Pork tapeworms are parasitic flatworms that use pigs as intermediate hosts but complete their life cycle in humans. Infection in humans occurs through ingestion of improperly prepared pork.
Pork tapeworms are parasites of the digestive tract. The tapeworm itself is simple, consisting of a head, or scolex, with organs of attachment and a body comprising many reproductive units. Pork tapeworms enter pigs as eggs, often in unclean fodder. They develop into the larval stage in their pig host, at which point they are capable of infecting a human.
Undercooked pork is the primary means of infection in humans. In its human host, the pork tapeworm lives in the intestines. Tapeworm infection is frequently asymptomatic, with the host only becoming aware of infection by finding the worm in stool. Tapeworms get nourishment from the host body and in some cases cause symptoms such as nutrient deficiencies, abdominal pain, nausea, diarrhea, excessive appetite or loss of appetite. Pork tapeworms are most dangerous to humans if a human ingests the eggs instead of the larval stage. The eggs form cysts in skin, muscles, eyes or the brain. Pork tapeworm cysts in the brain are a common cause of seizures and may cause dangerous amounts of pressure on important brain areas.