Which helminth produces an elongate, barrel-shaped egg with colorless polar plugs?

Which helminth produces an elongate, barrel-shaped egg with colorless polar plugs?

• A. Trichuris trichiura
• B. Ascaris lumbricoides
• C. Hymenolepis nana
• D. Necator americanus

Answer: (A)

Whipworm eggs have a distinctive barrel-like, elongated shape with clear colorless polar plugs at both ends. That combination—barrel shape plus plugs—is a classic, diagnostic feature of Trichuris trichiura. The other parasites produce different egg forms: Ascaris lumbricoides eggs are round to oval with a thick, mammillated shell; Hymenolepis nana eggs are small and spherical; Necator americanus eggs are thin-shelled and oval with a morula inside. So the described egg morphology points to Trichuris trichiura.

Whipworm eggs have a distinctive barrel-like, elongated shape with clear colorless polar plugs at both ends. That combination—barrel shape plus plugs—is a classic, diagnostic feature of Trichuris trichiura. The other parasites produce different egg forms: Ascaris lumbricoides eggs are round to oval with a thick, mammillated shell; Hymenolepis nana eggs are small and spherical; Necator americanus eggs are thin-shelled and oval with a morula inside. So the described egg morphology points to Trichuris trichiura.