Cestodes
Taenia solium & Taenia saginataTaenia saginata Beef tapeworm
Taenia solium Pork tapewormDisease : Taeniasis
Morphology of adult
1. They are flat , hermaphroditic worms ,live in small intestine of man.
2. Adult worms consist of a head , neck and
segmented body (proglottids) may reach
thousands.
3. The head (scolex) contain suckers (T. saginata), or suckers & hooks (T. solium).
Scolex of T. saginata
• Scolex of T. Solium
4. Mature segment contain both male & female sexual organs.5. Gravid segment contain only uterus full with
eggs which usually passed with eggs out with
feces as diagnostic stages.
6. The length of adult worms is usually 4-10 m for T. saginata and 2-7 meter for T. solium.
7 . T. saginata usually have 1,000 to 2,000 segments,
while T. solium have an average of 1,000 segments.
Adult worm of Taenia saginata
Adult worm of Taenia solium
Gravid segment of T.Saginata
longer than wide consist of median uterus with 15-30 lateral uterine branches with unilateral genital pore .Gravid segment of T.Solium
7 – 13 lateral uterine branches.
Gravid segment of T.Saginata
Gravid segment of T.Solium
Cysticercoids larvaIt is bladder like cyst called bladder worm with invagenated or evagenated scolex .They are infective stages to human and they are two type :
• C. Bovis: scolex without hooks in the muscles of cattles (T.saginata).
• C.cellulosae : scolex with hooks in muscles of pigs (T.solium).Cysticercus bovis
• Cysticercus cellulosae
Life cycle of T. saginata and Taenia solium
Taenia spp
definitive hosts : Humansintermediate host: Cattle for T. saginata and
pigs for T. solium.
infective stages: Cysticercus Larva
Diagnostic stages: egg , gravid segments in feces and scolex.
Laboratory Diagnosis
Microscopic identification of scolex and segments in feces are diagnostic for taeniasis.The gravid segments can differtiate between T.saginata and T. solium but the eggs are morphologically identical, and indistinguishable between taenia species.
