THE PRESENCE OF ANGIOSTRONGYLUS CANTONENSIS IN ISLANDS OF THE INDIAN OCEAN AND PROBABLE ROLE OF THE GIANT AFRICAN SNAIL, ACHATINA FULICA, IN DISPERSAL OF THE PARASITE TO THE PACIFIC ISLANDS

Abstract

The incidence of Angiostrongylus cantonensis in Madagascar, Mauritius, Ceylon, and Sarawak is for the first time being reported. The finding of the parasite in these areas and the comparatively recent occurrence of murine and human angiostrongylosis in Southeast Asia and the Pacific lead to the belief that the parasite was introduced to these areas from the islands of the Indian Ocean. The fact that Achatina fulica during the past two centuries has gradually spread eastward from East Africa to the Pacific Islands leads to speculation that it might have played an important role in the spread of the parasite. Supporting evidence includes (a) the finding of A. cantonensis along the same dispersal route as that of A. fulica; (b) the finding of the parasite among rats in parts of Asia and the Pacific after the introduction of the snail; (c) the existence of a comparatively close time relationship between the first appearance of the Achatina snail in the Pacific Islands and the first occurrence of eosinophilic meningitis in this area.