Paragonimus westermani Eggs: Microscopic Morphology

Microscopic features of Paragonimus westermani eggs in wet mounts: size, shape, operculum presence, and diagnostic criteria for trematodiasis.

Editorial team 1 min May 29, 2025

Native wet mount, two characteristic Paragonimus spp. eggs with operculum

Wet mount, asymmetrical Paragonimus westermani egg with thick shell

Microscopy of native preparation, elongated Paragonimus egg with operculum

Native preparation, unembryonated yellowish-brown Paragonimus egg

🔬 Paragonimus spp. eggs in unstained wet mounts.

Paragonimus westermani eggs are 80-120 µm long and 45-70 µm wide. They are yellowish-brown, ovoid or elongated, with a thick shell, often asymmetrical, with one slightly flattened end. The operculum is clearly visible at the larger end. The opposite (abopercular) end is thickened. The eggs are unembryonated when passed in sputum or feces.

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Image and description source: CDC database