Which of the following cestodes is unique in that it can complete its entire life cycle within a single human host without requiring an intermediate host?
- A Taenia saginata
- B Diphyllobothrium latum
- C Hymenolepis nana ✓
- D Echinococcus granulosus
Correct answer: C. Hymenolepis nana
Explanation
Hymenolepis nana, the dwarf tapeworm, is the only cestode that does not require an intermediate host. Eggs hatch in the small intestine, oncospheres penetrate the villi, and develop into cysticercoid larvae, which then mature into adults in the lumen. Taenia and Diphyllobothrium require intermediate hosts like cattle or copepods. Echinococcus requires sheep and dogs.
Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.