DICROCOELIUM DENDRITICUM IN WILD BOARS (SUS SCROFA) FROM SOUTHERN-CENTRAL ITALY

INTRODUCTION The wild boar (Sus scrofa) has been listed among the 100 most invasive species worldwide (Kmetiuk et al., 2023. One Health, 17: 100577) with populations increasing in Europe, including Italy (ISPRA, 2023). It shares habitats with livestock, acting as a potential reservoir of pathogens (Ruiz-Fons et al., 2008. Vet. J., 176: 158–169). Dicrocoelium dendriticum is a trematode infecting domestic and wild mammals, mainly small ruminants, and while well documented in domestic animals, data in wild boars are limited (Otranto & Traversa, 2003. Trends Parasitol., 19: 12–15). This study aimed to asses the occurrence of this liver fluke in wild boars from southern-central Italy. MATERIALS AND METHODS During the 2025–2026 hunting season, 90 wild boar livers were collected from the Campania and Latium regions. Livers were frozen at -20 °C until analysis. Data on sampling province, sex, and age class were recorded. Livers were macroscopically examined (Goater & Colwell, 2007. Can. J. Parasitol., 93: 491–494), the Liver Lesions Score (LLS) was assessed and adult flukes were collected, counted, and preserved in 70% ethanol for morphological and molecular analyses (Scarcelli et al., 2024. Eur. J. Wildl. Res., 70: 115). Prevalence, 95% confidence intervals (95% CI) and associations with host variables were assessed using Microsoft Excel. RESULTS AND CONCLUSIONS Overall, 26/90 wild boars were positive (28.9%, 95% CI: 19.5–38.3), with a mean intensity of 80.1 flukes per animal (range: 1–1,017). No liver lesions were observed (LLS=0). Morphological and molecular analysis confirmed the presence of D. dendriticum. Prevalence was significantly higher in Frosinone province (50.0%) compared to the other areas (p<0.05), while no significant differences emerged by sex and age. These findings confirm that wild boars can act as competent hosts for D. dendriticum, as most recovered flukes were gravid. The higher prevalence observed in Frosinone may be linked to the high density of small ruminant farms and is consistent with previous estimates reported for the Latium region (57.7%) (Cringoli, 2003, Mappe Parassitologiche 5, Litografia Vigilante S.r.l., Napoli). The results suggest a potential epidemiological role of wild boars, particularly in areas of overlap with livestock. In this context, wild boars, as untreated hosts, may contribute to maintaining susceptible parasite populations acting as animal in refugia (Brown et al., 2022. Biol. Lett., 18:20220057). Further studies are needed to clarify the role of this ungulate species in the eco-epidemiology of D. dendriticum by matching also the precise locations of infected wild boars (hunting areas) with the distribution of small ruminant farms and grazing areas to assess spatial overlap and potential transmission pathways.