Eosinophilic Meningitis in Okinawa

Abstract

Three cases of eosinophilic meningitis were observed in 1969 on Okinawa, in the Ryukyu Islands between 26°04′ and 26°51½′ North latitude. Each of the patients exhibited a clinical picture similar to that seen in Angiostrongylus cantonensis infections elsewhere in the Pacific Ocean area and Southeast Asia. Infection by this metastrongylid nematode is endemic in populations of Rattus norvegicus and Rattus rattus in Okinawa and certain other islands of the southern Ryukyus. In the cases in man, there had been exposure to infection by direct contact with an intermediate host, the abundant snail Achatina fulica, in one instance by deliberate ingestion in the raw state, but other modes of transmission were not excluded. These are the first suspected cases of angiostrongyliasis in man in the Ryukyu Islands and, to our knowledge, the only such cases in the subtropics at this latitude that have been reported.