In a stool smear, how do hookworm eggs differ from Trichuris eggs?

• A. Hookworm eggs are larger with bipolar plugs; Trichuris eggs are smaller and uniformly oval.
• B. Hookworm eggs are smaller, thin-shelled and more uniformly oval; Trichuris eggs are larger with prominent bipolar plugs.
• C. Hookworm eggs are irregularly shaped; Trichuris eggs are smooth and round.
• D. Hookworm eggs are coiled; Trichuris eggs are elongated.

Answer: (B)

Differentiating hookworm and Trichuris eggs in a stool smear comes down to size and shell features. Hookworm eggs are smaller and have a thin, delicate shell that yields a smooth, uniformly oval appearance. Trichuris eggs are larger and more robust, with a thick shell and a distinctive barrel shape, featuring prominent bipolar plugs at each end. Those polar plugs are a key identifying feature of Trichuris eggs, making them easy to recognize under the microscope.