title: Genetic and serological surveillance for non-primate hepacivirus in horses in Japan.
abstract: Non-primate hepacivirus (NPHV) is a recently discovered homolog of the hepatitis C virus in horses. The frequency and distribution of NPHV infections among horses in Japan is unknown. In this study, serum samples from 453 horses across Japan were screened for NPHV RNA using real-time RT-PCR and anti-nonstructural 3 protein (NS3) antibodies using the Gaussia luciferase immunoprecipitation system assay. In order to monitor the course of NPHV infection in horses, we examined 31 stored samples (9 adult horses and 22 young horses) obtained one year ago and compared the results to the recent data. Stored sera from 7 mare-foal pairs were also examined. The NS3 region sequences of 14 NPHV strains from NPHV RNA positive serum samples were determined and analyzed phylogenically. Of the 453 serum samples tested, 33.55% were positive for anti-NS3 antibody and 13.68% were positive for NPHV RNA. We found a higher rate of NPHV RNA detection in serum obtained from young horses (1-2 years of age) than that of adults, in two geographically distinct areas. We observed higher variation in the course of infection over one year in young horses than in adult horses. The foals were infected with NPHV after the weaning period. Phylogenic analysis revealed that while NPHV NS3 genes isolated in Japan clustered with sequences previously classified as NPHV, but the genetic diversity of the Japanese NPHV strains we detected was not correlated with their geographic origin. In conclusion, Japanese horses exhibit a high prevalence of NPHV. Young age appears to be a risk factor for such viral infection in Japan, although the infectious route was not determined.
authors.affiliation: Transboundary Animal Diseases Research Center, Joint Faculty of Veterinary, Kagoshima University, Korimoto, Kagoshima, Japan. Electronic address: matsuu@vet.kagoshima-u.ac.jp.
authors.forename: Aya
authors.initials: A
authors.lastname: Matsuu
authors.affiliation: Laboratory of Domestic Animal Internal Medicine, Joint Faculty of Veterinary Medicine, Kagoshima University, Kagoshima, Japan.
authors.forename: Seiji
authors.initials: S
authors.lastname: Hobo
authors.affiliation: Bloodhorse Training Center Horse Clinic, Urakawa, Hokkaido, Japan.
authors.forename: Kunihide
authors.initials: K
authors.lastname: Ando
authors.affiliation: International Animal Health and Management College, Setagaya, Tokyo, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Sanekata
authors.affiliation: Department of Equine Breeding Science, Hidaka Training and Research Center, Japan Racing Association, Urakawa, Hokkaido, Japan.
authors.forename: Fumio
authors.initials: F
authors.lastname: Sato
authors.affiliation: Miyazaki Yearling Training Farm, Japan Racing Association, Hanagashima, Miyazaki, Japan.
authors.forename: Yoshiro
authors.initials: Y
authors.lastname: Endo
authors.affiliation: Yamatokohgen Animal Medical Clinic, Habikino, Osaka, Japan.
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Amaya
authors.affiliation: Laboratory of Veterinary Surgery, Joint Department of Veterinary Medicine, Faculty of Agriculture, Tottori University, Tottori, Japan.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Osaki
authors.affiliation: Transboundary Animal Diseases Research Center, Joint Faculty of Veterinary, Kagoshima University, Korimoto, Kagoshima, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Horie
authors.affiliation: Transboundary Animal Diseases Research Center, Joint Faculty of Veterinary, Kagoshima University, Korimoto, Kagoshima, Japan.
authors.forename: Tatsunori
authors.initials: T
authors.lastname: Masatani
authors.affiliation: Transboundary Animal Diseases Research Center, Joint Faculty of Veterinary, Kagoshima University, Korimoto, Kagoshima, Japan; Laboratory of Animal Hygiene, Joint Faculty of Veterinary Medicine, Kagoshima University, Kagoshima, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Ozawa
authors.affiliation: Transboundary Animal Diseases Research Center, Joint Faculty of Veterinary, Kagoshima University, Korimoto, Kagoshima, Japan; Laboratory of Animal Hygiene, Joint Faculty of Veterinary Medicine, Kagoshima University, Kagoshima, Japan.
authors.forename: Kyoko
authors.initials: K
authors.lastname: Tsukiyama-Kohara
mesh_terms: D000367:Age Factors; D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D062665:Epidemiological Monitoring / Q000662:veterinary*; D005260:Female; D018178:Flaviviridae Infections / Q000453:epidemiology / Q000662:veterinary*; D016174:Hepacivirus / Q000235:genetics*; D006734:Horse Diseases / Q000453:epidemiology* / Q000821:virology*; D006736:Horses; D047468:Immunoprecipitation / Q000662:veterinary; D007564:Japan / Q000453:epidemiology; D008156:Luciferases; D010802:Phylogeny; D015995:Prevalence; D012367:RNA, Viral / Q000097:blood*; D060888:Real-Time Polymerase Chain Reaction / Q000662:veterinary; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000662:veterinary; D012307:Risk Factors; D017361:Viral Nonstructural Proteins / Q000276:immunology
chemical_list: D000914:Antibodies, Viral; D012367:RNA, Viral; D017361:Viral Nonstructural Proteins; D008156:Luciferases
keywords: Gaussia luciferase immunoprecipitation system; Horse; Non-primate hepacivirus