Sero-epidemiological survey on novel chamois respirovirus in alpine chamois (Rupicapra rupicapra rupicapra) and domestic small ruminants

The emergence of novel pathogens at the wildlife-livestock interface is an increasing global concern, with implications that extend beyond regional ecosystems, due to their potential impacts on biodiversity, animal health, and public health worldwide. A novel respirovirus phylogenetically related to Caprine respirovirus 3 (CRV3) identified in goats and sheep in China, was recently identified in Alpine chamois (CHRV3). In this context, this study investigates the seroprevalence of CHRV3 in chamois and domestic small ruminant populations, encompassing areas with varying levels of wildlife and livestock interaction in northern Italy and exploring the potential for cross-species transmission. Sera from 620 animals, including chamois, goats, and sheep, were tested for antibodies against CHRV3 and bovine respirovirus (BRV3) for cross-reactivity purposes. Results revealed a sustained circulation of CHRV3 in chamois population where it was previously detected, with significantly higher seroprevalence compared to BRV3. Sheep exhibited higher CHRV3 seroprevalence than goats, suggesting a possible role in transmission dynamics. Factors such as flock size, species, and seasonal grazing were significantly associated with seropositivity in domestic ruminants. These findings underscore the potential for CHRV3 cross-species transmission and its implications for wildlife conservation and livestock health. Continuous monitoring and integrative management strategies are essential to mitigate the spread of such emerging pathogens.