Prevalence of Equine Hepacivirus Infections in France and Evidence for Two Viral Subtypes Circulating Worldwide.

The research studied the prevalence and distribution of Equine Hepacivirus (NPHV), a horse equivalent of Human Hepatitis C Virus (HCV), in France and found that there are two major types of NPHV strains affecting horses worldwide.

Objective and Methodology of the Study

• The study investigated the prevalence and distribution of NPHV infections in France by analyzing 1033 horse serum samples from stud farms all over the country.
• The researchers used quantitative reverse transcription polymerase chain reaction (qRT-PCR) to determine the ongoing NPHV infections and viral load in the samples.

Findings and Interpretations

• The study found that 6.2% of the total horses were infected by NPHV. Moreover, the prevalence was higher among thoroughbreds with a rate of 8.3% which was significantly higher than in other breeds.
• The presence of the virus was not significantly related to any biological disturbances or clinical hepatic impairments in the horses.
• The researchers sequenced partial genomes (5’UTR, NS3, and NS5B genes) of NPHV from positive samples. The phylogenetic analysis based on both neighbour-joining and maximum-likelihood showed that two major groups of NPHV strains were infecting the domestic horses in France.

Conclusion and Implications

• The study concluded that, similar to other parts of the globe, two major strains of NPHV are infecting French domestic horses. Given the genetic differences, the researchers propose a classification into two NPHV subtypes.
• Viral loads in the serum of horses infected by the primary subtype were, on average, four times higher than those infected by the second subtype. This led the researchers to hypothesize that the amino acid substitutions in the palm domain of NS5B between NPHV subtypes could explain the distinct viral phenotypes.
• The findings are significant due to a limited amount of data available regarding the spread of hepacivirus infections in horses, thereby adding valuable information to the global data on equine hepacivirus (NPHV).