A 50-year-old farmer from West Bengal presents with microcytic hypochromic anemia. Stool examination reveals thin-shelled eggs with a developing ovum showing 4-8 blastomeres. Which feature differentiates the causative hookworm, Necator americanus, from Ancylostoma duodenale in the buccal capsule?

• A Necator has two pairs of ventral teeth; Ancylostoma has cutting plates
• B Both have identical buccal capsule structures and cannot be differentiated
• C Necator has a dorsal cone; Ancylostoma has no buccal structures
• D Necator has cutting plates; Ancylostoma has two pairs of ventral teeth ✓

Explanation

Necator americanus has cutting plates (semilunar cutting plates) in its buccal capsule, while Ancylostoma duodenale has two pairs of ventral teeth. This is the key morphological distinction between the two hookworm species. Hookworm eggs appear identical morphologically, so differentiation requires examination of adult worms or cultured larvae (rhabditiform/filariform).

Reference: Paniker's Textbook of Medical Parasitology, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.