Gastrointestinal parasites circulating in wild boars from central Italy and molecular characterization of Balantioides coli, Blastocystis sp. and Enterocytozoon bieneusi

The growing abundance and geographic spread of wild boar (Sus scrofa) populations in Europe have heightened concerns about their contribution to the transmission of parasites of zoonotic and veterinary importance. This study investigated the occurrence and zoonotic potential of gastrointestinal parasites in 46 wild boars sampled during the 2023 hunting season in Italy. Copromicroscopic analyses revealed that 47.8% of animals were positive for at least one parasite taxon, with frequent coinfections. Thirteen taxa were identified by microscopy, including protozoans (Entamoeba coli, Iodamoeba butschlii, Giardia duodenalis) chromists (Cystoisospora suis, Eimeria spp., Balantioides coli, Blastocystis sp.) and helminths (Dicrocoelium dendriticum, Ascaris spp., Trichuris sp., strongyliform larvae, gastrointestinal strongyle-type eggs, Metastrongylus spp.), some of zoonotic relevance. Molecular analyses confirmed the presence of Balantioides coli and identified Blastocystis subtype ST5. Additionally, Enterocytozoon bieneusi was molecularly detected in eight animals, representing the first evidence of this microsporidian in wild boars from Italy. Genotypes D, J, and I were identified, with genotype D clustering within the zoonotic Group 1. These findings emphasize the dual epidemiological role of wild boars as reservoirs and sentinel of potential zoonotic parasites and highlight the importance of integrated surveillance strategies within a One Health framework to better assess transmission risks at the wildlife-livestock-human interface.