Detection of antibodies to Eperythrozoon ovis by the use of an enzyme-linked immunosorbent assay

Specific antibody to Eperythrozoon ovis was detected by an enzyme-linked immunosorbent assay (elisa) in the sera of infected sheep. In the presence of parasite antigen, positive control serum showed a reaction approximately eight times that of negative serum. When compared to an immunofluorescent antibody test (ifat), the elisa was eight times more sensitive. Positive control sera gave a titre of 1:3200 by ifat and 1:25,600 by elisa. Through the use of a reference titration curve elisa could be used as a semi-quantitative system to determine antibody levels in test sera.