Homologous and heterologous resistance of Echinostoma revolutum and E. liei in ICR mice.

To study resistance of echinostomes in the mouse, female ICR mice were challenged homologously or heterologously with Echinostoma revolutum or E. liei metacercariae. Mice challenged homologously had significantly fewer worms which weighed less than those from control mice. In heterologous studies where the primary infection was not eliminated with an anthelmintic, the number of worms in challenged mice was not significantly different than that in controls which received only the primary infection. However, the mean dry weight/worm of the secondary infection was less than that of controls. Mice challenged with E. revolutum 2 days after a 21-day-old E. liei infection was eliminated with Zanil contained significantly fewer E. revolutum, which weighed less than those of controls.