Abstract:
Objective: To investigate the effect of pre-existing Schistosoma haematobium (S. haematobium) infection on malaria disease severity. Methods: The study involved the use of twenty-five imprinting control region mice, fifteen of which were initially infected with S. haematobium. Five of the remaining ten schisto-uninfected mice together with five schisto-infected mice were infected with Plasmodium berghei(P. berghei) after four weeks (acute stage) of schistosoma infection. The remaining five schisto-uninfected mice together with fve schisto-infected mice were also infected with P. bergheiafter seven weeks (chronic stage) of schistosoma infection. The last fve schisto-infected mice were used as control group. They were then monitored for changes in P. bergheiparasitaemia on Days 3, 5, 7, 9 and 11 post-infection. Records on their survivability were also taken. Results: The co-infected mice had signifcantly higher malaria parasitaemia, compared with the mono-infected mice during acute S. haematobium infection. In contrast, the co-infected mice had signifcantly lower malaria parasitaemia during chronic S. haematobium infection and a higher survival rate. Conclusions: Co-infection of mice with P. bergheiduring acute S. haematobium infection resulted in rapid P. bergheidevelopment and increased malaria parasitaemia. However, the co-infection resulted in slower P. bergheidevelopment and decreased malaria parasitaemia with enhanced survivability of the mice during chronic S. haematobium infection. Therefore, pre-existing chronic S. haematobium infection may provide some protection to the host by reducing parasitaemia
