A child with epilepsy and ring-enhancing CNS lesions on MRI undergoes serology. EITB (enzyme-linked immunoelectrotransfer blot) using lentil-lectin purified glycoproteins is positive. Which parasite is responsible and which larval form is involved in the CNS lesion?

• A Echinococcus granulosus — hydatid cyst
• B Taenia solium — cysticercus cellulosae ✓
• C Toxocara canis — larva migrans
• D Trichinella spiralis — encysted larva

Explanation

Neurocysticercosis is caused by the larval stage (cysticercus cellulosae) of Taenia solium, acquired by ingesting T. solium eggs (feco-oral, autoinfection or heterinfection). EITB with glycoprotein antigens is the most specific serological test (>99% specificity). Ring-enhancing lesions on CT/MRI represent degenerating cysticerci. Echinococcus causes hydatid cysts, which are larger and cystic. Toxocara causes visceral larva migrans with eosinophilia. Trichinella affects skeletal muscle, not CNS.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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