What is taeniasis and cysticercosis?
Infection with T. solium can result in two distinct conditions: taeniasis and cysticercosis. While the adult tapeworm in the human intestine (taeniasis) does not have major health impacts, humans can also develop cysticercosis with tapeworm larvae (cysticerci) in the muscles, skin, eyes and the central nervous system, with possible devastating effects on health. When cysts develop in the brain, the condition is referred to as neurocysticercosis. Symptoms include severe headache, blindness, convulsions and epileptic seizures and can be fatal.
Taeniasis is acquired by humans through the inadvertent ingestion of tapeworm larvae (cysticerci) in undercooked pork. Once in the human body, cysticerci develop into adult tapeworms that live in the intestine and release egg-bearing gravid proglottids (segments) which are passed out with faeces.
Cysticercosis is acquired when worm proglottids or eggs are ingested and the developing larvae migrate through the body and form cysts in tissues. This is the case in pigs and cattle but it can also affect humans, usually when they swallow T. solium egg-contaminated soil, water or food (mainly vegetables) or through self-infection when hygiene practices, such as hand washing after the toilet, are unsufficient. When the central nervous system is affected by the larvae, the infection is called neurocysticercosis.