Summary

In the present paper it had been investigated the morbidity and lethality of mice experimentally infected by Schistosoma mansoni according to a double schedule: one group was submitted to a single inoculation of high number of cercariae and the other one was infected four times with low number of cercariae. In both cases the total number of cercariae per mouse was the same. A third group of mice was maintained without infection as a control.
Twice a week all mice have been weighed and from the 60th up to the 120th day after infection all infected mice were submitted to faecal examination to determine the quantity of S.mansoni eggs eliminated per gram of faeces.

After the 120th day of infection all mice had been sacrified and the worm burden was determined by portal perfusion. At the same time the body, liver and spleen weights of all mice had also been obtained.

The data found had been analyzed by non-parametric statistical tests and did not show any difference between the mice submitted either to single or multiple infections.