[Killing effect of garlic extract on Schistosoma japonicum cercariae and Oncomelania snails]. 
The killing effect of different concentrations of garlic extract solution on Schistosoma japonicum cercariae and Oncomelania snails was observed under dissecting microscope.  Mice were infected by cercariae through the abdominal skin daubed by garlic solution or by deionized water as control.  The results showed that the cercariae were killed in (77.33 +/- 25.01) s in average, it needed (73.00 +/- 1.73)- (299.67 +/- 18.96) s under the garlic solution concentrations of 50.00%-0.79% respectively, while the cercariae kept alive in 600 s in the control.  The snails were killed in 1 d by 100% garlic solution but no death in the control in 2 d. No mouse daubed with different concentrations of garlic solution was found infected by schistosomes while 100% of the control mice got infected.  It is concluded that the garlic shows satisfactory effect in killing cercariae and Oncomelania snails, and may prevent schistosome infection by daubing the skin.