Cystic echinococcosis — DTM&H MCQ

Correct answer: E — Albendazole with specialist assessment for PAIR or surgery

The correct answer is E, albendazole with specialist assessment for PAIR or surgery. A 9 cm hepatic cyst with daughter cysts is a CE2/CE3b type on the WHO ultrasound classification, indicating an active, multivesicular hydatid cyst that will not resolve with drug therapy alone and requires an interventional approach. Current WHO guidance, followed in UK tropical medicine practice, recommends albendazole started before and continued after either PAIR (puncture, aspiration, injection, re-aspiration) or surgical removal, chosen according to cyst stage, size, and local expertise, since perioperative albendazole reduces the risk of secondary echinococcosis from spillage and improves cure rates. Because this cyst is large with daughter cysts but has not ruptured into the biliary tree, PAIR or surgery combined with albendazole is the appropriate stepwise, specialist-led plan rather than either drug or intervention alone. Why the other options are wrong: A. Percutaneous aspiration without antihelminthic cover: aspirating a hydatid cyst without albendazole cover risks spillage of viable protoscoleces, causing secondary peritoneal echinococcosis or anaphylaxis from cyst fluid antigens. D. Metronidazole and repeat ultrasound in a year: metronidazole has no activity against Echinococcus granulosus and simple observation is inappropriate for an active CE2/CE3b cyst of this size, which carries a real risk of rupture or infection. C. Praziquantel as monotherapy: praziquantel is protoscolicidal but not effective as sole systemic therapy for hepatic cystic echinococcosis and is not recommended as monotherapy in this setting. B. Corticosteroids and observation: steroids have no role in treating hydatid disease and do not address the underlying parasitic cyst; observation alone is unsafe for a large, multivesicular cyst. Key point: large or multivesicular (CE2/CE3b) hydatid liver cysts need albendazole combined with PAIR or surgery, chosen by specialist assessment, not drug or drainage alone.

Reference: WHO Guidelines for the Treatment of Cystic Echinococcosis, 2024, summarising albendazole with PAIR or surgery according to cyst stage (WHO/Guideline Central summary), consistent with BNF albendazole indication for hydatid disease as an adjunct to surgery or percutaneous treatment, https://www.guidelinecentral.com/guideline/4684056/