A comparison of the characteristics of two strains of Schistosoma intercalatum Fisher, 1934 in mice

Schistosoma intercalatum from Cameroon and Zaire each have their specific snail intermediate host. Hybridization experiments between S. intercalatum from Cameroon and Zaire have resulted in viable miracidia for only two generations. If the two strains are of the same species, cross breeding should be possible for several generations. This paper presents a comparison of the characteristics of the two strains of S. intercalatum in experimental infections in mice. Worm return, male-female worm ratio, growth rate, number of testes in male adult worms are compared. The quantitative distribution of eggs in the tissues of the mice is recorded. A comparison of the size and shape of the parasite eggs is described as are the changes in the weight of the liver and spleen of the infected mice. It is considered that the differences observed between the two strains of S. intercalatum do not necessitate a division of the two strains into two separate species.