RESUMEN
The Zika virus (ZIKV) epidemic has resulted in congenital abnormalities in fetuses and neonates. Although some cross-reactive dengue virus (DENV)-specific antibodies can enhance ZIKV infection in mice, those recognizing the DENV E-dimer epitope (EDE) can neutralize ZIKV infection in cell culture. We evaluated the therapeutic activity of human monoclonal antibodies to DENV EDE for their ability to control ZIKV infection in the brains, testes, placentas, and fetuses of mice. A single dose of the EDE1-B10 antibody given 3 d after ZIKV infection protected against lethality, reduced ZIKV levels in brains and testes, and preserved sperm counts. In pregnant mice, wild-type or engineered LALA variants of EDE1-B10, which cannot engage Fcg receptors, diminished ZIKV burden in maternal and fetal tissues, and protected against fetal demise. Because neutralizing antibodies to EDE have therapeutic potential against ZIKV, in addition to their established inhibitory effects against DENV, it may be possible to develop therapies that control disease caused by both viruses.
Asunto(s)
Anticuerpos Monoclonales/inmunología , Anticuerpos Antivirales/inmunología , Virus del Dengue/inmunología , Epítopos/inmunología , Proteínas del Envoltorio Viral/inmunología , Infección por el Virus Zika/inmunología , Animales , Encéfalo/inmunología , Encéfalo/virología , Chlorocebus aethiops , Reacciones Cruzadas/inmunología , Virus del Dengue/clasificación , Virus del Dengue/metabolismo , Femenino , Feto/inmunología , Feto/virología , Interacciones Huésped-Patógeno/inmunología , Humanos , Masculino , Ratones , Pruebas de Neutralización , Embarazo , Multimerización de Proteína/inmunología , Testículo/inmunología , Testículo/virología , Células Vero , Proteínas del Envoltorio Viral/química , Carga Viral/inmunología , Virus Zika/inmunología , Virus Zika/fisiología , Infección por el Virus Zika/virologíaRESUMEN
Adaptive immune responses protect against infection with dengue virus (DENV), yet cross-reactivity with distinct serotypes can precipitate life-threatening clinical disease. We found that clonotypes expressing the T cell antigen receptor (TCR) ß-chain variable region 11 (TRBV11-2) were 'preferentially' activated and mobilized within immunodominant human-leukocyte-antigen-(HLA)-A*11:01-restricted CD8+ T cell populations specific for variants of the nonstructural protein epitope NS3133 that characterize the serotypes DENV1, DENV3 and DENV4. In contrast, the NS3133-DENV2-specific repertoire was largely devoid of such TCRs. Structural analysis of a representative TRBV11-2+ TCR demonstrated that cross-serotype reactivity was governed by unique interplay between the variable antigenic determinant and germline-encoded residues in the second ß-chain complementarity-determining region (CDR2ß). Extensive mutagenesis studies of three distinct TRBV11-2+ TCRs further confirmed that antigen recognition was dependent on key contacts between the serotype-defined peptide and discrete residues in the CDR2ß loop. Collectively, these data reveal an innate-like mode of epitope recognition with potential implications for the outcome of sequential exposure to heterologous DENVs.
Asunto(s)
Linfocitos T CD8-positivos/inmunología , Reacciones Cruzadas/inmunología , Virus del Dengue/inmunología , Mutación de Línea Germinal/inmunología , Receptores de Antígenos de Linfocitos T alfa-beta/inmunología , Inmunidad Adaptativa/genética , Inmunidad Adaptativa/inmunología , Secuencia de Aminoácidos , Linfocitos T CD8-positivos/metabolismo , Linfocitos T CD8-positivos/virología , Regiones Determinantes de Complementariedad/genética , Regiones Determinantes de Complementariedad/inmunología , Dengue/genética , Dengue/inmunología , Dengue/virología , Virus del Dengue/clasificación , Virus del Dengue/genética , Epítopos de Linfocito T/química , Epítopos de Linfocito T/genética , Epítopos de Linfocito T/inmunología , Antígenos HLA-A/química , Antígenos HLA-A/genética , Antígenos HLA-A/inmunología , Humanos , Modelos Moleculares , Estructura Terciaria de Proteína , Receptores de Antígenos de Linfocitos T alfa-beta/química , Receptores de Antígenos de Linfocitos T alfa-beta/genética , Serina Endopeptidasas/genética , Serina Endopeptidasas/inmunología , Serotipificación , Resonancia por Plasmón de SuperficieRESUMEN
Dengue is a major health threat and the number of symptomatic infections caused by the four dengue serotypes is estimated to be 96 million1 with annually around 10,000 deaths2. However, no antiviral drugs are available for the treatment or prophylaxis of dengue. We recently described the interaction between non-structural proteins NS3 and NS4B as a promising target for the development of pan-serotype dengue virus (DENV) inhibitors3. Here we present JNJ-1802-a highly potent DENV inhibitor that blocks the NS3-NS4B interaction within the viral replication complex. JNJ-1802 exerts picomolar to low nanomolar in vitro antiviral activity, a high barrier to resistance and potent in vivo efficacy in mice against infection with any of the four DENV serotypes. Finally, we demonstrate that the small-molecule inhibitor JNJ-1802 is highly effective against viral infection with DENV-1 or DENV-2 in non-human primates. JNJ-1802 has successfully completed a phase I first-in-human clinical study in healthy volunteers and was found to be safe and well tolerated4. These findings support the further clinical development of JNJ-1802, a first-in-class antiviral agent against dengue, which is now progressing in clinical studies for the prevention and treatment of dengue.
Asunto(s)
Antivirales , Virus del Dengue , Dengue , Primates , Proteínas no Estructurales Virales , Animales , Humanos , Ratones , Antivirales/efectos adversos , Antivirales/farmacología , Antivirales/uso terapéutico , Ensayos Clínicos Fase I como Asunto , Dengue/tratamiento farmacológico , Dengue/prevención & control , Dengue/virología , Virus del Dengue/clasificación , Virus del Dengue/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Farmacorresistencia Viral , Técnicas In Vitro , Terapia Molecular Dirigida , Primates/virología , Unión Proteica/efectos de los fármacos , Proteínas no Estructurales Virales/antagonistas & inhibidores , Proteínas no Estructurales Virales/metabolismo , Replicación ViralRESUMEN
Dengue virus (DENV) is currently causing epidemics of unprecedented scope in endemic settings and expanding to new geographical areas. It is therefore critical to track this virus using genomic surveillance. However, the complex patterns of viral genomic diversity make it challenging to use the existing genotype classification system. Here, we propose adding 2 sub-genotypic levels of virus classification, named major and minor lineages. These lineages have high thresholds for phylogenetic distance and clade size, rendering them stable between phylogenetic studies. We present assignment tools to show that the proposed lineages are useful for regional, national, and subnational discussions of relevant DENV diversity. Moreover, the proposed lineages are robust to classification using partial genome sequences. We provide a standardized neutral descriptor of DENV diversity with which we can identify and track lineages of potential epidemiological and/or clinical importance. Information about our lineage system, including methods to assign lineages to sequence data and propose new lineages, can be found at: dengue-lineages.org.
Asunto(s)
Virus del Dengue , Dengue , Genoma Viral , Filogenia , Virus del Dengue/genética , Virus del Dengue/clasificación , Dengue/virología , Dengue/epidemiología , Humanos , Genotipo , Genómica/métodos , Variación Genética , Terminología como AsuntoRESUMEN
Dengue virus causes approximately 96 million symptomatic infections annually, manifesting as dengue fever or occasionally as severe dengue1,2. There are no antiviral agents available to prevent or treat dengue. Here, we describe a highly potent dengue virus inhibitor (JNJ-A07) that exerts nanomolar to picomolar activity against a panel of 21 clinical isolates that represent the natural genetic diversity of known genotypes and serotypes. The molecule has a high barrier to resistance and prevents the formation of the viral replication complex by blocking the interaction between two viral proteins (NS3 and NS4B), thus revealing a previously undescribed mechanism of antiviral action. JNJ-A07 has a favourable pharmacokinetic profile that results in outstanding efficacy against dengue virus infection in mouse infection models. Delaying start of treatment until peak viraemia results in a rapid and significant reduction in viral load. An analogue is currently in further development.
Asunto(s)
Antivirales/farmacología , Virus del Dengue/clasificación , Virus del Dengue/efectos de los fármacos , Dengue/virología , Proteínas de la Membrana/metabolismo , Proteínas no Estructurales Virales/metabolismo , Animales , Antivirales/farmacocinética , Antivirales/uso terapéutico , Dengue/tratamiento farmacológico , Virus del Dengue/genética , Virus del Dengue/metabolismo , Modelos Animales de Enfermedad , Femenino , Masculino , Proteínas de la Membrana/antagonistas & inhibidores , Ratones , ARN Helicasas/antagonistas & inhibidores , ARN Helicasas/metabolismo , Serina Endopeptidasas/metabolismo , Carga Viral/efectos de los fármacos , Proteínas no Estructurales Virales/antagonistas & inhibidores , Viremia/tratamiento farmacológico , Viremia/virología , Replicación Viral/efectos de los fármacosRESUMEN
Serum-neutralizing antibody titers are a critical measure of vaccine immunogenicity and are used to determine flavivirus seroprevalence in study populations. An effective dengue virus (DENV) vaccine must confer simultaneous protection against viruses grouped within four antigenic serotypes. Existing flavivirus neutralization assays, including the commonly used plaque/focus reduction neutralization titer (PRNT/FRNT) assay, require an individual assay for each virus, serotype, and strain and easily become a labor-intensive and time-consuming effort for large epidemiological studies or vaccine trials. Here, we describe a multiplex reporter virus particle neutralization titer (TetraPlex RVPNT) assay for DENV that allows simultaneous quantitative measures of antibody-mediated neutralization of infection against all four DENV serotypes in a single low-volume clinical sample and analyzed by flow cytometry. Comparative studies confirm that the neutralization titers of antibodies measured by the TetraPlex RVPNT assay are similar to FRNT/PRNT assay approaches performed separately for each viral strain. The use of this high-throughput approach enables the careful serological study in DENV endemic populations and vaccine recipients required to support the development of a safe and effective tetravalent DENV vaccine. IMPORTANCE: As a mediator of protection against dengue disease and a serological indicator of prior infection, the detection and quantification of neutralizing antibodies against DENV is an important "gold standard" tool. However, execution of traditional neutralizing antibody assays is often cumbersome and requires repeated application for each virus or serotype. The optimized RVPNT assay described here is high-throughput, easily multiplexed across multiple serotypes, and targets reporter viral particles that can be robustly produced for all four DENV serotypes. The use of this transformative RVPNT assay will support the expansion of neutralizing antibody datasets to answer research and public health questions often limited by the more cumbersome neutralizing antibody assays and the need for greater quantities of test serum.
Asunto(s)
Anticuerpos Neutralizantes , Anticuerpos Antivirales , Virus del Dengue , Dengue , Pruebas de Neutralización , Serogrupo , Anticuerpos Neutralizantes/inmunología , Anticuerpos Neutralizantes/sangre , Virus del Dengue/inmunología , Virus del Dengue/clasificación , Humanos , Anticuerpos Antivirales/inmunología , Anticuerpos Antivirales/sangre , Pruebas de Neutralización/métodos , Dengue/inmunología , Dengue/virología , Vacunas contra el Dengue/inmunología , Virión/inmunología , AnimalesRESUMEN
Dengue virus (DENV) gains genetic mutations during continuous transmission and evolution, making the virus more adaptive and virulent. The clade of DENV-1 genotype I has expanded and become the predominant genotype in Asia and the Pacific areas, but the underlying mechanisms are unclear. A combined analysis of nonsynonymous mutations in domain III of the envelope protein and their biological effects on virus pathogenesis and transmission was evaluated. Phylogenetic analyses found three nonsynonymous mutations (V324I, V351L, and V380I) in domain III of the envelope protein, which emerged in 1970s-1990s and stably inherited and expanded in contemporary strains after 2000. We generated reverse-mutated viruses (I324V, L351V, and I380V) based on an infectious clone of an epidemic DENV-1 strain (NIID02-20), and the results suggested that the infectivity of the contemporary epidemic virus (wild type, WT) has increased compared to the reverse mutant viruses in mammalian hosts but not mosquito vectors. The WT virus showed a higher binding affinity to host cells and increased virion stability. In addition, weaker immunogenicity and higher resistance to neutralizing antibodies of the WT virus indicated a trend of immune escape. The data suggested that nonsynonymous mutations of the E protein (V324I, V351L, and V380I) promote infectivity and immune evasion of DENV-1 genotype I, which may facilitate its onward transmission on a global scale. IMPORTANCE: We provide evidence that minor sequence variation among dengue virus (DENV) strains can result in increased adaptability and virulence, impacting both the biology of the virus and the antiviral immune response. The genetic mutations of DENV-1 gained during continuous transmission and evolution will offer new clues for the design of novel vaccines against flaviviruses.
Asunto(s)
Virus del Dengue , Dengue , Evolución Molecular , Genotipo , Mutación , Filogenia , Proteínas del Envoltorio Viral , Virus del Dengue/genética , Virus del Dengue/clasificación , Proteínas del Envoltorio Viral/genética , Humanos , Animales , Dengue/virología , Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/inmunología , Línea CelularRESUMEN
BACKGROUND: The increasing burden of dengue virus on public health due to more explosive and frequent outbreaks highlights the need for improved surveillance and control. Genomic surveillance of dengue virus not only provides important insights into the emergence and spread of genetically diverse serotypes and genotypes, but it is also critical to monitor the effectiveness of newly implemented control strategies. Here, we present DengueSeq, an amplicon sequencing protocol, which enables whole-genome sequencing of all four dengue virus serotypes. RESULTS: We developed primer schemes for the four dengue virus serotypes, which can be combined into a pan-serotype approach. We validated both approaches using genetically diverse virus stocks and clinical specimens that contained a range of virus copies. High genome coverage (>95%) was achieved for all genotypes, except DENV2 (genotype VI) and DENV 4 (genotype IV) sylvatics, with similar performance of the serotype-specific and pan-serotype approaches. The limit of detection to reach 70% coverage was 10-100 RNA copies/µL for all four serotypes, which is similar to other commonly used primer schemes. DengueSeq facilitates the sequencing of samples without known serotypes, allows the detection of multiple serotypes in the same sample, and can be used with a variety of library prep kits and sequencing instruments. CONCLUSIONS: DengueSeq was systematically evaluated with virus stocks and clinical specimens spanning the genetic diversity within each of the four dengue virus serotypes. The primer schemes can be plugged into existing amplicon sequencing workflows to facilitate the global need for expanded dengue virus genomic surveillance.
Asunto(s)
Virus del Dengue , Genoma Viral , Serogrupo , Secuenciación Completa del Genoma , Virus del Dengue/genética , Virus del Dengue/aislamiento & purificación , Virus del Dengue/clasificación , Secuenciación Completa del Genoma/métodos , Humanos , Genotipo , Dengue/virología , Dengue/diagnóstico , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , ARN Viral/genéticaRESUMEN
BACKGROUND: The 4 serotypes of dengue virus (DENV1-4) can each cause potentially deadly dengue disease, and are spreading globally from tropical and subtropical areas to more temperate ones. Nepal provides a microcosm of this global phenomenon, having met each of these grim benchmarks. To better understand DENV transmission dynamics and spread into new areas, we chose to study dengue in Nepal and, in so doing, to build the onsite infrastructure needed to manage future, larger studies. METHODS AND RESULTS: During the 2022 dengue season, we enrolled 384 patients presenting at a hospital in Kathmandu with dengue-like symptoms; 79% of the study participants had active or recent DENV infection (NS1 antigen and IgM). To identify circulating serotypes, we screened serum from 50 of the NS1+ participants by RT-PCR and identified DENV1, 2, and 3 - with DENV1 and 3 codominant. We also performed whole-genome sequencing of DENV, for the first time in Nepal, using our new on-site capacity. Sequencing analysis demonstrated the DENV1 and 3 genomes clustered with sequences reported from India in 2019, and the DENV2 genome clustered with a sequence reported from China in 2018. CONCLUSION: These findings highlight DENV's geographic expansion from neighboring countries, identify China and India as the likely origin of the 2022 DENV cases in Nepal, and demonstrate the feasibility of building onsite capacity for more rapid genomic surveillance of circulating DENV. These ongoing efforts promise to protect populations in Nepal and beyond by informing the development and deployment of DENV drugs and vaccines in real time.
Asunto(s)
Virus del Dengue , Dengue , Brotes de Enfermedades , Genoma Viral , Filogenia , Secuenciación Completa del Genoma , Nepal/epidemiología , Virus del Dengue/genética , Virus del Dengue/clasificación , Virus del Dengue/aislamiento & purificación , Humanos , Dengue/epidemiología , Dengue/virología , Secuenciación Completa del Genoma/métodos , Masculino , Adulto , Femenino , SerogrupoRESUMEN
We identified 3 clades of dengue virus serotype 3 belonging to genotype III isolated during 2019-2020 in Jamaica by using whole-genome sequencing and phylogenomic and phylogeographic analyses. The viruses likely originated from Asia in 2014. Newly expanded molecular surveillance efforts in Jamaica will guide appropriate public health responses.
Asunto(s)
Virus del Dengue , Dengue , Filogenia , Serogrupo , Virus del Dengue/genética , Virus del Dengue/clasificación , Jamaica/epidemiología , Humanos , Dengue/virología , Dengue/epidemiología , Genoma Viral , Genotipo , Filogeografía , Secuenciación Completa del GenomaRESUMEN
Dengue cases rose to record levels during 2023-2024. We investigated dengue in Valle del Cauca, Colombia, to determine if specific virus serotypes or lineages caused its large outbreak. We detected all 4 serotypes and multiple lineages, suggesting that factors such as climatic conditions were likely responsible for increased dengue in Colombia.
Asunto(s)
Virus del Dengue , Dengue , Brotes de Enfermedades , Serogrupo , Colombia/epidemiología , Humanos , Dengue/epidemiología , Dengue/virología , Virus del Dengue/genética , Virus del Dengue/clasificación , Filogenia , Historia del Siglo XXIRESUMEN
Major dengue epidemics throughout Nicaragua's history have been dominated by 1 of 4 dengue virus serotypes (DENV-1-4). To examine serotypes during the dengue epidemic in Nicaragua in 2022, we performed real-time genomic surveillance in-country and documented cocirculation of all 4 serotypes. We observed a shift toward co-dominance of DENV-1 and DENV-4 over previously dominant DENV-2. By analyzing 135 new full-length DENV sequences, we found that introductions underlay the resurgence: DENV-1 clustered with viruses from Ecuador in 2014 rather than those previously seen in Nicaragua; DENV-3, which last circulated locally in 2014, grouped instead with Southeast Asia strains expanding into Florida and Cuba in 2022; and new DENV-4 strains clustered within a South America lineage spreading to Florida in 2022. In contrast, DENV-2 persisted from the formerly dominant Nicaragua clade. We posit that the resurgence emerged from travel after the COVID-19 pandemic and that the resultant intensifying hyperendemicity could affect future dengue immunity and severity.
Asunto(s)
COVID-19 , Virus del Dengue , Dengue , Filogenia , SARS-CoV-2 , Serogrupo , Virus del Dengue/genética , Virus del Dengue/clasificación , Nicaragua/epidemiología , Humanos , Dengue/epidemiología , Dengue/virología , COVID-19/epidemiología , COVID-19/virología , SARS-CoV-2/genética , PandemiasRESUMEN
Guangzhou has been the city most affected by the dengue virus (DENV) in China, with a predominance of DENV serotype 1 (DENV-1). Viral factors such as dengue serotype and genotype are associated with severe dengue (SD). However, none of the studies have investigated the relationship between DENV-1 genotypes and SD. To understand the association between DENV-1 genotypes and SD, the clinical manifestations of patients infected with different genotypes were investigated. A total of 122 patients with confirmed DENV-1 genotype infection were recruited for this study. The clinical manifestations, laboratory tests, and levels of inflammatory mediator factors were statistically analyzed to investigate the characteristics of clinical manifestations and immune response on the DENV-1 genotype. In the case of DENV-1 infection, the incidence of SD with genotype V infection was significantly higher than that with genotype I infection. Meanwhile, patients infected with genotype V were more common in ostealgia and bleeding significantly. In addition, levels of inflammatory mediator factors including IFN-γ, TNF-α, IL-10, and soluble vascular cell adhesion molecule 1 were higher in patients with SD infected with genotype V. Meanwhile, the concentrations of regulated upon activation normal T-cell expressed and secreted and growth-related gene alpha were lower in patients with SD infected with genotype V. The higher incidence of SD in patients infected with DENV-1 genotype V may be attributed to elevated cytokines and adhesion molecules, along with decreased chemokines.
Asunto(s)
Virus del Dengue , Genotipo , Serogrupo , Dengue Grave , Humanos , Virus del Dengue/genética , Virus del Dengue/clasificación , China/epidemiología , Masculino , Femenino , Adulto , Persona de Mediana Edad , Dengue Grave/virología , Dengue Grave/epidemiología , Adulto Joven , Citocinas/sangre , Adolescente , Anciano , Incidencia , Niño , Dengue/virología , Dengue/epidemiologíaRESUMEN
Dengue, a mosquito-borne viral disease, poses a significant public health challenge in Pakistan, with a significant outbreak in 2023, prompting our investigation into the serotype and genomic diversity of the dengue virus (DENV). NS-1 positive blood samples from 153 patients were referred to the National Institute of Health, Pakistan, between July and October 2023. Among these, 98 (64.1%) tested positive using multiplex real-time PCR, with higher prevalence among males (65.8%) and individuals aged 31-40. Serotyping revealed DENV-1 as the predominant serotype (84.7%), followed by DENV-2 (15.3%). Whole-genome sequencing of 18 samples (DENV-1 = 17, DENV-2 = 01) showed that DENV-1 (genotype III) samples were closely related (>99%) to Pakistan outbreak samples (2022), and approx. > 98% with USA (2022), Singapore and China (2016), Bangladesh (2017), and Pakistan (2019). The DENV-2 sequence (cosmopolitan genotype; clade IVA) shared genetic similarity with Pakistan outbreak sequences (2022), approx. > 99% with China and Singapore (2018-2019) and showed divergence from Pakistan sequences (2008-2013). No coinfection with dengue serotypes or other viruses were observed. Comparisons with previous DENV-1 sequences highlighted genetic variations affecting viral replication efficiency (NS2B:K55R) and infectivity (E:M272T). These findings contribute to dengue epidemiology understanding and underscore the importance of ongoing genomic surveillance for future outbreak responses in Pakistan.
Asunto(s)
Virus del Dengue , Dengue , Brotes de Enfermedades , Variación Genética , Genoma Viral , Genotipo , Filogenia , Serogrupo , Secuenciación Completa del Genoma , Humanos , Pakistán/epidemiología , Virus del Dengue/genética , Virus del Dengue/clasificación , Virus del Dengue/aislamiento & purificación , Dengue/epidemiología , Dengue/virología , Masculino , Adulto , Femenino , Adulto Joven , Persona de Mediana Edad , Adolescente , Niño , Genoma Viral/genética , Preescolar , Anciano , Lactante , Serotipificación , ARN Viral/genéticaRESUMEN
A comprehensive and systematic examination of dengue virus (DENV) evolution is essential in Pakistan, where the virus poses a significant public health challenge due to its ability to adapt and evolve. To shed light on the intricate evolutionary patterns of all four DENV serotypes, we analyzed complete genome sequences (nâ =â 43) and Envelope (E) gene sequences (nâ =â 44) of all four DENV serotypes collected in Pakistan from 1994 to 2023, providing a holistic view of their genetic evolution. Our findings revealed that all four serotypes of DENV co-circulate in Pakistan with a close evolutionary relationship between DENV-1 and DENV-3. Among the genetically distinct serotypes DENV-2 and DENV-4, DENV-4 stands out as the most genetically different, while DENV-2 exhibits greater complexity due to the presence of multiple genotypes and the possibility of temporal fluctuations in genotype prevalence. Selective pressure analysis of the Envelope (E) gene revealed heterogeneity among sequences (nâ =â 44), highlighting 46 codons in the genome experiencing selective pressure, characterized by a bias toward balancing selection, indicating genetic stability of the virus. Furthermore, our study suggested an intriguing evolutionary shift of DENV-4 toward the DENV-2 clade, potentially influenced by antibodies with cross-reactivity to multiple serotypes, providing a critical insight into the complex factors, shaping DENV evolution and contributing to the emergence of new serotypes.
Asunto(s)
Virus del Dengue , Evolución Molecular , Serogrupo , Virus del Dengue/genética , Virus del Dengue/clasificación , Pakistán/epidemiología , Dengue/virología , Dengue/epidemiología , Filogenia , Genoma Viral , HumanosRESUMEN
BACKGROUND: Despite dengue virus (DENV) outbreak in Gabon a decade ago, less is known on the potential circulation of DENV serotypes in the country. Previous studies conducted in some areas of the country, are limited to hospital-based surveys which reported the presence of some cases of serotype 2 and 3 seven years ago and more recently the serotype 1. As further investigation, we extend the survey to the community of Moyen Ogooué region with the aim to assess the presence of the dengue virus serotypes, additionally to characterize chikungunya (CHIKV) infection and describe the symptomatology associated with infections. METHOD: A cross-sectional survey was conducted from April 2020 to March 2021. The study included participants of both sexes and any age one year and above, with fever or history of fever in the past seven days until blood collection. Eligible volunteers were clinically examined, and blood sample was collected for the detection of DENV and CHIKV using RT-qPCR. Positive samples were selected for the target sequencing. RESULTS: A total of 579 volunteers were included. Their mean age (SD) was 20 (20) years with 55% of them being female. Four cases of DENV infection were diagnosed giving a prevalence of 0.7% (95%CI: 0.2-1.8) in our cohort while no case of CHIKV was detected. The common symptoms and signs presented by the DENV cases included fatigue, arthralgia myalgia, cough, and loss of appetite. DENV-1was the only virus detected by RT-qPCR. CONCLUSION: Our results confirm the presence of active dengue infection in the region, particularly DENV-1, and could suggest the decline of DENV-2 and DENV-3. Continuous surveillance remains paramount to comprehensively describe the extent of dengue serotypes distribution in the Moyen-Ogooué region of Gabon.
Asunto(s)
Virus del Dengue , Dengue , Serogrupo , Humanos , Gabón/epidemiología , Virus del Dengue/genética , Virus del Dengue/clasificación , Virus del Dengue/aislamiento & purificación , Femenino , Masculino , Dengue/epidemiología , Dengue/virología , Estudios Transversales , Adulto , Adulto Joven , Adolescente , Preescolar , Niño , Persona de Mediana Edad , Lactante , Fiebre Chikungunya/epidemiología , Fiebre Chikungunya/virología , Anciano , Prevalencia , Virus Chikungunya/genética , Virus Chikungunya/clasificación , Virus Chikungunya/aislamiento & purificaciónRESUMEN
BACKGROUND: Dengue fever remains a significant public health challenge in tropical and subtropical regions, with its transmission dynamics being influenced by both environmental factors and human mobility. The Dominican Republic, a biodiversity hotspot in the Caribbean, has experienced recurrent dengue outbreaks, yet detailed understanding of the virus's transmission pathways and the impact of climatic factors remains limited. This study aims to elucidate the recent transmission dynamics of the dengue virus (DENV) in the Dominican Republic, utilizing a combination of genomic sequencing and epidemiological data analysis, alongside an examination of historical climate patterns. METHODS: We conducted a comprehensive study involving the genomic sequencing of DENV samples collected from patients across different regions of the Dominican Republic over a two-year period. Phylogenetic analyses were performed to identify the circulation of DENV lineages and to trace transmission pathways. Epidemiological data were integrated to analyze trends in dengue incidence and distribution. Additionally, we integrated historical climate data spanning several decades to assess trends in temperature and their potential impact on DENV transmission potential. RESULTS: Our results highlight a previously unknown north-south transmission pathway within the country, with the co-circulation of multiple virus lineages. Additionally, we examine the historical climate data, revealing long-term trends towards higher theoretical potential for dengue transmission due to rising temperatures. CONCLUSION: This multidisciplinary study reveals intricate patterns of dengue virus transmission in the Dominican Republic, characterized by the co-circulation of multiple DENV lineages and a novel transmission pathway. The observed correlation between rising temperatures and increased dengue transmission potential emphasizes the need for integrated climate-informed strategies in dengue control efforts. Our findings offer critical insights for public health authorities in the Dominican Republic and similar settings, guiding resource allocation and the development of preparedness strategies to mitigate the impacts of climate change on dengue transmission.
Asunto(s)
Clima , Virus del Dengue , Dengue , Filogenia , Serogrupo , República Dominicana/epidemiología , Dengue/epidemiología , Dengue/transmisión , Dengue/virología , Humanos , Virus del Dengue/genética , Virus del Dengue/clasificación , Brotes de EnfermedadesRESUMEN
BACKGROUND OBJECTIVES: Dengue and chikungunya infections are one of the major health problems that have plagued the human population globally. All dengue virus (DENV) serotypes circulate within Malaysia with particular serotypes dominating in different years/outbreaks. In the state of Kelantan, an increasing number of DENV and chikungunya virus (CHIKV) new cases have been reported, including several deaths. This study aimed to isolate and detect these arboviruses from adult mosquitoes in Kelantan. METHODS: Adult mo squito samples were collected from January to August 2019 and were identified according to gender, species and locality. The isolation of the virus was done in C6/36 cells. Dengue NS1 antigen was carried out using direct mosquito lysate and mosquito culture supernatant. Detection and serotyping of the DENV was performed using multiplex RT-PCR and CHIKV detection using a one-step RT-PCR assay. RESULTS: Of 91 mosquito pools, four were positive for NS1 antigen comprising two pools (2.2%) of male Ae. albopictus (Pulau Melaka and Kubang Siput) and two pools (2.2%) of Ae. aegypti (Kampung Demit Sungai). DENV 1 was detected in one pool (0.9%) of female Ae. albopictus among 114 tested Aedes pools. Two pools of 114 pools (1.7%) from both male Aedes species were positive with double serotypes, DENV 1 and DENV 2 (Pulau Melaka). However, no pool was positive for CHIKV. INTERPRETATION CONCLUSION: The presence of DENV and the main vectors of arboviruses in Kelantan are pertinent indicators of the need to improve vector controls to reduce arbovirus infections among people in the localities.
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Aedes , Virus Chikungunya , Virus del Dengue , Dengue , Mosquitos Vectores , Animales , Malasia , Virus del Dengue/genética , Virus del Dengue/aislamiento & purificación , Virus del Dengue/clasificación , Virus Chikungunya/genética , Virus Chikungunya/aislamiento & purificación , Virus Chikungunya/clasificación , Masculino , Femenino , Aedes/virología , Mosquitos Vectores/virología , Dengue/virología , Fiebre Chikungunya/virología , Humanos , Proteínas no Estructurales Virales/genética , SerogrupoRESUMEN
BACKGROUND OBJECTIVES: This study reports observation on circulating serotypes and genotypes of Dengue Virus in North India. METHODS: Serum samples were obtained from suspected cases of dengue referred to the virus diagnostic laboratory during 2014 to 2022. All samples were tested for anti-dengue virus IgM antibodies and NS1Ag by ELISA. NS1Ag positive samples were processed for serotyping and genotyping. RESULTS: Total 41,476 dengue suspected cases were referred to the laboratory of which 12,292 (29.6%) tested positive. Anti-Dengue Virus IgM antibodies, NS1Ag, both IgM and NS1Ag, were positive in 7007 (57.4%); 3200 (26.0%) and 2085 (16.0%) cases respectively. Total 762 strains were serotyped during 9-year period. DENV-1, DENV-2, DENV-3 and DENV-4 serotypes were found in 79 (10.37%), 506 (66.40%), 151 (19.82%) and 26 (3.41%) cases respectively. DENV-1, DENV-2 and DENV-3 were in circulation throughout. Total 105 strains were genotyped. Genotype IV of DENV-1 serotype was circulating till 2014 which was later replaced by genotype V. A distinct seasonality with increase in number of cases in post-monsoon period was seen. INTERPRETATION CONCLUSION: DENV-1, DENV-2 and DENV-3 were found to be in circulation in North India. Predominant serotype/genotype changed at times, but not at regular intervals.
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Anticuerpos Antivirales , Virus del Dengue , Dengue , Genotipo , Serogrupo , India/epidemiología , Virus del Dengue/genética , Virus del Dengue/clasificación , Virus del Dengue/aislamiento & purificación , Humanos , Dengue/virología , Dengue/epidemiología , Dengue/sangre , Anticuerpos Antivirales/sangre , Inmunoglobulina M/sangre , Femenino , Serotipificación , Masculino , Adulto , Niño , Ensayo de Inmunoadsorción Enzimática , Adolescente , Persona de Mediana Edad , Adulto Joven , Estaciones del Año , PreescolarRESUMEN
Although specific interactions between host and pathogen genotypes have been well documented in invertebrates, the identification of host genes involved in discriminating pathogen genotypes remains a challenge. In the mosquito Aedes aegypti, the main dengue virus (DENV) vector worldwide, statistical associations between host genetic markers and DENV types or strains were previously detected, but the host genes underlying this genetic specificity have not been identified. In particular, it is unknown whether DENV type- or strain-specific resistance relies on allelic variants of the same genes or on distinct gene sets. Here, we investigated the genetic architecture of DENV resistance in a population of Ae. aegypti from Bakoumba, Gabon, which displays a stronger resistance phenotype to DENV type 1 (DENV-1) than to DENV type 3 (DENV-3) infection. Following experimental exposure to either DENV-1 or DENV-3, we sequenced the exomes of large phenotypic pools of mosquitoes that are either resistant or susceptible to each DENV type. Using variation in single-nucleotide polymorphism (SNP) frequencies among the pools, we computed empirical p values based on average gene scores adjusted for the differences in SNP counts, to identify genes associated with infection in a DENV type-specific manner. Among the top 5% most significant genes, 263 genes were significantly associated with resistance to both DENV-1 and DENV-3, 287 genes were only associated with DENV-1 resistance and 290 were only associated with DENV-3 resistance. The shared significant genes were enriched in genes with ATP binding activity and sulfur compound transmembrane transporter activity, whereas the genes uniquely associated with DENV-3 resistance were enriched in genes with zinc ion binding activity. Together, these results indicate that specific resistance to different DENV types relies on largely non-overlapping sets of genes in this Ae. aegypti population and pave the way for further mechanistic studies.