Cysticercosis is a parasitic infection caused by the larval cysts of the tapeworm Taenia solium. Patients acquire the infection by ingesting the eggs, which reach a larval stage in various tissues. When the central nervous system (CNS) is involved, the condition is known as neurocysticercosis. It is the most common parasitic infection of the CNS. Infection with this organism is most frequently encountered in individuals from Mexico, South Central America, the Philippines, and Southeast Asia. In the CNS, the cysts act as space-occupying lesions and can cause hydrocephalus and/or seizures. Seizures are the most common initial presentation of patients with neurocysticercosis and may be focal or generalized. Signs of increased intracranial pressure such as headache, nausea, vomiting, or visual changes may also be present. Amebiasis is caused by Entamoeba histolytica. Patients typically present with diarrhea (often bloody), right lower quadrant abdominal pain, and fever. Amebic abscesses in the liver are a complication due to invasion of the poal venous system by the amoeba. Cytomegalovirus produces neonatal infections and infections in immunocompromised patients such as AIDS patients. CD4 counts are usually Echinococcosis is a parasitic nematode infection caused by either Echinococcus granulosis or E. multilocularis. The disease is hydatid cyst disease. The patient ingests the eggs from dogs and becomes an intermediate host. The cysts are classically in the liver, are calcified, and the patient shows eosinophilia.