EXPERIMENTAL SCHISTOSOMIASIS: THE EFFECT OF CHEMOTHERAPY ON CONCOMITANT IMMUNITY AND RESISTACE TO REINFECTION

Abstract

Schistosomiasis is a tropical disease estimated to afflict about 200 million people world wide (Jorden & Webb 1982). The disease is caused by various species of blood flukes of the genus Schistosoma which as adults live and lay eggs in the veins of the intestine or bladder.

The aim of the present work is to study the condition of concomitant inununity (resistance to reinfection) following successful chemotherapy of primary infection in mice infected with Schistosoma mansoni. Also, it is aiming to investigate the effect of duration of infection and time of treatment on this resistance.

This work was done on one hundred and sixty five laboratory bred swiss albino mice infection of 100 cercariae per mouse. They were classified into the following groups.

I. Untreated mice :

Composed of 45 infected mice were divided into the following subgroups

(each 15 mice):

Control subgroup : mice were infected and sacrified 4 weeks after infection.

Subgroup A : mice were challanged 8 weeks after infection by the same dose of crcariae as primary infection and sacrified 4 weeks after challange infection. Subgroup B: mice were challanged 16 weeks after infection and sacrifies 4

weeks later.