Cestodes Flashcards
General shape of Cestodes
Flat or Ribbon like
Cestodes do not contain
Alimentary tract and body cavity
Cestodes contain
Excretory, Nervous, Reproductive
All are HEXECANTH except
Echinococcus granulosus (hydatid cyst)
All are HETEROXENOUS except
Hymenolipis nana (Homoxenous)
All are CYCLOPHILLIDEA except
Dipholobotrium latum (pseudophillidea)
Cestodes body parts are
Head (scolex)
Neck
Trunk (Strobilla)
Head or Scolex function
Attachment or adapters (suckers, hooklets, rostellum)
Neck function
Location for growth and budding
Neck contains
Germinal cells to produce reproductive organ
NOPS means
No Ova and Parasite Seen
Diagnostic tool used for Cestodes
Stool
Biopsy
Perianal swab
Serologic Test
Stool recovers
Eggs, gravid proglottid, rare scolex
Biopsy detects
Echinoccus granulosus
Serologic test used
ELISA
Perianal swab recovers
Eggs
Adult worm in Small intestine
(Definitive host)
DTTHH
Dipholobotrium latum
T.solium
T.saginata
H.nana
H.diminuta
Larval stage in men
Accidental Intermediate host
DTE
D.latum
T.solium
E.granulosus
Trunk first part
Immature (tissue and muscles)
Trunk middle part
Mature (testes/ovaries)
Trunk last part
Riped/gravid excreted in feces
Cyclophiledia shape
Ovoidal shape
Pseudophalidea shape
Spatulate
Taenia solium egg SCOLEX characteristics
Globular scolex
Head with hooklets
Large rostellum
H.nana
Globular scolex
Refractile rostellum
Y shaped hooklets
Globular scolex with hooklets
E.granulosus
Prominent conical rostellum with protrusion
D.caninum
Almond/spatulate/spoon scolex
D.latum
Globular scolex withouth hooklets and rostellum
T.saginata
H.diminuta
Globular scolex with undeveloped/rudimentary apical ROSTELLUM
WITHOUT HOOKLETS
Neck main function
Growth for Strobila
Consist of chains of segments/proglottids
Hermaprodhitic
Mature segment
Uterus filled with egg
Gravid segment
Mature and Gravid of D.latum
Mature: No distinct
Gravid: Broader than longer
Mature and Gravid; T.solium
Mature: 100-200 follicular testes
Gravid: longer than broader
Mature and Gravid: T.saginata
Mature: 300-400 follicular testes
Gravid: Longer than broader
Mature and gravid: H.nana and H.diminuta
Mature: 3 testes - 1 ovary
Gravid: Saccular uterus
Mature and Gravid: E.granulosus
Mature: 1 reproductive set; 1 scolex, 1 mature, 1 immature, 1 gravid proglottid
Gravid: coiled, loosely twisted with midline lateral evagination
Common name of D.latum
Broad Fish Tapeworm
Russian broad tapeworm
ONLY CESTODES THAT CAN INFECT MAN
D.latum
D.latum clinical significance in man
V12 deficiency (Megaloblastic anemia)
D.latum shape and scolex
55-75 long, 40-55 wide
Scolex: almond, spatulate, spoon shaped
Embryo charac of D.latum
Undeveloped, coracidium
Shell charac of D.latum
Smooth, yellow-brown
Other charac of D.latum
1 operculum on one side
Terminal knob on opposite side
Definitive host of d.latum
Man
Intermediate host
Freshwater Crustaceans
1st IH of D.Latum
Cyclops/copepods
2nd IH of D.latum
Small fishes eaten by Large fishes (Eel, Pile, trout)
Infective Stage of D.latum
PLEROCERCOID (Secondary larval stage) in man
1st larval stage of D.latum
Procercoid
T.solium and T.saginata DEFINITIVE HOST
Man
Common name of T.solium
Armed Tapeworm
With rostellum, hooklets, and scolex
Common name T.saginata
Unarmed tapeworm
No rostellum and hooklets
Intermediate host: T.solium
Pork/pigs
Intermediate host: T.saginata
Cattle/cows
Infective stage: T.solium
Cysticercus cellulosae
Infective stage: T.saginata
Cysticercus bovis
Scolex shape: T.solium
Small and globular Rostellum with hooks double crown
Scolex shape: T.saginata
Large without rostellum and hooklets
Number of Proglottids: T.solium
<1000
Number of Proglottids: T.saginata
1000-2000
Uterus shape: T.solium
Square
7-15 thick
Dendritic
Uterus shape: T.saginata
15-30 thin
Rectangular
Dichotomous
Vaginal Sphincter
T.solium: Absent
T.saginata: Present
Accesorry ovarian lobe
T.solium: mature
T.saginata: none
Embryo of taenia
3 three pairs, hexacanth embryo
Other features of Taenia
Radial striation, yellow-brown embryosphore
Length of T.solium
2-3 nm
Length of T.saginata
5-10 nm
Natural detachment of gravid proglottid on main body
Apolosis
Hymenolepis dimunita common name
Rat Tapeworm
Infective stage of H.diminuta
Cystecercoid larva
Scolex of H.dimunita
Four suckers; apical/rudimentary undeveloped without hooklets
Proglottid: H.dimunita
Rectangular; sac like uterus
Hooklets of dimunita
Three hexacanth embryo
Polar thickenings; H.dimunita
Present
Polar Filaments: H.Dimunita
Absent
Embryophore; H.diminuta
Present; colorless
Dwarf Tapeworm
Hymenolepis nana
Hymenolepis is known to be the
Smallest intestinal cestode
Most common cestode worlwide
Scolex; H.nana
4 suckers; small rostellum with one row hooks
Proglottid; H.nana
Rectangular; saclike
Polar thickenings
Polar filaments
;H.nana
Present
Present
Common name of Dipylidium caninum
Pumpkin seed Tapeworm
Double pored Tapeworm
Dog/Cat Tapeworm
Infective stage; D. Caninum
Cystecercoid larva
Appearance of D. Caninum proglottid
Vase-shaped
Scolex; D. Caninum
Club shaped armed rostellum with 7 circlets
Proglottid; D. Caninum
Pumpkin seed mature and gravid
2 sets reproductive orgabs
2 genital pores
E. Granulosus common name
Hydatid Tapeworm
Dog tapeworm
Definitive host
Dogs
Intermediate host
Sheep/man
HIghly antigenic can cause anaphylactic shock
Hydatid cyst fluid
Skin test for granulosus
Casoni test
Infective stage: E.granulosus
Hydatid cyst