Echinococcus granulosus (and multilocularis ) . Cassandra Gallati Rachel Harjes Heather Hutchings. What is it?. Human Echinococcosis is caused by the larval stages of cestodes (tapeworms) of the genus Echinococcus Both have 3 proglottids , hooks and suckers E. granulosus
1. The adult Echinococcus granulosus resides in the small bowel of the definitive hosts, dogs or other canids.
2. Gravid proglottids release eggs that are passed in the feces.
3. The eggs are ingested by an intermediate host
4. The egg hatches in the small bowel
5. The egg releases an oncosphere that penetrates the intestinal wall
6. The oncosphere migrates through the circulatory system into various organs, especially the liver and lungs.
7. In the liver or lungs, the oncosphere develops into an infective hydatid cyst in the tissue of the tissue of what definitive host eats.
8. The hydatid cyst enlarges gradually
9. The hydatid cyst produces protoscolices and daughter cysts that fill the cyst interior.
10. After ingestion by the definitive host, the protoscolices evaginate.
11. The protoscolices then attach to the intestinal mucosa
12. The protoscolices then develop into adult stages in 32 to 80 days.