Which parasite is commonly acquired from eating raw fish and produces eggs with an operculum and a large size?

Which parasite is commonly acquired from eating raw fish and produces eggs with an operculum and a large size?

• A. Clonorchis sinensis
• B. Paragonimus westermani
• C. Fasciola hepatica
• D. Diphyllobothrium latum

Answer: (D)

A key clue is a tapeworm acquired from eating raw fish, with eggs that are operculated and notably large. Diphyllobothrium latum fits this pattern: humans acquire it by consuming raw or undercooked freshwater fish (such as certain pike, perch, or salmon depending on region). The eggs of this parasite are operculated, and, among the human helminths, the eggs and the worm itself are relatively large, reflecting the characteristic size of this fish-borne tapeworm. The parasite can grow to several meters in length, and infection may lead to vitamin B12 deficiency and anemia, adding clinical context that often accompanies this diagnosis. Other options involve organisms associated with fish or other foods, but their eggs are smaller or their transmission is linked to different vehicles (for example, certain lung or liver flukes or ingestion of aquatic plants or crustaceans), so they do not align as well with the combination of raw fish transmission and large, operculated eggs.

A key clue is a tapeworm acquired from eating raw fish, with eggs that are operculated and notably large. Diphyllobothrium latum fits this pattern: humans acquire it by consuming raw or undercooked freshwater fish (such as certain pike, perch, or salmon depending on region). The eggs of this parasite are operculated, and, among the human helminths, the eggs and the worm itself are relatively large, reflecting the characteristic size of this fish-borne tapeworm. The parasite can grow to several meters in length, and infection may lead to vitamin B12 deficiency and anemia, adding clinical context that often accompanies this diagnosis.

Other options involve organisms associated with fish or other foods, but their eggs are smaller or their transmission is linked to different vehicles (for example, certain lung or liver flukes or ingestion of aquatic plants or crustaceans), so they do not align as well with the combination of raw fish transmission and large, operculated eggs.