CESTODES Flashcards
Intestinal cestodes
Diphyllobothrium latum
Taenia solium
Taenia saginata
Hymenolepis nana
Somatic/Tissue cestodes
Taenia solium-cysticercosis
Echinococcus granulosus-hydatid disease
Host for intestinal taeniasis
Definitive-Man
Intermediate:saginata-cattle
Solium-pig
Infective form
Diagnostic form
Larva
Eggs
Life cycle
Man:larva->adult worm->self fertilisation->eggs in feces
Cattle/pigs:eggs->penetrate intestinal wall->skeletal muscle via blood->larva->encystation->deposit as cyst
Transmission
Ingestion of undercooked pork or beef containing larva
Larva of saginata and solium
Cysticercus bovis
Cysticercus cellulosae
T. Solium is also called called as
Armed tapeworm (scolex bears rostellum with 2 rows of hooklets)
Lab diagnosis
Stool examination:wet mount(saline or iodine)-demonstrate eggs
Eggs:morphologically similar.Embryo with six hooklets surrounded by embryophore. Bile stained,do not float in saturated salt solution
Proglottids
Antigen detection in stool:
ELISA detect Taenia specific antigen(coproantigen).cannot differentiate between saginata nd solium
Molecular method:
PCR detecting mitochondrial DNA,can distinguish b/w saginata nd solium
DOC for taeniasis,H.nana
Praziquantel
H.nana is also called
Dwarf tapeworm (smallest cestode infecting man)
Life cycle of H.nana
Host:Man
Infective,Diagnostic form-Eggs
Ingestion of contaminated food and water,autoinfection
Eggs->larva(cysticercoid)->adult worm->fertilization-> eggs produced->faeces
Lab diagnosis
Stool microscopy
Oval eggs, non bile stained
Two membranes that surround an embryo with 6 hooklets
Polar filaments at both poles
Rat tapeworm
Hymenolepis diminuta
Definitive-rodents
Intermediate-insects
Diphylidium caninum
Definitive-dogs nd cats(rarely man)
Intermediate-insects(fleas)
Detection of eggs(present in packets)
Proglottids-barrel shaped,contain 2 genital pores(double pored tapeworm)
