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1.
Viruses ; 13(1)2021 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-33477472

RESUMO

Influenza A Viruses (IAV) in domestic swine (IAV-S) are associated with sporadic zoonotic transmission at the human-animal interface. Previous pandemic IAVs originated from animals, which emphasizes the importance of characterizing human immunity against the increasingly diverse IAV-S. We analyzed serum samples from healthy human donors (n = 153) using hemagglutination-inhibition (HAI) assay to assess existing serologic protection against a panel of contemporary IAV-S isolated from swine in the United States (n = 11). Age-specific seroprotection rates (SPR), which are the proportion of individuals with HAI ≥ 1:40, corresponded with lower or moderate pandemic risk classifications for the multiple IAV-S examined (one H1-δ1, one H1-δ2, three H3-IVA, one H3-IVB, one H3-IVF). Individuals born between 2004 and 2013 had SPRs of 0% for the five classified H3 subtype IAV-S, indicating youth may be particularly predisposed to infection with these viruses. Expansion of existing immunologic gaps over time could increase likelihood of future IAV-S spillover to humans and facilitate subsequent sustained human-to-human transmission resulting in disease outbreaks with pandemic potential.


Assuntos
Vírus da Influenza A/imunologia , Influenza Humana/epidemiologia , Influenza Humana/transmissão , Infecções por Orthomyxoviridae/veterinária , Doenças dos Suínos/epidemiologia , Doenças dos Suínos/imunologia , Adulto , Idoso , Animais , Feminino , Humanos , Vírus da Influenza A/classificação , Influenza Humana/virologia , Masculino , Pessoa de Meia-Idade , Estações do Ano , Testes Sorológicos , Suínos , Doenças dos Suínos/virologia , Estados Unidos/epidemiologia
2.
Int J Infect Dis ; 97: 354-359, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32562848

RESUMO

OBJECTIVE: The aim of this study was to estimate influenza-attributable years of life lost (YLL) in older adults in subtropical Hefei, China during the years 2012-2017, based on a competing risks approach. METHODS: The quasi-Poisson model was fitted to weekly numbers of all-cause deaths by 5-year age groups for older adults ≥60 years of age. The product of the weekly influenza-like illness consultation rate and the proportion of specimens that tested positive for influenza was taken as the measurement of influenza activity, which was incorporated into the model as an exploratory variable. Excess deaths associated with influenza were calculated by subtracting baseline deaths (setting influenza activity to zero) from fitted deaths. Influenza-attributable YLL accounting for competing risks was estimated using restricted mean lifetime survival analysis. RESULTS: The annual influenza-attributable YLL was highest in the 75-79 years age group (565 per 100,000 persons, 95% confidence interval 550-580), followed by the 80-84, 70-74, 85-89, 65-69, and 60-64 years age groups. Influenza A(H3N2) virus was associated with higher YLL than A(H1N1) and B viruses. Influenza-attributable YLL accounted for 1.03-1.53% of total YLL, and the proportion would be overestimated to 2.91-7.34% if the traditional Kaplan-Meier method ignoring competing risks was used. CONCLUSIONS: Although influenza-associated mortality increased with age, influenza-attributable YLL was found to be highest in the 75-79 years age group.


Assuntos
Influenza Humana/mortalidade , Adulto , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Causas de Morte , Criança , Pré-Escolar , China/epidemiologia , Cidades/estatística & dados numéricos , Feminino , Humanos , Vírus da Influenza A/classificação , Vírus da Influenza A/genética , Vírus da Influenza A/isolamento & purificação , Influenza Humana/epidemiologia , Influenza Humana/virologia , Masculino , Pessoa de Meia-Idade , Modelos Teóricos , Estações do Ano , Análise de Sobrevida , Adulto Jovem
3.
Sci Rep ; 10(1): 8441, 2020 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-32439885

RESUMO

Avian influenza viruses (AIV) are negative sense RNA viruses posing a major threat to the poultry industry worldwide, with the potential to spread to mammals, including humans; hence, an accurate and rapid AIV diagnosis is essential. To date AIV detection relies on molecular methods, mainly RT-qPCR directed against AIV M gene segment. The evolution of AIV represents a relevant issue in diagnostic RT-qPCR due to possible mispriming and/or probe-binding failures resulting in false negative results. Consequently, RT-qPCR for AIV detection should be periodically re-assessed both in silico and in vitro. To this end, a specific workflow was developed to evaluate in silico the complementarity of primers and probes of four published RT-qPCR protocols to their target regions. The four assays and one commercially available kit for AIV detection were evaluated both for their analytical sensitivity using eight different viral dilution panels and for their diagnostic performances against clinical specimens of known infectious status. Differences were observed among the tests under evaluation, both in terms of analytical sensitivity and of diagnostic performances. This finding confirms the importance of continuously monitoring the primers and probes complementarity to their binding regions.


Assuntos
Simulação por Computador , Variação Genética , Vírus da Influenza A/classificação , Vírus da Influenza A/genética , Influenza Aviária/diagnóstico , RNA Viral/análise , Reação em Cadeia da Polimerase em Tempo Real/métodos , Proteínas Virais/genética , Animais , Aves , Técnicas In Vitro , Vírus da Influenza A/isolamento & purificação , Influenza Aviária/genética , Influenza Aviária/virologia , RNA Viral/genética , Curva ROC
4.
Emerg Microbes Infect ; 9(1): 886-888, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32312185

RESUMO

Since 2013, highly pathogenic avian influenza (HPAI) subtype H5N6 (clade 2.3.4.4) has been reported in wild birds and poultry in Asia as well as in other parts of the globe. In Africa, information on the presence of this virus subtype is lacking. This study reports the first detection of a HPAI (H5N6) virus (clade 2.3.4.4b) in a duck from a live bird market in Nigeria, whose genome is closely related to the European 2017-2018 H5N6 viruses, indricating a recent virus introduction into the African continent.


Assuntos
Animais Selvagens/virologia , Vírus da Influenza A/isolamento & purificação , Influenza Aviária/epidemiologia , Filogenia , Doenças das Aves Domésticas/virologia , Aves Domésticas/virologia , Animais , Surtos de Doenças/veterinária , Patos/virologia , Genoma Viral , Vírus da Influenza A/classificação , Influenza Aviária/virologia , Nigéria/epidemiologia , Doenças das Aves Domésticas/epidemiologia
5.
Nature ; 582(7811): 277-282, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32349121

RESUMO

The great majority of globally circulating pathogens go undetected, undermining patient care and hindering outbreak preparedness and response. To enable routine surveillance and comprehensive diagnostic applications, there is a need for detection technologies that can scale to test many samples1-3 while simultaneously testing for many pathogens4-6. Here, we develop Combinatorial Arrayed Reactions for Multiplexed Evaluation of Nucleic acids (CARMEN), a platform for scalable, multiplexed pathogen detection. In the CARMEN platform, nanolitre droplets containing CRISPR-based nucleic acid detection reagents7 self-organize in a microwell array8 to pair with droplets of amplified samples, testing each sample against each CRISPR RNA (crRNA) in replicate. The combination of CARMEN and Cas13 detection (CARMEN-Cas13) enables robust testing of more than 4,500 crRNA-target pairs on a single array. Using CARMEN-Cas13, we developed a multiplexed assay that simultaneously differentiates all 169 human-associated viruses with at least 10 published genome sequences and rapidly incorporated an additional crRNA to detect the causative agent of the 2020 COVID-19 pandemic. CARMEN-Cas13 further enables comprehensive subtyping of influenza A strains and multiplexed identification of dozens of HIV drug-resistance mutations. The intrinsic multiplexing and throughput capabilities of CARMEN make it practical to scale, as miniaturization decreases reagent cost per test by more than 300-fold. Scalable, highly multiplexed CRISPR-based nucleic acid detection shifts diagnostic and surveillance efforts from targeted testing of high-priority samples to comprehensive testing of large sample sets, greatly benefiting patients and public health9-11.


Assuntos
Proteínas Associadas a CRISPR/metabolismo , Sistemas CRISPR-Cas/genética , Técnicas Analíticas Microfluídicas/métodos , Viroses/diagnóstico , Viroses/virologia , Animais , Betacoronavirus/genética , Betacoronavirus/isolamento & purificação , Farmacorresistência Viral/genética , Genoma Viral/genética , HIV/classificação , HIV/genética , HIV/isolamento & purificação , Humanos , Vírus da Influenza A/classificação , Vírus da Influenza A/genética , Vírus da Influenza A/isolamento & purificação , Técnicas Analíticas Microfluídicas/instrumentação , RNA Guia/genética , Sensibilidade e Especificidade
6.
J Virol ; 94(12)2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-32269119

RESUMO

IgA antibodies on mucosal surfaces are known to play an important role in protection from influenza A virus (IAV) infection and are believed to be more potent than IgG for cross-protective immunity against IAVs of multiple hemagglutinin (HA) subtypes. However, in general, neutralizing antibodies specific to HA are principally HA subtype specific. Here, we focus on nonneutralizing but broadly cross-reactive HA-specific IgA antibodies. Recombinant IgG, monomeric IgA (mIgA), and polymeric secretory IgA (pSIgA) antibodies were generated based on the sequence of a mouse anti-HA monoclonal antibody (MAb) 5A5 that had no neutralizing activity but showed broad binding capacity to multiple HA subtypes. While confirming that there was no neutralizing activity of the recombinant MAbs against IAV strains A/Puerto Rico/8/1934 (H1N1), A/Adachi/2/1957 (H2N2), A/Hong Kong/483/1997 (H5N1), A/shearwater/South Australia/1/1972 (H6N5), A/duck/England/1/1956 (H11N6), and A/duck/Alberta/60/1976 (H12N5), we found that pSIgA, but not mIgA and IgG, significantly reduced budding and release of most of the viruses from infected cells. Electron microscopy demonstrated that pSIgA deposited newly produced virus particles on the surfaces of infected cells, most likely due to tethering of virus particles. Furthermore, we found that pSIgA showed significantly higher activity to reduce plaque sizes of the viruses than IgG and mIgA. These results suggest that nonneutralizing pSIgA reactive to multiple HA subtypes may play a role in intersubtype cross-protective immunity against IAVs.IMPORTANCE Mucosal immunity represented by pSIgA plays important roles in protection from IAV infection. Furthermore, IAV HA-specific pSIgA antibodies are thought to contribute to cross-protective immunity against multiple IAV subtypes. However, the mechanisms by which pSIgA exerts such versatile antiviral activity are not fully understood. In this study, we generated broadly cross-reactive recombinant IgG and pSIgA having the same antigen-recognition site and compared their antiviral activities in vitro These recombinant antibodies did not show "classical" neutralizing activity, whereas pSIgA, but not IgG, significantly inhibited the production of progeny virus particles from infected cells. Plaque formation was also significantly reduced by pSIgA, but not IgG. These effects were seen in infection with IAVs of several different HA subtypes. Based on our findings, we propose an antibody-mediated host defense mechanism by which mucosal immunity may contribute to broad cross-protection from IAVs of multiple HA subtypes, including viruses with pandemic potential.


Assuntos
Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Glicoproteínas de Hemaglutininação de Vírus da Influenza/imunologia , Imunoglobulina A/imunologia , Vírus da Influenza A/imunologia , Infecções por Orthomyxoviridae/prevenção & controle , Animais , Anticorpos Monoclonais/genética , Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/genética , Anticorpos Antivirais/genética , Proteção Cruzada , Reações Cruzadas , Cães , Feminino , Células HEK293 , Glicoproteínas de Hemaglutininação de Vírus da Influenza/classificação , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Humanos , Imunidade nas Mucosas , Imunoglobulina A/genética , Imunoglobulina G/genética , Imunoglobulina G/imunologia , Vírus da Influenza A Subtipo H1N1/genética , Vírus da Influenza A Subtipo H1N1/imunologia , Vírus da Influenza A Subtipo H2N2/genética , Vírus da Influenza A Subtipo H2N2/imunologia , Virus da Influenza A Subtipo H5N1/genética , Virus da Influenza A Subtipo H5N1/imunologia , Vírus da Influenza A/classificação , Vírus da Influenza A/genética , Influenza Humana/imunologia , Influenza Humana/prevenção & controle , Influenza Humana/virologia , Células Madin Darby de Rim Canino , Camundongos , Camundongos Endogâmicos BALB C , Testes de Neutralização , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/virologia , Liberação de Vírus
7.
PLoS Pathog ; 16(4): e1008409, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32287326

RESUMO

The continual emergence of novel influenza A strains from non-human hosts requires constant vigilance and the need for ongoing research to identify strains that may pose a human public health risk. Since 1999, canine H3 influenza A viruses (CIVs) have caused many thousands or millions of respiratory infections in dogs in the United States. While no human infections with CIVs have been reported to date, these viruses could pose a zoonotic risk. In these studies, the National Institutes of Allergy and Infectious Diseases (NIAID) Centers of Excellence for Influenza Research and Surveillance (CEIRS) network collaboratively demonstrated that CIVs replicated in some primary human cells and transmitted effectively in mammalian models. While people born after 1970 had little or no pre-existing humoral immunity against CIVs, the viruses were sensitive to existing antivirals and we identified a panel of H3 cross-reactive human monoclonal antibodies (hmAbs) that could have prophylactic and/or therapeutic value. Our data predict these CIVs posed a low risk to humans. Importantly, we showed that the CEIRS network could work together to provide basic research information important for characterizing emerging influenza viruses, although there were valuable lessons learned.


Assuntos
Doenças Transmissíveis Emergentes/veterinária , Doenças do Cão/virologia , Vírus da Influenza A Subtipo H3N2/isolamento & purificação , Vírus da Influenza A Subtipo H3N8/isolamento & purificação , Vírus da Influenza A/isolamento & purificação , Zoonoses/virologia , Animais , Doenças Transmissíveis Emergentes/transmissão , Doenças Transmissíveis Emergentes/virologia , Doenças do Cão/transmissão , Cães , Furões , Cobaias , Humanos , Vírus da Influenza A Subtipo H3N2/classificação , Vírus da Influenza A Subtipo H3N2/genética , Vírus da Influenza A Subtipo H3N8/classificação , Vírus da Influenza A Subtipo H3N8/genética , Vírus da Influenza A/classificação , Vírus da Influenza A/genética , Influenza Humana/transmissão , Influenza Humana/virologia , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Estados Unidos , Zoonoses/transmissão
8.
Acta Virol ; 64(1): 104-110, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32180425

RESUMO

In this report, an H12N2 influenza A virus was identified from a fecal sample in the falcated teal, Anas falcata, located in the Dongting Lake wetland. This is the first report of H12N2 IAV detected from wild birds in China. Phylogenetic analysis showed that all eight segments of this H12N2 virus clustered in the Eurasian lineage. This strain was also shown to be closely related to those from duck-origin, goose origin and wild bird origin. This suggested a transmission of influenza A virus along the East Asian-Australian flyway. In addition, these results implied an interaction between wild birds and domestic poultry and established the need of a long-term and systematic surveillance of wild bird populations. Keywords: influenza A virus; H12N2 subtype; Dongting Lake wetland; wild birds; phylogenetic analysis.


Assuntos
Patos/virologia , Vírus da Influenza A/classificação , Influenza Aviária/virologia , Filogenia , Animais , Austrália , China , Genômica , Vírus da Influenza A/isolamento & purificação
9.
Vet Microbiol ; 242: 108605, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32122608

RESUMO

The majority of influenza A virus strains are hosted in nature by avian species in the orders of Anseriformes and Charadriformes. A minority of strains have been able to cross species boundaries and establish themselves in novel non-avian hosts. Influenza viruses of horses, donkeys, and mules represent such successful events of avian to mammal influenza virus adaptation. Mongolia has over 3 million domestic horses and is home to two wild equids, the Asiatic wild ass or khulan (Equus hemionus hemionus), and Przewalski's horse (Equus ferus przewalskii). Domestic and wild equids are sympatric across most of their range in Mongolia. Epizootic influenza A virus outbreaks among Mongolian domestic horses have been frequently recorded. However, the exposure, circulation and relation to domestic horse influenza A virus outbreaks among wild equids is unknown. We evaluated serum samples of Asiatic wild asses in Mongolia for antibodies against influenza A viruses, using modified protein microarray technique. We detected antibodies against hemagglutinin (H) H1, H3, H5, H7, H8 and H10 influenza A viruses. Asiatic wild asses may represent a previously unidentified influenza A virus reservoir in an ecosystem shared with populations of domestic horses in which influenza strains circulate.


Assuntos
Reservatórios de Doenças/veterinária , Equidae/virologia , Vírus da Influenza A/imunologia , Infecções por Orthomyxoviridae/transmissão , Animais , Animais Selvagens/virologia , Anticorpos Antivirais/sangue , Reservatórios de Doenças/virologia , Ecossistema , Vírus da Influenza A Subtipo H3N8/patogenicidade , Vírus da Influenza A Subtipo H7N7/patogenicidade , Vírus da Influenza A/classificação , Vírus da Influenza A/patogenicidade , Mongólia/epidemiologia , Infecções por Orthomyxoviridae/epidemiologia , Infecções por Orthomyxoviridae/virologia
10.
Curr Med Sci ; 40(1): 63-68, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32166666

RESUMO

The contamination status of H5 avian influenza viruses and distribution of subtypes of H5N1 and H5N6 in poultry-related environment of Hubei areas were investigated. Urban and rural live poultry markets, poultry farms, intensive livestock farms and other monitoring types of 103 counties in 17 cities were selected in Hubei. Wiping samples from cage surface, wiping samples from chopping board, fecal specimens and other environmental samples were collected and tested by real-time RT-PCR using primers and probes of influenza A, avian influenza of H5, N1 and N6 from December 2017 to March 2018. The avian influenza virus positive rate was compared among different monitoring sites, samples, time and regions. Totally, 7132 environmental samples were collected in 1634 monitoring points with a positive rate of 2.24%. The positive rate of H5 avian influenza virus was the highest in urban and rural live poultry markets (3.44%, χ2=61.329, P<0.05) in 6 monitoring sites and wiping samples from chopping board (5.46%, χ2=67.072, P<0.05) in 6 sample types. H5N6 avian influenza viruses were detected more in eastern than western Hubei, and H5N6 avian influenza viruses were detected only in Xiangyang city of western Hubei. There were important high-risk places of human infection with H5 avian influenza virus in urban and rural live poultry markets and the poultry slaughtering plants. H5N6 has been the predominant subtype of H5 avian influenza viruses in the eastern and western Hubei and H5N6 avian influenza viruses were still present in a few areas of Hubei. Outbreaks of human H5N1 and H5N6 avian influenza remain at risk in Hubei province.


Assuntos
Vírus da Influenza A/isolamento & purificação , Influenza Aviária/epidemiologia , Influenza Humana/epidemiologia , Aves Domésticas/virologia , Animais , China/epidemiologia , Diagnóstico Precoce , Fezes/virologia , Humanos , Virus da Influenza A Subtipo H5N1/isolamento & purificação , Vírus da Influenza A/classificação , Vigilância da População , População Rural , População Urbana
11.
Proc Natl Acad Sci U S A ; 117(12): 6550-6558, 2020 03 24.
Artigo em Inglês | MEDLINE | ID: mdl-32152123

RESUMO

The 1918 influenza A virus (IAV) caused the most severe flu pandemic in recorded human history. Nonstructural protein 1 (NS1) is an important virulence factor of the 1918 IAV. NS1 antagonizes host defense mechanisms through interactions with multiple host factors. One pathway by which NS1 increases virulence is through the activation of phosphoinositide 3-kinase (PI3K) by binding to its p85ß subunit. Here we present the mechanism underlying the molecular recognition of the p85ß subunit by 1918 NS1. Using X-ray crystallography, we determine the structure of 1918 NS1 complexed with p85ß of human PI3K. We find that the 1918 NS1 effector domain (1918 NS1ED) undergoes a conformational change to bind p85ß. Using NMR relaxation dispersion and molecular dynamics simulation, we identify that free 1918 NS1ED exists in a dynamic equilibrium between p85ß-binding-competent and -incompetent conformations in the submillisecond timescale. Moreover, we discover that NS1ED proteins of 1918 (H1N1) and Udorn (H3N2) strains exhibit drastically different conformational dynamics and binding kinetics to p85ß. These results provide evidence of strain-dependent conformational dynamics of NS1. Using kinetic modeling based on the experimental data, we demonstrate that 1918 NS1ED can result in the faster hijacking of p85ß compared to Ud NS1ED, although the former has a lower affinity to p85ß than the latter. Our results suggest that the difference in binding kinetics may impact the competition with cellular antiviral responses for the activation of PI3K. We anticipate that our findings will increase the understanding of the strain-dependent behaviors of influenza NS1 proteins.


Assuntos
Vírus da Influenza A/fisiologia , Influenza Humana/virologia , Proteínas não Estruturais Virais/química , Proteínas não Estruturais Virais/metabolismo , Classe Ia de Fosfatidilinositol 3-Quinase/metabolismo , Interações Hospedeiro-Patógeno , Humanos , Vírus da Influenza A Subtipo H1N1/patogenicidade , Vírus da Influenza A Subtipo H1N1/fisiologia , Vírus da Influenza A Subtipo H3N2/patogenicidade , Vírus da Influenza A Subtipo H3N2/fisiologia , Vírus da Influenza A/classificação , Vírus da Influenza A/patogenicidade , Influenza Humana/epidemiologia , Ligação Proteica , Conformação Proteica , Domínios e Motivos de Interação entre Proteínas , Especificidade da Espécie , Relação Estrutura-Atividade , Fatores de Virulência/química , Fatores de Virulência/metabolismo
12.
Epidemiol Infect ; 148: e29, 2020 02 14.
Artigo em Inglês | MEDLINE | ID: mdl-32054544

RESUMO

In recent years, there have been a significant influenza activity and emerging influenza strains in China, resulting in an increasing number of influenza virus infections and leading to public health concerns. The aims of this study were to identify the epidemiological and aetiological characteristics of influenza and establish seasonal autoregressive integrated moving average (SARIMA) models for forecasting the percentage of visits for influenza-like illness (ILI%) in urban and rural areas of Shenyang. Influenza surveillance data were obtained for ILI cases and influenza virus positivity from 18 sentinel hospitals. The SARIMA models were constructed to predict ILI% for January-December 2019. During 2010-2018, the influenza activity was higher in urban than in rural areas. The age distribution of ILI cases showed the highest rate in young children aged 0-4 years. Seasonal A/H3N2, influenza B virus and pandemic A/H1N1 continuously co-circulated in winter and spring seasons. In addition, the SARIMA (0, 1, 0) (0, 1, 2)12 model for the urban area and the SARIMA (1, 1, 1) (1, 1, 0)12 model for the rural area were appropriate for predicting influenza incidence. Our findings suggested that there were regional and seasonal distinctions of ILI activity in Shenyang. A co-epidemic pattern of influenza strains was evident in terms of seasonal influenza activity. Young children were more susceptible to influenza virus infection than adults. These results provide a reference for future influenza prevention and control strategies in the study area.


Assuntos
Monitoramento Epidemiológico , Vírus da Influenza A/isolamento & purificação , Vírus da Influenza B/isolamento & purificação , Influenza Humana/epidemiologia , Influenza Humana/virologia , Adolescente , Adulto , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , China/epidemiologia , Feminino , Geografia , Hospitais , Humanos , Incidência , Lactente , Recém-Nascido , Vírus da Influenza A/classificação , Vírus da Influenza B/classificação , Masculino , Pessoa de Meia-Idade , População Rural , Estações do Ano , População Urbana , Adulto Jovem
13.
Virology ; 542: 8-19, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31957664

RESUMO

The H3 subtype avian influenza virus (AIV) poses a threat to both animal and human health. In this study, phylogenetic analysis showed that the H3 AIVs had various genomic constellations and extensive reassortments, increasing genetic diversity and the emergence of new pathogenic viruses that might infect human beings. Molecular analysis demonstrated that the major molecular markers linked to drug resistance were identified in M genes of three studied viruses, and there might be wide range of resistant virus infections in poultry in the future. Although all the H3 viruses preferentially bound to the avian-type receptor, the growth kinetics experiments showed that the selected H3 viruses were capable of efficient replication in mammalian cells, suggesting a potential cross-species transmission of H3 viruses. Overall, our results emphasize the need for continued surveillance of H3 outbreaks and may also help us improve knowledge on H3 AIVs prevention and control.


Assuntos
Vírus da Influenza A/genética , Influenza Aviária/virologia , Aves Domésticas/virologia , Células A549 , Animais , China/epidemiologia , Surtos de Doenças/veterinária , Cães , Monitoramento Ambiental , Monitoramento Epidemiológico/veterinária , Genoma Viral , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Humanos , Vírus da Influenza A/classificação , Vírus da Influenza A/isolamento & purificação , Influenza Aviária/epidemiologia , Influenza Humana/epidemiologia , Influenza Humana/virologia , Células Madin Darby de Rim Canino , Epidemiologia Molecular , Filogenia , Receptores Virais/metabolismo , Especificidade da Espécie
14.
Influenza Other Respir Viruses ; 14(1): 55-60, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31608599

RESUMO

BACKGROUND: Global influenza surveillance in humans and animals is a critical component of pandemic preparedness. The FluChip-8G Insight assay was developed to subtype both seasonal and potentially pandemic influenza viruses in a single assay with a same day result. FluChip-8G Insight uses whole gene segment RT-PCR-based amplification to provide robustness against genetic drift and subsequent microarray detection with artificial neural network-based data interpretation. OBJECTIVES: The objective of this study was to verify and validate the performance of the FluChip-8G Insight assay for the detection and positive identification of human and animal origin non-seasonal influenza A specimens. METHODS: We evaluated the ability of the FluChip-8G Insight technology to type and HA and NA subtype a sample set consisting of 297 results from 180 unique non-seasonal influenza A strains (49 unique subtypes). RESULTS: FluChip-8G Insight demonstrated a positive percent agreement ≥93% for 5 targeted HA and 5 targeted NA subtypes except for H9 (88%), and negative percent agreement exceeding 95% for all targeted subtypes. CONCLUSIONS: The FluChip-8G Insight neural network-based algorithm used for virus identification performed well over a data set of 297 naïve sample results, and can be easily updated to improve performance on emerging strains without changing the underlying assay chemistry.


Assuntos
Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Vírus da Influenza A/isolamento & purificação , Influenza Humana/virologia , Neuraminidase/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Proteínas Virais/genética , Primers do DNA/genética , Humanos , Vírus da Influenza A/classificação , Vírus da Influenza A/genética , Influenza Humana/diagnóstico , Influenza Humana/epidemiologia , Pandemias , Estados Unidos/epidemiologia
15.
Jpn J Infect Dis ; 73(1): 36-43, 2020 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-31666492

RESUMO

A 10-year-old girl was confirmed, by laboratory tests, to be infected with the H5N6 subtype of the highly pathogenic avian influenza virus in Suzhou city in November, 2018 (JSSZ01). The hemagglutinin (HA) gene of this H5N6 virus belonged to the 2.3.4.4 H5 clade, and the HA linkage peptide of the JSSZ01 strain was RERRRKR↓GLF with multiple basic amino acids. Q226L and G228S mutations were not observed, but S128P, S137A, and T160A substitutions were identified in the receptor binding sites. The resistance mutation D198N in the neuraminidase (NA) protein was also identified in this strain. Additionally, an 11 amino acid (AA positions 59-69) deletion was identified in the NA stalk region. Most genes of JSSZ01 exhibited highest identity with previously characterized H5N6 viruses, but its PA segment sequence was highly similar to previously identified avian H3 viruses (Accession Number: EPI596567 or EPI590058), indicating that JSSZ01 may be created by gene reassortment.


Assuntos
Evolução Molecular , Vírus da Influenza A/classificação , Influenza Humana/virologia , Filogenia , Vírus Reordenados/classificação , Animais , Galinhas/virologia , Criança , Feminino , Genoma Viral , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Humanos , Vírus da Influenza A/isolamento & purificação , Influenza Humana/diagnóstico , Mutação , Neuraminidase/genética , RNA Viral/genética , Vírus Reordenados/isolamento & purificação , Análise de Sequência de DNA
16.
Transbound Emerg Dis ; 67(2): 877-883, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31714018

RESUMO

H7 subtype avian influenza virus infection is an emerging zoonosis in some Asian countries and an important avian disease worldwide. A rapid and simple test is needed to confirm infection in suspected cases during disease outbreaks. In this study, we developed a reverse-transcription recombinase-aided amplification assay for the detection of H7 subtype avian influenza virus. Assays were performed at a single temperature (39°C), and the results were obtained within 20 min. The assay showed no cross-detection with Newcastle disease virus or infectious bronchitis virus, which are the other main respiratory viruses affecting birds. The analytical sensitivity was 102 RNA copies per reaction at a 95% probability level according to probit regression analysis, with 100% specificity. Compared with published reverse-transcription quantitative real-time polymerase chain reaction assays, the κ value of the reverse-transcription recombinase-aided amplification assay in 342 avian clinical samples was 0.988 (p < .001). The sensitivity for avian clinical sample detection was 100% (95%CI, 90.40%-100%), and the specificity was 99.96% (95%CI, 97.83%-99.98%). These results indicated that our reverse-transcription recombinase-aided amplification assay may be a valuable tool for detecting avian influenza H7 subtype virus.


Assuntos
Vírus da Influenza A/classificação , Influenza Aviária/diagnóstico , Influenza Humana/virologia , Recombinases/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa/veterinária , Animais , Aves , Humanos , Vírus da Influenza A/genética , Influenza Aviária/virologia , Técnicas de Amplificação de Ácido Nucleico/veterinária , Reação em Cadeia da Polimerase em Tempo Real , Transcrição Reversa , Sensibilidade e Especificidade , Zoonoses
17.
J Med Microbiol ; 69(2): 256-264, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31264957

RESUMO

Background. The Serious Outcomes Surveillance Network of the Canadian Immunization Research Network (CIRN SOS) has been performing active influenza surveillance since 2009 (ClinicalTrials.gov identifier: NCT01517191). Influenza A and B viruses are identified and characterized using real-time reverse-transcriptase polymerase chain reaction (RT-PCR), and multiplex testing has been performed on a subset of patients to identify other respiratory virus aetiologies. Since both methods can identify influenza A and B, a direct comparison was performed.Methods. Validated real-time RT-PCRs from the World Health Organization (WHO) to identify influenza A and B viruses, characterize influenza A viruses into the H1N1 or H3N2 subtypes and describe influenza B viruses belonging to the Yamagata or Victoria lineages. In a subset of patients, the Seeplex RV15 One-Step ACE Detection assay (RV15) kit was also used for the detection of other respiratory viruses.Results. In total, 1111 nasopharyngeal swabs were tested by RV15 and real-time RT-PCRs for influenza A and B identification and characterization. For influenza A, RV15 showed 98.0 % sensitivity, 100 % specificity and 99.7 % accuracy. The performance characteristics of RV15 were similar for influenza A subtypes H1N1 and H3N2. For influenza B, RV15 had 99.2 % sensitivity, 100 % specificity and 99.8 % accuracy, with similar assay performance being shown for both the Yamagata and Victoria lineages.Conclusions. Overall, the detection of circulating subtypes of influenza A and lineages of influenza B by RV15 was similar to detection by real-time RT-PCR. Multiplex testing with RV15 allows for a more comprehensive respiratory virus surveillance in hospitalized adults, without significantly compromising the reliability of influenza A or B virus detection.


Assuntos
Vírus da Influenza A/isolamento & purificação , Vírus da Influenza B/isolamento & purificação , Influenza Humana/virologia , Técnicas de Diagnóstico Molecular/métodos , Reação em Cadeia da Polimerase Multiplex/métodos , Adulto , Canadá/epidemiologia , Feminino , Hospitalização , Humanos , Vírus da Influenza A/classificação , Vírus da Influenza A/genética , Vírus da Influenza B/classificação , Vírus da Influenza B/genética , Influenza Humana/diagnóstico , Influenza Humana/epidemiologia , Influenza Humana/terapia , Masculino , Pessoa de Meia-Idade , Sensibilidade e Especificidade
18.
BMC Vet Res ; 15(1): 455, 2019 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-31852473

RESUMO

BACKGROUND: The threat of poultry-origin H6 avian influenza viruses to human health emphasizes the importance of monitoring their evolution. South Africa's H6N2 epidemic in chickens began in 2001 and two co-circulating antigenic sub-lineages of H6N2 could be distinguished from the outset. The true incidence and prevalence of H6N2 in the country has been difficult to determine, partly due to the continued use of an inactivated whole virus H6N2 vaccine and the inability to distinguish vaccinated from non-vaccinated birds on serology tests. In the present study, the complete genomes of 12 H6N2 viruses isolated from various farming systems between September 2015 and February 2019 in three major chicken-producing regions were analysed and a serological experiment was used to demonstrate the effects of antigenic mismatch in diagnostic tests. RESULTS: Genetic drift in H6N2 continued and antigenic diversity in sub-lineage I is increasing; no sub-lineage II viruses were detected. Reassortment patterns indicated epidemiological connections between provinces as well as different farming systems, but there was no reassortment with wild bird or ostrich influenza viruses. The sequence mismatch between the official antigens used for routine hemagglutination inhibition (HI) testing and circulating field strains has increased steadily, and we demonstrated that H6N2 field infections are likely to be missed. More concerning, sub-lineage I H6N2 viruses acquired three of the nine HA mutations associated with human receptor-binding preference (A13S, V187D and A193N) since 2002. Most sub-lineage I viruses isolated since 2015 acquired the K702R mutation in PB2 associated with the ability to infect humans, whereas prior to 2015 most viruses in sub-lineages I and II contained the avian lysine marker. All strains had an unusual HA0 motif of PQVETRGIF or PQVGTRGIF. CONCLUSIONS: The H6N2 viruses in South African chickens are mutating and reassorting amongst themselves but have remained a genetically pure lineage since they emerged more than 18 years ago. Greater efforts must be made by government and industry in the continuous isolation and characterization of field strains for use as HI antigens, new vaccine seed strains and to monitor the zoonotic threat of H6N2 viruses.


Assuntos
Galinhas/virologia , Vírus da Influenza A/genética , Influenza Aviária/virologia , Animais , Deriva Genética , Genoma Viral , Testes de Inibição da Hemaglutinação/veterinária , Vírus da Influenza A/classificação , Vírus Reordenados/genética , Testes Sorológicos , África do Sul/epidemiologia , Vacinas de Produtos Inativados
19.
Br Med Bull ; 132(1): 81-95, 2019 12 11.
Artigo em Inglês | MEDLINE | ID: mdl-31848585

RESUMO

BACKGROUND: Human infections with avian influenza viruses (AIV) represent a persistent public health threat. The principal risk factor governing human infection with AIV is from direct contact with infected poultry and is primarily observed in Asia and Egypt where live-bird markets are common. AREAS OF AGREEMENT: Changing patterns of virus transmission and a lack of obvious disease manifestations in avian species hampers early detection and efficient control of potentially zoonotic AIV. AREAS OF CONTROVERSY: Despite extensive studies on biological and environmental risk factors, the exact conditions required for cross-species transmission from avian species to humans remain largely unknown. GROWING POINTS: The development of a universal ('across-subtype') influenza vaccine and effective antiviral therapeutics are a priority. AREAS TIMELY FOR DEVELOPING RESEARCH: Sustained virus surveillance and collection of ecological and physiological parameters from birds in different environments is required to better understand influenza virus ecology and identify risk factors for human infection.


Assuntos
Influenza Aviária/epidemiologia , Influenza Humana/epidemiologia , Animais , Antivirais/uso terapêutico , Aves , Surtos de Doenças , Suscetibilidade a Doenças , Humanos , Vírus da Influenza A/classificação , Vacinas contra Influenza , Influenza Aviária/terapia , Influenza Aviária/transmissão , Influenza Humana/terapia , Influenza Humana/transmissão , Fatores de Risco , Zoonoses/epidemiologia , Zoonoses/terapia , Zoonoses/transmissão
20.
Viruses ; 11(12)2019 12 02.
Artigo em Inglês | MEDLINE | ID: mdl-31810278

RESUMO

Interferon-mediated host factors myxovirus (Mx) proteins are key features in regulating influenza A virus (IAV) infections. Viral polymerases are essential for viral replication. The Mx1 protein has been known to interact with viral nucleoprotein (NP) and PB2, resulting in the influence of polymerase activity and providing interspecies restriction. The equine influenza virus has evolved as an independent lineage to influenza viruses from other species. We estimated the differences in antiviral activities between human MxA (huMxA) and equine Mx1 (eqMx1) against a broad range of IAV strains. We found that huMxA has antiviral potential against IAV strains from non-human species, whereas eqMx1 could only inhibit the polymerase activity of non-equine species. Here, we demonstrated that NP is the main target of eqMx1. Subsequently, we found adaptive mutations in the NP of strains A/equine/Jilin/1/1989 (H3N8JL89) and A/chicken/Zhejiang/DTID-ZJU01/2013 (H7N9ZJ13) that confer eqMx1 resistance and sensitivity respectively. A substantial reduction in Mx1 resistance was observed for the two mutations G34S and H52N in H3N8JL89 NP. Thus, eqMx1 is an important dynamic force in IAV nucleoprotein evolution. We, therefore, suggest that the amino acids responsible for Mx1 resistance should be regarded as a robust indicator for the pandemic potential of lately evolving IAVs.


Assuntos
Doenças dos Cavalos/metabolismo , Doenças dos Cavalos/virologia , Interações Hospedeiro-Patógeno , Vírus da Influenza A/fisiologia , Proteínas de Resistência a Myxovirus/metabolismo , Infecções por Orthomyxoviridae/veterinária , Replicação Viral , Animais , Cães , Evolução Molecular , Células HEK293 , Cavalos , Humanos , Vírus da Influenza A/classificação , Vírus da Influenza A/genética , Influenza Humana/metabolismo , Influenza Humana/virologia , Células Madin Darby de Rim Canino , Mutação , Proteínas do Nucleocapsídeo , Filogenia , Ligação Proteica , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Especificidade da Espécie , Proteínas do Core Viral/genética , Proteínas do Core Viral/metabolismo
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