Posted by: Footler PJ12 JUN 2013
According to the World Health Organization, about two million people worldwide suffer with epilepsy because of neurocysticercosis, an infection of the brain or spinal cord caused by the pork tapeworm Taenia solium. The infection, the most common preventable epilepsy in the developing world, is usually found in poor rural communities around the world. But cases are on the rise in developed countries such as in the southwestern states of the US bordering Mexico.
Studying neurocysticercosis has proved difficult because the tapeworm’s complicated life cycle is almost impossible to maintain in the laboratory. The tapeworm lives in the human small intestine from where multiple proglottids, each containing up to 50,000 ova, are shed. Free-roaming pigs ingest human stools containing infectious ova which then lose their protective capsule on exposure to the gastric acid in the stomach and turn into larval cysts called oncospheres. The liberated oncospheres penetrate the intestinal mucosa and are carried to the muscles and other tissues of the pig to develop as cysts.
The infection (taeniasis) is passed on when a person eats raw or undercooked meat, drinks contaminated water or through poor sanitation and personal hygiene. The cysts can remain viable for many years.
However, not everyone infected with the cysts (cysticercosis) will develop neurocysticercosis. If the cysts do enter the brain or spinal cord they have to pass through four more stages of development before the symptoms of neurocysticercosis, which may include hydrocephalus and increased intracranial pressure as well as seizures, occur.
Neurocysticercosis may be treated with anticonvulsants and a combination of anthelmintics and corticosteroids but the tapeworm infection can be prevented with good personal hygiene and improved sanitation, by cooking pork thoroughly, and by preventing pigs from roaming freely and eating human waste.