Infectious Disease Online
Pathology of Cysticercosis
Cysticercosis, an infection by the larval stage (bladder worm) of Taenia solium, the pork tapeworm, usually noted where uncooked pork is eaten.
The adult Taenia solium is acquired by eating pork infected with cysticerci and pigs acquire cysticerci by ingesting eggs of Taenia solium shed in human faeces.
This normal cycle, although a public health problem, is essentially benign for both humans and pigs.
However, when humans accidentally ingest the eggs from human faeces and become infected with cysticerci, the consequences may be catastrophic.
The eggs release oncospheres, which penetrate the wall of the gut, enter the blood stream, lodge in tissue, encyst, and differentiate to cysticerci.
The cysticercus, a spherical, milky white cyst about 1 cm in diameter, contains fluid and an invaginated scolex with birefringent hooklets.
The cysticerci remain viable for an indefinite period and provoke no inflammation but compress adjacent tissue as they grow.
The cysticercus dies, leading to a granulomatous reaction with eosinophils, after which the lesion becomes scarred and calcified.
Cysticerci in the retina may lead to blindness.
Massive cysticercosis of the brain causes convulsions and death, and in the heart may cause arrhythmias and sudden death.
An aberrant cysticercus, called racemose cysticercus, can also be fatal.
It is sterile (without a scolex) and limited to the brain, and has an arborizing growth that produces a large, grapelike mass several centimeters in diameter. (Racemose cysticercus in human brain.)
The diagnosis is made from the morphology of the excised cyst.
Serologic tests are helpful but do not exclude echinococcosis.
A history of tapeworm infection in the patient is significant because autoinfection is possible.
Treatment of muscle disease is with praziquantel.
Neurocysticercosis is the most common helminthic disease of the nervous system and currently represents a major public health problem in developing countries of Latin America, Asia, and Africa, as well as in industrialized nations with a high immigration rate of people from endemic areas.
The disease occurs when humans become the intermediate host in the life cycle of Taenia solium by ingesting its eggs from contaminated food.
Neurocysticercosis is pleomorphic in its presentation due to individual differences in the number, size, and location of the parasites, as well as differences in the severity of the host's immune reaction to the parasite.
Epilepsy, focal neurological signs, and intracranial hypertension are the most common clinical manifestations of the disease.
The diagnosis of neurocysticercosis is based on clinical data, neuroimaging abnormalities, and the results of immunological tests.
Two drugs, albendazole and praziquantel, are cysticidal and destroy most intracranial parasites ; however, surgery may be necessary in the management of some forms of the disease, particularly hydrocephalus and intraventricular cysts.
Cysticercosis in an Egyptian mummy: Short report: cysticercosis in an Egyptian mummy of the late Ptolemaic period.
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