A 9-year-old child has a CT scan showing a cyst in the liver with a characteristic 'water lily sign.' Serological testing using indirect hemagglutination is positive at 1:640. The most appropriate initial pharmacological treatment is:

• A Praziquantel 40 mg/kg for 1 day
• B Mebendazole 100 mg twice daily for 3 days
• C Metronidazole 500 mg thrice daily for 10 days
• D Albendazole 400 mg twice daily for 28-day cycles ✓

Explanation

The water-lily sign (floating membranes from collapsed endocyst) on imaging combined with positive IHA serology is diagnostic of cystic echinococcosis (hydatid disease) caused by Echinococcus granulosus. Albendazole (400 mg BD, 28 days on/14 days off for at least 3 cycles) is the drug of choice for medical management and also used perioperatively for surgery. Praziquantel is used for other cestodes (taeniasis, neurocysticercosis) and not for hydatid. Metronidazole is used for Entamoeba liver abscess, which lacks the water-lily sign.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.