Publications by authors named "Samuel L Hong"

Motivation: Bayesian phylogeographic analyses are pivotal in reconstructing the spatio-temporal dispersal histories of pathogens. However, interpreting the complex outcomes of phylogeographic reconstructions requires sophisticated visualization tools.

Results: To meet this challenge, we developed spread.

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Background: Since the beginning of May 2022, cases of mpox have been reported in several European and American countries where the disease is nonendemic. We performed a retrospective genomic characterisation of the 2022 mpox outbreak in Belgium, and assessed the in vitro sensitivity of three antiviral compounds to a monkeypox virus (MPXV) strain from the 2022 outbreak.

Methods: We sequenced the complete genomes of MPXV isolated from skin-, throat-, anorectal- and genital swab samples using the Oxford Nanopore Technologies (ONT) GridION.

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Modern phylogenetics research is often performed within a Bayesian framework, using sampling algorithms such as Markov chain Monte Carlo (MCMC) to approximate the posterior distribution. These algorithms require careful evaluation of the quality of the generated samples. Within the field of phylogenetics, one frequently adopted diagnostic approach is to evaluate the and to investigate trace graphs of the sampled parameters.

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  • The study focuses on how SARS-CoV-2 evolves within immunocompromised patients, revealing new virus lineages resulting from prolonged infections, particularly the Omicron BF.7 sublineage that lasted over a year.
  • Researchers analyzed eight samples from a single patient, discovering 87 genetic changes, including variants and deletions, indicating significant viral diversity within different parts of the respiratory system.
  • The findings suggest that nasopharyngeal samples alone may not accurately reflect the full range of viral mutations, underlining the complexity of viral evolution in chronic infections.
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  • The study investigates the rapid spread and evolution of a specific strain of Porcine reproductive and respiratory syndrome virus (PRRSV) in China, focusing on sublineage 8.7, using data from a long-standing national surveillance program.
  • Comprehensive analyses reveal that Guangdong province is a significant hub for the virus's spread, influenced by human activities and local farming practices.
  • The research highlights a critical "leaky" period in vaccine effectiveness between 2011-2017, with specific mutations found in related genes, offering valuable insights for the future development of modified live vaccines (MLVs).
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  • The study focuses on SARS-CoV-2 lineage B.1.214.2, identified in Belgium in January 2021, which has a mutation that may affect its transmissibility and immune evasion, similar to the Omicron variant.
  • This variant spread significantly in Central Africa and Europe, with its origin traced back to the Republic of the Congo, and its transmission correlated with human travel patterns.
  • In Belgian nursing homes, the variant led to moderately severe outcomes, and unique immune responses in elderly patients suggest a need for targeted nasal vaccine strategies against emerging variants.
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Modern phylogenetics research is often performed within a Bayesian framework, using sampling algorithms such as Markov chain Monte Carlo (MCMC) to approximate the posterior distribution. These algorithms require careful evaluation of the quality of the generated samples. Within the field of phylogenetics, one frequently adopted diagnostic approach is to evaluate the (ESS) and to investigate trace graphs of the sampled parameters.

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Severe fever with thrombocytopenia syndrome virus (SFTSV) is a tick-borne virus recognized by the World Health Organization as an emerging infectious disease of growing concern. Utilizing phylodynamic and phylogeographic methods, we have reconstructed the origin and transmission patterns of SFTSV lineages and the roles demographic, ecological, and climatic factors have played in shaping its emergence and spread throughout Asia. Environmental changes and fluctuations in tick populations, exacerbated by the widespread use of pesticides, have contributed significantly to its geographic expansion.

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  • - The study analyzed how different variants of SARS-CoV-2, specifically Alpha, Delta, and Omicron-BA.1, were introduced into Spain using genomic and connectivity data.
  • - Findings indicated that France was the primary source of the Alpha variant, while the Delta and Omicron-BA.1 variants saw increased introductions from the UK and Germany as travel restrictions relaxed.
  • - The research highlights the need for careful monitoring of international travel and effective public health strategies to control the spread of COVID-19 variants.
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  • The study examines how social restrictions and different variants, specifically Alpha, Delta, and Omicron-BA.1, affected the spread of SARS-CoV-2 in Galicia, Spain.
  • Using genomic data and mobility statistics, the research found that initial variant introductions mostly came from other Spanish regions and France, later shifting to include imports from Portugal and the U.S.
  • Despite the number of introductions, most did not contribute significantly to the pandemic's evolution in Galicia, but major coastal cities were identified as key areas for viral transmission.
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  • Phylogeographic analyses use location data from molecular sequences to trace how pathogens spread over time and space.
  • Visualization software is essential for interpreting complex estimation results, and spread.gl is a user-friendly application that enables detailed visual representations of pathogen dispersal.
  • Spread.gl combines various data layers, including geographic maps and environmental factors, allowing users to examine the influence of these factors on pathogen spread, highlighted with examples like the animation of SARS-CoV-2 genomic sequences.
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  • The study investigates how social restrictions and different variants, specifically Alpha, Delta, and Omicron, affected SARS-CoV-2 transmission in Galicia, Spain.
  • Using genomic data and mobility information, the research shows that the Alpha variant initially spread from other Spanish regions and France, while later variants saw increased influences from Portugal and the USA.
  • Key coastal cities in Galicia were identified as significant hubs for the virus's dissemination, underscoring the importance of regional connectivity for public health strategies.
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  • The Omicron variant of SARS-CoV-2 first appeared in Belgium and Switzerland linked to an international water polo tournament held in November 2021 in Brno, Czechia.
  • Researchers performed contact tracing and genetic analysis, finding infected athletes from Belgium, Switzerland, and Germany, along with multiple secondary and tertiary infections.
  • The study concluded that the Omicron variant was likely spreading in Europe before its South Africa detection, highlighting the delay in implementing travel restrictions may not effectively prevent the spread of new variants.
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Since the latter part of 2020, SARS-CoV-2 evolution has been characterised by the emergence of viral variants associated with distinct biological characteristics. While the main research focus has centred on the ability of new variants to increase in frequency and impact the effective reproductive number of the virus, less attention has been placed on their relative ability to establish transmission chains and to spread through a geographic area. Here, we describe a phylogeographic approach to estimate and compare the introduction and dispersal dynamics of the main SARS-CoV-2 variants - Alpha, Iota, Delta, and Omicron - that circulated in the New York City area between 2020 and 2022.

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The emergence of recombinant viruses is a threat to public health, as recombination may integrate variant-specific features that together result in escape from treatment or immunity. The selective advantages of recombinant SARS-CoV-2 isolates over their parental lineages remain unknown. We identified a Delta-Omicron (AY.

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An adequate SARS-CoV-2 genomic surveillance strategy has proven to be essential for countries to obtain a thorough understanding of the variants and lineages being imported and successfully established within their borders. During 2020, genomic surveillance in Belgium was not structurally implemented but performed by individual research laboratories that had to acquire the necessary funds themselves to perform this important task. At the start of 2021, a nationwide genomic surveillance consortium was established in Belgium to markedly increase the country's genomic sequencing efforts (both in terms of intensity and representativeness), to perform quality control among participating laboratories, and to enable coordination and collaboration of research projects and publications.

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Healthcare workers (HCWs) are known to be at higher risk of developing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections although whether these risks are equal across all occupational roles is uncertain. Identifying these risk factors and understand SARS-CoV-2 transmission pathways in healthcare settings are of high importance to achieve optimal protection measures. We aimed to investigate the implementation of a voluntary screening program for SARS-CoV-2 infections among hospital HCWs and to elucidate potential transmission pathways though phylogenetic analysis before the vaccination era.

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  • SARS-CoV-2, the virus responsible for COVID-19, was first detected in Finland in January 2020 and has since caused fewer infections compared to other European countries.
  • A study analyzed the virus's lineage origins and dynamics in Finland, revealing 42 independent introductions in spring 2020, primarily from Italy, Austria, and Spain.
  • Findings indicated that one introduction from Spain caused about a third of the cases in Finland during that period, highlighting the impact of travel on virus spread and the importance of early public health measures.
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As with other pathogens, competitive interactions between strains drive infection risk. Vaccines are thought to perturb strain diversity through shifts in immune pressures; however, this has rarely been measured because of inadequate data and analytical tools. We used 3344 sequences from 23 countries to show that, on average, there are 28.

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Background: The emergence of recombinant viruses is a threat to public health. Recombination of viral variants may combine variant-specific features that together catalyze viral escape from treatment or immunity. The selective advantages of recombinant SARS-CoV-2 isolates over their parental lineages remain unknown.

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In spring 2021, an increasing number of infections was observed caused by the hitherto rarely described SARS-CoV-2 variant A.27 in south-west Germany. From December 2020 to June 2021 this lineage has been detected in 31 countries.

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  • Distinct SARS-CoV-2 lineage B.1.620 was identified in Lithuania, featuring multiple mutations in the spike protein commonly found in concerning variants like E484K and S477N.
  • The study highlights the lineage's potential resistance to neutralizing antibodies and documents local instances of transmission in Europe, particularly in Lithuania.
  • Evidence suggests that B.1.620 likely originated in Central Africa, supported by advanced phylogeographic methods and travel history data from infected individuals.
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  • - This study analyzes 203 whole genome sequences of SARS-CoV-2 from Rwanda between May 2020 and February 2021, revealing a shift towards the A.23.1 sub-lineage, which is now the dominant strain.
  • - The research also identified the first cases of the concerning B.1.1.7 and B.1.351 variants among travelers arriving at Kigali International Airport.
  • - It emphasizes the significant role of neighboring countries in introducing new cases to Rwanda and calls for ongoing genomic surveillance and regional cooperation to effectively tackle COVID-19.
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