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1.
J Virol ; 97(10): e0074323, 2023 10 31.
Artigo em Inglês | MEDLINE | ID: mdl-37800947

RESUMO

IMPORTANCE: Determining the relevant amino acids involved in antigenic drift on the surface protein hemagglutinin (HA) is critical to understand influenza virus evolution and efficient assessment of vaccine strains relative to current circulating strains. We used antigenic cartography to generate an antigenic map of the H9 hemagglutinin (HA) using sera produced in one of the most relevant minor poultry species, Japanese quail. Key antigenic positions were identified and tested to confirm their impact on the antigenic profile. This work provides a better understanding of the antigenic diversity of the H9 HA as it relates to reactivity to quail sera and will facilitate a rational approach for selecting more efficacious vaccines against poultry-origin H9 influenza viruses in minor poultry species.


Assuntos
Deriva e Deslocamento Antigênicos , Glicoproteínas de Hemaglutininação de Vírus da Influenza , Vírus da Influenza A Subtipo H9N2 , Influenza Aviária , Animais , Coturnix , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Vírus da Influenza A Subtipo H9N2/genética , Influenza Aviária/virologia , Aves Domésticas
2.
Euro Surveill ; 29(3)2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38240057

RESUMO

Under International Health Regulations from 2005, a human infection caused by a novel influenza A virus variant is considered an event that has potential for high public health impact and is immediately notifiable to the World Health Organisation. We here describe the clinical, epidemiological and virological features of a confirmed human case of swine influenza A(H1N2)v in England detected through community respiratory virus surveillance. Swabbing and contact tracing helped refine public health risk assessment, following this unusual and unexpected finding.


Assuntos
Vírus da Influenza A Subtipo H1N1 , Influenza Humana , Infecções por Orthomyxoviridae , Doenças dos Suínos , Animais , Humanos , Suínos , Vírus da Influenza A Subtipo H1N2 , Vírus da Influenza A Subtipo H1N1/genética , Doenças dos Suínos/diagnóstico , Doenças dos Suínos/epidemiologia , Influenza Humana/diagnóstico , Influenza Humana/epidemiologia , Inglaterra/epidemiologia
3.
Emerg Infect Dis ; 29(1): 170-174, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36573541

RESUMO

In late 2021, highly pathogenic avian influenza A(H5N8) clade 2.3.4.4b viruses were detected in domestic ducks in poultry markets in Cambodia. Surveillance, biosafety, and biosecurity efforts should be bolstered along the poultry value chain to limit spread and infection risk at the animal-human interface.


Assuntos
Vírus da Influenza A Subtipo H5N8 , Influenza Aviária , Influenza Humana , Doenças das Aves Domésticas , Animais , Humanos , Influenza Aviária/epidemiologia , Camboja/epidemiologia , Aves , Patos , Aves Domésticas , Filogenia
4.
J Virol ; 96(2): e0137421, 2022 01 26.
Artigo em Inglês | MEDLINE | ID: mdl-34757846

RESUMO

Human-to-swine transmission of influenza A virus (IAV) repeatedly occurs, leading to sustained transmission and increased diversity in swine; human seasonal H3N2 introductions occurred in the 1990s and 2010s and were maintained in North American swine. Swine H3N2 strains were subsequently associated with zoonotic infections, highlighting the need to understand the risk of endemic swine IAV to humans. We quantified antigenic distances between swine H3N2 and human seasonal vaccine strains from 1973 to 2014 using a panel of monovalent antisera raised in pigs in hemagglutination inhibition (HI) assays. Swine H3N2 lineages retained the closest antigenic similarity to human vaccine strains from the decade of incursion. Swine lineages from the 1990s were antigenically more similar to human vaccine strains of the mid-1990s but had substantial distance from recent human vaccine strains. In contrast, lineages from the 2010s were closer to human vaccine strains from 2011 and 2014 and the most antigenically distant from human vaccine strains prior to 2007. HI assays using ferret antisera demonstrated that swine lineages from the 1990s and 2010s had significant fold reductions compared to the homologous HI titer of the nearest pandemic preparedness candidate vaccine virus (CVV) or seasonal vaccine strain. The assessment of postinfection and postvaccination human serum cohorts demonstrated limited cross-reactivity to swine H3N2 from the 1990s, especially in older adults born before the 1970s. We identified swine strains to which humans are likely to lack population immunity or are not protected against by a current human seasonal vaccine or CVV to use in prioritizing future human CVV strain selection. IMPORTANCE Human H3N2 influenza A viruses spread to pigs in North America in the 1990s and more recently in the 2010s. These cross-species events led to sustained circulation and increased H3N2 diversity in pig populations. The evolution of H3N2 in swine led to a reduced similarity to human seasonal H3N2 and the vaccine strains used to protect human populations. We quantified the antigenic phenotypes and found that North American swine H3N2 lineages retained more antigenic similarity to historical human vaccine strains from the decade of incursion but had substantial differences compared to recent human vaccine strains. Additionally, pandemic preparedness vaccine strains demonstrated a loss of similarity to contemporary swine strains. Finally, human sera revealed that although these adults had antibodies against human H3N2 strains, many had limited immunity to swine H3N2, especially older adults born before 1970. Antigenic assessment of swine H3N2 provides critical information for pandemic preparedness and candidate vaccine development.


Assuntos
Vírus da Influenza A Subtipo H3N2/genética , Infecções por Orthomyxoviridae/virologia , Zoonoses Virais/virologia , Animais , Deriva e Deslocamento Antigênicos , Variação Antigênica , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Humanos , Soros Imunes/imunologia , Vírus da Influenza A Subtipo H3N2/classificação , Vírus da Influenza A Subtipo H3N2/imunologia , Vacinas contra Influenza/genética , Influenza Humana/transmissão , Influenza Humana/virologia , Infecções por Orthomyxoviridae/transmissão , Filogenia , Medição de Risco , Suínos , Zoonoses Virais/transmissão
5.
J Virol ; 95(20): e0063221, 2021 09 27.
Artigo em Inglês | MEDLINE | ID: mdl-34379513

RESUMO

Two separate introductions of human seasonal N2 neuraminidase genes were sustained in U.S. swine since 1998 (N2-98) and 2002 (N2-02). Herein, we characterized the antigenic evolution of the N2 of swine influenza A virus (IAV) across 2 decades following each introduction. The N2-98 and N2-02 expanded in genetic diversity, with two statistically supported monophyletic clades within each lineage. To assess antigenic drift in swine N2 following the human-to-swine spillover events, we generated a panel of swine N2 antisera against representative N2 and quantified the antigenic distance between wild-type viruses using enzyme-linked lectin assay and antigenic cartography. The antigenic distance between swine and human N2 was smallest between human N2 circulating at the time of each introduction and the archetypal swine N2. However, sustained circulation and evolution in swine of the two N2 lineages resulted in significant antigenic drift, and the N2-98 and N2-02 swine N2 lineages were antigenically distinct. Although intralineage antigenic diversity was observed, the magnitude of antigenic drift did not consistently correlate with the observed genetic differences. These data represent the first quantification of the antigenic diversity of neuraminidase of IAV in swine and demonstrated significant antigenic drift from contemporary human seasonal strains as well as antigenic variation among N2 detected in swine. These data suggest that antigenic mismatch may occur between circulating swine IAV and vaccine strains. Consequently, consideration of the diversity of N2 in swine IAV for vaccine selection may likely result in more effective control and aid public health initiatives for pandemic preparedness. IMPORTANCE Antibodies inhibiting the neuraminidase (NA) of IAV reduce clinical disease, virus shedding, and transmission, particularly in the absence of neutralizing immunity against hemagglutinin. To understand antibody recognition of the genetically diverse NA in U.S. swine IAV, we characterized the antigenic diversity of N2 from swine and humans. N2 detected in swine IAV were derived from two distinct human-to-swine spillovers that persisted, are antigenically distinct, and underwent antigenic drift. These findings highlight the need for continued surveillance and vaccine development in swine with increased focus on the NA. Additionally, human seasonal N2 isolated after 2005 were poorly inhibited by representative swine N2 antisera, suggesting a lack of cross-reactive NA antibody-mediated immunity between contemporary swine and human N2. Bidirectional transmission between humans and swine represents a One Health challenge, and determining the correlates of immunity to emerging IAV strains is critical to mitigating zoonotic and reverse-zoonotic transmission.


Assuntos
Epitopos/imunologia , Vírus da Influenza A/genética , Neuraminidase/genética , Animais , Variação Antigênica/genética , Antígenos Virais/imunologia , Reações Cruzadas/imunologia , Epitopos/genética , Evolução Molecular , Variação Genética/genética , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Humanos , Vírus da Influenza A Subtipo H3N2/genética , Vírus da Influenza A/patogenicidade , Influenza Humana/genética , Neuraminidase/imunologia , Neuraminidase/metabolismo , Infecções por Orthomyxoviridae/imunologia , Estações do Ano , Suínos , Doenças dos Suínos/virologia , Estados Unidos , Eliminação de Partículas Virais/imunologia
6.
Emerg Infect Dis ; 27(11): 2856-2863, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34670647

RESUMO

We report a disease and mortality event involving swans, seals, and a fox at a wildlife rehabilitation center in the United Kingdom during late 2020. Five swans had onset of highly pathogenic avian influenza virus infection while in captivity. Subsequently, 5 seals and a fox died (or were euthanized) after onset of clinical disease. Avian-origin influenza A virus subtype H5N8 was retrospectively determined as the cause of disease. Infection in the seals manifested as seizures, and immunohistochemical and molecular testing on postmortem samples detected a neurologic distribution of viral products. The fox died overnight after sudden onset of inappetence, and postmortem tissues revealed neurologic and respiratory distribution of viral products. Live virus was isolated from the swans, seals, and the fox, and a single genetic change was detected as a potential adaptive mutation in the mammalian-derived viral sequences. No human influenza-like illness was reported in the weeks after the event.


Assuntos
Encefalite , Vírus da Influenza A Subtipo H5N8 , Influenza Aviária , Focas Verdadeiras , Animais , Centros de Reabilitação , Estudos Retrospectivos
7.
J Virol ; 94(11)2020 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-32238581

RESUMO

Highly pathogenic avian influenza A(H5N8) viruses first emerged in China in 2010 and in 2014 spread throughout Asia and to Europe and the United States via migrating birds. Influenza A(H5N8) viruses were first detected in the Netherlands in 2014 and caused five outbreaks in poultry farms but were infrequently detected in wild birds. In 2016, influenza A(H5N8) viruses were reintroduced into the Netherlands, resulting in eight poultry farm outbreaks. This outbreak resulted in numerous dead wild birds with severe pathology. Phylogenetic analysis showed that the polymerase genes of these viruses had undergone extensive reassortment between outbreaks. Here, we investigated the differences in virulence between the 2014-15 and the 2016-17 outbreaks by characterizing the polymerase complex of influenza A(H5N8) viruses from both outbreaks. We found that viruses from the 2014-15 outbreak had significantly higher polymerase complex activity in both human and avian cell lines than did those from the 2016-17 outbreak. No apparent differences in the balance between transcription and replication of the viral genome were observed. Interestingly, the 2014-15 polymerase complexes induced significantly higher levels of interferon beta (IFN-ß) than the polymerase complexes of the 2016-17 outbreak viruses, mediated via retinoic acid-inducible gene I (RIG-I). Inoculation of primary duck cells with recombinant influenza A(H5N8) viruses, including viruses with reassorted polymerase complexes, showed that the polymerase complexes from the 2014-15 outbreak induced higher levels of IFN-ß despite relatively minor differences in replication capacity. Together, these data suggest that despite the lower levels of polymerase activity, the higher 2016-17 influenza A(H5N8) virus virulence may be attributed to the lower level of activation of the innate immune system.IMPORTANCE Compared to the 2014-15 outbreak, the 2016-17 outbreak of influenza A(H5N8) viruses in the Netherlands and Europe was more virulent; the number of dead or diseased wild birds found and the severity of pathological changes were higher during the 2016-17 outbreak. The polymerase complex plays an important role in influenza virus virulence, and the gene segments of influenza A(H5N8) viruses reassorted extensively between the outbreaks. In this study, the 2014-15 polymerase complexes were found to be more active, which is counterintuitive with the observed higher virulence of the 2016-17 outbreak viruses. Interestingly, the 2014-15 polymerase complexes also induced higher levels of IFN-ß. These findings suggest that the higher virulence of influenza A(H5N8) viruses from the 2016-17 outbreak may be related to the lower induction of IFN-ß. An attenuated interferon response could lead to increased dissemination, pathology, and mortality, as observed in (wild) birds infected during the 2016-2017 outbreak.


Assuntos
Proteínas Aviárias , Surtos de Doenças , Vírus da Influenza A Subtipo H5N8 , Influenza Aviária , Interferon beta , RNA Polimerase Dependente de RNA , Proteínas Virais , Animais , Proteínas Aviárias/genética , Proteínas Aviárias/imunologia , Coturnix , Cães , Patos , Células HEK293 , Humanos , Vírus da Influenza A Subtipo H5N8/genética , Vírus da Influenza A Subtipo H5N8/imunologia , Influenza Aviária/epidemiologia , Influenza Aviária/genética , Influenza Aviária/imunologia , Interferon beta/genética , Interferon beta/imunologia , Células Madin Darby de Rim Canino , RNA Polimerase Dependente de RNA/genética , RNA Polimerase Dependente de RNA/imunologia , Proteínas Virais/genética , Proteínas Virais/imunologia
8.
Nature ; 523(7559): 217-20, 2015 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-26053121

RESUMO

Understanding the spatiotemporal patterns of emergence and circulation of new human seasonal influenza virus variants is a key scientific and public health challenge. The global circulation patterns of influenza A/H3N2 viruses are well characterized, but the patterns of A/H1N1 and B viruses have remained largely unexplored. Here we show that the global circulation patterns of A/H1N1 (up to 2009), B/Victoria, and B/Yamagata viruses differ substantially from those of A/H3N2 viruses, on the basis of analyses of 9,604 haemagglutinin sequences of human seasonal influenza viruses from 2000 to 2012. Whereas genetic variants of A/H3N2 viruses did not persist locally between epidemics and were reseeded from East and Southeast Asia, genetic variants of A/H1N1 and B viruses persisted across several seasons and exhibited complex global dynamics with East and Southeast Asia playing a limited role in disseminating new variants. The less frequent global movement of influenza A/H1N1 and B viruses coincided with slower rates of antigenic evolution, lower ages of infection, and smaller, less frequent epidemics compared to A/H3N2 viruses. Detailed epidemic models support differences in age of infection, combined with the less frequent travel of children, as probable drivers of the differences in the patterns of global circulation, suggesting a complex interaction between virus evolution, epidemiology, and human behaviour.


Assuntos
Variação Antigênica , Vírus da Influenza A/genética , Vírus da Influenza B/genética , Influenza Humana/epidemiologia , Influenza Humana/virologia , Fatores Etários , Saúde Global , Humanos , Vírus da Influenza A/classificação , Vírus da Influenza B/classificação , Filogenia , Filogeografia , Estações do Ano
9.
J Intellect Disabil ; 25(3): 348-356, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31835956

RESUMO

This article evaluates the effectiveness of a multidisciplinary intensive community support service, using positive behavioural support (PBS) as a core intervention model to reduce behaviours of concern and to improve the quality of life and occupational involvement of individuals with a learning disability who present with behaviours that challenge. The service used outcome measures to evaluate the effectiveness of the PBS model. The study looks at pre- and post-outcome measures which showed a significant improvement in behaviour, quality of life and occupational outcomes for individuals with a learning disability presenting with complex behaviours of concern. This study contributes to the growing evidence base for PBS being delivered by specialist community learning disability teams.


Assuntos
Deficiência Intelectual , Deficiências da Aprendizagem , Terapia Comportamental , Humanos , Avaliação de Resultados em Cuidados de Saúde , Qualidade de Vida
11.
J Virol ; 93(2)2019 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-30355680

RESUMO

The hemagglutinin (HA), a glycoprotein on the surface of influenza A virus (IAV), initiates the virus life cycle by binding to terminal sialic acid (SA) residues on host cells. The HA gradually accumulates amino acid substitutions that allow IAV to escape immunity through a mechanism known as antigenic drift. We recently confirmed that a small set of amino acid residues are largely responsible for driving antigenic drift in swine-origin H3 IAV. All identified residues are located adjacent to the HA receptor binding site (RBS), suggesting that substitutions associated with antigenic drift may also influence receptor binding. Among those substitutions, residue 145 was shown to be a major determinant of antigenic evolution. To determine whether there are functional constraints to substitutions near the RBS and their impact on receptor binding and antigenic properties, we carried out site-directed mutagenesis experiments at the single-amino-acid level. We generated a panel of viruses carrying substitutions at residue 145 representing all 20 amino acids. Despite limited amino acid usage in nature, most substitutions at residue 145 were well tolerated without having a major impact on virus replication in vitro All substitution mutants retained receptor binding specificity, but the substitutions frequently led to decreased receptor binding. Glycan microarray analysis showed that substitutions at residue 145 modulate binding to a broad range of glycans. Furthermore, antigenic characterization identified specific substitutions at residue 145 that altered antibody recognition. This work provides a better understanding of the functional effects of amino acid substitutions near the RBS and the interplay between receptor binding and antigenic drift.IMPORTANCE The complex and continuous antigenic evolution of IAVs remains a major hurdle for vaccine selection and effective vaccination. On the hemagglutinin (HA) of the H3N2 IAVs, the amino acid substitution N 145 K causes significant antigenic changes. We show that amino acid 145 displays remarkable amino acid plasticity in vitro, tolerating multiple amino acid substitutions, many of which have not yet been observed in nature. Mutant viruses carrying substitutions at residue 145 showed no major impairment in virus replication in the presence of lower receptor binding avidity. However, their antigenic characterization confirmed the impact of the 145 K substitution in antibody immunodominance. We provide a better understanding of the functional effects of amino acid substitutions implicated in antigenic drift and its consequences for receptor binding and antigenicity. The mutation analyses presented in this report represent a significant data set to aid and test the ability of computational approaches to predict binding of glycans and in antigenic cartography analyses.


Assuntos
Substituição de Aminoácidos , Hemaglutininas Virais/química , Hemaglutininas Virais/metabolismo , Vírus da Influenza A/fisiologia , Suínos/virologia , Animais , Anticorpos Antivirais/metabolismo , Sítios de Ligação , Cães , Deriva Genética , Células HEK293 , Hemaglutininas Virais/genética , Humanos , Vírus da Influenza A/genética , Células Madin Darby de Rim Canino , Modelos Moleculares , Mutagênese Sítio-Dirigida , Polissacarídeos/metabolismo , Ligação Proteica , Replicação Viral
12.
J Virol ; 92(15)2018 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-29769347

RESUMO

Wild ducks and gulls are the major reservoirs for avian influenza A viruses (AIVs). The mechanisms that drive AIV evolution are complex at sites where various duck and gull species from multiple flyways breed, winter, or stage. The Republic of Georgia is located at the intersection of three migratory flyways: the Central Asian flyway, the East Africa/West Asia flyway, and the Black Sea/Mediterranean flyway. For six complete study years (2010 to 2016), we collected AIV samples from various duck and gull species that breed, migrate, and overwinter in Georgia. We found a substantial subtype diversity of viruses that varied in prevalence from year to year. Low-pathogenic AIV (LPAIV) subtypes included H1N1, H2N3, H2N5, H2N7, H3N8, H4N2, H6N2, H7N3, H7N7, H9N1, H9N3, H10N4, H10N7, H11N1, H13N2, H13N6, H13N8, and H16N3, and two highly pathogenic AIVs (HPAIVs) belonging to clade 2.3.4.4, H5N5 and H5N8, were found. Whole-genome phylogenetic trees showed significant host species lineage restriction for nearly all gene segments and significant differences in observed reassortment rates, as defined by quantification of phylogenetic incongruence, and in nucleotide sequence diversity for LPAIVs among different host species. Hemagglutinin clade 2.3.4.4 H5N8 viruses, which circulated in Eurasia during 2014 and 2015, did not reassort, but analysis after their subsequent dissemination during 2016 and 2017 revealed reassortment in all gene segments except NP and NS. Some virus lineages appeared to be unrelated to AIVs in wild bird populations in other regions, with maintenance of local AIVs in Georgia, whereas other lineages showed considerable genetic interrelationships with viruses circulating in other parts of Eurasia and Africa, despite relative undersampling in the area.IMPORTANCE Waterbirds (e.g., gulls and ducks) are natural reservoirs of avian influenza viruses (AIVs) and have been shown to mediate the dispersal of AIVs at intercontinental scales during seasonal migration. The segmented genome of influenza viruses enables viral RNA from different lineages to mix or reassort when two viruses infect the same host. Such reassortant viruses have been identified in most major human influenza pandemics and several poultry outbreaks. Despite their importance, we have only recently begun to understand AIV evolution and reassortment in their natural host reservoirs. This comprehensive study illustrates AIV evolutionary dynamics within a multihost ecosystem at a stopover site where three major migratory flyways intersect. Our analysis of this ecosystem over a 6-year period provides a snapshot of how these viruses are linked to global AIV populations. Understanding the evolution of AIVs in the natural host is imperative to mitigating both the risk of incursion into domestic poultry and the potential risk to mammalian hosts, including humans.


Assuntos
Aves/virologia , Ecossistema , Evolução Molecular , Genoma Viral , Vírus da Influenza A/fisiologia , Influenza Aviária/genética , Filogenia , Animais
13.
Emerg Infect Dis ; 24(12): 2309-2316, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30457545

RESUMO

We conducted a cross-sectional study in live bird markets (LBMs) in Dhaka and Chittagong, Bangladesh, to estimate the prevalence of avian influenza A(H5) and A(H9) viruses in different types of poultry and environmental areas by using Bayesian hierarchical logistic regression models. We detected these viruses in nearly all LBMs. Prevalence of A(H5) virus was higher in waterfowl than in chickens, whereas prevalence of A(H9) virus was higher in chickens than in waterfowl and, among chicken types, in industrial broilers than in cross-breeds and indigenous breeds. LBMs with >1 wholesaler were more frequently contaminated by A(H5) virus than retail-only LBMs. Prevalence of A(H9) virus in poultry and level of environmental contamination were also higher in LBMs with >1 wholesaler. We found a high level of circulation of both avian influenza viruses in surveyed LBMs. Prevalence was influenced by type of poultry, environmental site, and trading.


Assuntos
Vírus da Influenza A/genética , Influenza Aviária/epidemiologia , Influenza Aviária/virologia , Animais , Bangladesh/epidemiologia , Teorema de Bayes , Galinhas , Estudos Transversais , Patos , Microbiologia Ambiental , Humanos , Vírus da Influenza A/classificação , Prevalência , Vigilância em Saúde Pública
14.
Emerg Infect Dis ; 24(12): 2270-2283, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30457528

RESUMO

We analyzed the highly pathogenic avian influenza (HPAI) H5 epizootic of 2016-17 in Europe by epidemiologic and genetic characteristics and compared it with 2 previous epizootics caused by the same H5 Guangdong lineage. The 2016-17 epizootic was the largest in Europe by number of countries and farms affected and greatest diversity of wild birds infected. We observed significant differences among the 3 epizootics regarding region affected, epidemic curve, seasonality, and outbreak duration, making it difficult to predict future HPAI epizootics. However, we know that in 2005-06 and 2016-17 the initial peak of wild bird detections preceded the peak of poultry outbreaks within Europe. Phylogenetic analysis of 2016-17 viruses indicates 2 main pathways into Europe. Our findings highlight the need for global surveillance of viral changes to inform disease preparedness, detection, and control.


Assuntos
Vírus da Influenza A/classificação , Influenza Aviária/epidemiologia , Influenza Aviária/virologia , Animais , Animais Selvagens , Aves , Surtos de Doenças , Europa (Continente)/epidemiologia , Genoma Viral , Geografia Médica , História do Século XXI , Vírus da Influenza A/patogenicidade , Influenza Aviária/história , Influenza Aviária/transmissão , Morbidade , Mortalidade , Filogenia , Doenças das Aves Domésticas/epidemiologia , Doenças das Aves Domésticas/virologia , Análise Espaço-Temporal , Zoonoses
15.
J Virol ; 90(18): 8266-80, 2016 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-27384658

RESUMO

UNLABELLED: Influenza A virus (IAV) of the H3 subtype is an important respiratory pathogen that affects both humans and swine. Vaccination to induce neutralizing antibodies against the surface glycoprotein hemagglutinin (HA) is the primary method used to control disease. However, due to antigenic drift, vaccine strains must be periodically updated. Six of the 7 positions previously identified in human seasonal H3 (positions 145, 155, 156, 158, 159, 189, and 193) were also indicated in swine H3 antigenic evolution. To experimentally test the effect on virus antigenicity of these 7 positions, substitutions were introduced into the HA of an isogenic swine lineage virus. We tested the antigenic effect of these introduced substitutions by using hemagglutination inhibition (HI) data with monovalent swine antisera and antigenic cartography to evaluate the antigenic phenotype of the mutant viruses. Combinations of substitutions within the antigenic motif caused significant changes in antigenicity. One virus mutant that varied at only two positions relative to the wild type had a >4-fold reduction in HI titers compared to homologous antisera. Potential changes in pathogenesis and transmission of the double mutant were evaluated in pigs. Although the double mutant had virus shedding titers and transmissibility comparable to those of the wild type, it caused a significantly lower percentage of lung lesions. Elucidating the antigenic effects of specific amino acid substitutions at these sites in swine H3 IAV has important implications for understanding IAV evolution within pigs as well as for improved vaccine development and control strategies in swine. IMPORTANCE: A key component of influenza virus evolution is antigenic drift mediated by the accumulation of amino acid substitutions in the hemagglutinin (HA) protein, resulting in escape from prior immunity generated by natural infection or vaccination. Understanding which amino acid positions of the HA contribute to the ability of the virus to avoid prior immunity is important for understanding antigenic evolution and informs vaccine efficacy predictions based on the genetic sequence data from currently circulating strains. Following our previous work characterizing antigenic phenotypes of contemporary wild-type swine H3 influenza viruses, we experimentally validated that substitutions at 6 amino acid positions in the HA protein have major effects on antigenicity. An improved understanding of the antigenic diversity of swine influenza will facilitate a rational approach for selecting more effective vaccine components to control the circulation of influenza in pigs and reduce the potential for zoonotic viruses to emerge.


Assuntos
Anticorpos Antivirais/imunologia , Antígenos Virais/imunologia , Deriva Genética , Glicoproteínas de Hemaglutininação de Vírus da Influenza/imunologia , Vírus da Influenza A/imunologia , Substituição de Aminoácidos , Animais , Antígenos Virais/genética , Testes de Inibição da Hemaglutinação , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Vírus da Influenza A/genética , Pulmão/patologia , Mutagênese Sítio-Dirigida , Proteínas Mutantes/genética , Proteínas Mutantes/imunologia , Infecções por Orthomyxoviridae/patologia , Infecções por Orthomyxoviridae/transmissão , Infecções por Orthomyxoviridae/veterinária , Infecções por Orthomyxoviridae/virologia , Genética Reversa , Suínos , Doenças dos Suínos/patologia , Doenças dos Suínos/virologia , Virulência , Eliminação de Partículas Virais
16.
J Virol ; 89(22): 11213-22, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26311895

RESUMO

UNLABELLED: Human-like swine H3 influenza A viruses (IAV) were detected by the USDA surveillance system. We characterized two novel swine human-like H3N2 and H3N1 viruses with hemagglutinin (HA) genes similar to those in human seasonal H3 strains and internal genes closely related to those of 2009 H1N1 pandemic viruses. The H3N2 neuraminidase (NA) was of the contemporary human N2 lineage, while the H3N1 NA was of the classical swine N1 lineage. Both viruses were antigenically distant from swine H3 viruses that circulate in the United States and from swine vaccine strains and also showed antigenic drift from human seasonal H3N2 viruses. Their pathogenicity and transmission in pigs were compared to those of a human H3N2 virus with a common HA ancestry. Both swine human-like H3 viruses efficiently infected pigs and were transmitted to indirect contacts, whereas the human H3N2 virus did so much less efficiently. To evaluate the role of genes from the swine isolates in their pathogenesis, reverse genetics-generated reassortants between the swine human-like H3N1 virus and the seasonal human H3N2 virus were tested in pigs. The contribution of the gene segments to virulence was complex, with the swine HA and internal genes showing effects in vivo. The experimental infections indicate that these novel H3 viruses are virulent and can sustain onward transmission in pigs, and the naturally occurring mutations in the HA were associated with antigenic divergence from H3 IAV from humans and swine. Consequently, these viruses could have a significant impact on the swine industry if they were to cause more widespread outbreaks, and the potential risk of these emerging swine IAV to humans should be considered. IMPORTANCE: Pigs are important hosts in the evolution of influenza A viruses (IAV). Human-to-swine transmissions of IAV have resulted in the circulation of reassortant viruses containing human-origin genes in pigs, greatly contributing to the diversity of IAV in swine worldwide. New human-like H3N2 and H3N1 viruses that contain a mix of human and swine gene segments were recently detected by the USDA surveillance system. The human-like viruses efficiently infected pigs and resulted in onward airborne transmission, likely due to the multiple changes identified between human and swine H3 viruses. The human-like swine viruses are distinct from contemporary U.S. H3 swine viruses and from the strains used in swine vaccines, which could have a significant impact on the swine industry due to a lack of population immunity. Additionally, public health experts should consider an appropriate assessment of the risk of these emerging swine H3 viruses for the human population.


Assuntos
Vírus da Influenza A Subtipo H3N2/imunologia , Vírus da Influenza A Subtipo H3N2/patogenicidade , Infecções por Orthomyxoviridae/transmissão , Vírus Reordenados/imunologia , Vírus Reordenados/patogenicidade , Doenças dos Suínos/transmissão , Animais , Antígenos Virais/genética , Antígenos Virais/imunologia , Linhagem Celular , Reações Cruzadas/imunologia , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Humanos , Vírus da Influenza A Subtipo H3N2/genética , Influenza Humana/virologia , Neuraminidase/classificação , Neuraminidase/imunologia , Infecções por Orthomyxoviridae/virologia , Vírus Reordenados/genética , Suínos/virologia , Doenças dos Suínos/virologia , Estados Unidos
17.
J Appl Res Intellect Disabil ; 29(5): 445-54, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26121962

RESUMO

BACKGROUND: There are very few studies that investigate the qualitative experiences of people with a learning disability who have engaged in psychological therapy. Indeed, having a learning disability has traditionally been an exclusion criterion for good quality research about psychological treatments (Psychotherapy and Learning Disability. Council Report CR116. London: Royal College of Psychiatrists, 2004; Journal of Applied Research in Intellectual Disabilities, 19, 2005 and 5). The current research was developed in response to a clinical psychology service recognizing the need to evaluate their psychological service and, as part of this evaluation, the importance of consulting with service users about their experience of psychological therapies. The overall aim of gaining this feedback would be to improve the service offered and to ensure that people receive the best psychological care. METHODS: Six service users with a learning disability were interviewed about their experience of individual psychological therapy. The interviews were analysed using interpretative phenomenological analysis. RESULTS: Themes were generated from the interviews which highlighted both positive and negative feedback on the psychological therapy process. The feedback covered areas such as access to therapy, feelings about therapy, preparing for therapy, skill development and collaborative working, accessibility and making therapy fun, challenges to confidentiality, positive feelings towards the therapist, aspects of the therapeutic relationship, therapy being challenging but helpful, and positive outcomes. CONCLUSIONS: These results have contributed to the evidence base that people with a learning disability are able to meaningfully engage in research and provide essential feedback on the services that they receive. No longer can people be excluded from individual psychological therapy or research just because of their label.


Assuntos
Deficiências da Aprendizagem/reabilitação , Satisfação do Paciente , Psicoterapia/normas , Adulto , Humanos , Avaliação de Resultados da Assistência ao Paciente , Pesquisa Qualitativa , Adulto Jovem
18.
Hum Mutat ; 36(3): 296-300, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25504734

RESUMO

Mutations in FOXE3 are associated with both recessive and dominant inheritance of severe anterior ocular malformations and glaucoma. However, functional analyses of putative pathogenic mutations have not been performed. We tested the hypothesis that variations in FOXE3 activity underlie the different modes of inheritance and disease phenotype. In band shift assays, three recessive mutants showed loss-of-function, one retained DNA binding activity, whereas two dominant mutants showed altered activity. All six mutants showed reduced transactivation function compared with wild-type, and modeling the heterozygous state resulted in an intermediate level of activity providing no evidence for dominant negative action. Our in vitro data are consistent with loss-of-function below a dosage sensitive threshold as a mechanism of action for recessive mutations, but indicate an altered mutant protein function rather than a haploinsufficient mechanism for dominant mutations. This study provides the first functional evidence demonstrating that FOXE3 mutations identified in patients impair protein function with differential effects.


Assuntos
Oftalmopatias Hereditárias/genética , Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/metabolismo , Mutação , Humanos
19.
J Gen Virol ; 96(8): 2050-2060, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25904147

RESUMO

Low pathogenic avian influenza A viruses (IAVs) have a natural host reservoir in wild waterbirds and the potential to spread to other host species. Here, we investigated the evolutionary, spatial and temporal dynamics of avian IAVs in Eurasian wild birds. We used whole-genome sequences collected as part of an intensive long-term Eurasian wild bird surveillance study, and combined this genetic data with temporal and spatial information to explore the virus evolutionary dynamics. Frequent reassortment and co-circulating lineages were observed for all eight genomic RNA segments over time. There was no apparent species-specific effect on the diversity of the avian IAVs. There was a spatial and temporal relationship between the Eurasian sequences and significant viral migration of avian IAVs from West Eurasia towards Central Eurasia. The observed viral migration patterns differed between segments. Furthermore, we discuss the challenges faced when analysing these surveillance and sequence data, and the caveats to be borne in mind when drawing conclusions from the apparent results of such analyses.


Assuntos
Evolução Molecular , Genoma Viral , Vírus da Influenza A/genética , Influenza Aviária/virologia , Filogenia , Migração Animal , Animais , Animais Selvagens/virologia , Aves/fisiologia , Aves/virologia , Vírus da Influenza A/classificação , Vírus da Influenza A/isolamento & purificação , Influenza Aviária/fisiopatologia , Dados de Sequência Molecular , Filogeografia , RNA Viral/genética
20.
J Virol ; 88(9): 4752-63, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24522915

RESUMO

UNLABELLED: Swine influenza A virus is an endemic and economically important pathogen in pigs, with the potential to infect other host species. The hemagglutinin (HA) protein is the primary target of protective immune responses and the major component in swine influenza A vaccines. However, as a result of antigenic drift, vaccine strains must be regularly updated to reflect currently circulating strains. Characterizing the cross-reactivity between strains in pigs and seasonal influenza virus strains in humans is also important in assessing the relative risk of interspecies transmission of viruses from one host population to the other. Hemagglutination inhibition (HI) assay data for swine and human H3N2 viruses were used with antigenic cartography to quantify the antigenic differences among H3N2 viruses isolated from pigs in the United States from 1998 to 2013 and the relative cross-reactivity between these viruses and current human seasonal influenza A virus strains. Two primary antigenic clusters were found circulating in the pig population, but with enough diversity within and between the clusters to suggest updates in vaccine strains are needed. We identified single amino acid substitutions that are likely responsible for antigenic differences between the two primary antigenic clusters and between each antigenic cluster and outliers. The antigenic distance between current seasonal influenza virus H3 strains in humans and those endemic in swine suggests that population immunity may not prevent the introduction of human viruses into pigs, and possibly vice versa, reinforcing the need to monitor and prepare for potential incursions. IMPORTANCE: Influenza A virus (IAV) is an important pathogen in pigs and humans. The hemagglutinin (HA) protein is the primary target of protective immune responses and the major target of vaccines. However, vaccine strains must be updated to reflect current strains. Characterizing the differences between seasonal IAV in humans and swine IAV is important in assessing the relative risk of interspecies transmission of viruses. We found two primary antigenic clusters of H3N2 in the U.S. pig population, with enough diversity to suggest updates in swine vaccine strains are needed. We identified changes in the HA protein that are likely responsible for these differences and that may be useful in predicting when vaccines need to be updated. The difference between human H3N2 viruses and those in swine is enough that population immunity is unlikely to prevent new introductions of human IAV into pigs or vice versa, reinforcing the need to monitor and prepare for potential introductions.


Assuntos
Antígenos Virais/imunologia , Evolução Molecular , Variação Genética , Glicoproteínas de Hemaglutininação de Vírus da Influenza/imunologia , Vírus da Influenza A Subtipo H3N2/imunologia , Infecções por Orthomyxoviridae/virologia , Doenças dos Suínos/virologia , Substituição de Aminoácidos , Animais , Antígenos Virais/genética , Sítios de Ligação/genética , Análise por Conglomerados , Reações Cruzadas , Mapeamento de Epitopos , Testes de Inibição da Hemaglutinação , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Vírus da Influenza A Subtipo H3N2/genética , Suínos , Estados Unidos
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