Taenia solium, the pork tapeworm, is a parasitic flatworm that can cause both taeniasis and cysticercosis in humans. It has a worldwide distribution except where pork is not consumed. The adult worm lives in the small intestine and eggs passed in stool can infect pigs, causing the larval stage cysticercus cellulosae. Humans can also become infected by ingesting eggs, with the larvae then developing in tissues throughout the body, commonly in muscles and the brain. Symptoms vary depending on the infected tissue but can include seizures, hydrocephalus, and neurological or psychiatric disturbances in neurocysticercosis. Diagnosis involves finding eggs, proglottids or antigens in
2. WHERE DOES IT BELONG?
order
order
Phylum
Class
Order
Family
Genus
species
Platyhelminthes( flatworms)
Cestoidea
Cyclophyllidea
Taenidae
Taenia
solium
3. Taenia solium - pork tape worm
Taenia - band/tape
Worldwide in distribution except in regions
and communities who don’t consume pork
8. ADULT WORM
2-3 m long
Scolex small & globular(1mm)
4 large cup like suckers(acetabula)
Rostellum with double row of alternating round &
small dagger shaped hooks. (20-50 )
Neck is short and half as thick
Proglottids less than 1000
9. Gravid segments are twice as long & broad.
Testes composed of 150-200 follicles
An accessory lobe for ovary
Vaginal sphincter absent
Uterus has 5 to 10 thick lateral branches
A lateral thick lipped genital pore is present
alternating the right & left sides of adjacent
segments.
Gravid segments pass passively out as short
chains. Eggs escape from ruptured uterus
10. EGGS
Egg similar to T.saginata
Spherical 30-40 micro.m
Thin hyaline membrane around it which disappears
after release
Inner embryophore radially striated & is yellow
brown due to bile staining.
In the centre a fully developed embryo(oncosphere)
with 3 pairs of hooklets(hexacanth embryo)
Eggs do not float in saturated salt solution
Eggs are infective both pigs & humans.
11. LARVA
Larval stage of taenia – cysticercus
Of T.solium called cysticercus cellulosae
12. CYSTICERCUS
CELLULOSAE(BLADDERWORM)
Infective form
Develop in various organs of pig & human
Ovoid,opalescent milky-white
Measuring 8-10 mm in breadth and 5 mm in
length.
Scolex of larva with its suckers lie
invaginated within the bladder
It remains viable for several months.
15. When it causes cysticercosis
o Definitive host - man
o Intermediate - man
o Infective stage- eggs
o Mode of infection- by ingesting eggs
with contaminated food & water
o man harboring adult worm can auto
infect himself by unhygeinic habits or
reverse peristalsis.
16. o Oncospheres released in duodenum or
jejunum & penetrate intestinal wall
o They enter mesenteric venules & lymphatics
o Carried to different parts of body by
systemic circulation
o Filtered in to muscles & develop in to larval
stage in 60-70 days
o Larvae die without further development
17.
18.
19. Intestinal taeniasis
caused by T.solium & T.saginata
Sometimes asymptomatic
When symptomatic causes abdominal
discomfort,indigestion,nausea,diarrhea&
weight loss
Occasionaly acute appendicitis &
pancreatitis
20. Cysticercosis
• Caused by larval stage
• Larva-solitary or multiple
• Most common-subcutaneous tissue&
muscle
• Also affect-
eyes,brain,heart,liver,lungs,abdominal
cavity& spinlcord
21. • Larvae can evoke a cellular reaction starting
with infiltration of
neutrophils,eosinophils,lymphocytes,plasma
cells & giant cells
• Subcutaneous – asymptomatic
• Cysticercus surrounded by a fibrous capsule
except in eye & ventricles of brain
27. OCULAR CYSTICERCOSIS
Cysts found in vitreous humor,subretinal space & Conjunctiva
May present as blurred vision or loss of vision
Iritis ,uveitis & palpebral conjuctivitis
28.
29. TAENIASIS
1. Stool examination
Eggs
microscopic examination shows eggs
Formol ether sedimention of method of stool
concentration useful
Detected by cellophane swab method
Species identification not possible
30. Proglottids
Species identification possible using hand lens
When gravid proglottid pressed between two
slides branching can be made out
Only 13 lateral branches in T.solium
31. Detection of taenia antigen in feces
ELISA using polyclonal antisera to
detect coproantigen
More sensitive than microscopy
Cannot differentiate between T.solium
T.saginata
32. Serodiagnosis
specific abs detected by
ELISA
indirect immunoflouroscent test
indirect hemgglutination (IHA) test
Molecular diagnosis
DNA probes & PCR to detect & differentiate b/n T.solium &
T.saginata
35. Intestinal taeniasis
Single dose of praziquantel(10-20 mg)
Nicolsamide (2 g) single dose
Purgation is not necessary
36. Cysticercosis
Excision best method
Asymptomatic neurocysticercosis no treatment
Symptomatic cerebral cysticercosis-praziquantel – 50
mg/kg in divided dose for 20-30 days
Albentazole – 400 mg twice daily for 30 days
Corticosteroids to reduce inflammatory reactions
Antiepileptic drugs
Operative intervention indicated for hydrocephalous
37.
38. Inspection for cysticerci in slaughter house
Avoid undercooked pork
(temp 56 `c for 5 mts)
maintain clean personal habits & general
Sanitary measures
Prevention of fecal contamination
Detection & treatment of hosts