Angiostrongylus cantonensis infection in Ampullarius canaliculatus (Lamarck) in Kyushu, Japan.
The fresh-water snail Ampullarius canaliculatus was introduced into Japan in 1981 as a source of food. The snails now grow wild and cause considerable damage to rice and other aquatic plants. Examination of snails from 24 localities in the south-west islands and the main island of Kyushu showed that snails from 5 of 6 areas of Okinawa Island and from Ishigaki Island were naturally infected with third-stage larvae of Angiostrongylus cantonensis. In addition, wild-caught Amp. canaliculatus snails (from an area known to be free of Angiostrongylus-infected snails) infected experimentally with first-stage larvae of Ang. cantonensis supported their development to second- and third-stage larvae. The authors conclude that Amp. canaliculatus snails can act as intermediate hosts for Ang. cantonensis and if eaten raw are a potential public health risk as a source of the causative agent of human eosinophilic meningoencephalitis.newline˜Carolyn A. Brown<new para>ADDITIONAL ABSTRACT:<new para>Angiostrongylus cantonensis was present in Ampullarius canaliculatus (introduced into Japan in 1981 as a potential food source) at 5 of 6 sites on Okinawa Island and at the one site examined on Ishigaki Island, Japan. The prevalence rate was 12.5%. Experimental infection of 4 rats with the larvae was successful and all showed typical lung pathology. Snails from a further 15 localities on the Nansei Islands and the Kyushu Island were not infected. When uninfected A. canaliculatus were given fresh rat faeces containing L1, the numbers of L3 recovered 35 to 91 days pi varied from 1 to 1233/snail. A further 4 rats were successfully infected with these larvae.