Introduction & Objective: Fascioliasis is a zoonotic parasitic disease, caused by the liver fluke, Fasciola spp.. Human is occasional host when ingesting the metacercaria by eating contaminated aquatic vegetable. In the two past decades, human fasciolasis was emerging as a problem of public health in the Guilan province in Anzali city. Triclabendazole is a novel anti-helmenthic that during recent years has been used for fascioliasis treatment in this region. The aim of the present work is to study alteration in haematological and liver function indices during human infection with Fasciola spp. pre and post treatment with triclabendazole

Materials & Methods: The present work is a longitudinal clinical trail. In this regard, fifty confirmed fasciolasis patients, were chosen for parasitological, hematological and biochemical examinations pre-therapy as well as 1 and 6 months post-therapy. Formalin-ether and modified Telemann methods were used for stool examination. For Fasciola antibody detection ELISA technique was employed. Hematological and biochemical tests were performed by standard methods.

Results: Results indicated that, triclabendazole efficacy was 74% after usage as one dose of 20mg/kg and reached to 88% after repeating in the next month. Before triclabebdazole therapy the Hb and HCT of the patients were slightly found lower than normal ranges, meanwhile the ESR and eosinophil percentages were higher. However following receiving the drug, in the cured individuals, the indices returned to the normal ranges but in the non-cured individuals were not shifted to the normal. On the other hand liver function indices of the patients mostly were at normal ranges before and following drug therapy.

Conclusion: In conclusion haematological indices could be valuable indicator for successful therapy of patients treated with triclabendazole.