Importance of serological cross-reactivity amongToxoplasma gondii, Hammondiaspp.,Neosporaspp.,Sarcocystisspp. andBesnoitia besnoiti

Abstract

SUMMARYToxoplasma gondii, Neosporaspp.,Sarcocystisspp.,Hammondiaspp. andBesnoitia besnoitiare genetically related cyst-forming coccidia. Serology is frequently used for the identification ofT. gondii, Neosporaspp. andB. besnoiti-exposed individuals. Serologic cross-reactions occur in different tests among animals infected withT. gondiiandH. hammondi,as well as among animals infected byT. gondiiandN. caninum. Infections caused byN. caninumandN. hughesiare almost indistinguishable by serology.Neospora caninum, B. besnoitiandSarcocystisspp. infections in cattle show some degree of serologic cross-reactivity. Antibody cross-reactivity betweenNeosporaspp. andH. heydorni-infected animals is suspected, but not proven to occur. We review serologic cross-reactivity among animals and/or humans infected withT. gondii, Neosporaspp.,Sarcocystisspp.,Hammondiaspp. andB. besnoiti. Emphasis is laid upon antigens and serological methods forN. caninumdiagnosis which were tested for cross-reactivity with related protozoa. Species-specific antigens, as well as stage-specific proteins have been identified in some of these parasites and have promising use for diagnosis and epidemiological surveys.