METACERCARIAL PRECIPITIN TEST FOR DIAGNOSIS OF HUMAN FASCIOLIASIS

A metacercarial precipitin test was devised for diagnosis of human fas cioliasis. The sera tested were those of cases of fascioliasis (acute and chronic), of schistosomiasis and of normal healthy individuals. Me tacercariae were prepared in the laboratory from naturally infected sn ails. Serum dilutions of 1:5 (20%) and 1:10 (10%) were incubated with metacercariae for periods of 6, 24 and 48 hours. No precipitation was observed when the sera of healthy persons were used. With sera of fasc ioliasis cases a precipitate was formed which increased in amount with time. It was more rapid in its formation and greater in its quantity with sera of acute fascioliasis. When incubation was prolonged a free precipitate was seen in the medium. With sera of schistosoma cases, a precipitate was observed in a few cases only; it was negligible in amo unt and localized to the plug area. Metacercarial precipitin is consid ered a simple, sensitive and specific test for diagnosis of human fasc ioliasis. It is recommended to use the serum in a dilution of 1:5 (20% ), to give preliminary results after 6 hours incubation and to confirm 24 hours later.