First identification and phylogenetic analysis of equine hepacivirus in Korea.

This study discovers and evaluates Equine Hepacivirus (EqHV), related to Hepatitis C, in horses in Korea for the first time, revealing its presence in roughly 19% of tested samples with varying rates across genders, ages, breeds, and regions.

Objective of the Study

• This research aimed to investigate the presence and genetic makeup of Equine Hepacivirus (EqHV) in horses in Korea, as there had been no prior epidemiological studies into EqHV in the country.

Methodology

• The researchers tested 74 serum samples from horses across four regions in Korea for the presence of EqHV RNA, using nested RT-PCR.
• The samples that tested positive were then further examined based on gender, age, breed, and regional attributes.
• The team sequenced the partial NS3 region of 12 samples and the polyprotein encoding regions of two samples that were positive for EqHV RNA.

Findings

• Around 18.9% of the samples were found to be positive for EqHV, with higher positive rates found in males, young horses, and Thoroughbreds – although this varied on a regional basis.
• The Korean EqHV isolates revealed high levels of genetic homology when matched against each other at both nucleotide and deduced amino acid levels.
• Phylogenetic analysis showed that the partial NS3 genes were closely related to non-primate Hepacivirus (NPHV) sequences previously reported.
• There was evidence of sequence divergence among EqHV detected in horses from the same region.
• Although two representative EqHVs shared a certain level of genetic homology, their homology percentage significantly varied at nucleotide and deduced amino acid levels.
• Comparison among hepaciviruses from different hosts showed that NS3 and NS5B regions were the most conserved.

Implications

• The presence of a relatively high positive rate of EqHV in Korea was a significant finding of this study.
• The study’s outcomes reveal crucial information about the geographical distribution and genetic variability of Korean EqHV isolates and will likely contribute towards the improvement of the global epidemiology of EqHV.