Detection of antibodies of Fasciola hepatica excretory--secretory antigens in experimentally infected goats by enzyme immunosorbent assay.

An ELISA with excretory-secretory (ES) antigens has been evaluated as a technique for the early detection of specific antibodies in Fasciola hepatica infections in goats. Goats were experimentally infected with 100 or 200 metacercariae of bovine origin and serum samples were taken periodically over 365 days. The ELISA test was performed with ES antigens (10 micrograms mL-1), a single dilution of sera (1:800) and anti-goat IgG conjugate (1:1000). ES specific antigens were detected in all infected goats between 15 and 30 days postinfection (PI) and maximum antibody levels were reached at 90 days PI. Positive antibody levels (significantly different from those of controls) were still found at 365 days PI. No significant differences were observed between goats infected with 100 or 200 metacercariae. In all infected goats, eggs appeared in faeces between 60 and 90 days PI. ELISA with ES antigens could be a feasible method for the early diagnosis of goat fasciolosis.