Effects of Schistosoma mansoni experimental infection on some inorganic elements in the snail host Biomphalaria alexandrina.

The alteration in the concentrations of metallic ion Pb, Zn, K, Na, Co, Fe, and Cu in the soft parts of the Biomphalaria alexandrina snails shedding Schistosoma mansoni cercariae was detected by flame atomic absorption spectrometry. Six elements Pb, Zn, K, Na, Co, and Cu were found to be present at significantly higher concentrations in cercariae-shedding snails compared with uninfected snails. The concentration of Fe ion showed non-significant decrease in the tissues of cercariae-shedding snails. Variation in the present results compared with related previous studies lead to the suggestion that the effect of trematode parasitism on fresh-water snails should not be considered universal and might be varies according to the trematode-snail combination, the organs or the tissues analyzed and the analytical method used.