Eosinophilic Meningitis Caused by Angiostrongylus cantonensis.

Rat lungworm, Angiostrongylus cantonensis, is one major cause of human eosinophilic meningitis. This helminth is endemic in Southeast Asia, Pacific Islands, and the Caribbean and has recently expanded to South America. The infection is characterized by an elevated eosinophil count in cerebrospinal fluid. Common symptoms and signs include headache, neck stiffness, paresthesia and nausea/vomiting. The unique history of eating freshwater and land snails or slugs within 2 weeks before onset is helpful for diagnosis. Antihelminthic agents have not shown efficacy in human infection; treatment involves supportive care with management of inflammation and intracranial pressure.