Question:medium
Identify the parasite egg shown in the image.
Identify the parasite egg shown in the image.
Show Hint
Look for a barrel shape with a clear, transparent plug at each end.
Updated On: Jun 23, 2026
- Trichuris trichiura
- Ancylostoma duodenale
- Paragonimus
- Strongyloides
Show Solution
The Correct Option is A
Solution and Explanation
Clinical-image pearl: a parasite egg shaped like a barrel or lemon with a clear plug bulging out of each pole is Trichuris trichiura every time. Mnemonic: whipworm = two clear corks on a brown barrel.
Option elimination: hookworm (Ancylostoma) eggs are colourless ovals with a thin shell and an early-cleavage embryo inside, never plugged. Paragonimus (lung fluke) eggs are large, ovoid and operculated, with the operculum sitting in a shallow shoulder. Strongyloides is diagnosed from its rhabditiform larvae in fresh stool, not from a characteristic egg.
The brown colour comes from bile staining of the thick triple shell; the polar plugs stay colourless. The egg is roughly 50 um by 25 um and floats in concentrated salt flotation, which is how it is concentrated from faeces. Ref: Jawetz Medical Microbiology, 27e, p.724.
Option elimination: hookworm (Ancylostoma) eggs are colourless ovals with a thin shell and an early-cleavage embryo inside, never plugged. Paragonimus (lung fluke) eggs are large, ovoid and operculated, with the operculum sitting in a shallow shoulder. Strongyloides is diagnosed from its rhabditiform larvae in fresh stool, not from a characteristic egg.
The brown colour comes from bile staining of the thick triple shell; the polar plugs stay colourless. The egg is roughly 50 um by 25 um and floats in concentrated salt flotation, which is how it is concentrated from faeces. Ref: Jawetz Medical Microbiology, 27e, p.724.
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