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CESTODES
Dr Mohiedden M Abdul-Fattah
• Final host:
• Intermediate host (IH):
• Paratenic IH
• Reservoir Host:
• Prepatent period
• Auto infection:
• Non-patent Infection
Life cycle in human trematodes
Cestodes LC
Adults in the intestines of:
Eggs in water or soil
Aduts in human intestine1. D latum 4. Hymenolepis nana
Larva in tissues of1. Salmon fish
(plerocercoid)4.Villi of Man intestine or
flea (cysticercoid)
Larvae in tissues of Man & others
2. T. saginata
3. T.solium
5. H. diminuta
6. Dipylidium
5.Beetles ( cysticercoid)
6.Dog flea (cysticercoid)
2. Cattle (C bovis)
3. Pig (C cellulosae)
1. Cyclops (procercoid) & frogs, Man ( Sparganum)
2. Sheep, rat and Man (hydatid cyst and Coenurus)
3. Man and pigs ( cysticercus cellulosae)
1. Cats and dogs (Diphyllobothrium mansoni)
2. Dogs, foxes and cats (Echinococcus & Multiceps)
3. Man only (Taenia solium)
2-Egg in soil
3-Larva in tissue of IH
Pseudophyllidea: Diphyllobothrium latum
2-Egg in soil
1-Adult in intestine of
Man
3- Larvae in tissue of intestinal villi of
Man
Cyclophyllidea:H. Nana Direct LC
1-Adult in intestine of man
2-Egg in
water
3- 1st Larva in cyclops
4- 2nd larva in fish
Intestinal cestodes
1-Adult in intestine of
ManCyclophyllidea: 1.Taenia saginata2.T. solium3.Hymenolepis
nana. 4.H. diminuta5.Dipylidium
caninum
Man is usually infected by intestinal cestodes when ingests the larvae except H.nana, infection occurs by eggs.
All Cyclophyllidea must need one intermediate host in their life cycle except H. nana
The IH in Taenia is vertebrate host (cattle or pigs). In Hymenolepis and Dipylidium it is invertebrate
insect (fleas, beetles or cockroach) Pseudophyllidea (D. latum) needs two
intermediate hosts in their life cycles: (Cyclops as 1st IH and Salmon fish as 2nd IH.
OUTLINE OF LLIFE CYCLE IN INTESTINAL CESTODES
• Tissue cestodes: all are larvae.
• The larvae are either
• Solid in pseudophyllidea as 1. sparganum of (Spirometra) mansonoides, or
• Cystic in cyclophyllidea as
2. Cysticecus cellulosae of T.solium,
3. Coenurus of T.multiceps, and
4. hydatid cyst of Echinocccus granulosus
5. Alveolar hydatid cyst of E.multilocularis.
Sparganum
1) Ingestion of egg or larva never gives adult in man2A) Ingestion of eggs never gives adult in man but ingestion of
larva can2B & 2C) ingestion of egg or larva never gives adult in man
Human tissue cestodiases
• Man is infected by larval tissue cestodes when he ingests the eggs
• The only exception is the infection by sparganum
• It is caused by ingestion of procecoid in cyclops or plerocercoid (sparganum) larvae in fish or frogs.
• The cyclophylidean larval cestodes are cystic in vertebrate intermediate hosts.
• Pseudophyllidean larval cetodes are worm like in invertebrate IH (Cyclops) and/or vertebrate host.
Tissue cestodiases1. Sparganosis : by sparganum; larva of
Spirometra.
2. Cysticercosis: by cysticercus cellulosae; larva of T. solium.
3. Cystic hydatidosis: by hydatid cyst; larva of Echinococcus granulosis.
4. Alveolar hydatidosis: by multilocular hydatid cyst; larva of E. multilocularis
5. Coenurosis: by Coenurus; larva of Multiceps multiceps
Final hosts
Adult worm Intermediate hosts
Larval stages
1st Larva 2nd Larva
Dogs, cats
Diphyllobothrium mansonoides
Man, frogs
mammals
Procercoid
(Cyclops)
Sparganum
Man Taenia solium Man, pig Cysticercus cellulosae
Dogs, wolves, foxes
Multiceps multiceps
Man, Rabbits sheep
Coenurus cyst
Dogs Echinococcus granulosus
Man, Sheep camels
Hydatid cyst
cats, foxes
Echinococcus multilocularis
Man, rodents
Alveolar hydatid cyst
Tissue cestodes: larvae, their adults and hosts
Mode of infection in tissue cestodiases• Pseudophyllidea:I. Sparganosis1. Ingestion of Water contaminated by Cyclops
containing procercoid larva.2. Ingestion of meat of IH infected with sparganum
larva.3. Skin or mucous membranes contact with meat of IH
infected with Sparganum larva• Cyclophyllidea:• Cysticercosis:• Ingestion of egg of T. solium in human's feces
contaminating vegetables or food:
Mode of infection in more Cyclophyllidean tissue cestodes
o Ingestion of Taenia like egg in feces of dogs contaminating vegetables or food:
2. Coenurosis: dog's feces: (eggs of Multiceps)
3. Cystic hydatidosis: dog's feces: (eggs of E. granulosus)
4. Alveleolar hydatidosis: dog or cat's feces: (Eggs of E. multilocularis)
Intestinal Cestodes: Pseudophyllideaworm Dipyllobothrium latum
Man Final host
Reservoir Fish eating animals: cats, dog, birds
Habitat Small intestine
Exit stage Egg: Immature, operculate, abopercular knob, yellowish brown, 75 X50 µm.Segments with rosette shaped uterus passed in chains.
Intermediate host
1st : cyclops in fresh water2nd : Salmon fish
Infective stage Plerocercoid in fish
Mode of infection
Ingestion of plerocercoid in salmon fish
Disease 1. Enteritis & abdominal colic 2. megaloblastic anemia due to vitmin B12 consumption
diagnosis 1. Detection of eggs or segments passed in chains in stool
Treatment Oral Praziquantel
Control 1. Thorough freezing or cooking of fish04/08/2317
Intestinal Cestodes: Cyclophyllideaworm Taenia saginata Tenia solium
Man Final host
Reservoir None
Habitat Small intestine
Exit stage Egg: mature, round, striated shell, yellow brown, 30-40 µmGravid Segments with branched uterus singly in saginata, in chains (solium)
I. host Cattle Pigs
Infective stage Cysticercus bovis in beef Cysticercus cellulosae in pork
Mode of infection
Ingestion of C. bovis in beef Ingestion of C. cellulosae in pork
Disease 1. Enteritis 2. obstruction 1. Enteritis 2. obstruction• Cysticercosis: by antiperistalsis or by
external autoinfection
diagnosis 1. Detection of eggs or segments passed in stool
Treatment Oral Praziquantel or by Albendazole
Control 1. Thorough freezing or cooking of pork and beef.2. Sanitary disposal of human sewage
04/08/2318
Intestinal Cestodes: Cyclophyllideaworm Hymenolepis nana H. diminuta Dipylidium
Man Final host Occasional f. host Occasional final host
Reservoir None rodents dogs
Habitat Small intestine
Exit stage Mature, Spheroid egg, thin shelled, 30-45 µm with polar filaments
Mature ovoid 70-80µm with polar knobs
egg capsules with cluster of eggs each 20-30 µm
Intermediate host
None or fleas Beetles or fleas Fleas, dog lice
Infective stage Egg, cysticercoid in fleas Cysticercoid insect Cysticercoid
Mode of infection
Ingestion of egg in food or cysticercoid in insect
Imgestion of cysticercoid in fleas
Ingestion of cysticercoid in flea
Disease 1. Enteritis 2.Insomnia Enteritis enteritis
diagnosis Detection of egg in stool Detection of egg in stool
Detection of eggs or segments in stool
Treatment Oral niclosamide or Praziquantel
Control Health education.Personal hygiene
Flea controlRat control
Avoid playing with & treta pet animals04/08/2319
Tissue (Larval) Cestodes (Tapeworms): PseudophyllideaAdult worm Diphyllobothrium mansonoides
Larva Sparganum
Man Paratenic Blind end Intermediate host
Reservoir Frogs, snakes, birds (paratenic hosts)
Habitat Skin, muscles, eye, brain
Exit stage None
final host Cats
Infective stage Procercoid in cyclops and sparganum in frogs
Mode of infection
1. Ingestion of infected cyclops 2. ingestion of infected frogs.3. The use of meat of infected frogs as poultice on skin lesions
Disease 1. Skin and muscle nodes 2. Eye: conjuctivitis 3.Brain: fits
Diagnosis Identify larva in excision biopsy
Treatment Surgical removal or ethanol injection
Control Adequately cook meat of paratenic hostsDo not use this raw meat as poultice
04/08/2320
Tissue (larval) Cestodes: CyclophyllideaAdult Taenia solium T. multiceps E. granulosus E. multilocularis
Larva Cysticercus cellulosae Coenurus Hydatid cyst Alveolar hydatid
Man Blind end intermediate host
Reservoir Pigs Sheep, rabbits Sheep, camels rodents
Habitat Eye, brain, skin, muscles Eye, brain Liver, lung, brain Liver, lung, brain
Exit stage None None None None
final host Man Dog, foxes dogs Wolves, foxes, cats
Inf. stage Taenia solium egg egg egg eggMode of infection
1.ingestion of egg in foods2.Internal auto infection 3.external auto-infection
Ingestion of egg in foods
Ingestion of egg in foods
Ingestion of egg in foods
Disease Blindness, fits, skin nodes Blindness, fits Jaundice, hemoptysis, fits
Jaundice, hemoptysis
Diagnosis 1. Imaging 2. biopsy 3. serology (Immunoblot)Treat. Albendazole, cortisone,
surgerysurgery Albendazole,
surgeryEarly surgery
Control 1 Treat intestinal taeniasis2 sanitary disposal of sewage 3 avoid emetics
1. Avoid playing with dogs2. Treat pet dogs
1. Avoid cats2. Early diagnosis
04/08/2321
Spar-ganosis
Cysti-cercosis
Hyda-tidosis
Alveolar Hydatidosis
Coen-urosis
Final host Dogs, cats man dogs Dogs, cats dogs
Adult worm Spirometra T. solium E. granulosus
E. multilocularis
Multiceps
1st IH Cyclops Pigs
man
Sheep
man
Rodent
man
Sheep
man2nd IH
(paratenic)Frogs
(man)
nil nil nil nil
Inf. stage of man
Procercoid
sparganum
Taenia egg
Taenia like egg
Taenia like egg
Taenia like egg
Exit stage None None None None NoneDiagnosis Imaging, Biopsy, and sero-testing
Summary of Epidemio-Biologic Aspects of Tissue Cestodes
•Sparganosis• Definition: infection of human tissues with the
sparganum larvae of Spirometra mansonoides
I. Biology
I. BIOLOGY• Two species: 1. Spirometra. mansonoides2. S. proliferum (proliferative sparganosis); the larva
proliferate into surrounding tissue by lateral budding. • Man never acts as final host, but dogs and cats do.• Man acts only as dead end paratenic IH Host.• Habitat of larva in man: subcutaneous tissue,
muscles, eye and CNS.• Exit stage from man: none, but diagnosis made
when sparganum is surgically recovered.• Exit stage from dogs and cats: Immature eggs
passed in faeces (in water)
II. Epidemiology• Distribution: southeastern Asia and east Africa.• Transmission:• Intermediate hosts: • Cyclops is 1st IH and • Frogs, snakes, birds and mammals are 2nd IH.• Resevoirs: Birds and other mammals.• Infective stages: procercoid and sparganum.• Mode of infection:1. Ingestion of Cyclops containing procercoid of S.
mansonoides2. ingestion of sparganum in flesh of frogs, snakes or
birds.3. cutaneous exposure using the uncooked meat of these
infected animals as poultice on an inflamed skin or eye.
III. Host-parasite relationship• Pathogenesis:1. Depends on final location of migrating sparganum 2. Spargana may locate anywhere.3. subcutaneous tissue, breast, orbit, urinary tract,
pleural cavity, lungs, abdominal viscera and CNS• Clinical picture: 1. The migration in subcutaneous tissues is usually
painless, 2. but nodules on the chest and legs may be painful.3. in the brain: headache, fits may occur 4. In the orbit: conjunctivitis and periorbital oedema.5. In the inner ear: vertigo or deafness may occur.
IV. Diagnosis:
1. Excision and identification of sparganum in the lesion. ~5 cm white glistening worm.
2. Imaging: CT or MRI
3. Serotesting for specific antibodies (ELISA)
ophtlamoscopy
V. Treatment1. Spargana are resistant to praziquantel
and mebendazole.
• Currently there is no recommended drug therapy for sparganosis.
2. Surgical removal of the complete sparganum is the best treatment.
3. 40% ethanol injection with procaine to kill the larva in situ after which they are allowed to be absorbed.
VI. Control
• Avoid sources of infection:
1. Cyclops: Boiling or filtering of water in endemic areas.
2. Frogs and birds: Do not use their flesh as poultices.
3. Frogs and birds: Do not eat their undercooked meat.
CysticercosisInfection of human tissues by
cysticercus cellulosae; larva of Taenia solium.
I. Biology• Man act as final host and source of eggs. He
harbors the adult in his intestine.• Man act as dead end IH by harboring the larva
of T. solium (C. cellulosae) in his tissues.• Habitat of cystic larvae: 1. subcutaneous and intermuscular tissues, next
in the eye, then in the brain and other organs. 2. They are rare in spinal cord• Exit stage: none, but larva can be recovered
surgically
II. Epidemiology• Distribution: Mexico, south and central America,
Africa ,Asia.1. Intermediate host: pigs, monkeys, man.2. Reservoir hosts: the same animals.3. Infective stage: eggs or gravid segments of T. solium.4. Man is the only source of infection by cysticercosis5. Modes of infection:a. Ingestion of the eggs in contaminated food and drinks
(hetero-infection).b. Auto-infection of persons by faeco-oral transmission of
eggs from adult worms in their intestines.c. Internal autoinfection; eggs are carried by reversed
peristalsis back to the duodenum, hatch and induce cysticercosis.
III. Host parasite relationshipA.Pathogenesis• As the larva begin to die • a pronounced cellular reaction occurs,
followed by fibrosis, necrosis of the capsule and calcification of the larva in all tissues Except.
• In the eye, ventricles of the brain, and in the subarachnoid space.
• There is no fibrosis, but hydrocephalus occur• When cysts exist in vital organs; acute and
sometimes fatal sequences develop.• The location in the eye may be sub-choroidal,
sub-retinal, and intra-vitreous.
III. Host parasite relationshipB. Clinical picture:• Ocular cysticercosis: 1. visual impairment due to shadows cast by the
larva in front of retina.2. If not removed, it will produce uveitis, retinitis,
retinal detachment and blindness.• Cerebral cysticercosis:1. Adult onset epileptic fit.2. Obstructive hydrocephalus.3. Meningitis4. Behavioral disturbance.• Intermuscular nodules.• Subcutaneous nodules.
Subcutaneous nodules Intermuscular nodules
IV. Diagnosis• Detection of egg or gravid segment of Taenia
solium in stool may suggest auto-infection.• Imaging:1. Plain x-ray.2. CT and MRI: most effective in cerebral cysticercosis.• Detect specific antibodies in serum or CSF:1. ELISA using crude antigen extracted from the whole
cyst or its fluid, or using purified antigen fractions.2. immunoblot • Biopsy
V. Treatment• Recommend combined antiparasitic and
anti-inflammatory therapy.
• Praziquantel: PO for 15-30 days,or
• Albendazole: PO for 30 ds.
• Cortisone to to reduce inflammatory reaction due to dying cysticerci.
• Surgical excision for ocular cysticercosis, muscular and SC cysticerci
• CNS cases; non responders to drug.
VI. Prevention and Control• Prevent infection of man from pigs
Thorough cooking or freezing of pork.• Prevent infection of man from man
A. Prompt treatment of intestinal taeniasis solium.
B. Sanitary disposal of human excreta
C. Personal hygiene.
D. Proper washing of fruits and vegetable• Prevent auto infection of man
1. Avoid emetic drugs
Human tissue cestodiases
Final hosts
Adult worm Intermediate hosts
Larval stages
1st Larva 2nd Larva
Dogs, cats
Spirometra mansonoides
Man, frogs
mammals
Procercoid
(Cyclops)
Sparganum
Man Taenia solium Man, pig Cysticercus cellulosae
Dogs, wolves, foxes
Multiceps multiceps
Man, Rabbits sheep
Coenurus cyst
Dogs Echinococcus granulosus
Man, Sheep camels
Hydatid cyst
cats, foxes
Echinococcus multilocularis
Man, rodents
Alveolar hydatid cyst
Tissue cestodes: larvae, their adults and hosts
CoenurosisInfection of human tissue by Coenurus cerebralis;
Larva of Taenia multiceps
I. Biology• Final Hosts are dog, wolf and
fox : They harbor the Adult tapeworm that resembles Taenia .in their intestine.
• Man: harbors the cystic larva only and acts only as dead end intermediate host.
• Habitat in man: Cysts exist in all organs but more in eyes and brains.
• Exit stage: None, but cyst can be excised surgically.
• Exit stage from final hosts: Taenia like eggs
Cyst has multiple scolices, but no daughter cysts
I.B
iolo
gy: l
ife c
ycle
II. Epidemiology:• Distribution: North and east Africa, Zaire, USA
and England.
• Intermediate hosts: sheep, rabbits and man occasionally.
• Reservoir hosts: herbivores like sheep, Rabbits.
• Infective stage: egg of Taenia multiceps.
• Mode of infection: ingestion of fruits and vegetable contaminated by eggs of Multiceps.
III. Host parasite relationship• The transparent vesicle like cyst is space
occupying lesion that measures few mms to 5 cms.
• It has multiple scolices, but no daughter cysts.• Pathology depends on the site • If it tolerates mechanical pressure; no symp.• Muscle and SC tissues: painless nodules• Brain, eye and spinal cord are less tolerant sites;
so clinical picture develops:1. In brain: fits, headache, and hemi-plegia.2. In the eye: disturbed vision.
3. In spinal cord: paraplegia.
Coenurus excised from enucleated eye
IV. Diagnosis
• Imaging: X-ray, CT, and MRI.
• Recovery of the cyst by surgical excision.
• Ophthalmoscopic examination.
V. Treatment• Surgical removal of the coenurus
effectively treats intracranial and ocular coenurosis in most cases.
• Medical
• praziquantel.
• The drug of choice is albendazole
VI. Control• Prevention of infection of the dogs from
rabbit and sheep by1. Proper carcass disposal of potentially
infected intermediate hosts.• Prevention of man infection from dogs1. Elimination of stray dogs.2. Treatment of pet dogs.3. Avoid contact with dogs.4. Thorough washing of vegetable and fruits5. Personal hygiene.
Hydatid diseases
1.Cystic hydatid disease (cystic echinococcosis)
• Ecchinococcus granulosus
2.Alveolar hydatid disease ( alveolar echinococcosis)
• E. multilocularis
3.Polycystic hydatid diease.
• E. vogeli and oligarthus.
I. Biology• Two species Echinococcus: 1. Unilocular larva (hydatid cyst): of E. granulosus2. Multilocular larva (alveolar hydatid cyst): of E.
multilocularis.• Final hosts are canids: The adults exist in their
intestine.• Human never acts as final host of these worms.• But Man can harbor the larva in his tissue to act as
blind end intermediate host.• Habitat in man: liver (65%), lung (25%),and
kidneys, bone, heart and brains (10%).• Exit stage: none, but hydatid cyst, hydatid sands
can be obtained by excision or by puncturing.
I. Biology
Life cycle of Echinococcus granulosus
II. Epidemiology• Distribution: areas of sheep & camel raising.• Intermediate hosts: herbivores; sheep, camels,
Cysts in cattle are sterile. They do not act as IH.
• Human is dead end intermediate host• Reservoir host: sheep and camels.• The infective stage of man: The taenia like egg of
E. granulosus in feces of dogs.• Mode of infection of man: ingestion of foods
contaminated by eggs.• The infective stage of the final host (dogs): the
hydatid cyst.• Mode of infection of dogs: ingestion of meat of
animals infected by the larva (hydatid cyst).
III. Host parasite relationship• Pathogenecity:• Space occupying lesion:1. The growing cyst produce pressure atrophy of the
surrounding tissues, leading to organ dysfunction. 2. This effect depends on the size and site of the cyst3. The most affected sites: liver (65%), lung
(25%),and kidneys, bone, heart and brains (10%).• Rupture of cyst:1. Immune response• Immediate hypersensitivity reaction (Type I): slow leakage causes allergic features & rupture of
the cyst causes anaphylactic shock.2. Metastasis• The rupture may lead to metastasis of secondary
cysts in other organs
III. Host parasite relationship• Pathology:• Size : unilocular cyst 1-
10 cm.• Wall of the cyst is
formed of 3 layers:1. Outermost fibrous layer
by the host2. Laminated non cellular
layer3. Inner germinal from
which scolices develop• Content: fluid, scolices,
brood capsule, and daughter cyst
III. Host-parasite relationship• Clinical picture: depends on site and size of cyst. • Mostly asymptomatic• Symptoms take years to develop (5-20)1. Liver cysts: hepatomegaly & obstructive jaundice. 2. pulmonary cysts: cough hemoptysis & abscess. 3. Kidney cysts: renal dysfunction and scolices appear
in urine.4. In bone may induce spontaneous fracture.5. Brain cysts: intracranial pressure and epilepsy6. Minimal leakage of the cyst Contents produces
urticaria and other allergic manifestation.7. Rupture of the cyst: leads to anaphylactic shock,
death.
IV. Diagnosis1. Imaging tests: Sonography, and CT. They with
history and eosinophilia are almost diagnostic.2. Aspiration to detect hydatid sand; brood capsules,
protscolices3. Histology of an excised cyst .4. By serological tests to detect specific antibodies. a. Initial screening tests with crude antigens using IHAT,
IFAT and ELISA techniques b. Confirmatory tests with purified antigens, ie. arc-5
Counter current immuno-electrophoresis (CIEP) and IB.5. Casoni test: • Intradermal injection of 0.2ml of sterile fresh hydatid
fluid gives erythematous wheel of ~5cm in diameter within 15-20 minutes.
IMAGING Aspiration
Serotesting: CIEP
V. Treatment• Treatment: • Inoperable cases: • Albendazole is given in 3 to 12 cycles of each
one month followed by a two week rest period.• Operable cases:• pre and post-operative albendazole to prevent
recurrence. • Removal either by partial hepatic resection,
pericystectmy or cystectomy• PAIR approach; Puncture→ Aspirate→ Inject
albendazole or hypertonic saline→ Reaspirate.
VI. Control• Prevention of infection of dogs from sheep
and camels by1. Sanitary disposal of the infected offal.• Prevention of man infection from dogs1. Elimination of stray dogs.2. Treatment of pet dogs.3. Avoid contact with dogs.4. Thorough washing of vegetable and fruits5. Personal hygiene
• Alveolar Echincoccosis
• Infection of human tissues by the larva of E. multilocularis
(Alveolar Hydatid cyst)
II. Biology Final hosts: Fox, wolves, dogs and cats
Habitat in the final host: small intestine Exit stage from the final host: Taenia
like eggs in faeces of FH. Man occasionally harbors the larval cysts
and acts as blind end IH. Habitat in man: liver, lung and brain.
Exit stage from man: none, the larval mass can only be recovered
surgically in early cases.
Final hosts
Intermediate Host
Man : blind end Intermediate host
I. Biology
II. Epidemiology Distribution: Europe and N.
America Intermediate hosts (IH):
rodents and human but human is dead end I.H.
Resrvoir hosts: rodents only The infective stage of man:
Taenia like egg in feces of FH. Mode of infection of humans:
accidental ingestion of eggs in foods, drinks.
Infective stage of FH (dogs): alveolar hydatid cyst in rodent..
Host parasite relationship
• Pathology:1.The site is usually the liver
2.Tumor like spongy mass with irregular, multi-vesicular, infiltrating structure consisting of small vesicles embedded in stroma of connective tissue
III. Host parasite relationship
• .Pathology continued;
3. The mass is without or with very thin limiting membrane,
4. Inner germinal epithelium proliferates in any direction invading surrounding tissues.
5. Cysts contains jelly like material rather than fluid.
6. If vena cava or portal vein are invaded. The lesion metastasizes to other organs e.g. lung and brain.
Alveolar hydatid cyst
III. Host-parasite relationship
• Clinical picture:
1.The larva grows very slowly so symptoms occur in patients over 50 ys.
2.These include right upper abdominal pain, hepatomegaly and jaundice.
3.Occlusion of IVC, and common bile duct produce fatal sequelae.
• Metastasis to brain and lung causes related symptoms
IV. Diagnosis1. Imaging: ultrasonography (US),CT, MRI.
• In CT the characteristic lesion is called geographic map with irregular contours and alternating hypodense and hyperdense areas.
2. Serotesting by ELISA or IB to detect specific abs using:
• fractionated E-S antigens of scolices of Em .
3. Wide scale Sero-testing to screen population at high risk allow early diagnosis of lesion.
• This can result in improvement in quality of management.
V. Treatment• The cases are usually discovered in late stages.• Surgery:
1. Late cases are almost inoperable.
2. Partial hepatectomy might provide solution
3. Liver transplantation is life saving.
4. Medical in late cases:• Drug therapy slows the growth and delays
complications • Life long continuous mebendazole • Intermittent albendazole (400 mg twice daily for 28
days alternating with 14-day rest period
VI. Control• Prevention of infection of FH; cats and dogs from
rodents by
• Rodent control
• Prevention of infection of man from cats and dogs
1. Stray dog elimination in endemic areas.
2. Treatment of pet animals.
3. Careful washing of vegetable and fruits
• Early diagnosis and treatment of human infection
• Mass serological screening of population in the endemic areas
Human tissue cestodiases
Tissue cestodiases1. Sparganosis : by sparganum; larva of
Spirometra.
2. Cysticercosis: by cysticercus cellulosae; larva of T. solium.
3. Cystic hydatidosis: by hydatid cyst; larva of Echinococcus granulosis.
4. Alveolar hydatidosis: by multilocular hydatid cyst; larva of E. multilocularis
5. Coenurosis: by Coenurus; larva of Multiceps multiceps
Mode of infection in tissue cestodiases• Pseudophyllidea:I. Sparganosis1. Ingestion of Water contaminated by Cyclops
containing procercoid larva.2. Ingestion of meat of IH infected with sparganum
larva.3. Skin or mucous membranes contact with meat of IH
infected with Sparganum larva• Cyclophyllidea:• Cysticercosis:• Ingestion of egg of T. solium in human's feces
contaminating vegetables or food:
Mode of infection in more Cyclophyllidean tissue cestodes
o Ingestion of Taenia like egg in feces of dogs contaminating vegetables or food:
2. Coenurosis: dog's feces: (eggs of Multiceps)
3. Cystic hydatidosis: dog's feces: (eggs of E. granulosus)
4. Alveleolar hydatidosis: dog or cat's feces: (Eggs of E. multilocularis)
Spar-ganosis
Cysti-cercosis
Hyda-tidosis
Alveolar Hydatidosis
Coen-urosis
Final host Dogs, cats man dogs Dogs, cats dogs
Adult worm Spirometra T. solium E. granulosus
E. multilocularis
Multiceps
1st IH Cyclops Pigs
man
Sheep
man
Rodent
man
Sheep
man2nd IH
(paratenic)Frogs
(man)
nil nil nil nil
Inf. stage of man
Procercoid
sparganum
Taenia egg
Taenia like egg
Taenia like egg
Taenia like egg
Exit stage None None None None NoneDiagnosis Imaging, Biopsy, and sero-testing
Summary of Epidemio-Biologic Aspects of Tissue Cestodes
Outline of life cycles of cestodes
Human tissue
cestodes
Human
Intestinal
cetodes