Host and parasite determinants of morbidity in Egyptian children with schistosomiasis.

The relation of morbidity due to schistosomiasis in Egyptian children to egg count, eosinophilic count, antibodies mediating eosinophil damage to schistosomula, total immunoglobulins and specific antischistosomal antibodies IgG and IgM anti-cercarial antigen preparation (CAP), anti-soluble worm antigen preparation (SWAP) and anti-soluble egg antigen preparation (SEA) were evaluated. The behavior of the immune parameters after treatment was also determined. The studied children were 78 males, aged 9-11 years. They were classified to control (14), simple intestinal (26) and hepatosplenic schistosomiasis (38) groups according to the clinical, parasitological and sonographic basis. The egg count was found higher in hepatosplenic schistosomiasis compared to that in simple group. Eosinophilic count did not differ between the two groups. Studies of immune responses revealed that antibodies mediating eosinophil adherence and damage to schistosomula rose in both groups particularly in hepatosplenic group. The levels of total and specific immunoglobulins were not significantly differed in both groups. The immune response was measured 2 months after treatment. The level of total IgA was increased in simple and decreased in hepatosplenic group. Total IgG and IgM were not affected by treatment in simple but IgM increased in hepatosplenic after treatment. Total IgE was decreased after treatment in both groups. This denotes that the behavior of the two groups after treatment was similar as regards the levels of IgG and IgE and differed as regards IgA and IgM. IgG anti-CAP and anti-SEA were declined after treatment but IgG- anti SWAP was elevated after treatment in both groups. The treatment has no effect on the levels of specific IgM against all used antigens. The antibodies mediating eosinophil adherence and damage to schistosomula rose in both groups after treatment. These indicated consistency of specific immune responses after treatment in schistosomal children. It is concluded that high intensity of infection may be one of the determinants of morbidity due to Schistosoma mansoni infection in Egypt. The elevated response of antibodies mediating adherence and damage to schistosomula may be associated or play a role with morbidity. Eosinophilic count, total IgA, IgG, IgM, IgE and specific antischistosomiasis IgG and IgM (Anti-CAP, anti-SWAP and anti-SEA) are not related to morbidity.