title: Prevalence of Equine Hepacivirus Infections in France and Evidence for Two Viral Subtypes Circulating Worldwide.
abstract: Like hepatitis C virus (HCV) in humans, the newly identified equine hepacivirus (NPHV) displays a predominating liver tropism that may evolve into chronic infections. The genomes of the two viruses share several organizational and functional features and are phylogenetically closest amongst the Hepacivirus genus. A limited amount of data is available regarding the spread of hepacivirus infections in horses. In this study, we asked whether in a more representative sample the prevalence and distribution of NPHV infections in France would resemble that reported so far in other countries. A total of 1033 horses sera from stud farms throughout France were analysed by qRT-PCR to determine the prevalence of ongoing NPHV infections and viral loads; in positive samples, partial sequences of NPHV's genome (5'UTR, NS3 and NS5B genes) were determined. Serum concentrations of biliary acids, glutamate dehydrogenase (GLDH) and L-gamma-glutamyl transferase (γ-GT) were measured for most horses. We detected NPHV infections in 6.2% of the horses, a prevalence that reached 8.3% in thoroughbreds and was significantly higher than in other breeds. The presence of circulating virus was neither significantly associated with biological disturbances nor with clinical hepatic impairment. Our phylogenetic analysis was based on both neighbour-joining and maximum-likelihood approaches. Its result shows that, like almost everywhere else in the world so far, two major groups of NPHV strains infect French domestic horses. Based on genetic distances, we propose a classification into two separate NPHV subtypes. Viral loads in the serum of horses infected by the main subtype were, in average, four times higher than in those infected by the second subtype. We hypothesize that amino acid substitutions in the palm domain of NS5B between NPHV subtypes could underlie viral phenotypes that explain this result.
authors.affiliation: Unité de Recherche Risques Microbiens (U2RM), EA 4655, Université de Caen Basse-Normandie, Caen, France.|LABÉO Frank Duncombe, Caen, France.|Hippolia Fondation, Caen, France.
authors.forename: S
authors.initials: S
authors.lastname: Pronost
authors.affiliation: Unité de Recherche Risques Microbiens (U2RM), EA 4655, Université de Caen Basse-Normandie, Caen, France.|LABÉO Frank Duncombe, Caen, France.|Hippolia Fondation, Caen, France.
authors.forename: E
authors.initials: E
authors.lastname: Hue
authors.affiliation: LABÉO Frank Duncombe, Caen, France.|Hippolia Fondation, Caen, France.
authors.forename: C
authors.initials: C
authors.lastname: Fortier
authors.affiliation: Clinique Equine de la Boisrie, Chailloué, France.
authors.forename: M
authors.initials: M
authors.lastname: Foursin
authors.affiliation: Unité de Recherche Risques Microbiens (U2RM), EA 4655, Université de Caen Basse-Normandie, Caen, France.|LABÉO Frank Duncombe, Caen, France.|Hippolia Fondation, Caen, France.
authors.forename: G
authors.initials: G
authors.lastname: Fortier
authors.affiliation: Clinique Equine Desbrosse, Saint Lambert, France.
authors.forename: F
authors.initials: F
authors.lastname: Desbrosse
authors.affiliation: Structural Virology Unit - CNRS UMR 3569, Institut Pasteur, Paris, France.
authors.forename: F A
authors.initials: FA
authors.lastname: Rey
authors.affiliation: LABÉO Frank Duncombe, Caen, France.|Hippolia Fondation, Caen, France.
authors.forename: P-H
authors.initials: PH
authors.lastname: Pitel
authors.affiliation: LABÉO Frank Duncombe, Caen, France.|Hippolia Fondation, Caen, France.
authors.forename: E
authors.initials: E
authors.lastname: Richard
authors.affiliation: Structural Virology Unit - CNRS UMR 3569, Institut Pasteur, Paris, France.
authors.forename: B
authors.initials: B
authors.lastname: Saunier
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D005260:Female; D005602:France / Q000453:epidemiology; D005838:Genotype; D016174:Hepacivirus / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D006526:Hepatitis C / Q000453:epidemiology / Q000662:veterinary* / Q000821:virology; D006734:Horse Diseases / Q000453:epidemiology* / Q000821:virology; D006736:Horses; D006801:Humans; D016013:Likelihood Functions; D008297:Male; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010802:Phylogeny; D015995:Prevalence; D019562:Viral Load
keywords: breed; hepacivirus; horse; serum; subtype; viral load