Detection of antibodies in Schistosoma japonicum infections by a micro-technique of enzyme-linked immunosorbent assay (ELISA).

Antibodies in Schistosoma japonicum infections were successfully detected by micro-technique (0.3ml/well) of ELISA on polystyrene microtiter plates using peroxidase labelled anti-human IgG and 5-amino salicylic acid as conjugate and substrate, respectively. Serum samples collected from 22 proven patients in Leyte, Philippines showed titers of higher than 1:960 in 18 cases, 1:240 in 2 cases and 1:120 in 2 cases whereas titers of 22 proven negative sera collected in Tokyo were less than 1:15. Though the reaction was read by spectrophotometry in the present study, the difference of reactions between positive and negative sera was so clear as to be recognizable readily by visual readings.