Susan Montgomery, Barbara L. Herwaldt, Sharon L. Roy
Taenia solium, a cestode parasite.
Ingestion of eggs, excreted by a human carrier of the adult T. solium tapeworm, via fecally contaminated food or through close contact with the carrier. Autoinfection is also possible. Larval cysts of T. solium infect brain, muscle, or other tissues. 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. Occurs globally; endemic areas include Latin America, sub-Saharan Africa, India, and East Asia. Uncommon in travelers. Seen in immigrants from endemic regions.
The latent period ranges from months to decades. Symptoms depend on the number, location, and stage of cysts. The most important clinical manifestations are caused by cysts in the brain, where cysts can be parenchymal or extraparenchymal (ventricular, subarachnoid). The 2 most common presentations are seizures and increased intracranial pressure. Other presentations include encephalitis, symptoms of space-occupying lesions, and hydrocephalus. Cysticercosis should be excluded in any adult with new-onset seizures who comes from an endemic area or has had potential exposure to a tapeworm carrier.
Neuroimaging studies (CT and MRI) and confirmatory serologic testing. The most specific serologic test is the enzyme-linked immunotransfer blot, but the test results may be negative in up to 30% of patients with a single parenchymal lesion.
Control of symptoms is the cornerstone of therapy. Anticonvulsants, corticosteroids, or both may be indicated. For some lesions, surgical intervention may be the treatment of choice. Antiparasitic treatment (albendazole, praziquantel) is not indicated for all presentations of neurocysticercosis. In complicated cases, the priority is neurologic management (for example, corticosteroids, mannitol), neurosurgical management, or both. In 2018, guidelines for the clinical management of neurocysticercosis were published by the Infectious Diseases Society of America and the American Society of Tropical Medicine and Hygiene. Clinicians can consult CDC to obtain more information about diagnosis and treatment (CDC Parasitic Diseases Inquiries: 404-718-4745 or firstname.lastname@example.org).
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Garcia HH, Gonzales I, Lescano AG, Bustos JA, Zimic M, Escalante D, et al. Efficacy of combined antiparasitic therapy with praziquantel and albendazole for neurocysticercosis: a double-blind, andomized controlled trial. Lancet Infect Dis. 2014 Aug;14(8):687–95.
White AC, Coyle CM, Rajshekhar V, Singh G, Hauser WA, Mohanty A, et al. Diagnosis and treatment of neurocysticercosis: 2017 clinical practice guidelines by the Infectious Diseases Society of America (IDSA) and the American Society of Tropical Medicine and Hygiene (ASTMH). Clin Infect Dis. 2018 Feb; https://doi.org/10.1093/cid/cix1084.