Taenia solium vs. Taenia saginata

Properties

Taenia solium

Taenia saginata

 Common Name

 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

• 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)

• The scolex (“head”) is quadrate in outline and has four circular suckers.

• Rostellum and hooklets are absent (i.e. unarmed scolex)

 Proglottids 

• 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.

• 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 

• 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.