Cestoda (tapeworm)

Epidemiology

• cestodes (tapeworns) live in intestinal tracts of vertebrate species in their adult forms & in tissues or body cavities of intermediary hosts as larvae
• they attach to the intestinal mucosa via a scolex (head) that may have suckers, bothria (groove) or a rostellum with hooks
• the strobila or body of the worm contains an actively growing neck region & a series of proglottids that undergo sequential development to gravid forms at the posterior end
• adults lack an intestinal tract & absorb all nutrients through their integument
• each proglottid has both male & female gonads & is capable of producing fertile eggs
• eggs of cestodes infecting humans (except Diphyllobothrium) contain a 6-hooked embryo
• long lengths of strobila may pass in the feces & proglottids may actively migrate out of the anus.
• infections is usually fecal-oral transmission or ingestion of contaminated, undercooked meat

Clinical manifestations

• most tapeworm infections are asymptomatic
• abdominal discomfort, anorexia, weight loss, fatigue most common symptoms

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More general terms

• platyhelminth (flatworm)

More specific terms

• Cyclophyllidae
• Diphyllobothrium (fish tapeworm)
• Dipylidium
• Echinococcus
• Hymenolepis
• Mesocestoides
• Taenia

Additional terms

• bothrium
• rostellum
• scolex