How do Taenia saginata and Taenia solium differ in proglottid morphology and risk of cysticercosis?

• A. Taenia saginata has longer proglottids with many uterine branches; Taenia solium has shorter proglottids with fewer branches; cysticercosis risk is higher with Taenia solium
• B. Taenia saginata has shorter proglottids; Taenia solium longer proglottids
• C. Both have identical proglottids; cysticercosis risk only with Taenia saginata
• D. Taenia saginata causes cysticercosis more often than Taenia solium

Answer: (A)

The key idea is that you identify Taenia species by the structure of their gravid proglottids and remember how the eggs relate to disease. Gravid proglottids are the egg-filled segments you’d find in stool or passe. Taenia saginata has longer proglottids with many uterine branches, giving a highly branched, elongated appearance. Taenia solium has shorter proglottids with fewer branches. This morphological difference is a standard diagnostic cue to tell the two apart under the microscope.

In terms of disease, cysticercosis arises from humans ingesting eggs that hatch and form cysticerci in tissues. Taenia solium is the species whose eggs can cause cysticercosis (including neurocysticercosis). Taenia saginata eggs do not typically cause tissue cysts in humans. So the combination described—longer proglottids with many branches for saginata, shorter proglottids with fewer branches for solium, and cysticercosis risk higher with solium—is the correct pairing.