The intermediate host of schistosoma japonicum in China

Abstract

The snail which acts as the intermediate host of Schistosoma japonicum in Japan has been known since 1913 to be Blanfordia nosophora. No intermediate host for the parasite has heretofore been described for China. We selected the endemic region about Soochow, in Kiangsu Province, for our search. Our method consisted of first finding a case of the disease and then hunting in the neighborhood of the patient's home for a snail somewhat similar to Blanfordia nosophora. On August 11, 1922, such a snail was found in large numbers on the shore of a small terminal canal near which many cases of schistosomiasis japonica resided. Examination of these snails by crushing their shells revealed a five per cent. infection with cercariae morphologically similar to that of Schistosoma japonicum. A mouse immersed in water containing these cercariae was found, thirty-one days later, to harbor adult forms of Schistosoma japonicum in the portal and mesenteric veins. Snails of this type were exposed to miracidia of Schistosoma ...