Platyhelminths : Cestodes Pseudophyllidea Diphyllobothrium latum (pernicious anemia) Cyclophyllidea Taenia solium (pork tapeworm) Taenia saginata (beef tapeworm) Echinococcus granulosus (cystic, CE) Echinococcus multilocularis (alveolar, AE)

A rare and emerging disease

Macroparasite example 2 : Taenia solium : Disease Neurocysticercosis Cestode. Unique zoonosis. Under-reported disease. Diagnostic difficulties. Lack of epidemiological data.

Biology of Taenia solium Unique zoonosis : Human only known definitive host, pig intermediate host Humans carry both adult worms in the intestine & larval cysticercosis in the muscle & other tissues Infection with adult worm in humans dangerous to host & other contacts Under-reported disease Biology of Taenia solium

Symptomatology and pathology 1 Primarily due to pressure effects of a space-occupying cyst or lesion in an organ or tissue CNS involvement : Neurocysticercosis (NCC) : pathology relates to number, size, type (cellulose or racemose), condition & site of cysticerci in the brain Active versus inactive NCC Symptomatology and pathology 1

Symptomatology and Pathology 2 Active NCC : arachnoiditis (spinal fluid pleocytosis, increased CSF protein, positive CSF serologic test) Small number of patients : obstructive hydrocephalus, cranial nerve involvement, intercranial hypertension, arterial thrombosis & stroke Epilepsy, dementia, meningitis Symptomatology and Pathology 2 Intraocular cysts : visual impairment

Location of parasites in 2188 cases of cysticercosis CNS 82% Eye 17% Subcutaneous tissue 7% Muscle 5% Other organs 6% Generalized 1% Flisser & Craig, 2005

Adult worms Stool analysis : uterine branch structure or scolex morphology after treatment Molecular differentiation of adult worms Capture ELISA for coproantigen detection Diagnosis 1

Diagnosis 2 Cysticercosis Imaging methods (CT scan useful for brain & calcified cysts ; MRI not but excellent for detecting active cysts in soft tissue) Serology (ELISA versus Immunoblot) Diagnosis 2

Epidemiology : cysticercosis Retrospective case finding fixed time period, annual incidence rate per 100,000 population Active screening Mass radiological imaging surveys Immunodiagnostic surveys Autopsy surveys Epidemiology : cysticercosis

Cysticercosis in communities Endemic focus: Rural Latin America Major risk factor: current or past case of intestinal Taenia in the household Non-endemic community: New York City Significant number of human cysticercosis cases in an Orthodox Jewish community

Treatment : cysticercosis Until recently symptomatic patients : anticonvulsants, corticosteroids, surgery Chemotherapy CT useful for monitoring Active parenchymal brain cysts and subarachnoid (racemose) cysts : albendazole Albendazole also effective against ocular cysticercosis Alternative drug : praziquantel less effective

Control : Taenia solium Freezing and appropriate cooking of pork Identification and treatment of Taenia carriers (mass treatment ?) Improved health education, prevention of vegetables irrigated with contaminated water Confinement of pigs Porcine vaccine Control : Taenia solium