Lymnaea (Bullastra) cumingiana Pfeiffer (Pulmonata: Lymnaeidae): second intermediate host of Echinostoma malayanum in the Philippines.

Abstract

Adult flukes were obtained from laboratory rats and hamsters fed with metacercariae isolated from Lymnaea (Bullastra) cumingiana Pfeiffer and were identified as Echinostoma malayanum Leiper based on the presence of a circumoral collar of 43-45 spines and the highly lobed testes. This discovery is of public health significance because L. (Bullastra) cumingiana in eaten raw by certain local populations in northern Luzon. The proposed new species, Cathaemasia cabrerai (Jueco and Monzon, 1984), is probably invalid because it apparently was based on E. malayanum flukes that had lost their circumoral collar of spines after treatment with praziquantel and bithionol. This is the first case where L. (Bullastra) cumingiana has been proven to be of medical importance in the Philippines. i.e., as the natural second intermediate host of E. malayanum. The first intermediate host and reservoir host of this parasite in the country are still unknown. Previously, only E. ilocanum was reported to be present in the Philippines.