Cestodes

Cestodes

flat segmented tapeworms that live in the small intestines

Taenia solium

pig tapeworm that has hooks and can cause neurocysticercosis

Taenia saginata

beef tapeworm that has no hooks and causes intestinal infection

Taeniasis

intestinal infection caused by adult tapeworm

Neurocysticercosis

condition where T. solium larvae infect the brain causing seizures

Scolex

head of the tapeworm used for attachment to the intestine

Proglottids

body segments of the tapeworm that contain eggs

Gravid proglottids

mature segments filled with eggs

Direct fecal smear

lab test used to detect eggs or proglottids in stool

MRI

imaging test used to detect brain infection like neurocysticercosis

Life cycle of Taenia

eggs passed in stool are eaten by pig or cow then form cysts in muscle and infect humans when undercooked meat is eaten

Definitive host (Taenia)

human where adult worm lives

Intermediate host T. solium

pig

Intermediate host T. saginata

cow

Cysticercosis

infection caused by ingestion of T. solium eggs leading to larval cysts in tissues

Diphyllobothrium latum

fish tapeworm and the longest tapeworm infecting humans

Diphyllobothriasis

infection caused by Diphyllobothrium latum

Scolex of D. latum

has two elongated sucking grooves

Proglottids of D. latum

wider than they are long

Vitamin B12 deficiency

condition caused by D. latum leading to anemia

Megaloblastic anemia

type of anemia due to lack of Vitamin B12

Malnutrition

lack of proper nutrients due to parasite infection

Life cycle of Diphyllobothrium latum

eggs in water hatch then are eaten by crustaceans then fish then infect humans when raw fish is eaten

Definitive host (D. latum)

human or fish-eating mammals

First intermediate host (D. latum)

small crustacean

Second intermediate host (D. latum)

fish

Transmission of Taenia

eating undercooked pork or beef

Transmission of D. latum

eating raw or undercooked fish

Prevention of Taenia

proper cooking of meat and good hygiene

Prevention of D. latum

proper cooking of fish and avoiding raw fish