Schistosoma mansoni: unisexual infections sensitized mice for granuloma formation around intravenously injected eggs.

Mice carrying unisexual infection with male or female Schistosoma mansoni for 9 weeks developed accelerated and augmented reactions to S. mansoni eggs injected intravenously. The size of circumoval granulomas observed in the lungs of unisexually infected mice did not differ significantly from the reactions seen in bisexually infected mice. Tissue eosinophilia in the granulomas was also augmented similarly over that in naive mice by unisexual or bisexual infection. The cross-reactivity between worm and egg antigens is relevant to the development of acute toxemic schistosomiasis mansoni and, perhaps, to the consideration of antigens to be used for vaccination against S. mansoni infection.