- Taenia solium (pork tapeworm) and Taenia saginata (beef tapeworm) are intestinal cestodes.
- Cysticercosis including neurocysticercosis is the main concern of these tapeworm infections, caused by Taenia solium.
- Life cycle: additional details in CDC illustration.
- Eggs or gravid proglottids are passed in the stool.
- Pigs ingest contaminated vegetation, and oncospheres hatch in the intestine.
- Organisms invade the intestinal wall, migrate to striated muscles, and develop into cysticerci.
- Humans ingest raw or undercooked infected meat, and gastric juices activate larvae, leading to evagination of scolex and attachment to the small intestine.
- Over 2-4 months, cysticercus develops into an adult tapeworm; may grow up to 7 meters in length.
- Adults have up to 1,000 proglottids, each containing 50,000-100,000 eggs.
- Pigs are intermediate hosts; humans acquire intestinal tapeworm by eating undercooked pork containing cysticerci.
- Humans acquire disseminated cysticercosis by ingesting eggs in food/water contaminated by human tapeworm carriers.
There's more to see -- the rest of this topic is available only to subscribers.