Examination of CSF from a patient with meningo-encephalitis shows a thick-walled cyst with scolex, hooklets, and calcareous corpuscles. The scolex shows four suckers and a rostellum with hooks. Serology is positive for T. solium antibody. What is the diagnostic stage found in CSF and how did the patient acquire CNS disease?
- A Cysticercus stage; acquired by eating undercooked pork containing the larvae
- B Cysticercus stage; acquired by ingesting T. solium eggs from contaminated food or faeco-oral route ✓
- C Hydatid cyst stage; acquired by eating raw beef
- D Coenurus stage; acquired from infected dogs as definitive host
Explanation
Neurocysticercosis is caused by the cysticercus larvae of Taenia solium, which is acquired by humans acting as accidental intermediate hosts after ingesting T. solium eggs (faeco-oral route — contaminated food/water or autoinfection). Eating undercooked pork causes taeniasis (adult worm in intestine, not larval CNS disease). Eggs hatch in the intestine, releasing oncospheres that penetrate the gut wall, enter circulation, and lodge in the CNS, muscle, or eye, developing into cysticerci. The hydatid cyst is from Echinococcus; Coenurus is from Taenia multiceps. Praziquantel and albendazole are used in treatment.
Reference: Ananthanarayan & Paniker's Textbook of Microbiology, 11th ed.
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Written and medically reviewed by the StethoPrep medical team.