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Transboundary and emerging diseases2022; 69(5); e1734-e1748; doi: 10.1111/tbed.14509

Investigation of cross-regional spread and evolution of equine influenza H3N8 at US and global scales using Bayesian phylogeography based on balanced subsampling.

Abstract: Equine influenza virus (EIV) is a highly contagious pathogen of equids, and a well-known burden in global equine health. EIV H3N8 variants seasonally emerged and resulted in EIV outbreaks in the United States and worldwide. The present study evaluated the pattern of cross-regional EIV H3N8 spread and evolutionary characteristics at US and global scales using Bayesian phylogeography with balanced subsampling based on regional horse population size. A total of 297 haemagglutinin (HA) sequences of global EIV H3N8 were collected from 1963 to 2019 and subsampled to global subset (n = 67), raw US sequences (n = 100) and US subset (n = 44) datasets. Discrete trait phylogeography analysis was used to estimate the transmission history of EIV using four global and US genome datasets. The North American lineage was the major source of globally dominant EIV variants and spread to other global regions. The US EIV strains generally spread from the southern and midwestern regions to other regions. The EIV H3N8 accumulated approximately three nucleotide substitutions per year in the HA gene under heterogeneous local positive selection. Our findings will guide better decision making of target intervention strategies of EIV H3N8 infection and provide the better scheme of genomic surveillance in the United States and global equine health.
Publication Date: 2022-03-16 PubMed ID: 35263501DOI: 10.1111/tbed.14509Google Scholar: Lookup
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  • Journal Article

Summary

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This research article investigates the pattern of spread and evolution of equine influenza virus H3N8 on global and US scales using Bayesian phylogeography based on balanced subsampling.

Study Background and Purpose

  • The article revolves around the analysis of Equine Influenza Virus (EIV), a highly contagious pathogen that affects horses and other equids.
  • The pathogen often leads to outbreaks in the United States and globally, with variations of the H3N8 strain particularly noted.
  • The purpose of the study was to understand the pattern of distribution and evolution of this strain on a regional, national (US), and global scale.
  • This knowledge is hoped to inform better decision making for intervention strategies and improve genomic surveillance in global equine health.

Methods Used in the Study

  • The researchers used Bayesian phylogeography, a method that uses mathematical models and statistical inference to trace the geographic spread and genetic variation of diseases over time.
  • The study required balanced subsampling based on regional horse population size, which refers to selecting sample sizes from various regions proportionate to the size of the local equine population.
  • The study collected and subsampled 297 hemagglutinin (HA) sequences of global EIV H3N8 from 1963 to 2019.
  • The collected sequences were divided into a global subset, raw US sequences, and a subset of US sequences.
  • A method known as discrete trait phylogeography analysis was used to estimate the transmission history of EIV using these datasets. This method can trace back the paths of evolution and spread of a certain disease.

Findings of the Study

  • The study discovered that the North American lineage was the main source of globally dominant EIV variants and was responsible for the spread to other global regions.
  • EIV strains in the US generally spread from southern and midwestern regions to other areas.
  • The EIV H3N8 strain accumulated approximately three nucleotide substitutions per year in the HA gene, suggesting a state of ongoing evolution under the influence of local positive selection.
  • These findings are important for shaping interventions to control EIV H3N8 infection and for improving genomic surveillance strategies for both the United States and the global equine health sectors.

Cite This Article

APA
Lee K, Pusterla N, Barnum SM, Lee DH, Martínez-López B. (2022). Investigation of cross-regional spread and evolution of equine influenza H3N8 at US and global scales using Bayesian phylogeography based on balanced subsampling. Transbound Emerg Dis, 69(5), e1734-e1748. https://doi.org/10.1111/tbed.14509

Publication

ISSN: 1865-1682
NlmUniqueID: 101319538
Country: Germany
Language: English
Volume: 69
Issue: 5
Pages: e1734-e1748

Researcher Affiliations

Lee, Kyuyoung
  • Department of Medicine & Epidemiology, Center for Animal Disease Modeling and Surveillance (CADMS), School of Veterinary Medicine, University of California, Davis, California.
Pusterla, Nicola
  • Department of Medicine & Epidemiology, School Veterinary Medicine, University of California, Davis, California.
Barnum, Samantha M
  • Department of Medicine & Epidemiology, School Veterinary Medicine, University of California, Davis, California.
Lee, Dong-Hun
  • College of Veterinary Medicine, Konkuk University, Seoul, Republic of Korea.
Martínez-López, Beatriz
  • Department of Medicine & Epidemiology, Center for Animal Disease Modeling and Surveillance (CADMS), School of Veterinary Medicine, University of California, Davis, California.

MeSH Terms

  • Animals
  • Bayes Theorem
  • Hemagglutinins
  • Horse Diseases / epidemiology
  • Horses
  • Humans
  • Influenza A Virus, H3N8 Subtype / genetics
  • Influenza, Human
  • Nucleotides
  • Orthomyxoviridae Infections / epidemiology
  • Orthomyxoviridae Infections / veterinary
  • Phylogeography

Grant Funding

  • Graduate Student Support Program (GSSP) in the School of Veterinary Medicine at UC Davis
  • Graduate group in epidemiology Fellowship at UC Davis
  • Center for Equine Health (CEH) grant award 17-18 at UC Davis
  • #1838207 / US National Science Foundation (NSF)
  • NRF-2018M3A9H4056535 / Bio and Medical Technology Development Program of the National Research Foundation, funded by the Government of South Korea

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Citations

This article has been cited 3 times.
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