CESTODES 2 Flashcards
______________ having both male and female
reproductive organs in the same individual.
Hermaphroditic
____________ includes the Tapeworms & Flukes
Phylum platyhelminthes (flatworms)
Multicellular animals characterized by a flat,
bilaterally symmetric body. It is dorsoventrally
flattened and is solid (no body cavity).
flarworms
The classes_______________ contain species parasitic to humans.
Cestoda (tapeworms) and Trematoda
(flukes)
Overall size varies greatly, some members are as
small as 1mm, and others may be 20 meters or
longer
flatworms
___________ are the tapeworms: flat, segmented body with
various length (several mm ~ several meters)
cestodes
___________ are hermaphroditic with each proglottid developing
both male and female reproductive organs, and
mature eggs developing in the most distal
proglottids
cestodes
cestode don’t have ______ and _________
have no circulatory system
have no digestive tract
outward projections
Microtriches
similar to microvilli of our gut mucosal
cells
increase the surface area for nutrient
absorption
interdigitate with host microvilli
Microtriches - cestodes
are diagnosed by finding eggs or proglottids in the
feces
CESTODES
Habitat of adult tapeworm: cestodes
intestine of the DH
Intermediate host: cestodes
larval stage encysted in the
tissue
cestodes are Consist of three basic portions:
- Scolex
- Neck: germinal portion
- Strobila: immature, mature, gravid
proglottids (segments)
Consist of three basic portions:
1. Scolex
For attachment:
__________: armed with hooks
Suckers
Rostellum
___________ is germinal portion
Neck
__________ immature, mature, gravid
proglottids (segments)
Strobila
The segments bud from behind the scolex and are ___________
immature
As they are pushed back, they _______, and fill with
________.
mature-eggs
Once eggs are fertilized, they become “________”
proglottids
gravid
reproductive organs are undifferentiated
immature proglottids
reproductive organs are differentiated
mature proglottids
uterus with lateral branches filled with eggs
gravid
A. Cestodes (Cyclophillidians)
Taenia solium
Taenia saginata
Hymenolepis nana
Hymenolepis diminuta
Dipylidium caninum
Raillietina garrisoni
B. Cestodes (Pseudophyllidians)
Diphyllobothrium latum
_________ - infection of humans with the
adult pork tapeworm
Taeniasis (solium)
Ingestion of raw, insufficiently cooked pork
containing cysticercus cellulosae
TAENIA SOLIUM
what is the definitive host of taenia cellulosae
humans
___________ refers to infection of human
with the larval stage of the parasite
Human Cysticercosis
intermediate host of taenia solium
man
examination of gravid segment between 2 slides
Species differentiation
examining biopsy material from cysts
Definitive Diagnosis
Common name of taenia solium
pork tapeworm or hook tapeworm
Mode of transmission of taenia solium
Ingestion of embryonated egg (human cysticercosis)/ (ingestion of “measly pork”
Infective stage of taenia solium
cysticercus cellulosae
intermediate host of taenia solium
pig or swine, human
Definitive host of taenia solium
human
Taenia solium
Common name:
Mode of transmission:
Infective stage:
Intermediate host:
Definitive host:
CMIID
pork tapeworm or hook tapeworm
ingestion of embryonated egg (human cysticercosis) or ingestion of “measly pork”
cysticercosis cellulosae
pig or swine, humans
humans
taenia solium pathology
________ - infection of human with adult pork tapeworm
Ingestion of ________
Man: _________
________- refers to infection of human with the larval stage of the parasite
ingestion of __________
man:__________
taenia solium
ingestion of raw, insufficiently cooked pork containing cystercircus cellulosae
definitive host
human cysticercosis
eggs of t. solium
intermediate host
taeniasis prevention
Avoid eating raw pork
Proper excreta disposal
cysticercosis prevention
Good personal hygiene
Avoid niclosamide and dichlorphen
- disintegration of gravid segments
and can release more eggs.
MORPHOLOGY: OVA
Taenia eggs
-spherical/ subspherical
-brownish with thick embryopore, numerous pits
-inside: oncosphere with three pairs of hooklets
Smaller and more spherical with 4 acetabulla,
cushion like rostellum double crown of large and
small hooks
T. solium
Cuboidal, 1-2 mm
4 acetabula (ventral suckers)
Unarmed: no hooks or rostellum
T. saginata
HYMENOLEPIS NANA
Common Name?
Mode of transmission?
Infective stage?
IH: ?
DH: ?
Dwarf Tapeworm
Ingestion of embryonated egg (direct) or
ingestion of flour beetle (indirect)
Infective stage: Cysticercoid larvae (may not
require intermediate host)
IH: Rat Flea, Dog Flea, Human Flea Rice and
Flour Beetles, Cockroaches
DH: Human, Rat
HYMENOLEPIS NANA: PATHOLOGY
mild abdominal discomfort to abdominal pain,
nausea, vomiting diarrhea, anorexia
HYMENOLEPIS NANA: DIAGNOSIS
Fecalysis - eggs
HYMENOLEPIS NANA: TREATMENT
Drugs of Choice: Praziquantel, Bithionol
Long term basis with 7 day interval in between
cycles
Personal hygiene
Environmental sanitation- rodent control
Properly stored food
HYMENOLEPIS DIMINUTA
Common Name?
Mode of transmission?
Infective stage?
IH: ?
DH: ?
AH: ?
Rat Tapeworm
Accidental ingestion of insects with
cysticercoid larvae
Infective stage: Cysticercoid larvae (require
intermediate host)
IH: Flea, beetle, earwig, mealworm
DH: Rat
AH: Human
HYMENOLEPIS DIMINUTA: PATHOLOGY
light and asymptomatic
no autoinfection
HYMENOLEPIS DIMINUTA: DIAGNOSIS
Fecalysis - eggs
HYMENOLEPIS DIMINUTA: TREATMENT
Treatment, Prevention and Control
Characteristic feature of scolex, gravid
segments and eggs
Fecalysis- eggs
MORPHOLOGY: OVA
__________ contains oncosphere with 6 hooklets and polar filaments
___________ circular, yellowish brown
oncosphere enclosed in inner membrane no filaments
H. nana
H. diminuta
MORPHOLOGY: SCOLEX
subglobular with 4 cup-shaped suckers
Rostellum: with ______ y-shaped hooklets
small, rounded with 4 cup shaped suckers
rudimentary rostellum
20-30
H. nana
H. diminuta
Contain three ovoid testes and one ovary
in a more less straight pattern across the
segment
H. nana
Broader than long, similar arrangement
and number of sexual organs
Three ovoid testes and one ovary in a
straight manner
H. diminuta
Testes and ovary disappear while uterus hollows
out and becomes filled with eggs
H. nana
Contains a sac like-uterus filled with eggs.
Disintegrate when separated from the body then
release eggs
H. diminuta
RAILLIETINA GARRISONI
Common Name?
Mode of transmission?
Infective stage?
IH: ?
DH: ?
AH: ?
Madagascar tapeworm
Accidental ingestion of insects with
cysticercoid larvae
Infective stage: Cysticercoid larvae
IH: Ants, Flour beetle (Tribolium
confusum)
DH: Rat
AH: Human
RAILLIETINA GARRISONI: PATHOLOGY
Human infection- asymptomatic
RAILLIETINA GARRISONI: DIAGNOSIS
Identification of gravid segments
(glistening white, rice grain
appearance) and contain egg capsules
with 1-4 spindle shaped eggs
RAILLIETINA GARRISONI: TREATMENT
Treatment, Prevention and Control
Praziquantel and bithionol
Environmental sanitation
Proper food storage
DIPYLIDIUM CANINUM
Common Name?
Mode of transmission?
Infective stage?
IH: ?
DH: ?
AH: ?
DIPYLIDIUM CANINUM
Dog tapeworm, Double-pored
tapeworm
Accidental ingestion of insects with
cysticercoid larvae
Infective stage: Cysticercoid larvae
IH: Dog flea, Cat flea, human flea, dog
louse
DH: Cat, Dog
AH: Human
DIPYLIDIUM CANINUM: PATHOLOGY
usually no symptoms
intestinal disturbances, weight loss,
anorexia, urticaria
DIPYLIDIUM CANINUM: DIAGNOSIS
Fecalysis - gravid segments
2 genital pores on each side of
segment
8-15 eggs
DIPYLIDIUM CANINUM: TREATMENT
Treatment, Prevention and Control
Drugs of Choice
Niclosamide, Bithionol, Praziquantel
Periodic deworming of cats and dogs
Insecticide dusting of cats and dogs
ECHINOCOCCUS GRANULOSUS
common Name?
Mode of transmission?
Infective stage?
IH: ?
DH: ?
AH: ?
Hydatid tapeworm
man ingests embryonated egg
Infective stage (human): embryonated egg
IH: Sheep
DH: Dog
AH: Human
ECHINOCOCCUS GRANULOSUS: PATHOLOGY
Mechanical and toxic
growing cyst: lodged in vital organs (liver,
lungs, brain and heart) and interferes with
function
Osseous hydatid cyst
Cyst in bone cells
Migrate to bone canal and erode
Symptoms develop 5-10 years after infection
Allergic reaction- rupture of cyst
ECHINOCOCCUS GRANULOSUS: DIAGNOSIS
Hydatid cyst
1. CXR
2. Exploratory Cyst Puncture
3. Immunologic Test
a. Intradermal
b. Precipitin
c. Complement fixation
d. Hemagglutination
e. Fluorescent antibody test
accessible sites
Surgical removal
inoperable
Biological Method
ECHINOCOCCUS GRANULOSUS: TREATMENT
Treatment, Prevention and Control
Surgical removal- accessible sites
no spillage of the cyst fluid or hydatid sand
Biological Method-inoperable
not always successful
Albendazole 400mg bid for 4 weeks
Strict personal hygiene
Human infection: fondling of dogs, ingesting eggs in dirt,
on vegetables or utensils or contaminated clothing
Dogs should not eat sheep, cattle and hog carcasses
Deworming
MORPHOLOGY: OVA
eggs measure ~75x95 micrometers. They are
usually included in capsules inside the gravid
segments
R. garrisoni
MORPHOLOGY: OVA
Eggs are spherical, thin shelled with a
hexacanth embryo
D. Caninum
MORPHOLOGY: OVA
subspherical with a brown radially striated
embryophore
E. granulosus
MORPHOLOGY: SCOLEX
Subglobular scolex with four acetabula
Rostellum is armed with 2 alternating circular
rows of hammer-shaped hooks
R. garrisoni
MORPHOLOGY: SCOLEX
Small and globular with four cupped suckers and
protrusible rostellum armed with one to seven
rows of rose thorn hooklets
D. Caninum
MORPHOLOGY: SCOLEX
rostellum with double row of 10-40 hooklets and
cuplike suckers
E. granulosus
MORPHOLOGY: PROGLOTTIDS
scolex, neck and 3 segments (immature
proglottid, elongated mature proglottid
and gravid proglottid)
2.5 to 9mm
E. granulosus
MORPHOLOGY: MATURE PROGLOTTID
bilobed ovary with 36-50 ovoid testes
R. garrisoni
MORPHOLOGY: MATURE PROGLOTTID
narrow, with double set of reproductive organs
and a genital pore on each margin
D. Caninum
MORPHOLOGY: GRAVID PROGLOTTID
200-400 egg capsules with one to four spindle
shaped eggs.
R. garrisoni
MORPHOLOGY: GRAVID PROGLOTTID
pumpkin seed shaped with capsules (8-15 eggs)
(may crawl out of anus)
D. Caninum
DIPHYLLOBOTHRIUM LATUM
Common Name?
Mode of transmission?
Infective stage: 1st IH? 2nd IH? DH?
IH: 1st IH? 2nd IH?
DH: ?
Fish tapeworm, broad tapeworm
Ingestion of raw or uncooked infected fish
Infective stage:
1st IH: Coracidium
2nd IH: Procercoid larva
DH: Plerocercoid (sparganum) larva
Intermediate Host:
1st IH: Copepad
2nd IH: Fish (perch, trout salmon, pike)
Definitive H0st: Human, mammals
Nonspecific complaints to mechanical
obstruction of intestines and biliary ducts
Diphyllobothriasis
Bothricephalus anemia or tapeworm
pernicious anemia; competes with host for
Vit B12 in the diet.
Human Sparganosis
Ingestion of infected Cyclops with
procercoid stage — sparganum
DIPHYLLOBOTHRIUM LATUM: PATHOLOGY
Bothricephalus anemia or tapeworm
pernicious anemia; competes with host for
Vit B12 in the diet
Diphyllobothriasis
Ingestion of infected Cyclops with
procercoid stage — sparganum
Human Sparganosis
DIPHYLLOBOTHRIUM LATUM: DIAGNOSIS
Fecalysis - eggs
Sparganosis - surgical removal and damage of
involved areas
surgical removal and damage of
involved areas
Sparganosis
DIPHYLLOBOTHRIUM LATUM: TREATMENT
Drugs of Choice- Niclosamide, Praziquantel
Sparganosis- removed through surgery
Ocular Sparganosis- injected with 40% ethyl
alcohol with procaine
Thorough cooking
Freezing of fish at 14⁰F for 24-48 hours
Boiling and filter
MORPHOLOGY: OVA
Yellowish brown with moderate thick shell with
operculum.
Opposite is a knob like thickening
D. latum
MORPHOLOGY: SCOLEX
Spatulate with two bothria or sucking
grooves which are located dorsally and
ventrally
D. latum
MORPHOLOGY: MATURE PROGLOTTID
Has a longer width than length and contains one set of
reproductive organs. Testes located dorsolateral.
D. latum
MORPHOLOGY: GRAVID PROGLOTTID
Disintegrate only when segment has completed
its reproductive function
D. latum
