Competitive mating interactions between Schistosoma haematobium and S. intercalatum (Lower Guinea strain)

Schistosoma haematobium and S. intercalatum belong to the S. haematobium group of schistosomes and can hybridize in nature where they are sympatric. They are therefore able to co-infect the same human host. Hybridization and competitive mating interactions with S. haematobium have been implicated in restricting the distribution of S. intercalatum in Africa and in the remarkably rapid replacement of S. intercalatum by S. haematobium at Loum, Cameroon. Previous studies have demonstrated the greater pairing ability of S. haematobium over S. intercalatum in hamsters infected with both species simultaneously or infected first with S. intercalatum (Lower Guinea strain) and later with S. haematobium. The present study demonstrates the greater pairing ability of S. haematobiumover S. intercalatum in hamsters infected first with S. intercalatum (Lower Guinea) and later with S. haematobium, and indicates that S. intercalatumis unlikely to spread to areas where S. haematobium is already established.