Tapeworm Infection: Lifecycle, Symptoms, Diagnosis, and Treatment

Tapeworms (cestodes) are flat, segmented intestinal parasites. Humans acquire them by eating undercooked meat (beef, pork, fish) containing larval cysts.

Common Species

• Taenia saginata (beef tapeworm) – up to 25m.
• Taenia solium (pork tapeworm) – risk of cysticercosis (larvae in tissues, including brain = neurocysticercosis).
• Diphyllobothrium latum (fish tapeworm) – B12 deficiency.
• Hymenolepis nana (dwarf tapeworm) – direct fecal-oral.

Symptoms

• Often asymptomatic.
• Abdominal discomfort, nausea, diarrhea, weight loss.
• Passage of proglottids (segments) in stool – diagnostic clue.
• Neurocysticercosis: seizures, headaches, hydrocephalus.

Diagnosis

• Stool O&P (ova and parasites) ×3 – low sensitivity for T. saginata.
• Scotch tape test (perianal) for T. solium eggs.
• PCR, antigen detection (improved sensitivity).
• Imaging (CT/MRI) for cysticercosis.

Treatment

• Praziquantel 5–10 mg/kg single dose (drug of choice for most).
• Albendazole for cysticercosis (with corticosteroids).
• Niclosamide (alternative, not in US).

Prevention

• Cook meat to ≥145°F (63°C) whole cuts, ≥160°F (71°C) ground; freeze fish/meat.
• Hand hygiene, sanitation.
• Treat infected pets/livestock.