Serum enzyme and hematological profile of Fasciola gigantica immunized and experimentally infected riverine buffaloes.

Sixteen male, yearling Murrah buffaloes were randomly assigned to four groups of four buffaloes each. Each animal in Gr-I and II were immunized, respectively, with 4.8 mg of excretory secretory antigen and 1,300 microg Infection Specific Antigen, in three divided doses. Subsequently, each animal in Gr-I, II, and III was per os infected with 800 viable Fasciola gigantica metacercariae (bubaline origin) on week-6 after the start of the experiment, while animals in Gr-IV served as healthy controls. The aspartate aminotransferase (AST) and alanine aminotransferase (ALT) concentrations progressively increased during the prepatency and respectively attained the highest levels during week-6 and 8 post-infection (PI). The alkaline phosphatase (AP) exhibited elevated trends from eighth week PI onward and continued to be higher until the end (p < 0.05-0.01). With the cessation of traumatic activities of the diastomes, the AST and ALT levels declined yet were throughout significantly higher than the healthy controls (p < 0.05-0.01). In the immunized animals (Gr-I and II), the fluctuation patterns were similar but the values were significantly lower than the non-immunized (Gr-III) animals (p < 0.05-0.01). The elevated levels of the enzymes had positive correlation with depressed erythrocytic indices, leucocytosis, eosinophilia, necropsy worm recovery, and hepatic lesion score in the respective groups. The increased concentrations of the enzymes revealed two clearly demarcated stages: (a) remarkably elevated AST (40.8%) and ALT (140.0%) levels during the prepatency, signifying traumatic lesions inflicted by the F. gigantica adolescercariae and (b) the significant increase in AP (107.9%), suggestive of bile duct hyperplasia, cholangitis, periportal fibrosis, and biliary obstruction etc. from sixth week PI onward. None of healthy controls developed clinical signs and had normal hematological and serum enzyme profiles. Diagnostic significance of these marker enzymes in the disease forecasting and in time application of control strategies to combat tropical fasciolosis in buffaloes in the endemic areas has been discussed.