Abstract: Fasciolosis is an anthropozoonotic disease caused by the Trematoda Fasciola hepatica. This worm is a common parasite of ruminants namely sheep, goats and cattle. Adult worms are usually found in the bile ducts of the final host liver, causing significant economic losses in the animal husbandry industry. The diagnosis of Fasciola hepatica infection, in definitive hosts, is usually done by microscopic identification of parasite eggs in the stools, observation of adult worms in liver ducts, or by serology. However, no diagnostic tool as been described for utilization directly in the animals in the farm. The disclosed subject matter describes a cDNA clone codifying for a 69 amino acids polypeptide and 8 kDa molecular weight, and identified as Fh8 or “fasciolin” (Genbank number AF213970). Results show that the polypeptide FH8 act as an allergen.