8/7/2019 Tissue Cestodes Concise Pharmacy
1/31
TISSUE CESTODES
Dr Mohiedden M Abdul-Fattah
8/7/2019 Tissue Cestodes Concise Pharmacy
2/31
Final host:
Intermediate host(IH):
Paratenic IH
Reservoir Host: Prepatent period
Auto infection:
Non-patent Infection
8/7/2019 Tissue Cestodes Concise Pharmacy
3/31
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 granulosus5. Alveolar hydatid cyst of E.multilocularis.
8/7/2019 Tissue Cestodes Concise Pharmacy
4/31
Sparganum
8/7/2019 Tissue Cestodes Concise Pharmacy
5/31
1) Ingestion of egg or larva never gives adult in man
2A) Ingestion of eggs never gives adult in man but ingestion oflarva can
2B & 2C) ingestion of egg or larva never gives adult in man
8/7/2019 Tissue Cestodes Concise Pharmacy
6/31
Man is infected by larval cestodiases 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.
8/7/2019 Tissue Cestodes Concise Pharmacy
7/31
Sparganosis Definition: infection of human tissues with thesparganum larvae ofSpirometra mansonoides
8/7/2019 Tissue Cestodes Concise Pharmacy
8/31
I. Biology
8/7/2019 Tissue Cestodes Concise Pharmacy
9/31
I. BIOLOGY Two species:
1. Spirometra. mansonoides
2. S. proliferum (proliferative sparganosis); the larvaproliferate 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)
8/7/2019 Tissue Cestodes Concise Pharmacy
10/31
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 Cyclops containing procercoid ofS.mansonoides
2. ingestion of sparganum in flesh of frogs, snakes orbirds.
3. cutaneous exposure using the uncooked meat of theseinfected animals as poultice on an inflamed skin or eye.
8/7/2019 Tissue Cestodes Concise Pharmacy
11/31
8/7/2019 Tissue Cestodes Concise Pharmacy
12/31
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.
8/7/2019 Tissue Cestodes Concise Pharmacy
13/31
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)
8/7/2019 Tissue Cestodes Concise Pharmacy
14/31
ophtlamoscopy
8/7/2019 Tissue Cestodes Concise Pharmacy
15/31
V. Treatment
1. Spargana are resistant to praziquanteland 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 killthe larva in situafter which they are
allowed to be absorbed.
8/7/2019 Tissue Cestodes Concise Pharmacy
16/31
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 theirundercooked meat.
8/7/2019 Tissue Cestodes Concise Pharmacy
17/31
CysticercosisInfection of human tissues by
cysticercus cellulosae; larva of Taenia
solium.
8/7/2019 Tissue Cestodes Concise Pharmacy
18/31
8/7/2019 Tissue Cestodes Concise Pharmacy
19/31
8/7/2019 Tissue Cestodes Concise Pharmacy
20/31
8/7/2019 Tissue Cestodes Concise Pharmacy
21/31
III. Host parasite relationshipA.Pathogenesis
As the larva begin to die a pronounced cellular reaction occurs,
followed by fibrosis, necrosis of the capsuleand calcification of the larva in all tissuesExcept.
In the eye, ventricles of the brain, and in thesubarachnoid space.
There is no fibrosis, but hydrocephalus occur When cysts exist in vital organs; acute andsometimes fatal sequences develop.
The location in the eye may be sub-choroidal,
sub-retinal, and intra-vitreous.
8/7/2019 Tissue Cestodes Concise Pharmacy
22/31
III. Host parasite relationshipB. Clinical picture:
Ocular cysticercosis:1. visual impairment due to shadows cast by thelarva 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. Meningitis
4. Behavioral disturbance. Intermuscular nodules.
Subcutaneous nodules.
8/7/2019 Tissue Cestodes Concise Pharmacy
23/31
Subcutaneous nodules Intermuscular nodules
8/7/2019 Tissue Cestodes Concise Pharmacy
24/31
8/7/2019 Tissue Cestodes Concise Pharmacy
25/31
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 wholecyst or its fluid, or using purified antigen fractions.
2. immunoblot Biopsy
8/7/2019 Tissue Cestodes Concise Pharmacy
26/31
V. Treatment
Recommend combined antiparasitic andanti-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.
8/7/2019 Tissue Cestodes Concise Pharmacy
27/31
VI. Prevention and Control
Prevent infection of man from pigsThorough 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
8/7/2019 Tissue Cestodes Concise Pharmacy
28/31
Human tissue cestodiases
8/7/2019 Tissue Cestodes Concise Pharmacy
29/31
8/7/2019 Tissue Cestodes Concise Pharmacy
30/31
CoenurosisInfection of human tissue by Coenurus cerebralis;
Larva of Taenia multiceps
8/7/2019 Tissue Cestodes Concise Pharmacy
31/31
I. Biology Final Hosts are dog, wolf and
fox : They harbor the Adulttapeworm that resemblesTaenia .in their intestine.
Man: harbors the cystic larvaonly and acts only as dead endintermediate host.
Habitat in man: Cysts exist in allorgans but more in eyes andbrains.
Exit stage: None, but cyst canbe excised surgically.
Exit stage from final hosts:Taenia like eggs
Cyst has
multiple
scolices, but
no daughter
cysts
Top Related