Taeniasis (Tapeworm)

An intestinal infection caused by adult tapeworms of the genus Taenia.

Aetiology

Causative Organisms

The two most important species are:

Taenia saginata — beef tapeworm

Taenia solium — pork tapeworm

Morphology

Feature	Taenia saginata	Taenia solium
Intermediate host	Cattle	Pig
Transmission	Undercooked beef	Undercooked pork
Length of adult worm	4–10 m	2–7 m
Proglottids	Highly motile	Less motile
Uterine branches	15–30	7–13
Scolex	No hooks	Hooks present
Causes cysticercosis	No	Yes

Pathophysiology

The infection occurs via eating undercooked meat containing larval cysts (cysticerci).

Life Cycle Stages

Eggs released in human feces

Eggs ingested by intermediate host (cow/pig)

Larvae develop into cysticerci in muscle

Humans ingest undercooked infected meat

Cysticerci develop into adult worms in small intestine

Important distinction:

Infection Type	Cause
Taeniasis	Eating cysticerci in meat
Cysticercosis	Ingesting eggs of T. solium

Clinical Presentation

Most patients are asymptomatic.

Symptoms	Explanation
Abdominal discomfort	Intestinal irritation
Nausea	Mild GI irritation
Diarrhea or constipation	GI disturbance
Weight loss	Nutrient competition
Perianal itching	Migration of proglottids
Passage of worm segments	Common complaint

Cysticercosis

Larvae invade tissues forming cysts.

Common sites:

Organ	Manifestation
Brain	Seizures, hydrocephalus
Muscle	Painless nodules
Eye	Visual disturbance
Subcutaneous tissue	Small nodules

Severe form: Neurocysticercosis.

Complications

Complication	Cause
Intestinal obstruction	Large worm burden
Appendicitis	Proglottid migration
Biliary obstruction	Rare migration
Cysticercosis	Eggs of T. solium

Investigations

Test	Findings
Stool microscopy	Eggs or proglottids
Stool exam	Taenia eggs
Proglottid examination	Species identification
CT / MRI brain	For neurocysticercosis
Serology (ELISA)	Detect antibodies

Important note:

Eggs of T. saginata and T. solium are morphologically identical, so species identification requires proglottid examination or scolex.

Egg and Worm Identification

Feature	Description
Egg	Round with thick shell
Embryo	Hexacanth embryo (6 hooks)
Scolex of T. saginata	4 suckers, no hooks
Scolex of T. solium	4 suckers + hooklets

Management

First-Line Treatment

Drug	Dose
Praziquantel	5–10 mg/kg single dose
Albendazole	400 mg 1x1 for 3 days
Niclosamide	2 g single dose (adult)

Treatment for Cysticercosis

Drug	Dose	Notes
Albendazole	400 mg 2x1 for 8–30 days	First-line
Praziquantel	50 mg/kg/day	Alternative
Corticosteroids	Adjunct	Reduce inflammation
Antiepileptics	If seizures	Symptomatic