Taenia asiatica is limited to Asia.

T. solium tapeworm infections can lead to human cysticercosis.

The major differences between T. solium and T. saginata are summarized in this table: 

PropertiesTaenia soliumTaenia saginata
 Common Name Taenia Solium Taenia saginata
 Definitive host Human Human
 Intermediate Host Pig Cow/Cattle
 Disease  Taeniasis and Cysticercosis Taeniasis only
 Transmission Infection is common among those eating raw or insufficiently cooked measly pork containing the cysticerci. Human beings are infected through the eating of undercooked beef containing the cysticerci (“measly” beef)
 Size Size of adult worm: 2-7 m Size of adult worm: 5 m or less (sometimes up to 25 m)
 Scolex Scolex of Taenia solium

 

  • The scolex head is globular in outline and has four circular suckers.
  • The head is provided with the rostellum armed with a double row of alternating large and small hooklets. The rostellar hooklets are shaped like daggers or Arbian poniards (armed scolex)
 Scolex of Taenia Saginata

 

  • The scolex (“head”) is quadrate in outline and has four circular suckers.
  • Rostellum and hooklets are absent (i.e. unarmed scolex)
 Proglottids  Gravid proglotids of T solium

 

  • The total number of proglottids (segments) is an average of 1000.
  • The gravid uterus consists of a median longitudinal stem with 5- 13 compound lateral branches on each side
  • The gravid segments are expelled passively, in chains of 5-6 at a time, and not singly.
  • T. solium may produce 50,000 eggs per proglottid.
 Gravid proglottids of T. saginata

 

  • The number of proglottids varies from 1000 to 2000.
  • The gravid uterus consists of a central longitudinal stem with 15-30 lateral branches on each side; these in turn sub-branch leaving practically no space in between.
  • The gravid segments are expelled singly
  • T. saginata may produce up to 100,000 eggs per proglottid.
 Eggs  Taenia_egg

 

  • The eggs are about 30-35 micrometers in diameter and are bile stained.
  • The internal oncosphere contains six refractile hooks.
  • The eggs are not floated in the saturated solution of NaCl.
  • Eggs of Taenia solium and Taenia saginata are morphologically indistinguishable.
Eggs of T. solium and T. saginata are morphologically indistinguishable.
 Eggs (Infectious nature) Infectious to humans (humans who ingest  food contaminated with eggs of Taenia solium may develop cysticercosis) Eggs of T. saginata are not infectious. Humans who ingest T. saginata eggs do not develop cysticercosis.

Note: Most of the photos of the parasite posted here are taken from Website of CDC

References

  1. Harrison, L. J., & Parkhouse, R. M. (1989). Taenia saginata and Taenia solium: reciprocal models. Acta Leidensia, 57(2), 143–152. 
  2. Mayta, H., Talley, A., Gilman, R. H., Jimenez, J., Verastegui, M., Ruiz, M., Garcia, H. H., & Gonzalez, A. E. (2000). Differentiating Taenia solium and Taenia saginata infections by simple hematoxylin-eosin staining and PCR-restriction enzyme analysis. Journal of clinical microbiology, 38(1), 133–137. https://doi.org/10.1128/JCM.38.1.133-137.2000 

Acharya Tankeshwar

Hello, thank you for visiting my blog. I am Tankeshwar Acharya. Blogging is my passion. As an asst. professor, I am teaching microbiology and immunology to medical and nursing students at PAHS, Nepal. I have been working as a microbiologist at Patan hospital for more than 10 years.

5 thoughts on “Taenia solium vs. Taenia saginata 

  1. Very nice post. I was looking for the lateral branches and found your table very useful. Consider adding treatment for completeness!

  2. Sir i greatly admire you for your work. Please help us with specialized lab diagnostic procedures with each topic. Thank you for this worderful website! 😁

  3. You clearly indicated the difference between T.saginata and T. solium. I think both adult stages of this helminths can be found in man producing eggs but the cystic stage of T. Saginata is not infective to man but the cystic stage of T. Solium is infective and cause cysticercosis in man accidentally or due to reverse peristalysis. You see reverse peristalsis also occurring in case of T saginata. But what do you think that eggs of teania saginata does not infect human but that of T solium is infective? Why? I need some infornation.

  4. Taenia saginata dont have hooklets found in the scolex but some sources say the oncosphere has 6 hooklets. Is this true? if so, how does it go from a hexacanth embryo just like T.solium to a scolex without hooklets

We love to get your feedback. Share your queries or comments

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Recent Posts