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Hepatitis B virus (HBV) and hepatitis D virus (HDV) coinfection confers a greater risk for accelerated liver disease progression. Full-length characterization of HDV genome is necessary to understand pathogenesis and treatment response. However, owing to its high variability and tight structure, sequencing approaches remain challenging. Herein, we present a workflow to amplify, sequence, and analyze the whole HDV genome in a single fragment. Sequencing was based on the Oxford Nanopore Technologies long-read sequencing followed by a turnkey analysis pipeline (VIRiONT, VIRal in-house ONT sequencing analysis pipeline) that we developed and make available online for free. For the first time, HDV genome was successfully amplified and full-length sequenced in a single fragment, allowing accurate subtyping from 30 clinical samples. High variability of edition, a crucial step in viral life cycle, was found among samples (from 0% to 59%). Additionally, a new subtype of HDV genotype 1 was identified. We provide a complete workflow for assessment of HDV genome at full-length quasispecies resolution overcoming genome assembly issues and helping to identify modifications throughout the whole genome. This will help a better understanding of the impact of genotype/subtype, viral dynamics, and structural variants on HDV pathogenesis and treatment response.
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Coinfecção , Hepatite B , Hepatite D , Humanos , Vírus Delta da Hepatite/genética , Vírus da Hepatite B/genética , GenótipoRESUMO
We aimed to evaluate the association between the humoral and cellular immune responses and symptomatic SARS-CoV-2 infection with Delta or Omicron BA.1 variants in fully vaccinated outpatients. Anti-receptor binding domain (RBD) IgG levels and interferon-gamma (IFN-γ) release were evaluated at PCR-diagnosis of SARS-CoV-2 in 636 samples from negative and positive patients during Delta and Omicron BA.1 periods. Median levels of anti-RBD IgG in positive patients were significantly lower than in negative patients for both variants (p < 0.05). The frequency of Omicron BA.1 infection in patients with anti-RBD IgG concentrations ≥1000 binding antibody units (BAU)/mL was 51.0% and decreased to 34.4% in patients with concentrations ≥3000 BAU/mL. For Delta infection, the frequency of infection was significantly lower when applying the same anti-RBD IgG thresholds (13.3% and 5.3% respectively, p < 0.05). In addition, individuals in the hybrid immunity group had a 4.5 times lower risk of Delta infection compared to the homologous vaccination group (aOR = 0.22, 95% CI: [0.05-0.64]. No significant decrease in the risk of Omicron BA.1 infection was observed in the hybrid group compared to the homologous group, but the risk decreased within the hybrid group as anti-RBD IgG titers increased (aOR = 0.08, 95% CI: [0.01-0.41], p = 0.008). IFN-γ release post-SARS-CoV-2 peptide stimulation was not different between samples from patients infected (either with Delta or Omicron BA.1 variant) or not (p > 0.05). Our results show that high circulating levels of anti-RBD IgG and hybrid immunity were independently associated with a lower risk of symptomatic SARS-CoV-2 infection in outpatients with differences according to the infecting variant (www.clinicaltrials.gov; ID NCT05060939).
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COVID-19 , Hepatite D , Humanos , Pacientes Ambulatoriais , SARS-CoV-2 , COVID-19/prevenção & controle , Interferon gama , Imunoglobulina G , Anticorpos AntiviraisRESUMO
BackgroundSuccessive epidemic waves of COVID-19 illustrated the potential of SARS-CoV-2 variants to reshape the pandemic. Detecting and characterising emerging variants is essential to evaluate their public health impact and guide implementation of adapted control measures.AimTo describe the detection of emerging variant, B.1.640, in France through genomic surveillance and present investigations performed to inform public health decisions.MethodsIdentification and monitoring of SARS-CoV-2 variant B.1.640 was achieved through the French genomic surveillance system, producing 1,009 sequences. Additional investigation of 272 B.1.640-infected cases was performed between October 2021 and January 2022 using a standardised questionnaire and comparing with Omicron variant-infected cases.ResultsB.1.640 was identified in early October 2021 in a school cluster in Bretagne, later spreading throughout France. B.1.640 was detected at low levels at the end of SARS-CoV-2 Delta variant's dominance and progressively disappeared after the emergence of the Omicron (BA.1) variant. A high proportion of investigated B.1.640 cases were children aged under 14 (14%) and people over 60 (27%) years, because of large clusters in these age groups. B.1.640 cases reported previous SARS-CoV-2 infection (4%), anosmia (32%) and ageusia (34%), consistent with data on pre-Omicron SARS-CoV-2 variants. Eight percent of investigated B.1.640 cases were hospitalised, with an overrepresentation of individuals aged over 60 years and with risk factors.ConclusionEven though B.1.640 did not outcompete the Delta variant, its importation and continuous low-level spread raised concerns regarding its public health impact. The investigations informed public health decisions during the time that B.1.640 was circulating.
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COVID-19 , SARS-CoV-2 , Criança , Humanos , Pessoa de Meia-Idade , Idoso , SARS-CoV-2/genética , COVID-19/epidemiologia , França/epidemiologia , PandemiasRESUMO
BackgroundTo cope with the persistence of the COVID-19 epidemic and the decrease in antibody levels following vaccination, a third dose of vaccine has been recommended in the general population. However, several vaccine regimens had been used initially for the primary vaccination course, and the heterologous Vaxzevria/Comirnaty regimen had shown better efficacy and immunogenicity than the homologous Comirnaty/Comirnaty regimen.AimWe wanted to determine if this benefit was retained after a third dose of an mRNA vaccine.MethodsWe combined an observational epidemiological study of SARS-CoV-2 infections among vaccinated healthcare workers at the University Hospital of Lyon, France, with a prospective cohort study to analyse immunological parameters before and after the third mRNA vaccine dose.ResultsFollowing the second vaccine dose, heterologous vaccination regimens were more protective against infection than homologous regimens (adjusted hazard ratio (HR)â¯=â¯1.88; 95% confidence interval (CI): 1.18-3.00; p = 0.008), but this was no longer the case after the third dose (adjusted HRâ¯=â¯0.86; 95% CI: 0.72-1.02; p = 0.082). Receptor-binding domain-specific IgG levels and serum neutralisation capacity against different SARS-CoV-2 variants were higher after the third dose than after the second dose in the homologous regimen group, but not in the heterologous group.ConclusionThe advantage conferred by heterologous vaccination was lost after the third dose in terms of both protection and immunogenicity. Immunological measurements 1â¯month after vaccination suggest that heterologous vaccination induces maximal immunity after the second dose, whereas the third dose is required to reach the same level in individuals with a homologous regimen.
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COVID-19 , Vacinas , Humanos , Anticorpos Antivirais , Vacina BNT162 , COVID-19/epidemiologia , COVID-19/prevenção & controle , Vacinas contra COVID-19 , França/epidemiologia , Estudos Prospectivos , SARS-CoV-2 , VacinaçãoRESUMO
Since the first reports in summer 2020, SARS-CoV-2 reinfections have raised concerns about the immunogenicity of the virus, which will affect SARS-CoV-2 epidemiology and possibly the burden of COVID-19 on our societies in the future. This study provides data on the frequency and characteristics of possible reinfections, using the French national COVID-19 testing database. The Omicron variant had a large impact on the frequency of possible reinfections in France, which represented 3.8% of all confirmed COVID-19 cases since December 2021.
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COVID-19 , SARS-CoV-2 , COVID-19/epidemiologia , Teste para COVID-19 , Humanos , ReinfecçãoRESUMO
We describe a March 2020 co-occurrence of Legionnaires' disease (LD) and coronavirus disease in France. Severe acute respiratory syndrome coronavirus 2 co-infections were identified in 7 of 49 patients from LD case notifications. Most were elderly men with underlying conditions who had contracted severe pneumonia, illustrating the relevance of co-infection screening.
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COVID-19 , Coinfecção , Legionella , Idoso , Coinfecção/epidemiologia , França/epidemiologia , Humanos , Legionella/genética , Masculino , SARS-CoV-2RESUMO
We report a novel severe acute respiratory syndrome coronavirus 2 variant derived from clade 19B (HMN.19B variant or Henri Mondor variant). This variant is characterized by the presence of 18 amino acid substitutions, including 7-8 substitutions in the spike protein and 2 deletions. These variants actively circulate in different regions of France.
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COVID-19 , SARS-CoV-2 , Substituição de Aminoácidos , França/epidemiologia , Humanos , Glicoproteína da Espícula de Coronavírus/genéticaRESUMO
We report the strategy leading to the first detection of variant of concern 202012/01 (VOC) in France (21 December 2020). First, the spike (S) deletion H69-V70 (ΔH69/ΔV70), identified in certain SARS-CoV-2 variants including VOC, is screened for. This deletion is associated with a S-gene target failure (SGTF) in the three-target RT-PCR assay (TaqPath kit). Subsequently, SGTF samples are whole genome sequenced. This approach revealed mutations co-occurring with ΔH69/ΔV70 including S:N501Y in the VOC.
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Sequência de Bases , COVID-19/epidemiologia , Genoma Viral , SARS-CoV-2/genética , Deleção de Sequência/genética , Glicoproteína da Espícula de Coronavírus/genética , França/epidemiologia , HumanosRESUMO
The emergence of SARS-CoV-2 variant 20I/501Y.V1 (VOC-202012/1 or GR/501Y.V1) is concerning given its increased transmissibility. We reanalysed 11,916 PCR-positive tests (41% of all positive tests) performed on 7-8 January 2021 in France. The prevalence of 20I/501Y.V1 was 3.3% among positive tests nationwide and 6.9% in the Paris region. Analysing the recent rise in the prevalence of 20I/501Y.V1, we estimate that, in the French context, 20I/501Y.V1 is 52-69% more transmissible than the previously circulating lineages, depending on modelling assumptions.
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COVID-19 , SARS-CoV-2 , COVID-19/epidemiologia , França/epidemiologia , Humanos , ParisRESUMO
We report a rapid increase in enterovirus D68 (EV-D68) infections, with 139 cases reported from eight European countries between 31 July and 14 October 2021. This upsurge is in line with the seasonality of EV-D68 and was presumably stimulated by the widespread reopening after COVID-19 lockdown. Most cases were identified in September, but more are to be expected in the coming months. Reinforcement of clinical awareness, diagnostic capacities and surveillance of EV-D68 is urgently needed in Europe.
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COVID-19 , Enterovirus Humano D , Infecções por Enterovirus , Enterovirus , Mielite , Infecções Respiratórias , Controle de Doenças Transmissíveis , Surtos de Doenças , Enterovirus Humano D/genética , Infecções por Enterovirus/diagnóstico , Infecções por Enterovirus/epidemiologia , Europa (Continente)/epidemiologia , Humanos , Mielite/epidemiologia , SARS-CoV-2RESUMO
We report a seasonal increase of enterovirus D68 (EV-D68) cases in France, with 54 cases detected between 19 August and 14 November 2018. Molecular typing revealed that 20 of 32 of the isolates belonged to clade D1, only sporadically detected before in France. Median age of D1-cases was 42 years, 10 developed severe respiratory signs and one had neurological complications. The 2018-D1 viruses showed a genetic divergence of 3.34 % with D1 viruses identified previously.
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Enterovirus Humano D/isolamento & purificação , Infecções por Enterovirus/diagnóstico , Infecções por Enterovirus/epidemiologia , Infecções Respiratórias/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Doenças Transmissíveis Emergentes/epidemiologia , Surtos de Doenças , Enterovirus Humano D/genética , Infecções por Enterovirus/virologia , Feminino , França/epidemiologia , Genótipo , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Tipagem Molecular , Filogenia , Vigilância da População/métodos , Análise de Sequência de DNA , Adulto JovemRESUMO
BackgroundUnderstanding enterovirus D68 (EV-D68) circulation patterns as well as risk factors for severe respiratory and neurological illness is important for developing preventive strategies. Methods: Between 2010 and 2016, 11,132 respiratory specimens from hospitalised patients in Lyon, France, were screened for EV-D68 by PCR. Phylogenetic relationships of the viral-protein-1 sequences were reconstructed using maximum-likelihood and Bayesian-Markov-Chain-Monte-Carlo approaches. Results: Overall, 171 infections with a biennial pattern were detected, including seven, one, 55, none, 42, one and 65 cases annually during 2010-16. Children (< 16 years-old; n = 150) were mostly affected and 71% (n = 121) of the total patients were under 5 years-old. In 146 patients with medical reviews, 73% (n = 107) presented with acute respiratory distress. Among paediatric patients with medical reviews (n = 133), 55% (n=73) had an asthma/wheezing history, while among adults (n = 13), 11 had underlying diseases. In total, 45 patients had severe infections and 28 patients needed intensive care unit stays. No acute flaccid myelitis (AFM) was detected. We found genotypes A, B1, B2 B3 and D circulating, and no associations between these and clinical presentations. During the study, new genotypes continuously emerged, being replaced over time. We estimated that ancestors of currently circulating genotypes emerged in the late-1990s to 2010. Rises of the EV-D68 effective population size in Lyon coincided with infection upsurges. Phylogenetic analyses showed ongoing diversification of EV-D68 worldwide, coinciding with more infections in recent years and increases of reported AFM paediatric cases. Conclusions: Reinforcement of diagnostic capacities and clinical-based surveillance of EV-D68 infections is needed in Europe to assess the EV-D68 burden.
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Enterovirus Humano D/genética , Enterovirus Humano D/isolamento & purificação , Infecções por Enterovirus/virologia , Infecções Respiratórias/virologia , Proteínas Estruturais Virais/genética , Adolescente , Adulto , Criança , Pré-Escolar , Enterovirus Humano D/classificação , Infecções por Enterovirus/epidemiologia , Infecções por Enterovirus/fisiopatologia , Feminino , França/epidemiologia , Genótipo , Hospitalização , Hospitais Universitários , Humanos , Lactente , Pulmão/virologia , Masculino , Dados de Sequência Molecular , Paralisia/etiologia , Paralisia/virologia , Filogenia , Reação em Cadeia da Polimerase , Infecções Respiratórias/epidemiologia , Infecções Respiratórias/fisiopatologiaRESUMO
Considered for years as sterile, respiratory tract contains very variable bacterial microbiome. Driven by next generation sequencing techniques, microbiome analyses allow a better understanding of viral infection pathophysiology, in terms of incidence and lethality. After a short reminder of microbiome characterization methods, this review will describe its impact on adaptive and innate immunity of the infected host. Studied by viral challenges after antibiotic administration, microbiome depletion has an important impact on clinical outcome of the host. Patient's management and therapeutic choices could exploit results of this field of research, using microbiome characteristics as prognostic biomarkers. Numerous immunologic pathways are impacted by modification of the microbiome and its restoration, using probiotic or innovative molecules could confer better clinical prognostic of viral respiratory diseases.
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During host infection, viral replication generates multiple subpopulations. Studies of viral diversity using high-throughput sequencing technologies provide a better understanding of the therapeutic effects as well as of the viral pathogenesis. This technical evolution led to an impressive number of studies analyzing this viral characteristic. In this review, we will discuss the principles of the evaluation of viral diversity, before summarizing the main physiological consequences for respiratory viruses. To date, although no study clearly established its role in pathogenesis of severe forms, viral diversification can be alternately a formidable virulence advantage or deleterious to the virus, resulting in its extinction (error-threshold). Because of these differences, it is important to study it in the context of respiratory virus infection, such as Influenza, respiratory syncitial virus (RVS) or rhinovirus. The precise understanding of this property allows us to consider multiple clinical applications, i.e. therapeutic or preventive.
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A few studies have highlighted the importance of the respiratory microbiome in modulating the frequency and outcome of viral respiratory infections. However, there are insufficient data on the use of microbial signatures as prognostic biomarkers to predict respiratory disease outcomes. In this study, we aimed to evaluate whether specific bacterial community compositions in the nasopharynx of children at the time of hospitalization are associated with different influenza clinical outcomes. We utilized retrospective nasopharyngeal (NP) samples (n=36) collected at the time of hospital arrival from children who were infected with influenza virus and had been symptomatic for less than 2 days. Based on their clinical course, children were classified into two groups: patients with mild influenza, and patients with severe respiratory or neurological complications. We implemented custom 16S rRNA gene sequencing, metagenomic sequencing and computational analysis workflows to classify the bacteria present in NP specimens at the species level. We found that increased bacterial diversity in the nasopharynx of children was strongly associated with influenza severity. In addition, patients with severe influenza had decreased relative abundance of Staphylococcus aureus and increased abundance of Prevotella (including P. melaninogenica), Streptobacillus, Porphyromonas, Granulicatella (including G. elegans), Veillonella (including V. dispar), Fusobacterium and Haemophilus in their nasopharynx. This pilot study provides proof-of-concept data for the use of microbial signatures as prognostic biomarkers of influenza outcomes. Further large prospective cohort studies are needed to refine and validate the performance of such microbial signatures in clinical settings.
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Disbiose , Influenza Humana/complicações , Influenza Humana/diagnóstico , Microbiota , Nasofaringe/microbiologia , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Criança , Análise por Conglomerados , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Humanos , Filogenia , Prognóstico , RNA Ribossômico 16S/genética , Estudos Retrospectivos , Análise de Sequência de DNARESUMO
Causing an international outbreak of respiratory disease, Enterovirus D68 quickly entered the closed circle of emerging viral pathogens of public health significance. As rapid and accurate detection of EV-D68 is essential for an efficient clinical management, we designed and validated a new highly efficient one-step quantitative rRT-PCR specific to EV-D68 VP4-VP2 region. With 100% specificity and 95.6% sensitivity to all EV-D68 strains, this new assay can be reliably used to detect and quantify EV-D68 in respiratory samples and represents an interesting additional tool for diagnosis as it targets an original region of the genome.
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Enterovirus Humano D/isolamento & purificação , Infecções por Enterovirus/diagnóstico , Reação em Cadeia da Polimerase em Tempo Real/métodos , Infecções Respiratórias/virologia , Proteínas Estruturais Virais/genética , Surtos de Doenças , Enterovirus Humano D/genética , Infecções por Enterovirus/epidemiologia , Infecções por Enterovirus/virologia , Humanos , Filogenia , Infecções Respiratórias/diagnóstico , Estações do Ano , Sensibilidade e EspecificidadeRESUMO
UNLABELLED: The 1918-1919 influenza pandemic remains the single greatest infectious disease outbreak in the past century. Mouse and nonhuman primate infection models have shown that the 1918 virus induces overly aggressive innate and proinflammatory responses. To understand the response to viral infection and the role of individual 1918 genes on the host response to the 1918 virus, we examined reassortant avian viruses nearly identical to the pandemic 1918 virus (1918-like avian virus) carrying either the 1918 hemagglutinin (HA) or PB2 gene. In mice, both genes enhanced 1918-like avian virus replication, but only the mammalian host adaptation of the 1918-like avian virus through reassortment of the 1918 PB2 led to increased lethality. Through the combination of viral genetics and host transcriptional profiling, we provide a multidimensional view of the molecular mechanisms by which the 1918 PB2 gene drives viral pathogenicity. We demonstrate that 1918 PB2 enhances immune and inflammatory responses concomitant with increased cellular infiltration in the lung. We also show for the first time, that 1918 PB2 expression results in the repression of both canonical and noncanonical Wnt signaling pathways, which are crucial for inflammation-mediated lung regeneration and repair. Finally, we utilize regulatory enrichment and network analysis to define the molecular regulators of inflammation, epithelial regeneration, and lung immunopathology that are dysregulated during influenza virus infection. Taken together, our data suggest that while both HA and PB2 are important for viral replication, only 1918 PB2 exacerbates lung damage in mice infected with a reassortant 1918-like avian virus. IMPORTANCE: As viral pathogenesis is determined in part by the host response, understanding the key host molecular driver(s) of virus-mediated disease, in relation to individual viral genes, is a promising approach to host-oriented drug efforts in preventing disease. Previous studies have demonstrated the importance of host adaptive genes, HA and PB2, in mediating disease although the mechanisms by which they do so are still poorly understood. Here, we combine viral genetics and host transcriptional profiling to show that although both 1918 HA and 1918 PB2 are important mediators of efficient viral replication, only 1918 PB2 impacts the pathogenicity of an avian influenza virus sharing high homology to the 1918 pandemic influenza virus. We demonstrate that 1918 PB2 enhances deleterious inflammatory responses and the inhibition of regeneration and repair functions coordinated by Wnt signaling in the lungs of infected mice, thereby promoting virus-associated disease.
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Vírus da Influenza A Subtipo H1N1/enzimologia , Vírus da Influenza A Subtipo H1N1/patogenicidade , Infecções por Orthomyxoviridae/patologia , Infecções por Orthomyxoviridae/virologia , RNA Polimerase Dependente de RNA/metabolismo , Proteínas Virais/metabolismo , Fatores de Virulência/metabolismo , Via de Sinalização Wnt/imunologia , Animais , Linhagem Celular , Modelos Animais de Doenças , Feminino , Perfilação da Expressão Gênica , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Glicoproteínas de Hemaglutininação de Vírus da Influenza/metabolismo , Humanos , Inflamação/patologia , Vírus da Influenza A Subtipo H1N1/genética , Vírus da Influenza A Subtipo H1N1/imunologia , Pulmão/patologia , Pulmão/virologia , Camundongos Endogâmicos BALB C , RNA Polimerase Dependente de RNA/genética , Vírus Reordenados/enzimologia , Vírus Reordenados/patogenicidade , Proteínas Virais/genética , Virulência , Fatores de Virulência/genéticaRESUMO
From January to April 2015, Réunion experienced a major outbreak of acute haemorrhagic conjunctivitis (AHC) caused by coxsackievirus A24, which heavily impacted the healthcare system. According to the general practitioners' (GP) sentinel network, the number of medical consultations due to conjunctivitis during this period was estimated at ca 100,000. This report describes the characteristics of the outbreak, which were obtained through several different yet complementary surveillance systems on the island. These included the network of hospital emergency departments (OSCOUR network), the GPs' sentinel network, an Internet-based population cohort ('Koman i lé') participating in a survey on distinct symptoms including 'red eyes' and the monitoring of eye drop sales. Overall the results of the different surveillance approaches were in good agreement regarding the outbreak dynamic. A peak of patients with conjunctivitis was detected in the first 15 days of March (week 10 and 11), coinciding with increased eye drop sales on the island. Strains recovered from outbreak cases belonged to genotype IV and were most closely related to strains identified in AHC outbreaks in China, Egypt and Japan since 2010. Continued surveillance of AHC in Réunion remains important not only locally, but also because frequent exchanges between the island and mainland France may lead to introduction of this virus in Europe.
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Conjuntivite Hemorrágica Aguda/epidemiologia , Conjuntivite Hemorrágica Aguda/virologia , Infecções por Coxsackievirus/epidemiologia , Infecções por Coxsackievirus/virologia , Surtos de Doenças/estatística & dados numéricos , Enterovirus Humano C/isolamento & purificação , Adolescente , Adulto , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Conjuntivite Hemorrágica Aguda/prevenção & controle , Infecções por Coxsackievirus/prevenção & controle , Surtos de Doenças/prevenção & controle , Enterovirus Humano C/classificação , Enterovirus Humano C/genética , Feminino , Humanos , Incidência , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Reunião/epidemiologia , Fatores de Risco , Vigilância de Evento Sentinela , Distribuição por Sexo , Adulto JovemRESUMO
In 2014, the United States (US) experienced a nationwide outbreak of enterovirus D68 (EV-D68) infection with 1,152 cases reported mainly in hospitalised children with severe asthma or bronchiolitis. Following the US alert, 11 laboratories of the French enterovirus (EV) surveillance network participated in an EV-D68 survey. A total of 6,229 respiratory samples, collected from 1 July to 31 December 2014, were screened for EV-D68 resulting in 212 EV-D68-positive samples. These 212 samples corresponded to 200 EV-D68 cases. The overall EV-D68 positivity rates among respiratory samples were of 5% (184/3,645) and 1.1% (28/2,584) in hospitalised children and adults respectively. The maximum weekly EV-D68 positivity rates were of 16.1% for children (n = 24/149; week 43) and 2.6% for adults (n = 3/115; week 42). Of 173 children with EV-D68 infection alone, the main symptoms were asthma (n = 83; 48.0%) and bronchiolitis (n = 37; 21.4%). One child developed acute flaccid paralysis (AFP) following EV-D68-associated pneumonia. Although there was no significant increase in severe respiratory tract infections reported to the French public health authorities, 10.7% (19/177) of the EV-D68 infected children and 14.3% (3/21) of the EV-D68 infected adults were hospitalised in intensive care units. Phylogenetic analysis of the viral protein 1 (VP1) sequences of 179 EV-D68 cases, revealed that 117 sequences (65.4%), including that of the case of AFP, belonged to the B2 variant of clade B viruses. Continuous surveillance of EV-D68 infections is warranted and could benefit from existing influenza-like illness and EV surveillance networks.
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Enterovirus Humano D/isolamento & purificação , Infecções por Enterovirus/diagnóstico , Infecções por Enterovirus/epidemiologia , Pneumonia Viral/diagnóstico , Pneumonia Viral/epidemiologia , Vigilância da População/métodos , Adolescente , Adulto , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Infecções por Enterovirus/virologia , Feminino , França/epidemiologia , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Pneumonia Viral/virologia , Prevalência , Fatores de Risco , Distribuição por Sexo , Adulto JovemRESUMO
UNLABELLED: The sudden emergence of severe acute respiratory syndrome coronavirus (SARS-CoV) in 2002 and, more recently, Middle Eastern respiratory syndrome CoV (MERS-CoV) underscores the importance of understanding critical aspects of CoV infection and pathogenesis. Despite significant insights into CoV cross-species transmission, replication, and virus-host interactions, successful therapeutic options for CoVs do not yet exist. Recent identification of SARS-CoV NSP16 as a viral 2'-O-methyltransferase (2'-O-MTase) led to the possibility of utilizing this pathway to both attenuate SARS-CoV infection and develop novel therapeutic treatment options. Mutations were introduced into SARS-CoV NSP16 within the conserved KDKE motif and effectively attenuated the resulting SARS-CoV mutant viruses both in vitro and in vivo. While viruses lacking 2'-O-MTase activity had enhanced sensitivity to type I interferon (IFN), they were not completely restored in their absence in vivo. However, the absence of either MDA5 or IFIT1, IFN-responsive genes that recognize unmethylated 2'-O RNA, resulted in restored replication and virulence of the dNSP16 mutant virus. Finally, using the mutant as a live-attenuated vaccine showed significant promise for possible therapeutic development against SARS-CoV. Together, the data underscore the necessity of 2'-O-MTase activity for SARS-CoV pathogenesis and identify host immune pathways that mediate this attenuation. In addition, we describe novel treatment avenues that exploit this pathway and could potentially be used against a diverse range of viral pathogens that utilize 2'-O-MTase activity to subvert the immune system. IMPORTANCE: Preventing recognition by the host immune response represents a critical aspect necessary for successful viral infection. Several viruses, including SARS-CoV, utilize virally encoded 2'-O-MTases to camouflage and obscure their viral RNA from host cell sensing machinery, thus preventing recognition and activation of cell intrinsic defense pathways. For SARS-CoV, the absence of this 2'-O-MTase activity results in significant attenuation characterized by decreased viral replication, reduced weight loss, and limited breathing dysfunction in mice. The results indicate that both MDA5, a recognition molecule, and the IFIT family play an important role in mediating this attenuation with restored virulence observed in their absence. Understanding this virus-host interaction provided an opportunity to design a successful live-attenuated vaccine for SARS-CoV and opens avenues for treatment and prevention of emerging CoVs and other RNA virus infections.