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1.
J Trop Pediatr ; 70(4)2024 Jul 13.
Article in English | MEDLINE | ID: mdl-39002166

ABSTRACT

Dengue is a significant health problem due to the high burden of critical infections during outbreaks. In 1997, the World Health Organization (WHO) classified dengue as dengue fever (DF), dengue hemorrhagic fever (DHF), and dengue shock syndrome (DSS). It was revised in 2009 (updated in 2015), and the new guidelines recommended classifying patients as dengue without warning signs (DNS), dengue with warning signs (DWS), and severe dengue (SD). Although the utility of the revised 2009 classification for clinical studies is accepted, for immunological studies it needs to be clarified. We determined the usefulness of the 2009 classification for pediatric studies that analyze the circulating interleukin (IL)-6 and IL-8, two inflammatory cytokines. Plasma levels of IL-6 and IL-8 were evaluated in the acute and convalescent phases by flow cytometry in children with dengue classified using the 1997 and 2009 WHO guidelines. The plasma levels of IL-6 and IL-8 were elevated during the acute and decreased during convalescence, and both cytokines served as a good marker of acute dengue illness compared to convalescence. There were no differences in the plasma level of the evaluated cytokines among children with different clinical severity with any classification, except for the IL-8, which was higher in DWS than DNS. Based on the levels of IL-8, the 2009 classification identified DWS plus SD (hospital-treated children) compared to the DNS group [area under the curve (AUC): 0.7, p = 0.028]. These results support the utility of the revised 2009 (updated in 2015) classification in studies of immune markers in pediatric dengue.


Subject(s)
Dengue , Interleukin-6 , Interleukin-8 , World Health Organization , Humans , Dengue/immunology , Dengue/diagnosis , Child , Male , Female , Interleukin-6/blood , Child, Preschool , Interleukin-8/blood , Severe Dengue/diagnosis , Severe Dengue/immunology , Severe Dengue/blood , Adolescent , Severity of Illness Index , Biomarkers/blood , Dengue Virus/immunology , Practice Guidelines as Topic , Flow Cytometry , Infant , Cytokines/blood
2.
Bull Math Biol ; 83(8): 85, 2021 06 17.
Article in English | MEDLINE | ID: mdl-34142264

ABSTRACT

Sequential infections with different dengue serotypes (DENV-1, 4) significantly increase the risk of a severe disease outcome (fever, shock, and hemorrhagic disorders). Two hypotheses have been proposed to explain the severity of the disease: (1) antibody-dependent enhancement (ADE) and (2) original T cell antigenic sin. In this work, we explored the first hypothesis through mathematical modeling. The proposed model reproduces the dynamic of susceptible and infected target cells and dengue virus in scenarios of infection-neutralizing and infection-enhancing antibody competition induced by two distinct serotypes of the dengue virus during secondary infection. The enhancement and neutralization functions are derived from basic concepts of chemical reactions and used to mimic binding to the virus by two distinct populations of antibodies. The analytic study of the model showed the existence of two equilibriums: a disease-free equilibrium and an endemic one. Using the concept of the basic reproduction number [Formula: see text], we performed the asymptotic stability analysis for the two equilibriums. To measure the severity of the disease, we considered the maximum value of infected cells as well as the time when this maximum is reached. We observed that it corresponds to the time when the maximum enhancing activity for the infection occurs. This critical time was calculated from the model to be a few days after the occurrence of the infection, which corresponds to what is observed in the literature. Finally, using as output [Formula: see text], we were able to rank the contribution of each parameter of the model. In particular, we highlighted that the cross-reactive antibody responses may be responsible for the disease enhancement during secondary heterologous dengue infection.


Subject(s)
Coinfection , Dengue Virus , Dengue , Antibodies, Neutralizing , Antibodies, Viral , Antibody-Dependent Enhancement , Humans , Mathematical Concepts , Severity of Illness Index
3.
Viruses ; 12(11)2020 10 29.
Article in English | MEDLINE | ID: mdl-33138336

ABSTRACT

Dengue manifestations range from a mild form, dengue fever (DF), to more severe forms such as dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). The ability of the host to present one of these clinical forms could be related to polymorphisms located in genes of the Toll-like receptors (TLRs) which activate the pro-inflammatory response. Therefore, the genotyping of single nucleotide genetic polymorphisms (SNPs) in TLR3 (rs3775291 and rs6552950), TLR4 (rs2737190, rs10759932, rs4986790, rs4986791, rs11536865, and rs10983755), TLR7 (rs179008 and rs3853839), and TLR8 (rs3764880, rs5741883, rs4830805, and rs1548731) was carried out in non-genetically related DHF patients, DF patients, and general population (GP) subjects. The SNPs were analyzed by real-time PCR by genotyping assays from Applied Biosystems®. The codominance model showed that dengue patients had a lower probability of presenting the TLR4-rs2737190-G/G genotype (odds ratio (OR) (95% CI) = 0.34 (0.14-0.8), p = 0.038). Dengue patients showed a lower probability of presenting TLR4-rs11536865-G/C genotype (OR (95% CI) = 0.19 (0.05-0.73), p = 0.0092) and had a high probability of presenting the TACG haplotype, but lower probability of presenting the TGCG haplotype in the TLR4 compared to GP individuals (OR (95% CI) = 0.55 (0.35-0.86), p = 0.0084). In conclusion, the TLR4-rs2737190-G/G and TLR4-rs11536865-G/C genotypes and TGCG haplotype were associated with protection from dengue.


Subject(s)
Dengue/genetics , Genetic Predisposition to Disease , Polymorphism, Single Nucleotide , Toll-Like Receptor 3/genetics , Toll-Like Receptor 4/genetics , Toll-Like Receptor 7/genetics , Toll-Like Receptor 8/genetics , Adult , Aged , Alleles , Case-Control Studies , Dengue/blood , Dengue/epidemiology , Epidemics , Female , Genotype , Haplotypes , Humans , Male , Mexico/epidemiology , Middle Aged
4.
Rev. Soc. Bras. Med. Trop ; Rev. Soc. Bras. Med. Trop;51(6): 753-760, Nov.-Dec. 2018. tab, graf
Article in English | LILACS | ID: biblio-977105

ABSTRACT

Abstract INTRODUCTION: Dengue is one of the most important mosquito-borne infections. Severe cases are more frequently observed in adults. However, in 2008, the State of Rio de Janeiro, Brazil, experienced a severe dengue epidemic that primarily affected children and caused many cases of dengue hemorrhagic fever (DHF) and death. METHODS: A cross-sectional analytical study was conducted to examine laboratory diagnosis and clinical epidemiologic factors for confirmed dengue cases in patients aged less than 16 years, from January to June 2008, at a municipal hospital in the City of Rio de Janeiro, Brazil. Variables associated with severe outcomes and P values less than .05 were evaluated by means of a logistic regression model. RESULTS: Of the 419 dengue cases studied, 296 were classified as DHF and 123 as classical dengue. Six patients who had DHF died. In multivariate analysis, some laboratory and clinical variables were independently associated with DHF: age 5 years or older (odds ratio [OR], 4.94; 95% confidence interval [CI], 1.30-18.71), abdominal pain (OR, 8.59; 95% CI, 3.17-23.27), hepatomegaly (OR, 15.87; 95% CI, 5.38-46.85), and positive tourniquet test (OR, 10.84; 95% CI, 3.96-29.71). Hypoalbuminemia occurred more frequently than hemoconcentration in DHF cases, and high aminotransferase levels were associated with severity. CONCLUSIONS: Age greater than 5 years, abdominal pain, painful hepatomegaly, and positive tourniquet test were predictors of DHF. The high frequency of hepatic impairment suggests that acetaminophen should be avoided in severe cases of dengue.


Subject(s)
Humans , Male , Female , Infant, Newborn , Infant , Child, Preschool , Child , Adolescent , Severe Dengue/epidemiology , Brazil/epidemiology , Cross-Sectional Studies , Risk Factors
5.
J Med Virol ; 90(6): 1160-1163, 2018 06.
Article in English | MEDLINE | ID: mdl-29446480

ABSTRACT

Immunological factors, such as cytokines, have been proposed as a cause of changes in the lipid profile of dengue patients. We studied whether serum lipid levels and serum TNF-α levels are associated in a group of dengue patients from an endemic region in the Northwest of Mexico. We found statistically important differences in the serum lipid profile and the TNF-α levels of dengue patients compared with the control group, were observed. However, TNF-α levels did not correlate with the lipid profile of dengue patients.


Subject(s)
Dengue/pathology , Lipids/blood , Tumor Necrosis Factor-alpha/blood , Adult , Aged , Blood Donors , Case-Control Studies , Female , Humans , Male , Mexico , Middle Aged , Serum/chemistry
6.
Epidemiol Infect ; 145(14): 2961-2970, 2017 10.
Article in English | MEDLINE | ID: mdl-28903788

ABSTRACT

Vitamin D could modulate pathways leading to dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS). We examined the associations of serum total 25-hydroxy vitamin D [25(OH)D] and vitamin D binding protein (VDBP) concentrations in patients with uncomplicated dengue fever (DF) with risk of progression to DHF/DSS. In a case-control study nested in a cohort of DF patients who were followed during the acute episode in Bucaramanga, Colombia, we compared 25(OH)D and VDBP at onset of fever between 110 cases who progressed to DHF/DSS and 235 DF controls who did not progress. 25(OH)D concentrations were also compared between the acute sample and a sample collected >1 year post-convalescence in a subgroup. Compared with 25(OH)D ⩾75 nmol/l, adjusted odds ratios (95% CI) for progression were 0·44 (0·22-0·88) and 0·13 (0·02-1·05) for 50 to 75 nmol/l (vitamin D insufficiency) and <50 nmol/l (vitamin D deficiency), respectively (P, trend = 0·003). Mean 25(OH)D concentrations were much lower post-convalescence compared with the acute episode, regardless of case status. Compared with controls, mean VDBP was non-significantly lower in cases. We conclude that low serum 25(OH)D concentrations in DF patients predict decreased odds of progression to DHF/DSS.


Subject(s)
Dengue/epidemiology , Disease Progression , Vitamin D/blood , Adolescent , Adult , Aged , Case-Control Studies , Child , Colombia/epidemiology , Dengue/blood , Dengue/virology , Dengue Virus , Female , Humans , Male , Middle Aged , Prevalence , Seroepidemiologic Studies , Severe Dengue/blood , Severe Dengue/epidemiology , Severe Dengue/virology , Young Adult
7.
Microbiol Immunol ; 61(10): 433-441, 2017 Oct.
Article in English | MEDLINE | ID: mdl-28881485

ABSTRACT

Heterologous secondary infections are at increased risk of developing dengue hemorrhagic fever (DHF) because of antibody-dependent enhancement (ADE). IgG subclasses can fix and activate complement and bind to Fcɣ receptors. These factors may also play an important role in the development of ADE and thus in the pathogenesis of DHF. The aim of this study was to analyze the indices of anti-dengue IgG subclasses in adult patients with febrile and hemorrhagic dengue in the acute phase. In 2013, 129 patients with dengue fever (DF) and 57 with DHF in Veracruz, Mexico were recruited for this study and anti-dengue IgM and IgG determined by capture ELISA. Anti-dengue IgG subclasses were detected by indirect ELISA. Anti-dengue IgG2 and IgG3 subclasses were detected in patients with dengue. IgG1 increased significantly in the sera of patients with both primary and secondary infections and DHF, but was higher in patients with secondary infections. The IgG4 subclass index was significantly higher in the sera of patients with DHF than in that of those with DF, who were in the early and late acute phase of both primary and secondary infection. In conclusion, indices of subclasses IgG1 and IgG4 were higher in patients with DHF.


Subject(s)
Antibodies, Viral/blood , Dengue Virus/immunology , Dengue/immunology , Immunoglobulin G/blood , Severe Dengue/immunology , Adult , Dengue/virology , Dengue Virus/classification , Dengue Virus/isolation & purification , Dengue Virus/pathogenicity , Female , Humans , Immunoglobulin G/classification , Immunoglobulin M/blood , Immunoglobulin M/pharmacology , Lymphocytes/virology , Male , Mexico , Middle Aged , Monocytes/immunology , Monocytes/virology , Neutrophils/immunology , Neutrophils/virology , RNA, Viral/analysis , Serotyping , Severe Dengue/virology , Severity of Illness Index , Young Adult
8.
Viral Immunol ; 30(8): 615-621, 2017 10.
Article in English | MEDLINE | ID: mdl-28650708

ABSTRACT

To evaluate the association of the -308 and -238 tumor necrosis factor alpha (TNF-α) gene polymorphisms with clinical manifestations of dengue and TNF-α serum levels in a northwestern Mexican population. The study populations included dengue fever (DF) and dengue hemorrhagic fever (DHF) patients, and a group of healthy controls (HCs) without history of dengue. Polymerase chain reaction-restriction fragment length polymorphism and Enzyme-Linked Immunosorbent Assay were performed to determine genotypes and serum concentration of TNF-α, respectively. There were no significant differences in alleles, genotypes, and haplotype frequencies between patients and HCs. However, when patients were separated into DF and DHF, there was an increased prevalence of the -308 GA genotype in HCs compared to DHF (odds ratio [OR] = 0.129, 95% confidence interval [CI] = 0.018-0.945, p = 0.025), as well as the GG haplotype (OR = 0.49, 95% CI = 0.273-0.880, p = 0.01757) in DF. The genotypes of both polymorphisms were not associated with hematologic manifestations. Serum TNF-α levels were significantly higher in patients than in HCs (p = 0.004). Our results suggest a minimal effect of the -308 and -238 TNF-α gene polymorphisms in dengue patients and that their increased serum levels of TNF-α are independent of genotypes.


Subject(s)
Dengue/genetics , Genetic Predisposition to Disease , Polymorphism, Single Nucleotide , Severe Dengue/genetics , Tumor Necrosis Factor-alpha/genetics , Adult , Alleles , Case-Control Studies , Dengue/blood , Dengue/immunology , Female , Genotype , Haplotypes , Humans , Male , Mexico , Middle Aged , Severe Dengue/blood , Severe Dengue/immunology , Tumor Necrosis Factor-alpha/blood , Tumor Necrosis Factor-alpha/immunology
9.
J Clin Virol ; 89: 39-45, 2017 04.
Article in English | MEDLINE | ID: mdl-28242509

ABSTRACT

BACKGROUND: DENV infection can induce different clinical manifestations varying from mild forms to dengue fever (DF) or the severe hemorrhagic fever (DHF). Several factors are involved in the progression from DF to DHF. No marker is available to predict this progression. Such biomarker could allow a suitable medical care at the beginning of the infection, improving patient prognosis. OBJECTIVES: The aim of this study was to compare the serum expression levels of acute phase proteins in a well-established cohort of dengue fever (DF) and dengue hemorrhagic fever (DHF) patients, in order to individuate a prognostic marker of diseases severity. STUDY DESIGN: The serum levels of 36 cytokines, chemokines and acute phase proteins were determined in DF and DHF patients and compared to healthy volunteers using a multiplex protein array and near-infrared (NIR) fluorescence detection. Serum levels of IL-1ra, IL-23, MIF, sCD40 ligand, IP-10 and GRO-α were also determined by ELISA. RESULTS: At the early stages of infection, GRO-α and IP-10 expression levels were different in DF compared to DHF patients. Besides, GRO-α was positively correlated with platelet counts and IP-10 was negatively correlated with total protein levels. CONCLUSIONS: These findings suggest that high levels of GRO-α during acute DENV infection may be associated with a good prognosis, while high levels of IP-10 may be a warning sign of infection severity.


Subject(s)
Biomarkers/blood , Cytokines/blood , Dengue/pathology , Protein Array Analysis , Adolescent , Adult , Female , Humans , Male , Prognosis , Serum/chemistry , Volunteers , Young Adult
10.
Rev. Soc. Bras. Med. Trop ; Rev. Soc. Bras. Med. Trop;49(5): 656-659, Sept.-Oct. 2016. tab, graf
Article in English | LILACS | ID: lil-798125

ABSTRACT

Abstract Dengue infection can have spectrum of manifestations, often with an unpredictable clinical progression and outcome. There have been increasing reports of atypical manifestations. Abdominal pain or tenderness and persistent vomiting (warning signs) are present in the majority of cases with severe dengue prior to clinical deterioration. We report a 10-year-old child who presented with fever, persistent vomiting, and abdominal pain. A diagnosis of acute pancreatitis was made. This is a very infrequently reported complication of dengue hemorrhagic fever.


Subject(s)
Humans , Female , Child , Pancreatitis/etiology , Severe Dengue/complications , Pancreatitis/diagnosis , Acute Disease , Severe Dengue/diagnosis
11.
Rev. Soc. Bras. Med. Trop ; Rev. Soc. Bras. Med. Trop;48(6): 783-785, Nov.-Dec. 2015.
Article in English | LILACS | ID: lil-767819

ABSTRACT

Abstract: Dengue is an arbovirosis that ranges from an asymptomatic presentation to a more severe disease, which is characterized by a vascular leakage syndrome where abdominal pain is a major symptom. Transplant recipients are immunosuppressed and are less likely to develop a severe form of the disease because of a reduction in immune-mediated responses that trigger plasma extravasation events. Herein, we report two cases of severe dengue in the early postoperative period of two kidney transplant recipients. Considering the severity of the cases, we emphasize the importance of dengue screening immediately before transplantation in areas endemic for the disease.


Subject(s)
Adolescent , Humans , Male , Young Adult , Kidney Transplantation/adverse effects , Postoperative Complications/virology , Severe Dengue/complications , Fatal Outcome , Immunocompromised Host , Kidney Failure, Chronic/surgery , Severe Dengue/immunology
12.
J Clin Virol ; 69: 63-7, 2015 Aug.
Article in English | MEDLINE | ID: mdl-26209381

ABSTRACT

BACKGROUND: The four dengue virus serotypes (DENV1-4) are responsible for the most prevalent mosquito-borne viral illness in humans. DENV causes a spectrum of disease from self-limiting dengue fever (DF) to severe, life-threatening dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS). Antibodies from one infection can contribute to either protection or increased disease severity in a subsequent infection with a distinct DENV serotype. The effectiveness of the antibody response is modulated by both the affinity and avidity of the antibody/antigen interaction. OBJECTIVES: We investigated how antibody avidity developed over time following secondary DENV2 infection across different disease severities. STUDY DESIGN: We analyzed sera from 42 secondary DENV2-infected subjects (DF, n=15; DHF, n=16; DSS, n=11) from a pediatric hospital-based dengue study in Nicaragua. IgG avidity against DENV2 virions was measured in samples collected during acute and convalescent phases as well as 3, 6, and 18 months post-illness using a urea enzyme-linked immunosorbent assay. RESULTS: The data show a significant increase in avidity from acute to convalescent phase followed by a decrease from convalescent phase to 3 months post-symptom onset, then a plateau. Linear regression analysis comparing antibody avidity between disease severity groups over time indicate that individuals with more severe disease (DHF/DSS) experienced greater decay in antibody avidity over time compared to less severe disease (DF), and ROC curve analysis showed that at 18 months post-illness, lower avidity was associated with previously having experienced more severe disease. CONCLUSIONS: These data suggest that increased dengue disease severity is associated with lower antibody avidity at later time-points post-illness.


Subject(s)
Antibodies, Viral/blood , Antibody Affinity , Coinfection/immunology , Dengue Virus/immunology , Dengue/immunology , Immunoglobulin G/blood , Severe Dengue/immunology , Adolescent , Child , Child, Preschool , Dengue/virology , Dengue Virus/classification , Enzyme-Linked Immunosorbent Assay , Female , Humans , Infant , Male , Nicaragua , Serogroup , Severe Dengue/virology
13.
Rev Bras Hematol Hemoter ; 36(2): 115-20, 2014 Mar.
Article in English | MEDLINE | ID: mdl-24790536

ABSTRACT

BACKGROUND: Dengue is an infectious disease with a recurring incidence, especially in developing countries. Despite recent economic growth, success in disease control has not been achieved, and dengue has evolved from cyclic epidemic outbreaks to a lack of seasonality. The lack of scientific basis for the proper management of cases with hemorrhagic manifestations, especially regarding transfusion procedures, might contribute to the high death rate in potentially avoidable cases. OBJECTIVE: The aim of the study was to identify the clinical and laboratory manifestations in hemorrhagic dengue fever treated at the emergency services in Rio Branco, AC, Brazil, as well as to describe transfusion characteristics of patients and identify possible prognostic factors. METHODS: A retrospective descriptive study was performed to analyze the distribution of relative frequencies of clinical and laboratory variables. The study was carried out in Rio Branco with confirmed dengue fever cases. Secondary data were obtained by Acre Epidemiological Surveillance teams of cases with bleeding or platelet counts under 100.0 × 10(9)/L. The patients' clinical, laboratory and transfusion data were obtained from hospital records. RESULTS: A total of 90,553 dengue cases were reported of which 7,447 had serologic confirmation; 267 cases had hemorrhagic manifestations and 193 patients were located. Nearly half of the patients had anemia and the mean of the lowest platelet count of these patients was 26.4 × 10(9)/L. Platelet concentrate was transfused in 22.3% of cases with a mean of 7.5 IU/patient, fresh frozen plasma in 21.2% with a mean of 5.2 IU/patient and just 2.6% of patients received concentrated red blood cells with a mean of 3.2 IU/patient. Bleeding led to transfusions. Signs of plasma leakage and cardiopulmonary dysfunction were correlated to unfavorable outcomes. CONCLUSION: The pattern of clinical and laboratory criteria observed in this investigation does not differ from the literature. Transfusions were used as part of the treatment of dengue hemorrhagic fever manifestations. Some of the clinical manifestations may be related to unfavorable outcomes.

14.
Rev. bras. hematol. hemoter ; Rev. bras. hematol. hemoter;36(2): 115-120, Mar-Apr/2014. tab, graf
Article in English | LILACS | ID: lil-710196

ABSTRACT

Background: Dengue is an infectious disease with a recurring incidence, especially in developing countries. Despite recent economic growth, success in disease control has not been achieved, and dengue has evolved from cyclic epidemic outbreaks to a lack of seasonality. The lack of scientific basis for the proper management of cases with hemorrhagic manifestations, especially regarding transfusion procedures, might contribute to the high death rate in potentially avoidable cases. Objective: The aim of the study was to identify the clinical and laboratory manifestations in hemorrhagic dengue fever treated at the emergency services in Rio Branco, AC, Brazil, as well as to describe transfusion characteristics of patients and identify possible prognostic factors. Methods: A retrospective descriptive study was performed to analyze the distribution of relative frequencies of clinical and laboratory variables. The study was carried out in Rio Branco with confirmed dengue fever cases. Secondary data were obtained by Acre Epidemiological Surveillance teams of cases with bleeding or platelet counts under 100.0 × 109/L. The patients' clinical, laboratory and transfusion data were obtained from hospital records. Results: A total of 90,553 dengue cases were reported of which 7,447 had serologic confirmation; 267 cases had hemorrhagic manifestations and 193 patients were located. Nearly half of the patients had anemia and the mean of the lowest platelet count of these patients was 26.4 × 109/L. Platelet concentrate was transfused in 22.3% of cases with a mean of 7.5 IU/patient, fresh frozen plasma in 21.2% with a mean of 5.2 IU/patient and just 2.6% of patients received concentrated red blood cells with a mean of 3.2 IU/patient. Bleeding led to transfusions. Signs of plasma leakage and cardiopulmonary dysfunction were correlated to unfavorable outcomes...


Subject(s)
Humans , Blood Transfusion , Hemorrhagic Disorders , Platelet Transfusion , Severe Dengue
15.
J. bras. med ; 102(2)março-abril 2014. graf, tab
Article in Portuguese | LILACS | ID: lil-712222

ABSTRACT

A dengue é uma doença infecciosa de evolução aguda, transmitida por vírus (RNA vírus). Infecta o homem através da picada do inseto fêmea Aedes aegypti. Seus sinais e sintomas são variáveis, com formas oligossintomáticas, formas clássicas (febris) e formas graves hemorrágicas, podendo até apresentar síndrome cardiovascular hipovolêmica. O diagnóstico envolve critérios clínico-laboratoriais. O diagnóstico sorológico tem fundamental importância na classificação de infecção primária ou secundária, já que a dengue hemorrágica surge com maior frequência nas infecções secundárias. O isolamento do vírus é geralmente realizado para fins de pesquisa ou epidemiológicos. As epidemias ocorrem principalmente no verão, durante ou após períodos chuvosos.


The dengue is an infectious disease of acute evolution transmitted by virus (RNA virus), infecting humans through the bite of the Aedes aegypti female insect. Presenting signs and symptoms variables with oligosymptomatic forms, classical forms (fever) and severe hemorrhagic form (DHF), this can lead to cardiovascular hypovolemic syndrome. The diagnoses of dengue disease involves clinical and laboratory criteria. Serological diagnosis has fundamental importance in the classification of primary or secondary infection, since DHF appears most often in secondary infections.Virus isolation is usually carried out for research or epidemiological studies. Epidemics occur mainly in the summer, during or after rainy periods.


Subject(s)
Humans , Male , Female , Severe Dengue/diagnosis , Dengue/diagnosis , Clinical Diagnosis , Platelet Count/methods , Fever/diagnosis , Oligosymptomatic Diseases , Clinical Laboratory Techniques , Serologic Tests/methods , Dengue Virus/immunology , Dengue Virus/isolation & purification
16.
J Med Virol ; 86(7): 1193-7, 2014 Jul.
Article in English | MEDLINE | ID: mdl-24114877

ABSTRACT

Dengue infection is an important tropical disease worldwide. The host immune response has been studied in order to better understand lesion mechanisms. It was performed an immunohistochemical study in 14 specimens of liver from patients with dengue hemorrhagic fever (DHF) to characterize cytokines and some factors present in liver lesions and their possible role in the pathogenesis of hepatic injury. Portal tract and hepatic acinus presented high expression of TLR2, TLR3, IL6, and granzyme B. Hepatic acinus also presented iNOS, IL18, and TGF-beta. Cells expressing IL12, IL13, JAk1, STAT1, and NF-κB were rarely visualized. Treg cells foxp3+ were absent. TLR2 and TLR3 seem to participate in cellular activation and cytokine production. Cytotoxic response seems to play a role. Although TGF-beta promotes the activation of Foxp3+ regulatory T cells, IL6 can significantly suppresses their generation. The expression of Treg cells is diminished probably as a result of the high frequency of these cytokines. Both cytokines play a role in the increased vascular permeability and edema observed in dengue liver specimens, with consequent plasma leakage and severity of the disease. It was observed a regular expression of IL-18 in hepatocytes and lymphocytes of the inflammatory infiltrate in portal tract, which reflects the acute inflammatory response that occurs in the liver and contributes to hepatic injury. At least in part, the increased number of cells expressing IL-18 could play a role of "up" regulation of FasL and correlate to the phenomenon of apoptosis, a mechanism of destruction of hepatocytes in DHF.


Subject(s)
Liver/pathology , Severe Dengue/immunology , Severe Dengue/pathology , Apoptosis , Cytokines/analysis , Hepatocytes/immunology , Humans , Immunohistochemistry , Immunologic Factors/analysis , Lymphocyte Activation , Lymphocyte Subsets/immunology , Microscopy
17.
Infectio ; 17(4): 172-176, oct.-dic. 2013. ilus
Article in Spanish | LILACS, COLNAL | ID: lil-705229

ABSTRACT

Antecedentes: El virus del dengue afecta distintos órganos, pero se ha determinado que el hígado es el principal blanco de acción y en donde ocurre la mayor severidad del daño. Existen pocos estudios sobre los cambios histológicos durante la infección por dengue. Objetivos: Analizar las alteraciones histopatológicas post-mortem en hígados de pacientes que presentaron la forma grave del dengue. Métodos: Se revisaron los cortes de hígado de 20 pacientes con dengue severo y se realizaron coloraciones y pruebas para glucógeno. Resultados: Encontramos pérdida de glucógeno citoplasmático en todos los casos analizados y la presencia de glucógeno intranuclear en dos de ellos. Conclusiones: En este estudio se reporta por primera vez la presencia de masas de glucógeno intranuclear en hepatocitos de dos niños fallecidos con dengue grave.


Background: Dengue virus affects various organs, but the liver is the main target of damage and where the most severe damage can occur. There are few studies on the histological changes in the liver during dengue infection. Aims: To analyze the histopathological post-mortem alterations in livers from patients with Methods: We revised serial liver sections, which were stained and tested for glycogen, from 20 patients with severe dengue. Results: We found loss of cytoplasmic glycogen in all cases analyzed and the presence of intranuclear glycogen in two of them. Conclusions: This is the first report of the presence of intranuclear glycogen masses during severe dengue.


Subject(s)
Humans , Severe Dengue , Liver Glycogen , Mortality , Hepatocytes , Dengue , Dengue/pathology , Amylases
18.
Clinics ; Clinics;68(10): 1299-1304, out. 2013. tab, graf
Article in English | LILACS | ID: lil-689981

ABSTRACT

OBJECTIVE: Dengue is a worldwide public health problem with approximately 50 million cases reported annually. The World Health Organization proposed a revised classification system in 2008 to more effectively identify the patients who are at increased risk of complications from dengue. Few studies have validated this new classification system in clinical practice. We conducted a cross-sectional study of patients hospitalized for dengue in Dourados, Mato Grosso do Sul, Brazil, to evaluate the capacity of the two classification systems for detecting severe cases of dengue. MATERIALS AND METHODS: We conducted a cross-sectional study of survey data from the medical records of patients admitted to the University Hospital of the Federal University of Grande Dourados under clinical suspicion of dengue during an epidemic from September 2009 to April 2010. RESULTS: The distribution of patients according to the traditional classification system was as follows: dengue fever, 150/181 (82.9%); dengue hemorrhagic fever, 27/181 (14.9%); and dengue hemorrhagic shock, 4/181 (2.2%). Using the revised classification system, the distribution was as follows: dengue without warning signs, 45/181 (24.3%); dengue with warning signs, 107/181 (59.1%); and severe dengue, 29/181 (15.6%). Of the 150 patients classified as having dengue fever, 105 (70%) were reclassified as having dengue with warning signs or severe dengue. CONCLUSION: These data demonstrate that the revised classification system has greater discriminatory power for detecting patients at risk of progression to severe disease and those needing hospitalization. .


Subject(s)
Adolescent , Adult , Aged , Aged, 80 and over , Child , Child, Preschool , Female , Humans , Infant , Male , Middle Aged , Young Adult , Dengue/classification , Dengue/epidemiology , Age Distribution , Brazil/epidemiology , Cross-Sectional Studies , Hospitalization , Hospitals, University , Intensive Care Units , Medical Records/statistics & numerical data , Severity of Illness Index , Sex Distribution , World Health Organization
19.
Biomédica (Bogotá) ; Biomédica (Bogotá);33(supl.1): 14-21, set. 2013. ilus, graf, tab
Article in Spanish | LILACS | ID: lil-695792

ABSTRACT

El dengue es en la actualidad la enfermedad viral más relevante de transmisión vectorial hiperendémica en las Américas. El incremento en el número de casos se ha relacionado con la aparición de dengue durante la gestación y en el periodo neonatal. De acuerdo con la edad de gestación en la que ocurra la infección, podrían presentarse manifestaciones en el feto, como aborto, y en los pacientes a término, dengue neonatal. En este artículo se presenta una reseña de los casos reportados a nivel mundial, y especialmente en las Américas, así como aspectos fisiopatogénicos de la enfermedad.


Dengue is currently the most important viral disease transmitted by arthropods and which is hyperendemic in the Americas. An increase in the number of cases is related to dengue during pregnancy and the neonatal period. According to the gestational age in which infection occurs, there could be different manifestations in the fetus including abortion, malformations or neonatal dengue in newborns. This article presents a review regarding some cases reported worldwide, especially in the Americas, and some pathophysiologic issues related to perinatal dengue.


Subject(s)
Infant, Newborn , Dengue , HELLP Syndrome , Severe Dengue
20.
Rev. Soc. Bras. Med. Trop ; Rev. Soc. Bras. Med. Trop;46(5): 629-632, Sept-Oct/2013. tab, graf
Article in English | LILACS | ID: lil-691422

ABSTRACT

Introduction The prognosis of dengue depends on early diagnosis and treatment, which can help prevent severe forms whose characteristics were evaluated here. Methods A cross-sectional study was conducted involving dengue cases in Vitória, State of Espírito Santo, Brazil, in 2011. Results Two health regions registered 56.3% of 371 cases of severe dengue. Of these cases, 21.3% presented with dengue hemorrhagic fever. There were associations between dengue hemorrhagic fever with younger ages and a longer time before receiving care. Conclusions There was a greater involvement of dengue hemorrhagic fever in young people. Delay in care, poor urban quality and high endemicity were identified as possible risk factors for dengue severity. .


Subject(s)
Adolescent , Adult , Female , Humans , Male , Epidemics , Severe Dengue/epidemiology , Brazil/epidemiology , Cross-Sectional Studies , Incidence , Risk Factors , Socioeconomic Factors
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