A child presents with periorbital oedema, myalgia, and eosinophilia after eating undercooked pork. Muscle biopsy shows coiled larvae within a nurse cell. Which organism is responsible and what is the best serological test?
- A Taenia solium; ELISA for cysticercus antigen
- B Trichinella spiralis; ELISA for anti-Trichinella IgG ✓
- C Toxocara canis; ELISA for larval antigen
- D Echinococcus granulosus; Casoni intradermal test
Correct answer: B. Trichinella spiralis; ELISA for anti-Trichinella IgG
Explanation
Trichinellosis presents with the triad of periorbital oedema (pathognomonic), myalgia, and eosinophilia following ingestion of undercooked pork containing encysted Trichinella spiralis larvae. The nurse cell is the modified muscle cell surrounding the coiled larva. ELISA for anti-Trichinella IgG using excretory-secretory larval antigens is the preferred serological test, becoming positive 3–5 weeks after infection. Taenia solium causes cysticercosis but does not produce nurse cells. Treatment is albendazole plus corticosteroids for severe disease.
Reference: Ananthanarayan & Paniker's Textbook of Microbiology, 11th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.