COMPARISON OF 3 ELISA TESTS FOR SEROEPIDEMIOLOGY OF BOVINE FASCIOLIASIS

The aim of the present study was to compare the sensitivity, specifici ty and usefulness of the DIG-ELISA, DOT-ELISA and Indirect ELISA tests for determining the seroprevalence of fasciolosis in cattle under tro pical conditions in Mexico. To standardize the tests, positive and neg ative sera to F. hepatica from 88 Holstein Freisian adult cows located in an enzootic area of fascioliosis acid 88 crossbred adult cattle fr om a fluke-free area were used. For the epidemiological study, 85 cros sbred cattle between 1 to 7 years of age were used. Animals were bled every two months, from March 1995 to September 1996 and the sera obtai ned were stored at -70 degrees C, until used. Indirect ELISA showed a sensitivity of 96.5% and a specificity of 98.8%, DIG-ELISA 97.5% and 8 0.0% and DOT-ELISA 93.1% and 95.4%, respectively. During 1995, Indirec t ELISA yielded the highest levels of IgG anti-F. hepatica antibodies, However, in 1996, after animal treatment with triclabendazole, DIG-EL ISA tended to show higher percentages of antibody-positive animals, bu t it was not significantly different (p>0.05) from the other tests. Co mparisons made in parallel to the faecal sedimentation test demonstrat ed that all serological tests detected higher percentages of positive animals. Only one serum out of ten (10%) of Paramphistomum spp, cross- reacted with the DOT-ELISA test, but no cross-reaction was observed wi th sera from animals with other parasites, All ELISA tests were highly sensitive and specific; they may be recommended for use in seroepidem iological surveys for F. hepatica. (C) 1998 Elsevier Science B.V.