A 28-year-old woman presents with seizures. MRI shows multiple ring-enhancing lesions in the brain parenchyma. Serology for cysticercus (EITB) is positive. She recalls eating undercooked pork. What is the infective stage responsible for neurocysticercosis?

• A Proglottids from Taenia saginata colonising brain tissue
• B Hydatid cyst of Echinococcus granulosus in brain
• C Encysted metacestode (cysticercus cellulosae) from ingested Taenia solium eggs ✓
• D Sparganosis from Spirometra mansoni

Explanation

Neurocysticercosis results from ingestion of Taenia solium eggs (not the cyst from pork); eggs hatch into oncospheres that penetrate the gut wall, enter the bloodstream, and encyst as cysticercus cellulosae in brain, muscle, or eye. The patient acts as an intermediate host. Eating undercooked pork containing cysticerci results in intestinal taeniasis (adult worm), not cysticercosis. EITB (enzyme-linked immunoelectrotransfer blot) is the most specific serological test.

Reference: Ananthanarayan & Paniker's Textbook of Microbiology, 11th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.