7.7 Intestinal Cestodes Flashcards
Characterized by a dorsoventrally flattened, most are hermaphroditic
Taenia
Taenia spp distinct three regions
Scolex, neck, strobila
Hookless tapeworm, 4-8 m, 4 suckers 2 lobes, 300-400 testes, 15-30 uterine branches
T. saginata
Hook tapeworm, 2-4 m, 4 suckers, rostellum and hooklets, 3 lobes testes, 7-12 uterine branches
T. solium
Larval form of tapeworm, consisting of a single scolex enclosed in a bladder-like cyst
Cysticercus
Cyst form of T. solium
Hooklets are visible
Cystecircus cellulosae
Cyst form of T. saginata
No hooklets
Cystercircus bovis
Taenia spp definitive host
Humans
Clinical manifestations of Taenia infection
Deprivation of nutrition, dysfunction of the intestine, allergic reactions, appendicitis, obstruction of instetines
Intrinsic or extrinsic autoinfection
Cysticercosis
Pathogenic factor of cysticercosis
Cysticercus cellulosae
Tapeworm infection treatment
PZQ
Dog tapeworm
Echinococcus granulosus
Caused by the larval stages of cestodes of the genus Echinococcus
Hydatid disease
Causes cystic echinococcosis
E. granulosus
Causes alveolar echinococcosis
E. multilocularis
Causes polycystic echinococcosis
E. vogeli
Extremely rare cause of human echinococcosis
E. oligarthus
Made up of immature echinococcus, consists of cystic fluid, brood capsule, protoscolex and daughter cyst
Hydatid cst
Prostocolices generally settle down at the bottom of the cyst
Hydatid sand
Adult Echinococcus granulosus worms reside in the ___
Small bowel of dogs
Intermediate host of E. granulosus
Cattle, sheep, goat, human
After ingestion of E. granulosus eggs, they hatch in the small bowel and release an ___
Penetrates the intestinal wall and migrates through the circulatory system in various organs (lungs and liver)
Oncospheres
The scolex are the sucking discs, above which is the rostellum with hooks
Hymenolepis nana
H. nana eggs exhibit ___ lying between the egg shell and the hexacanth embryo
Polar filaments
H nana definitive hosts
Man, rodents
Largest human tapeworm
Diphyllobothrium latum
Spatulate, almone-shaped with a pair of suctorial grooves called ___
Bothria
Proglottids of D. latum
Rosette-shaped uterus
The only cestode with an operculated egg
D. latum
Intermediate hosts of D. latum
Copepods, fish
Definitive hosts of D. latum
Bears, cats, dogs and humans
Infective stage of D. latum for mamals
Plerocercoid larva