Dataset Information

No Evidence of Mosquito Involvement in the Transmission of Equine Hepacivirus (Flaviviridae) in an Epidemiological Survey of Austrian Horses.

ABSTRACT: Prevalence studies have demonstrated a global distribution of equine hepacivirus (EqHV), a member of the family Flaviviridae. However, apart from a single case of vertical transmission, natural routes of EqHV transmission remain elusive. Many known flaviviruses are horizontally transmitted between hematophagous arthropods and vertebrate hosts. This study represents the first investigation of potential EqHV transmission by mosquitoes. More than 5000 mosquitoes were collected across Austria and analyzed for EqHV ribonucleic acid (RNA) by reverse transcription quantitative polymerase chain reaction (RT-qPCR). Concurrently, 386 serum samples from horses in eastern Austria were analyzed for EqHV-specific antibodies by luciferase immunoprecipitation system (LIPS) and for EqHV RNA by RT-qPCR. Additionally, liver-specific biochemistry parameters were compared between EqHV RNA-positive horses and EqHV RNA-negative horses. Phylogenetic analysis was conducted in comparison to previously published sequences from various origins. No EqHV RNA was detected in mosquito pools. Serum samples yielded an EqHV antibody prevalence of 45.9% (177/386) and RNA prevalence of 4.15% (16/386). EqHV RNA-positive horses had significantly higher glutamate dehydrogenase (GLDH) levels (p = 0.013) than control horses. Phylogenetic analysis showed high similarity between nucleotide sequences of EqHV in Austrian horses and EqHV circulating in other regions. Despite frequently detected evidence of EqHV infection in Austrian horses, no viral RNA was found in mosquitoes. It is therefore unlikely that mosquitoes are vectors of this flavivirus.

SUBMITTER: Badenhorst M

PROVIDER: S-EPMC6893842 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:BackgroundEquine parvovirus-hepatitis (EqPV-H) research is in its infancy. Information regarding prevalence, geographical distribution, genetic diversity, pathogenesis and risk factors enhances understanding of this potentially fatal infection.ObjectivesDetermining the prevalence of EqPV-H in Austrian equids. Investigating factors increasing probability of infection, liver-associated biochemistry parameters, concurrent equine hepacivirus (EqHV) infection and phylogenetic analysis of Austrian EqPV-H variants.Study designCross-sectional study.MethodsSera from 259 horses and 13 donkeys in Austria were analysed for anti-EqPV-H VP1-specific antibodies by luciferase immunoprecipitation system (LIPS) and EqPV-H DNA by nested polymerase chain reaction (PCR). Associations between infection status, sex and age were described. Glutamate dehydrogenase (GLDH), gamma-glutamyl transferase (GGT), bile acids and albumin concentrations were compared between horses with active infection and PCR-negative horses. PCR targeting partial EqPV-H NS1 was performed and phylogenetic analysis of Austrian EqPV-H variants was conducted. Complete coding sequences (CDS) of four Austrian variants were determined by next-generation sequencing (NGS) and compared with published sequences.ResultsHorses' EqPV-H seroprevalence was 30.1% and DNA prevalence was 8.9%. One horse was co-infected with EqHV. Significantly, higher probability of active EqPV-H infection was identified in 16- to 31-year-old horses, compared with 1- to 8-year-old horses (P = 0.002; OR = 8.19; 95% CI = 1.79 to 37.50) and 9- to 15-year-old horses (P = 0.03; OR = 2.96; 95% CI = 1.08 to 8.17). Liver-associated plasma parameters were not significantly different between horses with active infection and controls. Austrian EqPV-H variants revealed high similarity to sequences worldwide. No evidence of EqPV-H was detected in donkeys.Main limitationsEquids' inclusion depended upon owner consent. There was only one sampling point per animal and the sample of donkeys was small.ConclusionsEqPV-H antibodies and DNA are frequently detected in Austrian horses, without associated hepatitis in horses with active infection. The risk of active EqPV-H infection increases with increasing age. Phylogenetic evidence supports close relation of EqPV-H variants globally, including Austrian variants.

Project description:Equine hepacivirus (EHcV) has been identified as a closely related homologue of hepatitis C virus (HCV) in the United States, the United Kingdom, and Germany, but not in Asian countries. In this study, we genetically and serologically screened 31 serum samples obtained from Japanese-born domestic horses for EHcV infection and subsequently identified 11 PCR-positive and 7 seropositive serum samples. We determined the full sequence of the EHcV genome, including the 3' untranslated region (UTR), which had previously not been completely revealed. The polyprotein of a Japanese EHcV strain showed approximately 95% homology to those of the reported strains. HCV-like cis-acting RNA elements, including the stem-loop structures of the 3' UTR and kissing-loop interaction were deduced from regions around both UTRs of the EHcV genome. A comparison of the EHcV and HCV core proteins revealed that Ile(190) and Phe(191) of the EHcV core protein could be important for cleavage of the core protein by signal peptide peptidase (SPP) and were replaced with Ala and Leu, respectively, which inhibited intramembrane cleavage of the EHcV core protein. The loss-of-function mutant of SPP abrogated intramembrane cleavage of the EHcV core protein and bound EHcV core protein, suggesting that the EHcV core protein may be cleaved by SPP to become a mature form. The wild-type EHcV core protein, but not the SPP-resistant mutant, was localized on lipid droplets and partially on the lipid raft-like membrane in a manner similar to that of the HCV core protein. These results suggest that EHcV may conserve the genetic and biological properties of HCV.EHcV, which shows the highest amino acid or nucleotide homology to HCV among hepaciviruses, was previously reported to infect horses from Western, but not Asian, countries. We herein report EHcV infection in Japanese-born horses. In this study, HCV-like RNA secondary structures around both UTRs were predicted by determining the whole-genome sequence of EHcV. Our results also suggest that the EHcV core protein is cleaved by SPP to become a mature form and then is localized on lipid droplets and partially on lipid raft-like membranes in a manner similar to that of the HCV core protein. Hence, EHcV was identified as a closely related homologue of HCV based on its genetic structure as well as its biological properties. A clearer understanding of the epidemiology, genetic structure, and infection mechanism of EHcV will assist in elucidating the evolution of hepaciviruses as well as the development of surrogate models for the study of HCV.

Dataset Information

No Evidence of Mosquito Involvement in the Transmission of Equine Hepacivirus (Flaviviridae) in an Epidemiological Survey of Austrian Horses.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets