Ingestion of eggs, excreted by a human carrier of the pork tapeworm, on fecally contaminated food or through close contact with the carrier. Autoinfection is also possible. Eating undercooked pork with cysticerci results in tapeworm infection (taeniasis), not human cysticercosis.
Common where sanitary conditions are poor and where pigs have access to human feces. Endemic areas include Mexico, Latin America, sub-Saharan Africa, India, and East Asia. Uncommon in travelers. Seen in immigrants from endemic regions.
Median latent period of 5 years (range, 1–30 years). Symptoms depend on the number, location, and stage of cysts. The most common location is brain parenchyma, with late-onset seizures. Other presentations include increased intracranial pressure, encephalitis, symptoms of space-occupying lesion, and hydrocephalus. Cysticercosis should be ruled out in any adult with new-onset seizures who comes from an endemic area or has potential exposure to a tapeworm carrier.
Neuroimaging studies (CT or MRI) and confirmatory serologic testing. The most reliable serologic test is the enzyme-linked immunotransfer blot, but this test may be negative in up to 30% of patients with a single parenchymal lesion.
Control of symptoms is the cornerstone of therapy. Anticonvulsants, dexamethasone, or both may be indicated. For some lesions, surgical intervention may be the treatment of choice. Antiparasitic treatment (albendazole, praziquantel) should not be initiated in patients with heavy infections, cysticercotic encephalitis, or increased intracranial pressure, as dying cysts can cause or worsen some symptoms. In these cases, the priority is neurologic management (steroids, mannitol), neurosurgical management, or both. Physicians can consult with CDC to obtain more information about diagnosis and treatment (www.dpd.cdc.gov/dpdx, 404-718-4745; firstname.lastname@example.org).