Reemergence of H3N8 Equine Influenza A virus in Chile, 2018.
Ontology highlight
ABSTRACT:
SUBMITTER: Mena J
PROVIDER: S-EPMC8638617 | biostudies-literature |
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:Equine Influenza virus H3N8 Targeted Locus segment 4 hemagglutinin
| PRJNA274313 | ENA
Project description:Equine influenza viruses (EIV)-H3N8 continue to circulate in equine population throughout the world. They evolve by the process of antigenic drift that leads to substantial change in the antigenicity of the virus, thereby necessitating substitution of virus strain in the vaccines. This requires frequent testing of the new vaccines in the in vivo system; however, lack of an appropriate laboratory animal challenge model for testing protective efficacy of equine influenza vaccine candidates hinders the screening of new vaccines and other therapeutic approaches. In the present investigation, BALB/c mouse were explored for suitability for conducting pathogenecity studies for EIV. The BALB/c mice were inoculated intranasally @ 2×106.24 EID50 with EIV (H3N8) belonging to Clade 2 of Florida sublineage and monitored for setting up of infection and associated parameters. All mice inoculated with EIV exhibited clinical signs viz. loss in body weights, lethargy, dyspnea, etc, between 3 and 5 days which commensurate with lesions observed in the respiratory tract including rhinitis, tracheitis, bronchitis, bronchiolitis, alveolitis and diffuse interstitial pneumonia. Transmission electron microscopy, immunohistochemistry, virus quantification through titration and qRT-PCR demonstrated active viral infection in the upper and lower respiratory tract. Serology revealed rise in serum lactate dehydrogenase levels along with sero-conversion. The pattern of disease progression, pathological lesions and virus recovery from nasal washings and lungs in the present investigations in mice were comparable to natural and experimental EIV infection in equines. The findings establish BALB/c mice as small animal model for studying EIV (H3N8) infection and will have immense potential for dissecting viral pathogenesis, vaccine efficacy studies, preliminary screening of vaccine candidates and antiviral therapeutics against EIV.
| S-EPMC4654517 | biostudies-literature
Project description:Because little is known about the ecology of influenza viruses in camels, 460 nasal swab specimens were collected from healthy (no overt illness) Bactrian camels in Mongolia during 2012. One specimen was positive for influenza A virus (A/camel/Mongolia/335/2012[H3N8]), which is phylogenetically related to equine influenza A(H3N8) viruses and probably represents natural horse-to-camel transmission.
| S-EPMC4257804 | biostudies-literature
Project description:Serological evidence for influenza A, subtype H1 and H3 virus infections of bovines, associated with respiratory disease and decreased milk production, has been reported. Equine H3N8 influenza virus circulates widely and was responsible for the introduction of H3N8 influenza into canines.To explore the possibility that equine H3N8 influenza might also infect bovines.To assess the incidence of seroconversion in the field, a retrospective survey of bovine serum samples was carried out. Also, primary cultures of bovine nasal turbinate cells, and live beef calves, were studied for their permissiveness to infection.We found serological evidence of exposure of bovines in Kentucky to H3 influenza. We demonstrate that cultured bovine respiratory epithelium is permissive for the growth of equine H3N8 influenza virus in vitro, but this virus does not replicate extensively or produce disease in experimentally inoculated cattle.
| S-EPMC4634616 | biostudies-other
Project description:Equine influenza is a major cause of respiratory infections in horses and can spread rapidly despite the availability of commercial vaccines. In this study, we carried out molecular characterization of Equine Influenza Virus (EIV) isolated from the Malaysian outbreak in 2015 by sequencing of the HA and NA gene segments using Sanger sequencing. The nucleotide and amino acid sequences of HA and NA were compared with representative Florida clade 1 and clade 2 strains using phylogenetic analysis. The Florida clade 1 viruses identified in this outbreak revealed numerous amino acid substitutions in the HA protein as compared to the current OIE vaccine strain recommendations and representative strains of circulating Florida sub-lineage clade 1 and clade 2. Differences in HA included amino acids located within antigenic sites which could lead to reduced immune recognition of the outbreak strain and alter the effectiveness of vaccination against the outbreak strain. Detailed surveillance and genetic information sharing could allow genetic drift of equine influenza viruses to be monitored more effectively on a global basis and aid in refinement of vaccine strain selection for EIV.
| S-EPMC6852086 | biostudies-literature
Project description:Equine influenza viruses (EIVs) of the H3N8 and H7N7 subtypes are the causative agents of an important disease of horses. While EIV H7N7 apparently is extinct, H3N8 viruses have circulated for more than 50 years. Like human influenza viruses, EIV H3N8 caused a transcontinental pandemic followed by further outbreaks and epidemics, even in populations with high vaccination coverage. Recently, EIV H3N8 jumped the species barrier to infect dogs. Despite its importance as an agent of infectious disease, the mechanisms that underpin the evolutionary and epidemiological dynamics of EIV are poorly understood, particularly at a genomic scale. To determine the evolutionary history and phylodynamics of EIV H3N8, we conducted an extensive analysis of 82 complete viral genomes sampled during a 45-year span. We show that both intra- and intersubtype reassortment have played a major role in the evolution of EIV, and we suggest that intrasubtype reassortment resulted in enhanced virulence while heterosubtypic reassortment contributed to the extinction of EIV H7N7. We also show that EIV evolves at a slower rate than other influenza viruses, even though it seems to be subject to similar immune selection pressures. However, a relatively high rate of amino acid replacement is observed in the polymerase acidic (PA) segment, with some evidence for adaptive evolution. Most notably, an analysis of viral population dynamics provided evidence for a major population bottleneck of EIV H3N8 during the 1980s, which we suggest resulted from changes in herd immunity due to an increase in vaccination coverage.
| S-EPMC3094979 | biostudies-literature
Project description:We analyzed the complete genome sequence containing the 3' and 5' noncoding regions (NCRs) of the Korean H3N8 equine influenza virus (EIV), which will provide a better understanding of the pathogenesis, transmission, and evolution of EIV.
| S-EPMC4022817 | biostudies-literature
Project description:We report the complete genomic sequence of A/equine/Heilongjiang/1/2010, a strain of Florida sublineage clade 2 of H3N8 subtype equine influenza virus (EIV) isolated in northern China. This is the first announcement of a complete genomic sequence of EIV of such a clade in China.
| S-EPMC3751611 | biostudies-literature
Project description:In August 2015, Malaysia experienced an outbreak of acute respiratory disease in racehorses. Clinical signs observed were consistent with equine influenza (EI) infection. The index cases were horses recently imported from New Zealand. Rapid control measures, including temporary cancellation of racing, were implemented to minimize the impact of the outbreak. By November, the disease outbreak was resolved, and movement restrictions were lifted. The aim of this study was to confirm the clinical diagnosis and characterize the causal virus. A pan-reactive influenza type A real-time RT-PCR was used for confirmatory diagnosis. Antigenic characterization by haemagglutinin inhibition using a panel of specific ferret antisera indicated that the causal virus belonged to clade 1 of the H3N8 Florida sub-lineage. The genetic characterization was achieved by the whole genome sequencing of positive nasal swabs from clinically affected animals. Pylogenetic analysis of the haemagglutinin (HA) and neuraminidase (NA) genes demonstrated ≥99% homology with several EI strains that had recently circulated in the USA and Japan. The antigenic and genetic characterization did not indicate that the current World Organisation for Animal Health (OIE) recommendations for EI vaccine composition required modification.
| S-EPMC6630255 | biostudies-literature
Project description:Equine influenza virus is a major respiratory pathogen in horses, and outbreaks of disease often lead to substantial disruption to and economic losses for equestrian industries. The hemagglutinin (HA) protein is of key importance in the control of equine influenza because HA is the primary target of the protective immune response and the main component of currently licensed influenza vaccines. However, the influenza virus HA protein changes over time, a process called antigenic drift, and vaccine strains must be updated to remain effective. Antigenic drift is assessed primarily by the hemagglutination inhibition (HI) assay. We have generated HI assay data for equine influenza A (H3N8) viruses isolated between 1968 and 2007 and have used antigenic cartography to quantify antigenic differences among the isolates. The antigenic evolution of equine influenza viruses during this period was clustered: from 1968 to 1988, all isolates formed a single antigenic cluster, which then split into two cocirculating clusters in 1989, and then a third cocirculating cluster appeared in 2003. Viruses from all three clusters were isolated in 2007. In one of the three clusters, we show evidence of antigenic drift away from the vaccine strain over time. We determined that a single amino acid substitution was likely responsible for the antigenic differences among clusters.
| S-EPMC3209411 | biostudies-literature