Interference with homologous immunity and faecal egg excretion in Schistosoma infections in mice concurrently infected with Trypanosoma brucei and Schistosoma mansoni.

The effects of the blood protozoan, Trypanosoma brucei, was assessed on the homologous immunity to Schistosoma mansoni infection and the distribution of S. mansoni eggs in the tissues and faeces of dually infected mice. The trypanosome infection reduced the homologous protection induced by a primary S. mansoni infection against a challenge infection and the faecal excretion of eggs during the primary schistosome infection. The findings are discussed in relation to the immunosuppressive action of Trypanosoma infection.