Cestodes (Tapeworms)

Taenia solium

Ingesting raw or undercooked meat(pork)

Proglottids or eggs on stool surface

Humans can be intermediate host

Cysticercosis in CNS, muscles, or eyes diagnosed with biopsy

Scolex has four suckers and armed rostellum

Proglottids have <13 lateral uterine branches

Taenia saginata

Ingesting raw or undercooked meat(beef)

Proglottids or eggs on stool surface

Scolex has four suckers and unarmed rostellum

Progottitds have >15 lateral uterine branches

Hymenolepis sp

Infected when cystircercoid-infected arthropods are ingested

Diagnosed by eggs in stool - polar filaments

H. nana “Dwarf tapeworm”

Frequent in humans in children and institutionalized

H. diminuta “rat tapeworm”

Diphyllobothrium latum/Dibothriocephalus latus

Broad fish tapeworm

Longest human tapeworm

Infected by eating undercooked fish

Elongated spoon scolex

Two sucking grooves, bothria

Diagnosed by eggs with operculum in feces or proglottids

Dipylididium caninum

Double-pored dog tapeworm

Dog and cat are typical host

Infected by ingesting infected flea

Diganosed by proglottids in feces (rice grain or cucumber seed appearance)

Typical proglottids or egg packets

Echinococcus granulosus

Cystic hydatid disease

Infected by ingestion of embryonated eggs in feces

5-20 year latent period

Diagnosed by hydatid cyst in liver or lungs

Dogs feeding on sheep viscera

Wolves, moose, or caribou

Echinococcus multilocularis

Infected by ingestion of embryonated eggs in feces

Rapid growing, destructive, not contained in outer cyst

Usually liver but occaisionally lungs or brain

Identification of larva from cyst contents

PAIR (puncture apsiration injection re-aspiration)