Cysticercosis update.

Already the most common brain parasite disease, cysticercosis has been increasingly seen throughout the American Southwest. Symptoms arise from infection with larvae of Taenia solium, the pork tapeworm. Seizures, hydrocephalus, focal deficits and chronic meningitis most commonly result. Cerebrospinal fluid eosinophilia, serology by indirect hemagglutination and computed tomography are helpful adjuncts to diagnosis. New evidence suggests that selective immunosuppression is important for the parasites' survival and that cyst death permits renewed host immunity, which may actually precipitate an acute neurologic presentation. New larvicides, including praziquantel, are being tested in humans; caution is indicated in assessing these drugs because of the acute worsening associated with cyst death. Conventional therapy includes anticonvulsants, steroids or ventricular drainage as needed. Prevention remains the best management. Person-to-person transmission within the United States has recently been documented and merits public health scrutiny.