Early events following challenge of rabbits with Trypanosoma evansi and T. evansi components.

The intradermal injection of Trypanosoma evansi or T. evansi components into rabbits evoked trypanosome-specific responses in the skin. The strongest responses, which were those against the parasite surface-associated components, had the characteristics of an immediate type hypersensitivity reaction, followed by a delayed type. The responses were greater in rabbits from which infections had been cleared by chemotherapy than in animals with patient infections. These findings suggest that variant surface glycoprotein (VSG)-specific antibody activity and immunosuppression are effective in the skin and influence the outcome of infection with T. evansi in previously infected animals.