A 40-year-old Egyptian man presents with painless hematuria. Cystoscopy shows bladder granulomas. Urine microscopy reveals eggs with a terminal spine. The intermediate host of the causative parasite is:

• A Freshwater crab (Portunus species)
• B Freshwater fish
• C Aedes mosquito
• D Freshwater snail (Bulinus species) ✓

Explanation

Eggs with a terminal spine are characteristic of Schistosoma haematobium, which causes urogenital schistosomiasis endemic in Africa and the Middle East. The intermediate host is the freshwater snail Bulinus species. Cercariae released from snails penetrate human skin during water contact. Adult worms reside in the perivesical venous plexus, and egg deposition in the bladder wall causes granulomatous inflammation, fibrosis, and increased risk of squamous cell carcinoma of the bladder. Freshwater crabs are intermediate hosts for Paragonimus westermani (lung fluke).

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.