Evaluation of Risk Determinants and Molecular Characterisation for Non-Primate Hepacivirus Infection in Turkish Horses

The genus <i>Hepacivirus</i> (HCV) has long been a dynamic group, increasing its number by myriads of species collectively referred to as non-primate hepaciviruses (NPHVs). NPHV exhibits a broad hepatotropism and is often attributed to chronic infection in horses and dogs. However, recent studies and meta-analyses on NPHV in horses have remained inconclusive regarding the determination of risk factors for infection. Therefore, our main goal was to investigate the frequencies and molecular characteristics of NPHV infection linked to geographical location, horse breeds, genders, and ages. For this purpose, we tested the positivity of 152 samples collected from ten cities in Turkey by conventional PCR, targeting the highly conserved 5' UTR sequence, and compiled our results with pedigree data of horses for statistical analyses. We further implemented sequencing of the 5' UTR, NS3, and NS5B regions and used in silico approaches to evaluate the characteristics of our novel isolates. Our results revealed a high incidence of NPHV infection (52.3%), which fluctuated among cities (26.1-75.0%), and comparative statistical analyses indicated that age and geographical region, together with managemental alterations, could be key determinants in NPHV infection. Furthermore, our phylogenetic analyses and 3D modelling approaches on genomic sequences revealed fundamental characteristics of novel NPHV strains. In conclusion, our study contributed to providing a better understanding of NPHV distribution and revealed some hints on diagnostics and good practices for disease prevention.