Eosinophilic meningitis due to Angiostrongylus cantonensis.

Angiostrongylus cantonensis is the most common etiological agent of eosinophilic meningitis. Adults are harbored in the pulmonary arteries of rats. Larvae develop within various natural (mollusks) and paratenic (snails...) hosts. After ingestion, larvae reach the human central nervous system where they cannot complete their life cycle. This zoonosis is usually seen in Southeast Asia and South Pacific islands. Nevertheless, a few imported cases have been reported in Western countries, possible because of the incubation delay. Mild meningeal irritation signs, paresthesia, cranial nerve abnormalities (i.e: II, III, VI, VII) are the most usual by encountered signs. Severe cases with brain involvement have been reported. In endemic areas, typical clinical signs associated with C.S.F. eosinophilic pleocytosis allow the diagnosis but Elisa test may be useful. Prognosis is always excellent even if headache and malaise may last a few weeks. No antihelminthic agent is efficient against Angiostrongylus cantonensis. Prophylaxia by public health counselling program is fruitful.