The Immunological Relationship between Typanosoma evansi and Trypanosoma vivax: Serum Neutralization Studies Findings

Abstract

Trypanosoma evansi and Trypanosoma vivax show very high cross-reactivity in serology. This suggests that there is a close immunological relationship between the two parasite species and the possibility that antiserum against one species contains lytic antibodies against the other species was investigated. T. evansi and T. vivax cell free trypanosomes were mixed with negative serum control, anti T. vivax and anti T. evansi sera respectively at room temperature for three hours. Trypanosome counts after incubation showed that anti T. evansi serum contained lytic antibodies that lysed a large proportion of T. vivax trypomastigotes but anti T. vivax serum had no effect on T. evansi trypomastigotes. And the two parasite species were still able to induce infection in sheep after incubation in the above antisera.

Keywords: Immunological relationship, T. evansi, T. vivax, lytic antibodies