[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Microbiology](https://durgical.com/en/microbiology/) › [Cestodes (tapeworms)](https://durgical.com/en/microbiology/groups/cestodes/) › Taenia solium

[Microbiology](https://durgical.com/en/microbiology/) · [Cestodes (tapeworms)](https://durgical.com/en/microbiology/groups/cestodes/)

# Taenia solium

- Parasite
- Exam priority: high

Pork tapeworm. Undercooked pork gives the gut tapeworm; swallowing its eggs puts cysts in the brain (neurocysticercosis), a major cause of epilepsy.

Updated 2026-11-01

Also called: pork tapeworm, cysticercus

## Key points

- Eating pork gives the tapeworm; swallowing human-shed eggs gives cysticercosis (pork does not transmit it directly).
- In many endemic areas it accounts for about 30% of epilepsy cases (WHO).
- Cyst with a scolex on MRI = viable neurocysticercosis; calcification = inactive lesion.
- Antiparasitics are paired with corticosteroids: a dying cyst inflames.
- An armed scolex and 7–13 uterine branches separate it from T. saginata.

## At a glance

**Shape**
Scolex with 4 suckers and a rostellum with a double crown of hooks (armed)

**Family**
Taeniidae

**Type**
Cestode (flatworm); humans can host the adult or the larva

**Size**
Adult 2–7 m; cysticercus 0.5–2 cm

## Morphology

- Gravid proglottid with 7–13 lateral uterine branches (the key to telling it from T. saginata).
- Spherical egg with a radially striated embryophore and a six-hooked oncosphere; identical to T. saginata and similar to Echinococcus.
- Cysticercus: a fluid-filled vesicle with an invaginated scolex (the 'dot' seen on MRI).

## Transmission

- Eating raw or undercooked pork with cysticerci → taeniasis (adult tapeworm in the gut).
- Swallowing eggs shed by a human carrier (hands, food, water) → cysticercosis; the carrier is often in the same household.
- Autoinfection of the carrier by the anus-hand-mouth route.

**Reservoir:** Humans are the only definitive host; Pigs as the usual intermediate host

### Isolation precautions

What the care team adds to standard precautions.

- Standard

## Life cycle

- The human carrier passes gravid proglottids and eggs in stool; the eggs are infective at once.
- A pig (or a person) swallows the eggs; the oncosphere hatches in the gut and invades the wall.
- Through the blood it reaches muscle, brain, eye and subcutaneous tissue and forms cysticerci in about 60–70 days.
- A person who eats undercooked pork with cysticerci releases the scolex, which attaches to the small bowel.
- In about 2 months the adult tapeworm matures and starts shedding proglottids: the cycle closes.
- A human who swallows eggs becomes an accidental intermediate host: that is cysticercosis.

## Virulence factors

- While alive, the cysticercus dampens the immune response and often goes unnoticed.
- When the cyst degenerates, inflammation of the surrounding tissue triggers seizures and oedema.
- Ventricular or subarachnoid (racemose) cysts block CSF flow and cause hydrocephalus.
- The adult tapeworm causes few symptoms but makes the carrier an egg source for everyone nearby.

## Diseases it causes

- Neurocysticercosis: seizures, headache and raised intracranial pressure [Neurocysticercosis →](https://durgical.com/en/conditions/neurocysticercosis/)
- Intestinal taeniasis, usually asymptomatic
- Acquired epilepsy: neurocysticercosis is its leading preventable cause in endemic areas [Epilepsy and seizures →](https://durgical.com/en/conditions/epilepsy-and-seizures/)
- Hydrocephalus from ventricular or subarachnoid cysts [Hydrocephalus →](https://durgical.com/en/conditions/hydrocephalus/)

## Clinical picture

- First seizure in a young adult from an endemic rural area.
- Headache, vomiting and papilloedema from hydrocephalus.
- Ocular cysticercosis or subcutaneous nodules.
- Symptoms may start months or years after infection, when the cyst begins to die.

## Diagnosis

- Neuroimaging: MRI shows cysts with a scolex; CT is better for calcifications.
- Immunoblot (EITB) with T. solium antigens in serum or CSF to confirm; it does not separate active from inactive infection.
- Carrier: eggs or proglottids in stool; the number of uterine branches identifies the species.
- Fundoscopy before antiparasitic treatment to rule out eye cysts.

## Treatment

Taeniasis: praziquantel or niclosamide. Neurocysticercosis: antiparasitics (albendazole, sometimes with praziquantel) only when cysts are viable, always with corticosteroids and antiseizure drugs; hydrocephalus needs surgery or a shunt, and calcified lesions get no antiparasitic.

Drug class only; doses and regimens are set by the clinician from the current guideline.

In Pharmacology:

- [Praziquantel](https://durgical.com/en/pharmacology/praziquantel/)
- [Albendazole](https://durgical.com/en/pharmacology/albendazole/)

## Prevention

- Cook pork thoroughly and strengthen meat inspection.
- Find and treat tapeworm carriers and their households.
- Handwashing, latrines and an end to open defecation.
- Penned pig rearing with pig deworming and vaccination (One Health).

## In Colombia

Endemic in rural areas where pigs roam free and latrines are lacking. Neurocysticercosis is a frequent cause of late-onset epilepsy in Colombian neurology clinics.

## Memory aid

Pork puts the worm in your gut; a carrier's hands put the cyst in your brain.

## Test yourself

Think of the answer, then tap the question to see it.

## How is neurocysticercosis acquired?

By swallowing T. solium eggs shed by a human tapeworm carrier (contaminated hands, food or water), not by eating pork.

## Which MRI finding suggests a viable cysticercus?

A cyst with an eccentric dot inside it: the scolex.

## Why are corticosteroids given with albendazole in neurocysticercosis?

Because dying cysts cause inflammation and oedema that can worsen seizures or intracranial pressure.

## Which test confirms cysticercosis serology?

The immunoblot (EITB) with T. solium antigens, in serum or CSF.

## Which proglottid feature separates T. solium from T. saginata?

T. solium has 7–13 uterine branches per side; T. saginata has 12–30.

[Add to my cards (5)](https://durgical.app/estudiar/?add=/en/microbiology/taenia-solium/)

## Related

- [Taenia saginata](https://durgical.com/en/microbiology/taenia-saginata/)
- [Echinococcus granulosus](https://durgical.com/en/microbiology/echinococcus-granulosus/)

## Related conditions

- [Neurocysticercosis](https://durgical.com/en/conditions/neurocysticercosis/)
- [Epilepsy and seizures](https://durgical.com/en/conditions/epilepsy-and-seizures/)
- [Hydrocephalus](https://durgical.com/en/conditions/hydrocephalus/)

## What the colours mean

**Gram-positive**
Thick peptidoglycan wall: stains purple.

**Gram-negative**
Thin wall with an outer membrane: stains pink.

**Acid-fast**
Lipid-rich wall (mycobacteria): Ziehl–Neelsen stain.

[← Back to the group: Cestodes (tapeworms)](https://durgical.com/en/microbiology/groups/cestodes/)

Educational content on microorganisms; not a treatment guide and no substitute for a health professional's advice. No doses are given.

Sources: [CDC - DPDx - Cysticercosis](https://www.cdc.gov/dpdx/cysticercosis/index.html) (CDC, 2019); [CDC - DPDx - Taeniasis](https://www.cdc.gov/dpdx/taeniasis/index.html) (CDC, 2024); [Taeniasis/cysticercosis](https://www.who.int/news-room/fact-sheets/detail/taeniasis-cysticercosis) (WHO, 2022); [About Cysticercosis | Cysticercosis | CDC](https://www.cdc.gov/cysticercosis/about/index.html) (CDC, 2024).

## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake

Representative model, for educational purposes only.

---
Source: https://durgical.com/en/microbiology/taenia-solium/
License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/microbiology/taenia-solium/