Cysticercosis

Infection with the larval (cysticercus) stage of Taenia solium, acquired by ingesting T. solium eggs, distinct from intestinal taeniasis (the adult tapeworm infection acquired by eating undercooked infected pork containing cysticerci, which then mature into an adult tapeworm in the human intestine).

A tapeworm carrier (taeniasis) is themselves the source of eggs that, if ingested by that person or others (fecal-oral transmission, including autoinfection), cause cysticercosis, most significantly neurocysticercosis (see that dedicated entry for the CNS-specific presentation and management).

Cysticerci can lodge in subcutaneous tissue and muscle (palpable, often painless nodules), the eye (visual disturbance, potentially significant inflammation), and, most significantly, the CNS (see Neurocysticercosis entry).

Intestinal taeniasis itself (the adult tapeworm) is often asymptomatic or causes mild nonspecific GI symptoms, with proglottids (tapeworm segments) sometimes noticed in stool.

• Intestinal taeniasis: stool microscopy for eggs or proglottids (though species differentiation from Taenia saginata on eggs alone is not reliable; proglottid morphology or PCR distinguishes species, an important distinction since only T. solium carriage poses a cysticercosis transmission risk)
• Subcutaneous/muscular cysticercosis: palpable nodules, confirmed by ultrasound or excisional biopsy showing the characteristic cyst with scolex
• Ocular cysticercosis: fundoscopic or slit-lamp examination
• See Neurocysticercosis entry for CNS-specific diagnostic approach (MRI, serology, Del Brutto criteria)

• Intestinal taeniasis: praziquantel 5 to 10 mg/kg PO as a single dose, or niclosamide 2 g PO single dose, both highly effective at eliminating the adult tapeworm and interrupting further egg transmission
• Subcutaneous or muscular cysticercosis without CNS involvement: often managed conservatively (surgical excision of symptomatic nodules) without systemic antiparasitic treatment given the generally benign, self-limited course at these sites
• Ocular cysticercosis: surgical removal is generally preferred over antiparasitic drug treatment, given the risk of a damaging inflammatory response to a dying cyst within the confined ocular space
• Neurocysticercosis: see that dedicated entry for full antiparasitic and corticosteroid management detail
• Public health: identification and treatment of tapeworm carriers, improved sanitation, and food safety education are the key preventive measures given the fecal-oral transmission route responsible for cysticercosis

Referral: infectious disease/tropical medicine; neurology for any CNS involvement; ophthalmology for ocular disease.