Comparative infectivity and survival of first-stage larvae of Angiostrongylus cantonensis and Angiostrongylus malaysiensis.

Angiostrongylus malaysiensis was isolated from wild rats Rattus norvegicus in a seaport area of Kitakyushu City, Kyushu, Japan in 1990. The infectivity and survival capacities of first-stage larvae of A. malaysiensis and Angiostrongylus cantonensis were compared under various conditions. Infectivity of first-stage larvae of the former in Biomphalaria glabrata was much lower than that of the latter. In an exposure at various pHs, and with various proteases and tissue homogenates of B. glabrata, the survival of first-stage larvae of A. malaysiensis was also lower than that of A. cantonensis. This lower survival was compared to that of A. cantonensis in response to desiccation of rat feces and high water temperature. First-stage larvae of A. malaysiensis thus appear to be influenced by conditions in the host's feces, specifically temperature and desiccation, and also show a greater sensitivity to pH and component proteases in the snail body than A. cantonensis.