The effect of Mg2+ and Fe3+ on the distribution of Schistosoma japonicum miracidia and use of this information in simulated snails.

Objective To observe the effect of Mg2+ and Fe3+ on the distribution of Schistosoma japonicum miracidia and use this information in simulated snails.Methods A modified form of Roberts' method of comparison was used.Results The ratio of S.japonicum miracidia for the experimental group and control group was 93:21(P0.01) when adding 1.00 mol/L Mg2+.The ratio of S.japonicum miracidia for the experimental group and control group was respectively 81:29(P0.01),24:5(P0.01),225:39(P0.01),41:7(P0.01),and 52:17(P0.01) when the concentration of Fe3+ was 0.05,0.10,0.25,0.50,and 1.00 mol/L.Fe3+ released from a gelatin mixture with a certain proportion of Mg2+ and Fe3+ had greater ability to attract S.japonicum miracidia than water conditioned by snails.Conclusion Mg2+ and Fe3+ significantly affected the distribution of S.japonicum miracidia.Simulated snails had greater ability to attract S.japonicum miracidia than water conditioned by snails.