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1.
Ciênc. Saúde Colet ; 25(2): 665-672, Feb. 2020. tab, graf
Article in Portuguese | LILACS | ID: biblio-1055817

ABSTRACT

Resumo A dengue ocorre no Timor-Leste desde 2005, porém não existe um programa de monitoramento e controle do "Aedes aegypti". O objetivo deste estudo foi de avaliar a armadilha ovitrampa iscada com atraente natural como uma possível ferramenta para monitorar o vetor das arboviroses: Dengue (DENV), Chikungunya (CHIKV) e Zika (ZIKV). O estudo foi realizado na cidade de Dili, capital do Timor-Leste, entre as semanas epidemiológicas 32 (02/08) a 48 (02/12) de 2016. Foram instaladas 70 armadilhas Ovitrampa, em residências de 15 sucos (ruas), de quatro Postos Administrativos (bairros) da cidade. Para as analises dos dados utilizou-se os indicadores entomológicos: Índice de Positividade de Ovitrampa (IPO), Índice de Densidade Vetorial (IDV) e Índice de Densidade de Ovos (IDO). Durante o experimento foram coletados 158.904 ovos de Aedes spp.. O IPO demonstrou que todas as áreas tiveram 98% a 100% de armadilhas contendo ovos de Aedes spp.. Os indicadores IDO e IPO apresentaram correlações positivas e significativa com a temperatura. A defasagem de duas e três semanas para precipitação indicou correlação positiva significativa para IDV e IDO. Portanto, a armadilha ovitrampa é uma ferramenta que pode integrar as ações de um programa de monitoramento e controle de Aedes spp. no Timor-Leste.


Subject(s)
Humans , Animals , Female , Mosquito Control/methods , Aedes/virology , Mosquito Vectors/virology , Oviposition , Chikungunya virus/isolation & purification , Aedes/physiology , Dengue/prevention & control , Dengue/transmission , Dengue Virus/isolation & purification , Timor-Leste , Chikungunya Fever/prevention & control , Chikungunya Fever/transmission , Zika Virus/isolation & purification , Zika Virus Infection/prevention & control , Zika Virus Infection/transmission
2.
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
3.
Einstein (Säo Paulo) ; 18: eAO5078, 2020. tab
Article in English | LILACS | ID: biblio-1056051

ABSTRACT

ABSTRACT Objective: To evaluate the performance of indirect immunofluorescence for serological diagnosis of dengue virus in a population with high prevalence of arboviruses. Methods: Two-hundred serum samples from patients with clinical suspicion of dengue fever were tested by immunoenzymatic and indirect immunofluorescence assay BIOCHIP® mosaic. Specificity, sensitivity and Kappa coefficient were calculated. Discordant samples were tested by polymerase chain reaction for confirmation. Results: Of the 200 samples, 20% were positive and 80% negative for anti-dengue virus IgM antibodies in the immunoenzymatic test. Of the 40 positives, 25% were negative in indirect immunofluorescence. Of these ten discordant results, only 20% were also negative in the polymerase chain reaction (PCR). Of the 160 negatives in the immunoenzymatic test, 5% were positive in indirect immunofluorescence. Of these nine discordant results, 33% were positive in the PCR. The Kappa coefficient was 0.7 (0.572-0.829). Sensitivity and specificity of indirect immunofluorescence were respectively 75% and 94%. For anti-dengue virus IgG antibodies, of the 200 samples, 15.5% were positive and 84.5% were negative in the immunoenzymatic test. Of the 31 positives, 12.9% were negative in indirect immunofluorescence. Of these four discordant results, 25% were negative in the PCR. Of the 169 negatives, 8% were positive in indirect immunofluorescence. Of these 14 discordant results, 64% were also positive in the PCR. The Kappa coefficient was 0.695 (0.563-0.83). Sensitivity and specificity of indirect immunofluorescence were 87.1% and 91.7%, respectively. Conclusion: For diagnosis of acute infection, the immunoenzymatic test is enough, and the use of additional methods is not warranted. Replacing the immunoenzymatic test by indirect immunofluorescence would compromise the sensitivity for IgM. However, indirect immunofluorescence can distinguish three arboviruses simultaneously, an advantage during concomitant epidemics.


RESUMO Objetivo: Avaliar o desempenho da imunofluorescência indireta no diagnóstico sorológico de dengue em uma população com alta prevalência de arboviroses. Métodos: Duzentas amostras de soro de pacientes com suspeita clínica de dengue foram testadas por ensaio imunoenzimático e imunofluorescência indireta mosaico BIOCHIP®. Foram calculados especificidade, sensibilidade e coeficiente Kappa. Nas amostras discordantes, realizou-se reação em cadeia da polimerase como método confirmatório. Resultados: Das 200 amostras, 20% foram positivas e 80% negativas para IgM antivírus da dengue no ensaio imunoenzimático. Das 40 positivas, 25% foram negativas na imunofluorescência indireta. Destas dez negativas, apenas 20% eram também negativas na reação em cadeia da polimerase. Das 160 negativas no ensaio imunoenzimático, 5% foram positivas na imunofluorescência indireta. Por fim, dentre as nove discordantes, 33% tiveram vírus da dengue detectado na reação em cadeia da polimerase. O coeficiente Kappa foi 0,70 (0,57-0,82). Sensibilidade e especificidade por imunofluorescência indireta foram, respectivamente, 75% e 94%. Para IgG antivírus da dengue, de 200 amostras, 15,5% foram positivas e 84,5% negativas no ensaio imunoenzimático. Das 31 positivas, 12,9% foram negativas na imunofluorescência indireta. Destas quatro discordantes, 25% apresentaram vírus da dengue não detectado na reação em cadeia da polimerase. Das 169 negativas, 8% foram positivas na imunofluorescência indireta. Destas, 64% foram positivas também na reação em cadeia da polimerase. O coeficiente Kappa foi 0,695 (0,56-0,83). Sensibilidade e a especificidade por imunofluorescência indireta foram, respectivamente, 87,1% e 91,7%. Conclusão: Ensaio imunoenzimático seria suficiente para diagnóstico sorológico de infecção aguda, não justificando a incorporação da imunofluorescência indireta. Substituir ensaio imunoenzimático pela imunofluorescência indireta poderia comprometer a sensibilidade para IgM. Contudo, a imunofluorescência indireta auxilia diferenciar três arboviroses simultaneamente, sendo vantajoso em epidemias concomitantes.


Subject(s)
Enzyme-Linked Immunosorbent Assay/methods , Fluorescent Antibody Technique, Indirect/methods , Dengue/diagnosis , Arboviruses/isolation & purification , Reference Standards , Brazil , Immunoglobulin G/immunology , Immunoglobulin M/immunology , Enzyme-Linked Immunosorbent Assay/standards , Serologic Tests/methods , Serologic Tests/standards , Polymerase Chain Reaction , Sensitivity and Specificity , Fluorescent Antibody Technique, Indirect/standards , Dengue/immunology , Dengue Virus/isolation & purification , Antibodies, Viral/immunology
4.
Einstein (Säo Paulo) ; 18: eRW4890, 2020. tab, graf
Article in English | LILACS | ID: biblio-1056050

ABSTRACT

ABSTRACT Objective To demonstrate the impact of pneumococcal conjugate vaccine in Streptococcus pneumoniae carriage status in children younger than 5 years in Latin America and the Caribbean. Methods A systematic literature review was carried out on the direct and indirect effects of pneumococcal vaccine in the carriage status, after implementation in childhood immunization programs. Studies carried out in children younger than 5 years were selected from the PubMed® and Virtual Health Library databases, and data collected after implementation of pneumococcal vaccine in Latin America and the Caribbean, between 2008 and 2018. Results From 1,396 articles identified, 738 were selected based on titles and abstracts. After duplicate removal, 31 studies were eligible for full-text reading, resulting in 6 publications for analysis. All selected publications were observational studies and indicated a decrease in the carriage and vaccine types, and an increase in the circulation of non-vaccine serotypes, such as 6A, 19A, 35B, 21 and 38. We did not identify changes in the antimicrobial resistance after vaccine implementation. Conclusion A decrease in the carriage status of vaccine types and non-vaccine types was detected. The continuous monitoring of pneumococcal vaccine effect is fundamental to demonstrate the impact of the carriage status and, consequently, of invasive pneumococcal disease, allowing better targeting approaches in countries that included pneumococcal vaccine in their immunization programs. Our study protocol was registered in PROSPERO (www.crd.york.ac.uk/prospero) under number CRD42018096719.


RESUMO Objetivo Demonstrar o impacto das vacinas pneumocócicas conjugadas no estado de portador de Streptococcus pneumoniae em crianças menores de 5 anos na América Latina e no Caribe. Métodos Foi realizada revisão sistemática da literatura sobre os efeitos diretos e indiretos da vacina pneumocócica no estado de portador em crianças menores de 5 anos, após a implantação da vacina nos calendários de imunização infantil. A partir de dados da PubMed®e da Biblioteca Virtual da Saúde, foram selecionados estudos de portador em crianças menores de 5 anos, com dados coletados após implementação da vacina de 2008 a 2018, na América Latina e no Caribe. Resultados Dos 1.396 artigos identificados, 738 foram selecionados mediante leitura de títulos e resumos. Após a extração dos duplicados, 31 foram elegíveis para leitura do texto completo, restando 6 artigos para análise. Todos os estudos selecionados eram observacionais e indicavam diminuição do portador e tipos vacinais, e aumento da circulação de sorotipos não vacinais, como 6A, 19A, 35B, 21 e 38. Não foi observada alteração na resistência antimicrobiana após a introdução da vacina. Conclusão Detectou-se redução no estado de portador, dos tipos vacinais e não vacinais. O monitoramento contínuo do efeito das vacinas pneumocócicas é fundamental, para demonstrar o impacto do estado de portador e, consequentemente, da doença pneumocócica invasiva, permitindo o melhor direcionamento nas ações em saúde para os países que incluíram a vacina no calendário de imunização. Nosso protocolo de estudo foi registrado no PROSPERO (www.crd.york.ac.uk/prospero) sob o número CRD42018096719.


Subject(s)
Humans , Enzyme-Linked Immunosorbent Assay/methods , Fluorescent Antibody Technique, Indirect/methods , Dengue/diagnosis , Arboviruses/isolation & purification , Reference Standards , Brazil , Immunoglobulin G/immunology , Immunoglobulin M/immunology , Enzyme-Linked Immunosorbent Assay/standards , Serologic Tests/methods , Serologic Tests/standards , Polymerase Chain Reaction , Sensitivity and Specificity , Fluorescent Antibody Technique, Indirect/standards , Dengue/immunology , Dengue Virus/isolation & purification , Antibodies, Viral/immunology
5.
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
6.
Epidemiol. serv. saúde ; 29(3): e2019354, 2020. tab, graf
Article in English, Portuguese | LILACS | ID: biblio-1101140

ABSTRACT

Objetivo: descrever a circulação viral de dengue em Belo Horizonte, Brasil, de 2009 a 2014. Métodos: trata-se de estudo de série de casos de dengue infectados por diferentes sorotipos do vírus, identificados por isolamento viral ou RT-PCR; foi realizado linkage das bases de dados do Sistema de Informação de Agravos de Notificação (Sinan), do Sistema de Informações Hospitalares do Sistema Único de Saúde (SIH/SUS) e do Gerenciador de Ambiente Laboratorial (GAL). Resultados: foram relacionados 91,1% dos registros (n=775); entre os casos (n=851), 60,4% (n=514) foram confirmados como DENV-1, 22,1% (n=188) como DENV-4, 9,8% (n=83) como DENV-2 e 7,7% (n=66) como DENV-3; DENV-2 apresentou maior percentual de casos graves (4,5%). Conclusão: DENV-1 prevaleceu e circulou em todos os anos avaliados.


Objetivo: describir la circulación viral del dengue en Belo Horizonte, Brasil, de 2009 a 2014. Métodos: se trata de estudio de una serie de casos de dengue infectados por diferentes serotipos del virus, identificados por aislamiento viral o RT-PCR; se realizó una conexión con las bases de datos del Sistema de Información para Enfermedades de Notificación (Sinan), el Sistema del Información Hospitalaria del Sistema Único de Salud (SIH/SUS) y el Gestor de Ambiente de Laboratorio (GAL). Resultados: fueron relacionados 91,1% de los registros (n=775); entre los casos (n=851), el 60,4% (n=514) fue confirmado como DENV-1, 22,1% (n=188) como DENV-4, 9,8% (n=83) como DENV-2 y 7,7% (n=66) como DENV-3; DENV-2 tuvo un mayor porcentaje de casos graves (4,5%). Conclusión: DENV-1 prevaleció y circuló en todos los años evaluados.


Objective: to describe dengue virus circulation in Belo Horizonte, Brazil, from 2009 to 2014. Methods: this is a series study of cases of dengue infected by different virus serotypes, identified by virus isolation or RT-PCR; database linkage was performed between the Notifiable Health Conditions Information System (SINAN), the Brazilian National Health System Hospital Information System (SIH/SUS) and the Laboratory Environment Manager (GAL). Results: 91.1% of the records were linked (n=775); among the cases (n=851), 60.4% (n=514) were confirmed as DENV-1, 22.1% (n=188) DENV-4, 9.8% (n=83) as DENV-2, and 7.7% (n=66) as DENV-3; DENV-2 accounted for a higher percentage of severe cases (4.5%). Conclusion: DENV-1 prevailed and circulated in all evaluated years.


Subject(s)
Humans , Male , Female , Dengue/diagnosis , Dengue/epidemiology , Dengue Virus/isolation & purification , Brazil/epidemiology , Disease Notification/statistics & numerical data , Reverse Transcriptase Polymerase Chain Reaction , Epidemiological Monitoring , Health Information Systems/statistics & numerical data
7.
Braz. j. med. biol. res ; 52(11): e8339, 2019. tab, graf
Article in English | LILACS | ID: biblio-1039262

ABSTRACT

A progressive increase in the circulation of arboviruses in tropical countries has been observed, accounting for 700,000 yearly deaths in the world. The main objective of this article was to identify the presence of Zika (ZIKV), dengue (DENV), and Chikungunya (CHIKV) viruses in immature stages of Aedes aegypti and Ae. albopictus. Household collections of immature phases of the vectors were carried out in the years 2015 and 2016. A total of 2902 dwellings were visited and the rate of infestation with larvae and pupae of Aedes mosquitoes was 283/1462 (19.4%) in March 2015 and 55/1440 (3.8%) in June 2015. In March 2015, 907 larvae/pupae were collected (583 or 64.3% of Ae. aegypti and 324 or 35.7% of Ae. albopictus) while in June 2015 there was a reduction in the number of immature forms found: 197 larvae/pupae (121 or 61.4% of Ae. aegypti and 76 or 38.6% of Ae. albopictus). This reduction was accompanied by a decrease in suspected human ZIKV cases from March to June 2015. The RT-qPCR performed in 18 pools identified that three (two of Ae. aegypti and one of Ae. albopictus) were positive for ZIKV, and none were positive for DENV or CHIKV. Our findings demonstrated that ZIKV was present in immature stages of insect vectors in the study region at least five months prior to the peak of ZIKV associated cases. Xenomonitoring of immature phases of the vectors may prove useful for predicting outbreaks.


Subject(s)
Humans , Animals , Chikungunya virus/isolation & purification , Aedes/virology , Dengue Virus/isolation & purification , Zika Virus/isolation & purification , Mosquito Vectors/virology , Seasons , RNA, Viral/analysis , Aedes/classification , Real-Time Polymerase Chain Reaction , Zika Virus Infection/transmission , Mosquito Vectors/classification
8.
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
9.
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
10.
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
11.
Braz. j. infect. dis ; 22(1): 63-69, Jan.-feb. 2018. tab, graf
Article in English | LILACS | ID: biblio-951619

ABSTRACT

ABSTRACT Dengue fever is a vector-transmitted viral infection. Non-vectorial forms of transmission can occur through organ transplantation. We reviewed medical records of donors and recipients with suspected dengue in the first post-transplant week. We used serologic and molecular analysis to confirm the infection. Herein, we describe four cases of dengue virus transmission through solid organ transplantation. The recipients had positive serology and RT-PCR. Infection in donors was detected through serology. All cases presented with fever within the first week after transplantation. There were no fatal cases. After these cases, we implemented dengue screening with NS1 antigen detection in donors during dengue outbreaks, and no new cases were detected. In the literature review, additional cases had been published through August 2017. Transmission of Dengue virus can occur through organ donation. In endemic regions, it is important to suspect and screen for dengue in febrile and thrombocytopenic recipients in the postoperative period.


Subject(s)
Humans , Male , Adult , Middle Aged , Tissue Donors , Dengue/transmission , Dengue Virus/isolation & purification , Transplant Recipients , Heart Transplantation/adverse effects , Liver Transplantation/adverse effects , Reverse Transcriptase Polymerase Chain Reaction
12.
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
13.
Mem. Inst. Oswaldo Cruz ; 113(4): e170208, 2018. tab, graf
Article in English | LILACS | ID: biblio-1040593

ABSTRACT

The lack of an experimental animal model for the study of dengue pathogenesis is a limiting factor for the development of vaccines and drugs. In previous studies, our group demonstrated the susceptibility of BALB/c mice to infection by dengue virus (DENV) 1 and 2, and the virus was successfully isolated in several organs. In this study, BALB/c mice were experimentally infected intravenously with DENV-4, and samples of their saliva were collected. Viral RNA extracted from the saliva samples was subjected to qRT-PCR, with a detection limit of 0.002 PFU/mL. The presence of DENV-4 viral RNA was detected in the saliva of two mice, presenting viral titers of 109 RNA/mL. The detection of DENV RNA via saliva sampling is not a common practice in dengue diagnosis, due to the lower detection rates in human patients. However, the results observed in this study seem to indicate that, as in humans, detection rates of DENV RNA in mouse saliva are also low, correlating the infection in both cases. This study reports the first DENV detection in the saliva of BALB/c immunocompetent mice experimentally infected with non-neuroadapted DENV-4.


Subject(s)
Humans , Animals , Male , Mice , Saliva/virology , Dengue Virus/isolation & purification , RNA, Viral/isolation & purification , RNA, Viral/genetics , Immunocompromised Host , Viral Load/genetics , Reverse Transcriptase Polymerase Chain Reaction , Dengue Virus/genetics , Disease Models, Animal , Mice, Inbred BALB C
14.
Mem. Inst. Oswaldo Cruz ; 112(12): 829-837, Dec. 2017. tab, graf
Article in English | LILACS | ID: biblio-894854

ABSTRACT

BACKGROUND Dengue viruses (DENV) are considered one of the most important emerging pathogens and dengue disease is a global health threat. The geographic expansion of dengue viruses has led to co-circulation of all four dengue serotypes making it imperative that new DENV control strategies be devised. OBJECTIVES Here we characterize dengue serotype-specific innate immune responses in Aedes aegypti and Aedes albopictus using DENV from Puerto Rico (PR). METHODS Ae. aegypti and Ae. albopictus were infected with dengue serotype 1 and 2 isolated from Puerto Rico. DENV infected mosquito samples were collected and temporal change in expression of selected innate immune response pathway genes analyzed by quantitative real time PCR. FINDINGS The Toll pathway is involved in anti-dengue response in Ae. aegypti, and Ae. albopictus. Infections with PR DENV- 1 elicited a stronger response from genes of the Toll immune pathway than PR DENV-2 in Ae. aegypti but in infected Ae. albopictus expression of Toll pathway genes tended to be similar between the serotypes. Two genes (a ribosomal S5 protein gene and a nimrod-like gene) from Ae. albopictus were expressed in response to DENV. MAIN CONCLUSIONS These studies revealed a role for antiviral genes in DENV serotype-specific interactions with DENV vectors, demonstrated that infections with DENV-2 can modulate the Toll immune response pathway in Ae. aegypti and elucidated candidate molecules that might be used to interfere with serotype specific vector-virus interactions.


Subject(s)
Animals , Aedes/classification , Aedes/virology , Dengue Virus/isolation & purification , Dengue Virus/genetics , Dengue Virus/immunology , Insect Vectors/classification , Insect Vectors/virology , Real-Time Polymerase Chain Reaction
15.
Rev. Assoc. Med. Bras. (1992) ; 63(11): 957-961, Nov. 2017. tab, graf
Article in English | LILACS | ID: biblio-896318

ABSTRACT

Summary Introduction: Global climate changes directly affect the natural environment and contribute to an increase in the transmission of diseases by vectors. Among these diseases, dengue is at the top of the list. The aim of our study was to understand the consequences of temporal variability of air temperature in the occurrence of dengue in an area comprising seven municipalities of the Greater São Paulo. Method: Characterization of a temporal trend of the disease in the region between 2010 and 2013 was performed through analysis of the notified number of dengue cases over this period. Our analysis was complemented with meteorological (temperature) and pollutant concentration data (PM10). Results: We observed that the months of January, February, March, April and May (from 2010 to 2013) were the ones with the highest number of notified cases. We also found that there is a statistical association of moisture and PM10 with the reported cases of dengue. Conclusion: Although the temperature does not statistically display an association with recorded cases of dengue, we were able to verify that temperature peaks coincide with dengue outbreak peaks. Future studies on environmental pollution and its influence on the development of Aedes aegypti mosquito during all stages of its life cycle, and the definition of strategies for better monitoring, including campaigns and surveillance, would be compelling.


Resumo Objetivo: As alterações globais que têm ocorrido interferem no ambiente natural, influenciando diretamente no crescimento da transmissão de doenças ocasionadas por vetores, das quais se destaca a dengue. O objetivo deste estudo foi compreender as consequências da variabilidade temporal das condições climáticas em relação à ocorrência de dengue na população da região metropolitana de São Paulo, constituída por sete municípios. Método: A caracterização da tendência temporal da dengue foi realizada por meio da análise dos números de casos de dengue notificados nos anos de 2010 a 2013, de dados meteorológicos (umidade e temperatura) e dados de concentração de poluentes (PM10). Resultados: Observou-se que os meses de janeiro a abril (de 2010 a 2013) foram os que apresentaram maior número de casos notificados de dengue, com associação estatística entre a umidade e PM10 com os casos de dengue notificados. Conclusão: Embora a temperatura não assuma, estatisticamente, uma associação com os casos de dengue registrados, foi possível verificar que os picos de temperatura coincidem com os picos epidêmicos de dengue. Seriam interessantes futuros estudos referentes à poluição ambiental e a sua influência no desenvolvimento do mosquito Aedes aegypti em todas as suas fases do ciclo de vida e definição de estratégias para melhor monitoração, campanhas e vigilância.


Subject(s)
Humans , Animals , Dengue/epidemiology , Insect Vectors/growth & development , Urban Population , Brazil/epidemiology , Incidence , Cross-Sectional Studies , Cities/epidemiology , Aedes , Dengue/transmission , Dengue Virus/isolation & purification , Air Pollution , Insect Vectors/virology , Meteorological Concepts
16.
Rev. salud pública ; 19(4): 460-467, jul.-ago. 2017. tab
Article in Spanish | LILACS | ID: biblio-903131

ABSTRACT

RESUMEN Objetivo Determinar la actividad en suero de CK y CK-MB en pacientes con dengue. Métodos Se realizó un estudio de corte en el Departamento de Antioquia. La población de estudio estuvo constituida por 54 pacientes con diagnóstico de dengue y por 10 controles sanos. A todos los participantes se les tomó muestra de suero para confirmar la infección por dengue y para hacer la medición de la actividad de CK y CK-MB. Resultados La mediana de la edad de los casos de dengue fue 18 años y la de los controles fue 28,5 años. La mitad de los pacientes con dengue (50,9 %) y ninguno del grupo control presentaron CK-MB elevada. Ningún paciente presentó miocarditis, sin embargo, se observó CK-MB elevada en 33,3 %, 44,4 % y 40 % de los casos con bradicardia, taquicardia e hipotensión respectivamente. En 29,6 % de los pacientes con dengue se detectó CK elevada, en contraste con 10 % en el grupo control. Se observó actividad de CK en pacientes con dengue con presencia de síntomas como vómito, hematemesis y dolor abdominal, 87,5 %, 60 % y 50 % respectivamente. Conclusiones En este estudio ningún paciente con dengue presentó cardiopatía o miositis, sin embargo, el hecho de encontrar mayor frecuencia de CK y CK-MB elevadas en los pacientes con dengue con respecto al grupo control, sugiere compromiso del músculo estriado y cardíaco en este grupo. Por esta razón sería pertinente el monitoreo de estas enzimas en pacientes con dengue como parte de la evolución de la enfermedad.(AU)


ABSTRACT Objective To determine the serum activity of CK and CK-MB in patients with dengue infection. Methods A cross section study was conducted in the State of Antioquia, Colombia. The study population consisted in 54 patients with diagnosis of dengue infection and 10 healthy controls. A blood sample was taken from all participants to confirm dengue infection and to measure the activity of CK and CK-MB. Results The median age of dengue cases was 18 years and the median age of healthy controls was 28.5 years. Half of dengue patients (50.9 %) had elevated levels of CK-MB, in contrast with the healthy controls in which none presented increase of this enzyme. No patient presented myocarditis; however, elevated CK-MB was observed in 33.3 %, 44.4 % and 40 % of cases with bradycardia, tachycardia and hypotension respectively. In 29.6 % of the dengue patients, high level of CK was detected, in contrast to 10 % in the control group. Activity of CK elevated was observed in dengue patients with symptoms such as vomiting, hematemesis and abdominal pain, 87.5 %, 60 % and 50 %, respectively. Conclusions In this study, no patient with dengue infection had heart disease or myositis; however, the finding of a higher frequency of elevated level CK and CK-MB in the dengue patients compared to the control group suggests the involvement of the striated muscle and of the cardiac muscle in this group. For this reason, the monitoring of these enzymes should be considered as part of the monitoring of patients with dengue.(AU)


Subject(s)
Humans , Creatine/blood , Dengue/epidemiology , Dengue Virus/isolation & purification , Epidemiology, Descriptive , Colombia/epidemiology
17.
Mem. Inst. Invest. Cienc. Salud (Impr.) ; 15(1): 7-15, abr. 2017. ilus
Article in Spanish | LILACS, BDNPAR | ID: biblio-1008720

ABSTRACT

Los flavivirus son responsables de una considerable morbi-mortalidad a nivel mundial. Entre ellos, el virus del dengue (DENV) es causante de graves problemas de salud pública en Paraguay. El objetivo del estudio fue detectar infecciones por flavivirus a través de una reacción de RT-nested PCR genérica para flavivirus en 195 muestras de individuos con sospecha de dengue, negativos por el test inmunocromatográfico (antígeno NS1 ­ DENV), provenientes del área metropolitana de Asunción entre 2011 y 2013. Las muestras positivas para flavivirus fueron sometidas a dos reacciones de RT-nested PCRs específicas para DENV. El límite de detección (LD) para flavivirus fue de 0,2 UFP/reacción. En total 43/195 muestras fueron positivas para flavivirus. De estas, 38/43 (88,4%) correspondieron a DENV (6 DENV-1, 30 DENV-2 y 2 DENV-3). Además, 5/43 casos (11,6%) positivos para flavivirus fueron negativos para DENV por ambas reacciones específicas, pudiendo deberse a infecciones por otros flavivirus. Los resultados sugieren que la utilización de una reacción genérica seguida de otras reacciones específicas para DENV en casos febriles negativos para NS1 por el método inmunocromatográfico permitiría detectar más casos de infecciones por DENV y además, podría contribuir a la identificación de casos debido a infecciones por otros flavivirus.


Flaviviruses are responsible for considerable worldwide morbidity and mortality. Among them, the dengue virus (DENV) causes serious public health problems in Paraguay. The objective of the study was to detect flavivirus infections using a generic RT-nested -PCR in 195 samples of individuals with suspected dengue and negative for the inmunochromatographic test (NS1 antigen ­ DENV), from the metropolitan area of Asuncion between 2011 and 2013. The flavivirus-positive samples were subjected to two reactions of DENV-specific RT-nested PCRs. The detection limit (DL) for flavivirus was 0.2 PFU / reaction. In total, 43/195 samples were positive for flavivirus. Of them, 38/43 (88,4%) corresponded to DENV (6 DENV-1, 30 DENV-2 and 2 DENV-3). In addition, 5/43 cases (11.6%) positive for flavivirus were negative for DENV by both specific reactions, and may be infections caused by other flaviviruses. The results suggest that the use of a generic reaction followed by other DENV specific reactions in febrile negative cases for NS1 by the immunochromatographic method would allow the detection of more cases of DENV infections and could contribute to the identification of cases due to infections by others flaviviruses.


Subject(s)
Humans , Male , Female , Infant , Child, Preschool , Child , Adolescent , Adult , Middle Aged , Aged , Aged, 80 and over , Flavivirus Infections/diagnosis , Dengue Virus/isolation & purification , Flavivirus/isolation & purification , Paraguay , Cross-Sectional Studies , Genome, Viral , Reverse Transcriptase Polymerase Chain Reaction , Dengue Virus/genetics , Dengue Virus/immunology , Fever , Flavivirus/genetics , Antigens, Viral/isolation & purification
18.
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
19.
Rev. salud pública ; 18(3): 1-1, mayo-jun. 2016. ilus, tab
Article in Spanish | LILACS | ID: lil-784965

ABSTRACT

Objetivo Comparar secuencias de nucleótidos y de aminoácidos de la proteína no estructural 1-NS1 de cepas DENV-2, aisladas de pacientes febriles de diferentes países suramericanos, que cursaron cuadros clínicos con severidad o sin ella. Materiales y Métodos El análisis filogenético fue realizado a partir de 28 secuencias moleculares completas (1 056 pb) del gen NS1 del serotipo DENV-2. Se realizó un análisis filogenético bayesiano utilizando el software MrBayes v.3.2.0, con el modelo SYM+G y un análisis filogenético con el método Neighbor-Joining con el modelo Jukes-Cantor. Además, las secuencias de aminoácidos fueron alineadas y comparadas entre sí, mediante el programa Clustal W incluido en el software MEGA v. 5.2. Resultados En las secuencias de aminoácidos asociadas a sangrado, la sustitución más frecuente fue isoleucina→ treonina, en la posición 93. Estas secuencias presentaron un mayor porcentaje (94,6 %) de homología de aminoácidos de la proteína NS1 en comparación con el porcentaje de homología (74 %) de los aislamientos DENV-2 no asociados a sangrado. Se identificaron cinco clados que agrupan la mayoría de las secuencias analizadas (19/24; 79,2 %) con valores de probabilidad posterior mayores o iguales al 58 %. Siete (87,5 %) secuencias asociadas a sangrado se relacionan filogenéticamente dentro de los clados 4 y 5, con valores de probabilidad posterior del 58 % y 97 %, respectivamente. Conclusión No se encontraron características filogenéticas ni tampoco diferencias entre las secuencias de aminoácidos de la proteína NS1-DENV-2 estudiadas, que pudieran ser relacionadas, de manera directa, con la severidad de la enfermedad.(AU)


Objective The objective of this in silico study was to compare nucleotide and amino acids DENV-2-NS1 sequences isolated from febrile patients, with and without disease severity, from different South American countries. Matherials and Methods A bayesian MCMC phylogenetic analysis was carried out using 28 complete sequences of the gene NS1 of the DENV-2 serotype (1 056 bp), using MrBayes v.3.2.0 software, with the model SYM+G (2.5 million generations). We also carried out a phylogenetic analysis with Neighbor-Joining method (Jukes-Cantor model). In addition, the amino acids sequences were aligned and compared with each other, using Clustal W included in MEGA v.5.2 software. Results In the amino acids sequences associated with bleeding, the most frequent substitution was isoleucine → threonine at posicion 93. These sequences showed a high percentage (94.6 %) of amino acid homology in comparison with the percentage of amino acids homology (74 %) of DENV-2 isolates not associated with bleeding. Five clades were identified that group the vast majority of the DENV-2-NS1 sequences analyzed (19/24; 79.2 %) with posterior probability values greater than or equal to 58 %. Seven sequences (87.5 %) associated with bleeding were phylogenetically related within clades 4 and 5, the posterior probability values were 58 % and 97 %, respectively. Conclusion Neither phylogenetic characteristics nor differences between amino acids of the DENV-2-NS1 sequences studied were found that could be associated directly with severity of the disease.(AU)


Subject(s)
Humans , Phylogeny , Viral Nonstructural Proteins/analysis , Severe Dengue/diagnosis , Dengue Virus/isolation & purification , South America , Computer Simulation
20.
Mem. Inst. Oswaldo Cruz ; 111(4): 233-240, Apr. 2016. tab, graf
Article in English | LILACS | ID: lil-779001

ABSTRACT

The Aedes aegypti vector for dengue virus (DENV) has been reported in urban and periurban areas. The information about DENV circulation in mosquitoes in Colombian rural areas is limited, so we aimed to evaluate the presence of DENV in Ae. aegypti females caught in rural locations of two Colombian municipalities, Anapoima and La Mesa. Mosquitoes from 497 rural households in 44 different rural settlements were collected. Pools of about 20 Ae. aegypti females were processed for DENV serotype detection. DENV in mosquitoes was detected in 74% of the analysed settlements with a pool positivity rate of 62%. The estimated individual mosquito infection rate was 4.12% and the minimum infection rate was 33.3/1,000 mosquitoes. All four serotypes were detected; the most frequent being DENV-2 (50%) and DENV-1 (35%). Two-three serotypes were detected simultaneously in separate pools. This is the first report on the co-occurrence of natural DENV infection of mosquitoes in Colombian rural areas. The findings are important for understanding dengue transmission and planning control strategies. A potential latent virus reservoir in rural areas could spill over to urban areas during population movements. Detecting DENV in wild-caught adult mosquitoes should be included in the development of dengue epidemic forecasting models.


Subject(s)
Humans , Animals , Male , Female , Aedes/virology , Dengue Virus/classification , Dengue Virus/isolation & purification , Insect Vectors/virology , Colombia , Dengue Virus/genetics , Dengue/transmission , Reverse Transcriptase Polymerase Chain Reaction , RNA, Viral/isolation & purification , Rural Population , Serogroup
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