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Questions and Answers
What are the intermediate hosts for Hymenolepis nana?
Beetles and fleas.
How long can H. nana eggs survive in the external environment?
No more than 10 days.
How long is the life span of adult H. nana worms?
4 to 6 weeks, but internal autoinfection allows the infection to persist for years.
Study Notes
- Hymenolepis nana eggs are immediately infective when passed with stool.
- Eggs can't survive more than 10 days in the external environment.
- Beetles and fleas can serve as intermediate hosts for H. nana.
- Oncospheres contained in the eggs are released upon ingestion.
- Oncospheres penetrate the intestinal villus and develop into cysticercoid larvae.
- Cysticercoids return to the intestinal lumen, evaginate their scoleces, and attach to the intestinal mucosa.
- Adult worms reside in the ileal portion of the small intestine and produce gravid proglottids.
- Eggs are passed in the stool through the genital atrium of proglottids or when proglottids disintegrate.
- Internal autoinfection is an alternate mode of infection.
- The life span of adult worms is 4 to 6 weeks, but internal autoinfection allows the infection to persist for years.
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Description
Test your knowledge on the life cycle of Hymenolepis nana, a common tapeworm that infects humans. Learn about the key stages in the life cycle, from the infective eggs passed in stool to the adult worms residing in the small intestine. Discover how beetles and fleas serve as intermediate hosts, and how internal autoinfection can lead to persistent infections. Challenge yourself with this informative quiz and enhance your understanding of this parasitic infection.
