Taeniasis (intestinal tapeworm infection)
Taeniasis is intestinal infection with the adult tapeworm Taenia solium (pork), Taenia saginata (beef), or Diphyllobothrium latum (fish tapeworm, from raw freshwater fish), acquired by eating undercooked meat or fish containing larval cysts, usually mild or asymptomatic, and treated with a single dose of praziquantel.
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What this article covers
- Overview
Taeniasis is infection of the small intestine with an adult tapeworm, acquired by eating undercooked meat or fish containing the larval stage: Taenia solium (pork), Taenia saginata (beef), and…
- Epidemiology
Worldwide distribution tracking local food practices: Taenia saginata (beef tapeworm) is more common where cattle graze on sewage-contaminated pastures; Taenia solium (pork tapeworm) is endemic in…
- Risk factors
Consumption of undercooked or raw pork (Taenia solium).
- Pathophysiology
Ingested larvae (cysticerci in pork or beef, plerocercoid larvae in fish) evaginate in the small intestine and attach to the mucosa by a scolex with suckers (and, for T.
- Clinical features
Most infections are asymptomatic, discovered only when the patient notices motile proglottids passed in stool or on clothing: this is the most common, and often the only, presenting complaint.
- Differential diagnosis
Cysticercosis/neurocysticercosis: a distinct disease from ingesting T.
- Diagnosis
The diagnosis of taeniasis is established by identifying tapeworm eggs or proglottids on stool ova and parasite examination, or by direct visual identification of a passed proglottid: microscopic…
- Management
First, for any suspected Taenia solium infection, screen for neurologic symptoms and obtain brain imaging if present, deferring antiparasitic treatment until neurocysticercosis has been excluded or, if found, has been separately managed.
- Complications
Vitamin B12 deficiency with megaloblastic anemia and, if prolonged, subacute combined degeneration with peripheral neuropathy: specific to heavy or prolonged Diphyllobothrium latum infection.
- Prognosis
Excellent with treatment: a single dose of praziquantel or niclosamide clears the adult worm in the great majority of patients, with resolution of any mild symptoms and cessation of proglottid shedding.
- Prevention
Cook pork, beef, and freshwater fish to a safe internal temperature to kill larval cysts before eating: at least 145°F (63°C) with a 3-minute rest for whole cuts, and 160°F (71°C) for ground meat…
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- Cysticercosis and neurocysticercosis
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Hookworm infection, caused by Necator americanus or Ancylostoma duodenale, is treated with albendazole 400 mg single dose plus iron repletion; it is acquired when soil larvae penetrate bare skin and produces microcytic iron-deficiency anemia from chronic intestinal blood loss by adult worms attached to the small bowel mucosa.