Taenia saginata — DTM&H MCQ

Correct answer: B — Praziquantel 10 mg/kg single dose

The correct answer is B, Praziquantel 10 mg/kg single dose. The stem describes flat, ribbon-like proglottids with more than 13 uterine branches in a patient who eats undercooked beef, which is the classic description of Taenia saginata (beef tapeworm) rather than Taenia solium (pork tapeworm, fewer than 13 branches, and associated with pork consumption and cysticercosis risk). For uncomplicated intestinal taeniasis due to T. saginata, praziquantel as a single oral dose is the treatment of choice, achieving high cure rates by paralysing the worm's musculature and allowing expulsion. Because there is no pork exposure and no risk of neurocysticercosis, praziquantel can be given safely without the theoretical concern of provoking an inflammatory reaction to CNS cysticerci that limits its use when T. solium infection with neurocysticercosis cannot be excluded. Why the other options are wrong: A, Albendazole 400 mg for 3 days: this is the regimen for soil-transmitted helminths and for hydatid or neurocysticercosis, not for adult intestinal tapeworm infection. C, Niclosamide 2 g single dose: an effective alternative when the Taenia species is uncertain or when T. solium/possible neurocysticercosis needs to be avoided with praziquantel, but praziquantel is preferred first-line once T. saginata is confirmed. D, Ivermectin 200 microgram/kg single dose: used for strongyloidiasis, onchocerciasis and scabies; it has no useful activity against cestodes. E, Mebendazole 500 mg single dose: this dose treats simple nematode infections such as threadworm, and is not an effective or licensed regimen for taeniasis. Key point: More than 13 uterine branches plus beef exposure confirms Taenia saginata, for which single-dose praziquantel 10 mg/kg is first-line, whereas niclosamide is reserved for uncertain species or when T. solium neurocysticercosis cannot be excluded.

Reference: BNF (NICE), Praziquantel, Indications and dose: tapeworm infection, https://bnf.nice.org.uk/drug/praziquantel.html