A 4-year-old boy with a habit of eating soil presents with fever, wheezing, hepatomegaly, and an absolute eosinophil count of 12,000 per microliter. Serology using excretory-secretory antigen of the causative nematode is strongly positive. The definitive host of this parasite, in which it reaches adulthood, is the dog. Which parasite causes visceral larva migrans in this child?

• A Ascaris lumbricoides
• B Toxocara canis ✓
• C Strongyloides stercoralis
• D Capillaria philippinensis

Explanation

Visceral larva migrans follows accidental ingestion of embryonated eggs of Toxocara canis shed by dogs. Humans are paratenic hosts: larvae hatch, migrate through liver, lungs, brain and eye, and never mature into adults, producing fever, hepatomegaly, respiratory symptoms and striking eosinophilia. Ascaris completes its cycle in humans and does not produce prolonged larval migratory disease of this pattern.

Reference: Paniker's Textbook of Medical Parasitology, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.