This document summarizes information about the beef tapeworm Taenia saginata, including its morphology, life cycle, pathogenesis, treatment, and prevention. It inhabits the human small intestine and can survive for up to 25 years. The adult worm passes eggs in feces that are ingested by cattle and develop into cysticerci larvae in muscle. Humans are infected by eating undercooked beef containing the larvae. Symptoms of infection include abdominal pain and anemia. Treatment involves niclosamide or mebendazole to kill the adult worm. Thorough cooking of beef prevents transmission.

1. Taenia saginata (beef tapeworm)
• In adult stage, T. saginata inhabits
the upper jejunum
• it may survive for as long as 25
years
• It causes intestinal infection,
Taeniasis
• It has worldwide distribution

2. Scolex……

3. Taenia saginata….. Morphology
• Adult worm measures 5-10 meters in
length
• The pyriform scolex has 4 suckers but
no rostellum
• The mature segments have irregularly
alternate lateral genital pores
• uterus made up of a median stem with
15-30 lateral branches.

4. Taenia saginata…….. Life cycle
• The adult worm lives in the small intestine of man
• Gravid segments pass out in the stool and become
disintegrated and eggs come out to the soil
• The gravid proglottid uterus contains about 100,000
eggs
• The egg of T. saginata is round, about 40 microns in
diameter
• The 6-hooked embryo is enclosed in a radially striated
embryophore
• Eggs are ingested by an intermediate host, cattle.

5. Taenia saginata…….. Life cycle
• The 6 hooked embryo escapes from its shell, penetrates
through the intestinal wall into the blood vessels and is
carried to the muscles,
•
• it develops into a larval stage, cysticercus bovis (made up of an
invaginated /inverted head and spherical body).
• Infection to man takes place by the ingestion of raw or
insufficiently cooked beef
• In the small intestine of man, the head of the cysticercus-
infective, attaches to intestinal wall, gets invaginated and
the body becomes segmented.

6. Life cycle of Taenia
saginata

7. Taenia saginata…… Pathogenicity
• epigastric pain
• abdominal discomfort/Diarrhea
• weight loss/nutrient competition in
malnourished hosts
• hunger sensation
• Vomiting
• Megaloblastic Anemia (caused by loss of
vitamin B12)
• Diagnosis
• Recovery of the gravid segments or the
eggs from the stool
• Cysticercus bovis ; @ necropsy
• Cysticercus bovis : Muscle & Heart
damage
• Beef Condemnation ("Measly Beef")

8. Taenia saginata…… Treatment
Niclosamide (Yomesan): 2g, is given to adults and older children as
a single morning dose on an empty stomach; the tablets should be
chewed. Children of 2 to 6 years should receive 1g, and those below
250mg
Mebendazole (Vermox): 100mg PO, twice for 3days, second course
if no response after 3-4 Wks. Also Albendazole can be given
The alternative is praziquantel, 5 to 10mg/kg as a single dose after
a light breakfast. After either drug the proximal part of the worm
disintegrates in the gut and the scolex cannot be found. Failure of
proglottids to reappear within 3 to 4months indicates cure

9. ♦ Thorough cooking of meat (above 570C)
♦ Proper disposal of human excreta
♦ Mass treatment of herd contacts, or whole adult populations
Prevention

10. T. solium:
The pork tapeworm

11. •Worldwide distribution
•Large tapeworm
•Cause taeniasis due to T. solium
•Larval infection of Taenia solium
may cause serious clinical disease -
--CYSTICERCOSIS
Taenia solium

12. Morphology
• 2 to 5 meters long
• globular scolex with four suckers
• 2 circular rows of hooks
(rostellum)
• The gravid proglottids are 5×10
mm
• 5-15 branched uterus
• The eggs of T. solium and
T. saginata are indistinguishable

13. Main points of the life cycle
• Man is the only definitive host, but he can also be the
intermediate host for T. solium
• Pig is the important intermediate host for T. solium
• Adult worm reside in the lumen of the upper part of
small intestine
• The infective stage to man are both egg/gravid proglottid
and cysticercus for T.solium

14. Lifecycle of T. solium
Transmission and diseases

15. Main points of the life cycle
• The adult may live in the small intestine as long as 25
years and pass gravid proglottids with the feces when
eggs consumed by pigs in which they hatch and form
cysticercus cellulosae
• T.solium eggs can also infect humans and cause
cysticercosis (larval cysts in lung, liver, eye, maxillofacial
region and brain)
• Eggs from ----auto-infection, external
• Eggs from ----auto-infection, internal
• Eggs from ----external

16. • A tapeworm larval cyst (cysticercus) is ingested with poorly
cooked meat
• The larva escapes the cyst and passes to the small intestine
where it attaches to the mucosa by the scolex suckers
• The proglottids develop as the worm matures in 3 to 4
months

17. • The cysticercus stage of T. solium can be found anywhere in
the body -- subcutaneous, muscles, eye, brain
• Regardless of the tissue affected, pathological consequences
are those of a space-occupying lesion
• Cysticerci in brain tend to grow to a larger size than those in
other tissues
• The process of calcification may be accompanied by the
release of antigens -- inflammatory reaction
Metacestode stage – Cysticercosis

18. Cysticercus

19. Pathogenesis and clinical features
• Adult worm —Teaniasis
• Light infections remain asymptomatic
• Heavier infections may produce
abdominal discomfort, epigastric pain,
vomiting and diarrhea

20. Cysticerci in brain

21. Cysticerci in heart

22. Cysticerci in tongue

23. subcutaneous
nodules
Cysticercus on
the eyeground
pseudohypertrophy of muscle
Cysticercosis in T. solium

24. DIAGNOSIS
• For adult worm infection (Teaniasis)
＊ History of eating raw pork
＊ Find gravid proglottids in feces
＊ Perianal swab to find eggs

25. Cysticercosis
＊ Specific diagnosis is difficult to establish, the
history and adult worm infection attribute to
strong suspicion
＊ Biopsy to subcutaneous lesions
＊ Computerized axial tomography or magnetic
resonance imaging
＊ Serological examination for specific antibody

26. PRINCIPLES OF CONTROL
• Treat all patients to eradicate the source of larvae
parasitism
• Pumpkin seed and areca nut ;
• Praziquantel
• Avoid the fecal contamination of pig feed
• Modernization of raising pigs
• Pay attention to personal and food hygiene
• Intensive examination of the pork
• Adequate cooking or freezing of meat are effective
precautions
• cysticerci do not survive at temperatures below -10℃ and
above 57 ℃.

27. Feature T. saginata T. solium
Length 5-10 meters 2-4 meters
Scolex Pyriform globular
No. of proglottids 1000-2000 800-900
Hooks/rostellum Absent 2 rows
Suckers 4 suckers 4 suckers
Uterine branches 15-30 5-10
Intermediate host Cattle Pig/Man
Infective stage Larvae Egg/Larvae
Clinical
disease(s)
Taeniasis Taeniasis/Cysticercosis
Comparison between Taenia saginata and Taenia solium