Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 88
Filter
1.
Braz. j. infect. dis ; 24(1): 58-64, Feb. 2020. tab, graf
Article in English | LILACS | ID: biblio-1089331

ABSTRACT

ABSTRACT Background: Although performance of rapid immunochromatographic tests (RITs) for dengue virus (DENV) serotypes 1, 2 and 3 is relatively settled, evidence on accuracy of RITs for DENV-4 are based on studies with small sample sizes and with discrepant results. Objectives: To assess accuracy and inter-observer agreement of RITs targeting dengue nonstructural protein-1 (NS1) antigen - Dengue NS1-Bioeasy™, Dengue NS1 Ag Strip-Bio-Rad™, IVB Dengue Ag NS1-Orangelife™ and Dengue NS1-K130-Bioclin™ in DENV-4 samples. Methods: Study sample (n = 324) included adults presenting at an emergency unit in Rio de Janeiro, Brazil, with fever of ≤72 h and two or more dengue symptoms. A serum sample from each patient was tested by each RIT. A positive reverse-transcription polymerase chain reaction was considered as the reference standard for dengue diagnosis. The diagnostic parameters analyzed for each RIT were sensitivity, specificity, positive and negative predictive values, and likelihood ratios. Each RIT was read by homogeneous (two junior nurses) or heterogeneous (one junior nurse and one senior biologist) pairs. Agreement was estimated by simple kappa with 95% confidence interval, positive (Ppos) and negative (Pneg) proportion concordance and prevalence and bias adjusted kappa, rated from poor (k < 0.0) to almost perfect (0.8 < k < 1.0), and perfect (k = 1). Results: NS1 RITs for DENV-4 diagnosis showed high specificity (95.9%-99.4%), but low sensitivity (14.7%-45.4%). Bioeasy™ had the best performance, with a positive likelihood ratio of 26.0 (95% CI: 8.4;81.0). Inter-observer agreement was almost perfect for all evaluated RITs. Mismatches in confirmed dengue were more common for the Bioclin™ (Ppos 88.3-90.0 %) and Orangelife™ (Ppos 91.7-94.1 %) tests. Conclusions: For DENV-4, the tested RITs had high specificity, but lower sensitivity compared to published results for other serotypes. They should not be used for screening purposes. Different brands may have very different performances. This should be considered upon deciding of using RITs in DENV-4 outbreaks.


Subject(s)
Humans , Male , Female , Adult , Middle Aged , Chromatography, Affinity/standards , Dengue/diagnosis , Dengue Virus/isolation & purification , Reference Standards , Brazil , Enzyme-Linked Immunosorbent Assay , Observer Variation , Cross-Sectional Studies , Prospective Studies , Reproducibility of Results , Chromatography, Affinity/methods , Sensitivity and Specificity , Reverse Transcriptase Polymerase Chain Reaction , Dengue/immunology , Dengue/virology , Serogroup
2.
Mem. Inst. Oswaldo Cruz ; 115: e190423, 2020. graf
Article in English | SES-SP, LILACS, SES-SP | ID: biblio-1135264

ABSTRACT

BACKGROUND Despite efforts to mitigate the impact of dengue virus (DENV) epidemics, the virus remains a public health problem in tropical and subtropical regions around the world. Most DENV cases in the Americas between January and July 2019 were reported in Brazil. São Paulo State in the southeast of Brazil has reported nearly half of all DENV infections in the country. OBJECTIVES To understand the origin and dynamics of the 2019 DENV outbreak. METHODS Here using portable nanopore sequencing we generated20 new DENV genome sequences from viremic patients with suspected dengue infection residing in two of the most-affected municipalities of São Paulo State, Araraquara and São José do Rio Preto. We conducted a comprehensive phylogenetic analysis with 1,630 global DENV strains to better understand the evolutionary history of the DENV lineages that currently circulate in the region. FINDINGS The new outbreak strains were classified as DENV2 genotype III (American/Asian genotype). Our analysis shows that the 2019 outbreak is the result of a novel DENV lineage that was recently introduced to Brazil from the Caribbean region. Dating phylogeographic analysis suggests that DENV2-III BR-4 was introduced to Brazil in or around early 2014, possibly from the Caribbean region. MAIN CONCLUSIONS Our study describes the early detection of a newly introduced and rapidly-expanding DENV2 virus lineage in Brazil.


Subject(s)
Humans , Genetic Variation , Genomics , Dengue/virology , Dengue Virus/genetics , Phylogeny , Brazil , RNA, Viral/genetics , Genotype
3.
Mem. Inst. Oswaldo Cruz ; 115: e200287, 2020. tab, graf
Article in English | LILACS | ID: biblio-1154869

ABSTRACT

BACKGROUND The heat-labile nature of Dengue virus (DENV) in serum samples must be considered when applying routine diagnostic tests to avoid issues that could impact the accuracy of test results with direct implications for case management and disease reporting. OBJECTIVES To check if pre-analytical variables, such as storage time and temperature, have an impact on the accuracy of the main routine diagnostic tests for dengue. METHODS Virus isolation, reverse transcription real-time polymerase chain reaction (RT-PCR) and NS1 enzyme-linked immunosorbent assay (ELISA) were evaluated using 84 samples submitted to different pre-analytical conditions. FINDINGS Sensitivity and negative predictive value were directly affected by sample storage conditions. RT-PCR and virus isolation showed greater dependence on well-conserved samples for an accurate diagnosis. Interestingly, even storage at -30ºC for a relatively short time (15 days) was not adequate for accurate results using virus isolation and RT-PCR tests. On the other hand, NS1 ELISA showed no significant reduction in positivity for aliquots tested under the same conditions as in the previous tests. MAIN CONCLUSIONS Our results support the stability of the NS1 marker in ELISA diagnosis and indicate that the accuracy of routine tests such as virus isolation and RT-PCR is significantly affected by inadequate transport and storage conditions of serum samples.


Subject(s)
Humans , Immunologic Tests/methods , Enzyme-Linked Immunosorbent Assay/methods , Viral Nonstructural Proteins/immunology , Reverse Transcriptase Polymerase Chain Reaction/methods , Dengue/diagnosis , Dengue Virus/isolation & purification , Antigens, Viral/blood , Predictive Value of Tests , Sensitivity and Specificity , Viral Nonstructural Proteins/genetics , Dengue/blood , Dengue/virology , Dengue Virus/genetics , Dengue Virus/immunology , Antibodies, Viral/blood , Antigens, Viral/immunology
4.
Rev. Soc. Bras. Med. Trop ; 53: e20190439, 2020. tab, graf
Article in English | LILACS | ID: biblio-1101443

ABSTRACT

Abstract INTRODUCTION: DENV-2 is the cause of most dengue epidemics worldwide and is associated with severe cases. METHODS: We investigated arboviruses in 164 serum samples collected from patients presenting with clinical symptoms of dengue fever and 152 mosquito pools. RESULTS: We detected the Asian II genotype of DENV-2 in humans and mosquitoes. Our results confirmed the circulation of the Asian II genotype in Brazil, in addition to the prevalent Asian/American genotype. CONCLUSIONS: The detection of Asian II genotype of DENV-2 in mosquito pools collected in a forest park may be related to a spillback event of human dengue virus.


Subject(s)
Humans , Animals , Dengue/virology , Dengue Virus/genetics , Culicidae/virology , Phylogeny , Seasons , Brazil , RNA, Viral/genetics , Polymerase Chain Reaction , Genotype , Culicidae/classification
5.
Rev. Soc. Bras. Med. Trop ; 52: e20190060, 2019. graf
Article in English | LILACS | ID: biblio-1041555

ABSTRACT

Abstract INTRODUCTION: In this study, we aimed to identify DENV-2 subtypes in Aedes aegypti pools collected between 2011 and 2017 in a rural area of Northern Cordoba, Colombia ("La Balsa"). METHODS: RT-PCR was performed to analyze the capsid/pre-membrane region (C-PrM). Sequencing and phylogenetic bayesian inference using reference DENV-2 sequences were performed. RESULTS: Twelve pools that tested positive for DENV-2 were characterized based on the C-PrM region and grouped under the Asian/American clade. CONCLUSIONS: This study is the first to report the DENV-2 Asian-American subtype in a rural area of Cordoba region, which is associated with severe dengue and local epidemics.


Subject(s)
Animals , Phylogeny , Aedes/virology , Dengue/virology , Dengue Virus/classification , Dengue Virus/genetics , Mosquito Vectors/virology , Serotyping , Bayes Theorem , Colombia/epidemiology , Severe Dengue , Reverse Transcriptase Polymerase Chain Reaction , Dengue/epidemiology , Dengue Virus/isolation & purification , Serogroup
6.
Braz. j. infect. dis ; 22(4): 257-272, July-Aug. 2018. tab, graf
Article in English | LILACS | ID: biblio-974229

ABSTRACT

ABSTRACT Dengue, the most prevalent arboviral disease worldwide, is caused by any of the four dengue virus (DENV) serotypes that co-circulate constantly in hyperendemic areas such as Medellin (Colombia), and these serotypes are transmitted by mosquitoes of the genus Aedes. In this study, we evaluated the replicative capacity of strains isolated in Medellin between 2003 and 2007 in C6/36 cells and in colonies of Aedes aegypti collected during 2010-2011 from high or low-incidence areas within the same city. The phylogenetic analysis grouped isolates according to the predominant genotypes found in the Americas, and the in vitro characterization showed differences in the morphological changes induced by the isolates of each of the isolated serotypes compared to the reference serotypes. In vitro replicative capacity studies demonstrated that genomic copy number increased at four days post-infection and that cell viability decreased significantly compared to the control for all serotypes. The largest number of genomic copies in C6/36 was produced by DENV-2, followed by DENV-1 and DENV-4; DENV-3 produced the smallest number of genomic copies and had the smallest negative effect on cell viability. Finally, differences in the in vivo replication of intercolonial serotypes between the Rockefeller colony and the field colonies and among the intracolonial serotypes were found. The replication of DENV-2 at 7 and 14 days in both high- and low-incidence colonies was higher than that of the other serotypes, and replication of DENV-3 in the mosquito colonies was the most stable on the days evaluated. Our results support the notion that replication and, possibly, DENV transmission and severity depend on many factors, including serotype and vector characteristics.


Subject(s)
Humans , Animals , Virus Replication , Aedes/virology , Dengue/transmission , Dengue Virus/physiology , Insect Vectors/virology , Phylogeny , Urban Population , Colombia , Dengue/virology , Dengue Virus/isolation & purification , Dengue Virus/genetics , Serogroup
7.
Rev. chil. infectol ; 35(2): 176-183, abr. 2018. tab, graf
Article in Spanish | LILACS | ID: biblio-959427

ABSTRACT

Resumen Introducción: La viremia plasmática es un factor cuyo rol en la gravedad de la infección por el virus del dengue se ha discutido ampliamente en los últimos años, siendo hallados resultados divergentes en los múltiples contextos evaluados. Métodos: Se realizó una revisión sistemática de la literatura utilizando las bases de datos Scopus, EBSCOhost, SpringerLink, Lilacs y Scielo. Se consideraron para su inclusión en la revisión estudios que evaluaran la relación entre la carga viral en plasma y las manifestaciones clínicas o la gravedad de la enfermedad. Resultados: Se obtuvieron 80 referencias en la búsqueda inicial, posterior a la aplicación de los criterios de inclusión/exclusión fueron seleccionados 20 artículos. En el estudio de este fenómeno son múltiples los parámetros desde los cuales debe ser evaluada la viremia, no sólo desde su magnitud, sino también desde su duración post-defervescencia y el día en el que se reporta el valor máximo, entre otros. Discusión: Los resultados de los estudios indican que las características de la viremia pueden jugar un rol de importancia que, junto con otros factores del contexto viral (serotipo del virus, tipo de infección) y del paciente (edad, genotipo, comorbilidades, etc), pueden determinar el desenlace clínico de la infección.


Background: Plasma viremia is a factor whose role in the severity of dengue virus infection has been widely discussed in recent years, with divergent results found in the multiple contexts evaluated. Methods: A systematic review of the literature using the Scopus, EBSCOhost, SpringerLink, Lilacs and Scielo databases was conducted. For inclusion in the review there were considered studies that evaluated the relationship between plasma viral load and clinical manifestations or severity of the disease. Results: We obtained 80 references in the initial search, after the application of the inclusion / exclusion criteria 20 articles were selected. In the study of this phenomenon there are multiple parameters from which viremia should be evaluated, not only from its magnitude, but also from the post-defervescence duration and the day in which the maximum value is reported, among others. Discussion: The results of the studies indicate that the characteristics of viremia may play an important role that, along with other factors of the viral (virus serotype, type of infection) and patient context (age, genotype, comorbidities, etc.), determine the clinical outcome of the infection.


Subject(s)
Humans , Male , Viremia/virology , Viral Load , Dengue/diagnosis , Dengue/virology , Dengue Virus/isolation & purification , Viremia/genetics , Severity of Illness Index , Dengue Virus/genetics , Serogroup , Genotype , Antibodies, Viral
8.
Mem. Inst. Oswaldo Cruz ; 113(8): e180036, 2018. graf
Article in English | LILACS | ID: biblio-1040599

ABSTRACT

The dengue virus (DENV), of the genus Flavivirus (Flaviviridae), has four antigenically distinct serotypes, of which DENV-3 is classified into five genotypes. Here, we describe the detection of DENV-3 genotype I in sera of a Brazilian patient travelling from Singapore to Rio de Janeiro, Brazil, by using multiplex real-time RT-PCR, DNA sequencing of the whole envelope protein gene, and phylogenetic analysis. The virus shares ancestry with those identified in Bali, Indonesia, in 2015. It is possible that arboviruses such as Chikungunya ECSA genotype, DENV-4 genotype I, and Zika were introduced in Brazil from other continents during the multiple international events hosted by the country over the last four years, including World Youth Day, the Soccer World Cup, and the Summer Olympics.


Subject(s)
Humans , Dengue/virology , Dengue Virus/genetics , Zika Virus/genetics , Zika Virus Infection/virology , Communicable Diseases, Imported/virology , Genotype , Phylogeny , Genetic Variation , Brazil , Polymerase Chain Reaction , Sequence Analysis, DNA , Dengue Virus/isolation & purification , Serogroup
9.
Rev. chil. infectol ; 35(6): 658-668, 2018. tab, graf
Article in Spanish | LILACS | ID: biblio-990849

ABSTRACT

Resumen Introducción: Los virus del dengue y chikungunya son transmitidos por la hembra de los mosquitos Aedes aegypti y Aedes albopictus, ampliamente distribuidos en zonas tropicales y subtropicales, lo que facilita la co-infección. Objetivo: Determinar la magnitud, la distribución geográfica y el cuadro clínico de la co-infección por dengue y chikungunya. Material y Métodos: Revisión narrativa. Búsqueda en las bases de datos PubMed y Lilacs, utilizando los términos MeSH "Chikungunya", "CHIKV", "DENV", "Dengue" y "coinfection. Se incluyeron los artículos de los últimos 20 años. Resultados: Se incluyeron 45 artículos. El mayor reporte de co-infección fue en Asia seguido de África. En las Américas la información es limitada por la reciente circulación del chikungunya. La magnitud de la co-infección varió entre 0 y 31,9%. No se encontraron diferencias en la distribución de la co-infección por sexo y edad. El cuadro clínico de la mono-infección y la co-infección fue similar. Algunos reportes de caso exponen cuadros graves con afección del sistema nervioso central, manifestaciones hemorrágicas y enfermedad de Still. Conclusión: Las manifestaciones clínicas de la co-infección por dengue y chikungunya son similares a la mono-infección, situación que dificulta el diagnóstico y la medición de su magnitud.


Background: Dengue and chikungunya viruses are transmitted by the female Aedes aegypti and Aedes albopictus, which are widely distributed in tropical and subtropical areas, facilitating coinfection. Aim: To determine the magnitude, geographical distribution and clinical picture of dengue and chikungunya coinfection. Material and Methods: Narrative review. A search in the PubMed and Lilacs databases was made, using the MeSH terms "Chikungunya", "CHIKV", "DENV", "Dengue" and "coinfection. The articles of the last 20 years were included. Results: A total of 45 articles were included. The largest coinfection report was in Asia followed by Africa. In the Americas, the information is limited because of the recent circulation of chikungunya. The magnitude of coinfection varies between 0% and 31.9%. No differences were found in the distribution of coinfection by sex and age. The clinical picture of monoinfection and coinfection was similar. Some case reports show severe cases with central nervous system involvement, hemorrhagic manifestations and Still's disease. Conclusion: The clinical manifestations of coinfection by dengue and chikungunya viruses are similar to those due to monoinfection, which difficult the diagnosis and measurement of its magnitude.


Subject(s)
Humans , Animals , Dengue/virology , Coinfection/virology , Chikungunya Fever/virology , Severity of Illness Index , Chikungunya virus/genetics , Dengue/diagnosis , Dengue/mortality , Dengue/transmission , Dengue Virus/genetics , Coinfection/diagnosis , Coinfection/mortality , Coinfection/transmission , Chikungunya Fever/diagnosis , Chikungunya Fever/mortality , Chikungunya Fever/transmission , Mosquito Vectors , Genotype , Geography
10.
Mem. Inst. Oswaldo Cruz ; 112(7): 520-522, July 2017. tab, graf
Article in English | LILACS | ID: biblio-841817

ABSTRACT

This study aimed to detect dengue virus (DENV) serotypes in serum samples obtained in Matamoros Tamaulipas, Mexico, and to determine the concordance of conventional nested reverse transcriptase polymerase chain reaction (RT-PCR) and a serological test [enzyme-linked immunosorbent assay (ELISA NS1)]. Here, we detected mixed infections consisting of four serotypes of DENV. The most prevalent serotype was DENV-1, followed by DENV-4. This is the first report of DENV-4 in our region. Mixed infections were also detected in 21.5% of samples, and the predominant coinfection consisted of DENV-1 and DENV-2. Therefore, continuous epidemiological surveillance of DENV in this area is required to predict future forms of dengue heterologous infections and the effect of this on health care.


Subject(s)
Humans , Male , Enzyme-Linked Immunosorbent Assay , Polymerase Chain Reaction , RNA-Directed DNA Polymerase , Dengue/diagnosis , Dengue/virology , Dengue Virus/genetics , Serogroup , Antibodies, Viral/blood , Mexico
11.
Mem. Inst. Oswaldo Cruz ; 112(6): 458-468, June 2017. tab, graf
Article in English | LILACS | ID: biblio-841802

ABSTRACT

ABSTRACT BACKGROUND Dengue fever may present hemorrhages and cavitary effusions as result of exacerbated immune responses. We investigated hydro-alcoholic extracts from leaves (UGL) and bark (UGB) of the medicinal species Uncaria guinanensis with respect to antiviral effects in Dengue virus (DENV) infection and in immunological parameters associated with in vivo physiopathological features. METHODS Chemical profiles from UGB or UGL were compared in thin layer chromatography and 1H nuclear magnetic resonance using flavonoid compounds and a pentacyclic oxindole alkaloid-enriched fraction as references. DENV-2-infected hepatocytes (Huh-7) were treated with extracts. Cell viability, DENV antigens and immunological factors were detected by enzyme-linked immunosorbent assay (ELISA) or flow cytometry. FINDINGS The UGL mainly differed from UGB by selectively containing the flavonoid kaempferitrin. UGB and UGL improved hepatocyte viability. Both extracts reduced intracellular viral antigen and inhibited the secretion of viral non-structural protein (NS1), which is indicative of viral replication. Reduction in secretion of macrophage migration inhibitory factor was achieved by UGB, of interleukin-6 by UGL, and of interleukin-8 by both UGB and UGL. MAIN CONCLUSIONS The U. guianensis extracts presented, antiviral and immunomodulatory effects for DENV and possibly a hepatocyte-protective activity. Further studies may be performed to consider these products as potential candidates for the development of an herbal product for the future treatment of dengue.


Subject(s)
Humans , Antiviral Agents/pharmacology , Plant Extracts/pharmacology , Cell Survival/drug effects , Cytokines/drug effects , Cytokines/immunology , Chemokines/drug effects , Chemokines/immunology , Uncaria/chemistry , Dengue/physiopathology , Dengue/immunology , Dengue/virology , Dengue Virus/drug effects , Dengue Virus/immunology , Antigens, Viral/drug effects , Antigens, Viral/immunology , Enzyme-Linked Immunosorbent Assay , Flow Cytometry
12.
Rev. Soc. Bras. Med. Trop ; 50(1): 104-109, Jan.-Feb. 2017. tab, graf
Article in English | LILACS | ID: biblio-1041395

ABSTRACT

Abstract: INTRODUCTION Currently, dengue fever, chikungunya fever, and zika virus represent serious public health issues in Brazil, despite efforts to control the vector, the Aedes aegypti mosquito. METHODS: This was a descriptive and ecological study of dengue deaths occurring from 2002 to 2013 in São Luis, Maranhão, Brazil. Geoprocessing software was used to draw maps, linking the geo-referenced deaths with urban/social data at census tract level. RESULTS: There were 74 deaths, concentrated in areas of social vulnerability. CONCLUSIONS: The use of geo-technology tools pointed to a concentration of dengue deaths in specific intra-urban areas.


Subject(s)
Humans , Animals , Male , Female , Disease Outbreaks , Dengue/mortality , Dengue Virus/genetics , Vulnerable Populations , Urban Population , Brazil/epidemiology , Aedes/virology , Dengue/virology , Spatio-Temporal Analysis , Insect Vectors/virology
13.
Rev. Soc. Bras. Med. Trop ; 50(1): 19-26, Jan.-Feb. 2017. tab, graf
Article in English | LILACS | ID: biblio-842823

ABSTRACT

ABSTRACT INTRODUCTION: Despite being the most prevalent arboviral disease worldwide, dengue has been neglected lately. However, recent epidemics of arboviruses such as Zika and chikungunya in locations throughout the world have alerted health authorities to these diseases. This study evaluated the incidence pattern of dengue, its clinical characteristics, and co-circulation of serotypes from 2007 to 2015 in Paraiba State, Northeast Brazil. METHODS: Data on dengue cases from 2007 to 2015 were extracted from clinical reports of the National System for Notifiable Diseases [Sistema Nacional de Agravos de Notificação (SINAN)] of Brazil provided by the Paraiba Health Department. Reverse transcription polymerase chain reaction (RT-PCR) assays for dengue serotypes were carried out on plasma samples obtained from patients with suspected dengue. The data were analysed using descriptive statistics. RESULTS: According to clinical features, dengue fever [n = 39,083 (70.2%)] and dengue without warning signs [n = 15,365 (27.7%)] were the most common classifications of dengue. On RT-PCR, DENV 1 was the most commonly identified serotype (80.5%) in all years studied. Co-circulation of all four DENV serotypes was observed in 2013 and 2014. Furthermore, we observed an increase in dengue notifications in 2015, possibly due to the rise of Zika and chikungunya. CONCLUSIONS: Our findings support the hypothesis that co-circulation of the four DENV serotypes may be a reason for the increased prevalence of severe forms of dengue in the years studied. This study may contribute to directing research, health policy, and financial resources toward reducing poorly controlled epidemic diseases.


Subject(s)
Humans , Male , Infant, Newborn , Infant , Child, Preschool , Child , Adolescent , Adult , Young Adult , Dengue/epidemiology , Dengue Virus/genetics , Brazil/epidemiology , Serotyping , Incidence , Molecular Epidemiology , Reverse Transcriptase Polymerase Chain Reaction , Dengue/virology , Middle Aged
15.
Braz. j. microbiol ; 47(supl.1): 38-50, Oct.-Dec. 2016. graf
Article in English | LILACS | ID: biblio-839330

ABSTRACT

ABSTRACT Arboviruses pose a serious threat to public health worldwide, overloading the healthcare system and causing economic losses. These viruses form a very diverse group, and in Brazil, arboviruses belonging to the families Flaviviridae and Togaviridae are predominant. Unfortunately, the number of arboviruses increases in proportion with factors such as deforestation, poor sanitation, climate changes, and introduction of new viruses like Chikungunya virus and Zika virus. In Brazil, dengue is endemic, along with the presence of other arboviruses. The situation is complicated by the scarcity of diagnostic infrastructure and the absence of approved vaccines for these diseases. Disease control, thus, relies solely on vector control. Therefore, enhanced clinical knowledge and improved general awareness about these arboviruses are indispensable to tackle diagnostic inadequacies.


Subject(s)
Humans , Animals , Virus Diseases/transmission , Virus Diseases/virology , Insect Vectors/virology , Culicidae/virology , Brazil/epidemiology , Virus Diseases/diagnosis , Virus Diseases/epidemiology , Alphavirus Infections/diagnosis , Alphavirus Infections/transmission , Alphavirus Infections/epidemiology , Alphavirus Infections/virology , Alphavirus/classification , Alphavirus/physiology , Dengue/transmission , Dengue/epidemiology , Dengue/virology , Dengue Virus/classification , Dengue Virus/physiology , Zika Virus Infection/diagnosis , Zika Virus Infection/transmission , Zika Virus Infection/epidemiology , Zika Virus Infection/virology
16.
Rev. chil. infectol ; 33(4): 464-467, ago. 2016. tab
Article in Spanish | LILACS | ID: biblio-830116

ABSTRACT

The recent outbreaks of Chikungunya (CHIK-V) virus in endemic areas of dengue (DEN-V) could increase the risk of co-infection. CHIK infection has been considered not severe and with very unusual mortality, however DEN is associated with severe manifestations and increased mortality. Little is known about coinfection. It is possible that co-infection could generate severe cases. We present a case report of co-infection DEN-V -3 and CHIK-V in an elderly patient who developed acute renal failure, dengue shock syndrome (DSS), progresses to multiple organ failure and died. With the recent emergence of CHIK-V in Colombia, the possibility of co-infection with DEN-V should be suspected, especially in severe cases.


La aparición reciente del virus Chikungunya (CHIK-V) en áreas endémicas de dengue (DEN-V) podría aumentar el riesgo de co-infección. Generalmente, se considera que la infección por CHIK-V es de menor gravedad y mortalidad que DEN-V. Poco se conoce sobre la co-infección de DEN-V y CHIK-V, sin embargo, se ha planteado que la co-infección podría ser de mayor gravedad. Se presenta un caso clínico de co-infección por DENV-3 y CHIK-V en un adulto mayor quien desarrolló falla renal aguda, síndrome de choque del dengue, progresión a disfunción orgánica múltiple y muerte. Con la reciente emergencia de CHIK-V en Colombia, es necesario estar atentos ante la posibilidad de co-infección con DEN-V, en especial en casos graves.


Subject(s)
Humans , Male , Aged , Dengue/epidemiology , Coinfection/epidemiology , Chikungunya Fever/epidemiology , Chikungunya virus/isolation & purification , Colombia/epidemiology , Viral Load , Dengue/blood , Dengue/virology , Dengue Virus/isolation & purification , Coinfection/virology , Chikungunya Fever/blood , Chikungunya Fever/virology , Multiple Organ Failure/virology
17.
Braz. j. microbiol ; 47(1): 251-258, Jan.-Mar. 2016. tab, graf
Article in English | LILACS | ID: lil-775122

ABSTRACT

Abstract Dengue is a major worldwide public health problem, especially in the tropical and subtropical regions of the world. Primary infection with a single Dengue virus serotype causes a mild, self-limiting febrile illness called dengue fever. However, a subset of patients who experience secondary infection with a different serotype can progress to a more severe form of the disease, called dengue hemorrhagic fever. The four Dengue virus serotypes (1–4) are antigenically and genetically distinct and each serotype is composed of multiple genotypes. In this study we isolated one Dengue virus 1 serotype, named BR/Alfenas/2012, from a patient with dengue hemorrhagic fever in Alfenas, South Minas Gerais, Brazil and molecular identification was performed based on the analysis of NS5 gene. Swiss mice were infected with this isolate to verify its potential to induce histopathological alterations characteristic of dengue. Liver histopathological analysis of infected animals showed the presence of inflammatory infiltrates, hepatic steatosis, as well as edema, hemorrhage and necrosis focal points. Phylogenetic and evolutionary analyses based on the envelope gene provided evidence that the isolate BR/Alfenas/2012 belongs to genotype V, lineage I and it is probably derived from isolates of Rio de Janeiro, Brazil. The isolate BR/Alfenas/2012 showed two unique amino acids substitutions (SER222THRE and PHE306SER) when compared to other Brazilian isolates from the same genotype/lineage. Molecular models were generated for the envelope protein indicating that the amino acid alteration PHE 306 SER could contribute to a different folding in this region located within the domain III. Further genetic and animal model studies using BR/Alfenas/2012 and other isolates belonging to the same lineage/genotype could help determine the relation of these genetic alterations and dengue hemorrhagic fever in a susceptible population.


Subject(s)
Animals , Humans , Mice , Dengue Virus/classification , Dengue Virus/genetics , Dengue/virology , Genetic Variation , Genotype , Phylogeny , Amino Acid Substitution , Animal Structures/pathology , Brazil , Disease Models, Animal , Dengue Virus/isolation & purification , Gene Products, env/chemistry , Gene Products, env/genetics , Histocytochemistry , Microscopy , Models, Molecular , Point Mutation , Protein Conformation , Viral Nonstructural Proteins/genetics
18.
Rev. Soc. Bras. Med. Trop ; 49(1): 125-129, Jan.-Feb. 2016. graf
Article in English | LILACS | ID: lil-776529

ABSTRACT

Abstract: A case of dengue virus 3 (DENV-3) genotype I infection with neurological manifestations occurred in Belo Horizonte, Minas Gerais in October 2012. The serotype was detected by PCR, and the genotype was assessed by sequencing and phylogenetic analysis of the C-prM region. The virus causing neurological manifestations clustered with other sequences of DENV-3 genotype I. Because neurological manifestations of DENV are possibly misdiagnosed in Brazil, this study serves as an alert of the importance of DENV diagnoses in CNS infections.


Subject(s)
Humans , Female , Young Adult , Central Nervous System Viral Diseases/virology , Dengue/virology , Dengue Virus/genetics , Phylogeny , RNA, Viral/genetics , Central Nervous System Viral Diseases/complications , Dengue/complications , Genotype
20.
Arq. neuropsiquiatr ; 73(8): 698-703, 08/2015. graf
Article in English | LILACS | ID: lil-753039

ABSTRACT

Dengue virus (DENV) infects approximately 390 million persons every year in more than 100 countries. Reports of neurological complications are more frequently. The objective of this narrative review is to bring up the advances in the dengue neuropathogenesis. DENV can access the nervous system through blood-brain barrier disturbance mediated by cytokine. The blood-cerebrospinal fluid (CSF) barrier seems to be also involved, considering the presence of the virus in the CSF of patients with neurological manifestations. As for neurotropism, several studies showed the presence of RNA and viral antigens in brain tissue and CSF in humans. In murine model, different virus mutations were associated to neurovirulence. Despite the advances in the dengue neuropathogenesis, it is still necessary to determine a more appropriate animal model and increase the number of cases of autopsy. The detection of neurovirulence markers may contribute to establish a prognosis, the disease control and vaccine development.


O vírus da dengue (DENV) infecta anualmente cerca de 390 milhões de indivíduos em mais de 100 países. Complicações neurológicas estão se tornando frequentes. O objetivo desta revisão narrativa é abordar os avanços sobre neuropatogênese na dengue. O DENV invade o sistema nervoso central através do distúrbio da barreira hemato-encefálica, mediado por citocina. A barreira hemato-liquórica (LCR) parece também estar envolvida, considerando a presença do vírus no LCR. Estudos demonstraram RNA e antígenos virais no tecido cerebral e LCR de indivíduos infectados pelo DENV, confirmando o neurotropismo viral. Em modelo murino, diferentes mutações virais foram associadas a neurovirulência. Apesar dos avanços no conhecimento da neuropatogênese da dengue, ainda são necessários a determinação de um modelo animal mais adequado e aumento do número de casos de autopsia. A determinação de marcadores de neurovirulência pode contribuir para o estabelecimento de prognóstico, controle da doença e no desenvolvimento de vacina.


Subject(s)
Animals , Humans , Central Nervous System Diseases/virology , Dengue Virus , Dengue/complications , Central Nervous System/virology , Disease Models, Animal , Dengue Virus/genetics , Dengue/virology , Medical Illustration , Mutation
SELECTION OF CITATIONS
SEARCH DETAIL