Angiostrongylus cantonensis eosinophilic meningitis.

In the past 50 years, Angiostrongylus cantonensis, the most common cause of eosinophilic meningitis, has spread from Southeast Asia to the South Pacific, Africa, India, the Caribbean, and recently, to Australia and North America, mainly carried by cargo ship rats. Humans are accidental, "dead-end" hosts infected by eating larvae from snails, slugs, or contaminated, uncooked vegetables. These larvae migrate to the brain, spinal cord, and nerve roots, causing eosinophilia in both spinal fluid and peripheral blood. Infected patients present with severe headache, vomiting, paresthesias, weakness, and occasionally visual disturbances and extraocular muscular paralysis. Most patients have a full recovery; however, heavy infections can lead to chronic, disabling disease and even death. There is no proven treatment for this disease. In the authors' experience, corticosteroids have been helpful in severe cases to relieve intracranial pressure as well as neurologic symptoms due to inflammatory responses to migrating and eventually dying worms.