SUMMARYFascioliasis is an emerging/re-emerging vector-borne disease with the widest known distribution. Approximately 17 million people are infected around the world, being the Andean region the most affected area. There is an important necessity to develop sensitive and specific diagnostic tools to treat patients early and to avoid complications. In this paper we evaluated the immune response of infected humans against two antigenic preparations: the total soluble extract (FhTSE) and the adult worm vomit (FhAWV) in order to identify antigenic fractions specific for Fasciola hepatica. Both preparations were processed by SDS-PAGE and Western blot with human sera with fascioliasis (F), other parasitosis and healthy individuals. In the immunoblot of FhTSE, sera F recognised 16 bands with MW between eight and 110 kDa, from which those of 8, 9, 10, 38, 45 and 57 kDa were specific. In the preparation FhAWV, sera F recognised nine bands with MW from eight to 85 kDa, from which those of 8, 12, 15 and 24 kDa were specific. Some bands of cross-reaction were evident with sera from patients with other parasitoses, more frequent with the FhTSE. Bands within the MW mentioned, particularly that of eight kDa, have been shown to be specific by others, and deserve additional characterisation for their potential use in immunodiagnosis.

Abstract. Human pathogens have evolved to infect vertebrate hosts other than human beings without causing symptoms of the disease, thus permitting them to complete their life cycle and to develop into infectious forms. The identification and management of infected animals are alternatives to control dissemination of the disease and to prevent human illness. In the current study, the potential use of staphylococcal A or streptococcal G proteins was evaluated with enzyme-linked immunosorbent assays (ELISAs) for seroepidemiological studies. Sera were collected from animals that were representative of 23 different Brazilian wild mammals. A high protein A binding rate was observed in all animals, except for the orders Didelphimorphia, Artiodactyla, and Rodentia, in which affinity was medium or low. Affinity for streptococcal G protein was higher in animals of the order Artiodactyla, whereas no streptococcal G protein binding was observed in samples obtained from felines (order Carnivora). Bacterial protein binding to mammalian immunoglobulins was confirmed by immunoblotting. The results suggest that secondary detection systems should be better investigated in ELISA protocols before their implementation in seroepidemiological studies involving wild mammals.