Upregulation of intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 in renal tissue in severe dengue in humans: Effects on endothelial activation/dysfunction

Abstract INTRODUCTION: Dengue is an important mosquito-borne disease in tropical and subtropical regions. Adhesion molecules have not been systematically characterized in the renal tissue of patients with severe dengue (SD). The objective of this study was to detect viral antigens in samples from patients that evolved with SD, correlating with the expression of ICAM-1, VCAM-1, VE-cadherin, and E-selectin to contribute to a better understanding of the pathophysiology of SD. METHODS: Kidney specimens from patients with SD were selected according to clinical and laboratorial data and submitted to histological and immunohistochemistry analysis. A semiquantitative evaluation was performed considering positive immunostaining in 20 glomeruli. RESULTS: Viral antigens were mainly detected in distal tubules. The intense immunostaining of VCAM-1 and ICAM-1 was observed. The expression of E-selectin was discrete, and VE-cadherin expression varied from mild to moderate. VCAM-1 was slightly intense in the glomerular capsule; the expression of ICAM-1 was diffuse. E-selectin was diffuse, and VE-cadherin varied from mild to moderate. The most frequent histological findings were glomerular congestion, mild glomerulitis, acute renal injury, and glomerular atrophy. CONCLUSIONS: The results appear to demonstrate an imbalance between vascular endothelial permeability regulating events in renal lesions in SD. The increase in the expression of ICAM-1 and VCAM-1 is an in-situ indicator of higher permeability with a consequent influx of cells favoring the inflammation of the endothelium. These molecules are important in the pathophysiology of the disease and provide the possibility of developing new markers for the evaluation, clinical follow-up, and therapeutic response of patients with SD.

Clinical and laboratory signs associated to serious dengue disease in hospitalized children / Sinais clínicos e laboratoriais para o dengue com evolução grave em crianças hospitalizadas

Abstract Objective: To evaluate the validity of clinical and laboratory signs to serious dengue disease in hospitalized children. Methods: Retrospective cohort of children (<18 years) hospitalized with dengue diagnosis (2007-2008). Serious dengue disease was defined as death or use of advanced life support therapy. Accuracy measures and area under the receiver operating characteristic curve were calculated. Results: Of the total (n = 145), 53.1% were female, 69% aged 2-11 years, and 15.9% evolved to the worse outcome. Lethargy had the best accuracy (positive likelihood ratio >19 and negative likelihood ratio <0.6). Pleural effusion and abdominal distension had higher sensitivity (82.6%). History of bleeding (epistaxis, gingival or gastrointestinal bleeding) and severe hemorrhage (pulmonary or gastrointestinal bleeding) in physical examination were more frequent in serious dengue disease (p < 0.01), but with poor accuracy (positive likelihood ratio = 1.89 and 3.89; negative likelihood ratio = 0.53 and 0.60, respectively). Serum albumin was lower in serious dengue forms (p < 0.01). Despite statistical significance (p < 0.05), both groups presented thrombocytopenia. Platelets count, hematocrit, and hemoglobin parameters had area under the curve <0.5. Conclusions: Lethargy, abdominal distension, pleural effusion, and hypoalbuminemia were the best clinical and laboratorial markers of serious dengue disease in hospitalized children, while bleeding, severe hemorrhage, hemoconcentration and thrombocytopenia did not reach adequate diagnostic accuracy. In pediatric referral hospitals, the absence of hemoconcentration does not imply absence of plasma leakage, particularly in children with previous fluid replacement. These findings may contribute to the clinical management of dengue in children at referral hospitals.

Resumo Objetivo Avaliar a validade dos sinais clínicos e laboratoriais para o dengue com evolução grave em crianças hospitalizadas. Métodos Coorte retrospectivo de crianças (<18 anos) internadas com dengue (2007-2008). Evolução grave foi definida como óbito ou pelo uso de terapia de suporte avançado de vida. Foram calculadas medidas de acurácia e área sob a curva ROC. Resultados Do total (n = 145), 53,1% casos eram do sexo feminino, 69% de 2 a 11 anos e 15,9% evoluíram para gravidade. Letargia obteve a melhor acurácia (razão de verossimilhança positiva RVP > 19 e RV negativa RVN < 0,6). Derrame pleural e distensão abdominal apresentaram maior sensibilidade (se = 82,6%). Relato de sangramentos (epistaxe, gengivorragia ou gastrointestinal) e hemorragia grave (pulmonar ou gastrointestinal) presente no exame físico foi mais frequente nos casos com evolução grave (p <0,01), porém com baixa acurácia (RVP = 1,89 e 3,89; RVN = 0,53 e 0,60, respectivamente). Os níveis de albumina sérica foram mais baixos nas formas graves (p <0,01). Ambos os grupos apresentaram trombocitopenia, apesar da diferença estatística (p <0,05). Contagem de plaquetas, hematócrito e hemoglobina apresentaram área sob a curva ROC < 0,5. Conclusões Letargia, distensão abdominal, derrame pleural e hipoalbuminemia foram os melhores marcadores clínicos e laboratoriais de dengue com evolução grave em crianças hospitalizadas, enquanto sangramento, hemorragia grave, hemoconcentração e trombocitopenia não tiveram boa acurácia diagnóstica. Em hospitais de referência pediátricos, a ausência de hemoconcentração não implica ausência de extravasamento plasmático, particularmente quando há reposição anterior de volume. Esses resultados podem contribuir para o manejo clínico do dengue em crianças em hospitais de referência.

Primary dengue haemorrhagic fever in patients from northeast of Brazil is associated with high levels of interferon-β during acute phase

Dengue is an acute febrile disease caused by the mosquito-borne dengue virus (DENV) that according to clinical manifestations can be classified as asymptomatic, mild or severe dengue. Severe dengue cases have been associated with an unbalanced immune response characterised by an over secretion of inflammatory cytokines. In the present study we measured type I interferon (IFN-I) transcript and circulating levels in primary and secondary DENV infected patients. We observed that dengue fever (DF) and dengue haemorrhagic fever (DHF) patients express IFN-I differently. While DF and DHF patients express interferon-α similarly (52,71 ± 7,40 and 49,05 ± 7,70, respectively), IFN- β were associated with primary DHF patients. On the other hand, secondary DHF patients were not able to secrete large amounts of IFN- β which in turn may have influenced the high-level of viraemia. Our results suggest that, in patients from our cohort, infection by DENV serotype 3 elicits an innate response characterised by higher levels of IFN- β in the DHF patients with primary infection, which could contribute to control infection evidenced by the low-level of viraemia in these patients. The present findings may contribute to shed light in the role of innate immune response in dengue pathogenesis.

Primary dengue virus infections induce differential cytokine production in Mexican patients

Severe dengue pathogenesis is not fully understood, but high levels of proinflammatory cytokines have been associated with dengue disease severity. In this study, the cytokine levels in 171 sera from Mexican patients with primary dengue fever (DF) and dengue haemorrhagic fever (DHF) from dengue virus (DENV) 1 (n = 116) or 2 (n = 55) were compared. DF and DHF were defined according to the patient’s clinical condition, the primary infections as indicated by IgG enzymatic immunoassay negative results, and the infecting serotype as assessed by real-time reverse transcription-polymerase chain reaction. Samples were analysed for circulating levels of interleukin (IL)-12p70, interferon (IFN)-γ, tumour necrosis factor (TNF)-α, IL-6, and IL-8 using a commercial cytometric bead array. Significantly higher IFN-γ levels were found in patients with DHF than those with DF. However, significantly higher IL-12p70, TNF-α, and IL-6 levels were associated with DHF only in patients who were infected with DENV2 but not with DENV1. Moreover, patients with DF who were infected with DENV1 showed higher levels of IL-12p70, TNF-α, and IL-6 than patients with DHF early after-fever onset. The IL-8 levels were similar in all cases regardless of the clinical condition or infection serotype. These results suggest that the association between high proinflammatory cytokine levels and dengue disease severity does not always stand, and it once again highlights the complex nature of DHF pathogenesis.

Intervenciones de enfermería para la atención del paciente con dengue grave en el segundo y tercer nivel de atención / Nursing interventions for the care of the patient with dengre grave in the second and third level

Introducción. El dengue es una enfermedad infecciosa sistémica, viral transmitida por el mosquito “Aedes”. La OMS calcula que cada año se producen entre 50 y 100 millones de infecciones por este virus en el mundo. En México en el transcurso de la última década ha habido un incremento de casos, especialmente de tipo hemorrágico.Métodos. Se realizó una búsqueda sistemática de artículos en cuatro etapas, retrospectiva a 10 años relacionada a dengue grave en PubMed, BVS, Tripdatabase y sitios Web; obteniendo 149 resultados, siendo útiles 40 para el desarrollo de esta guía: revisiones sistemáticas, meta análisis, ensayos clínicos aleatorizados, estudios observacionales y Guías de Práctica Clínica.Resultados. Revisiones sistemáticas mencionan que la desnutrición grado 2 o 3 proteico calórica severa protege contra la vasculopatía del dengue y que la fase crítica comienza alrededor del período de desaparición de fiebre, la leucopenia avanza y hay una rápida disminución de plaquetas, esto precede a la manifestación más específica y potencialmente mortal de esta fase: incrementa la permeabilidad capilar conduciendo a la pérdida de plasma y aumento en él hematocrito; un estudio transversal prospectivo encontró que infecciones sucesivas del virus del dengue aumentan el riesgo de dengue grave y un estudio multicéntrico refiere que las fallas orgánicas más desarrolladas fueron respiratorias, cardiovasculares, neurológicas y hepáticas.Conclusiones. La implementación de las recomendaciones están dirigidas principalmente a las intervenciones de enfermería que contribuyen a la prevención, recuperación, disminución de complicaciones y limitación de daños para el paciente con dengue grave.

Introduction. Dengue fever is a systemic, viral infectious disease transmitted by the ""Aedes"" mosquito. WHO estimates that each year occur between 50 and 100 million infections by this virus in the world. In Mexico over the course of the last decade, there has been an increase in cases, especially of hemorrhagic type. Methods. A systematic search of articles was carried out in four stages, back at 10 years related to severe dengue in PubMed, VHL, Tripdatabase and Web sites; 149 results, being useful 40 for the development of this guide: systematic reviews, meta analysis, clinical trials randomized, observational studies and clinical practice guidelines. Results. Systematic reviews mentioned malnutrition grade 2 or severe caloric protein 3 protects against vascular disease of dengue and the critical phase begins around the time of the disappearance of fever, leukopenia advances and there is a rapid decrease in platelets, this precedes the manifestation more specific and potentially deadly this phase: increases capillary permeability, leading to the loss of plasma and increase the hematocrit; a prospective cross-sectional study found that successive infections of the dengue virus increases the risk of serious dengue and a multicenter study concerns that more developed organic failures were respiratory, cardiovascular, neurological and hepatic.Conclusions. The implementation of the recommendations are directed mainly to the nursing interventions that contribute to the prevention, recovery, reduction of complications and limitation of patient with severe dengue.

Introdução. Dengue é uma doença infecciosa sistêmica, viral transmitida pelo mosquito ""Aedes"". O que estima-se que cada ano produzirá entre 50 e 100 milhões de infecções por este vírus no mundo. No México, durante a última década tem sido um aumento de casos, especialmente do tipo hemorrágico. Métodos. Uma busca sistemática dos artigos foi realizada em quatro etapas, em 10 anos relacionados com graves da dengue no PubMed, BVS, Tripdatabase e Web sites; 149 resultados, sendo 40 útil para o desenvolvimento deste guia: revisões sistemáticas, meta análise, ensaios clínicos randomizados, estudos observacionais e diretrizes de prática clínica.Resultados. Revisões sistemáticas mencionado o grau de desnutrição 2 ou proteína calórica grave 3 protege contra doença vascular de dengue e a fase crítica começa na época do desaparecimento da febre, leucopenia avança e há uma rápida diminuição de plaquetas, isto precede a manifestação mais específica e potencialmente mortal nesta fase: aumenta a permeabilidade capilar, levando à perda de plasma e aumento do hematócrito; um estudo transversal prospectivo descobriu que infecções sucessivas do vírus da dengue a aumentam o risco de dengue grave e um estudo multicêntrico refere-se que os defeitos orgânicos mais específica e potencialmente mortal nesta fase: aumenta a permeabilidade capilar, levando à perda de plasma e aumento do hematócrito; um estudo transversal prospectivo descobriu que infecções sucessivas do vírus da dengue a aumentam o risco de dengue grave e um estudo multicêntrico refere-se que os defeitos orgânicos mais desenvolvidos eram respiratórias, cardiovasculares, neurológicas e hepáticas. Conclusões. A implementação das recomendações são direcionados principalmente para eles, as intervenções de enfermagem que contribuem para a prevenção, recuperação, redução de complicações e a limitação de danos para o paciente com dengue grave.

Risk factors associated with death in Brazilian children with severe dengue: a case-control study

Objective: The purpose of this case-control study was to evaluate risk factors associated with death in children with severe dengue. Methods: The clinical condition of hospitalized patients with severe dengue who died (cases, n = 18) was compared with that of hospitalized patients with severe dengue who survived (controls, n = 77). The inclusion criteria for this study were age under 13 years; hospital admission in São Luis, northeastern Brazil; and laboratory-confirmed diagnosis of dengue. Results: Severe bleeding (hemoptysis), a defining criterion for dengue severity, was the factor most strongly associated with death in our study. We also found that epistaxis and persistent vomiting, both included as warning signs in the World Health Organization (WHO) classification of dengue, were strongly associated with death. No significant association was observed between any of the laboratory findings and death. Conclusions: The finding that epistaxis and persistent vomiting were also associated with death in children with severe dengue was unexpected and deserves to be explored in future studies. Because intensive care units are often limited in resource-poor settings, any information that can help to distinguish patients with severe dengue with a higher risk to progress to death may be crucial. .

Alteraciones bioquímicas como marcadores predictores de gravedad en pacientes con fiebre por dengue / Biochemical alterations as prediction markers for the severity of illness in dengue fever patients

Introducción. El dengue es la infección transmitida por mosquitos más importante en el mundo. Existe información de que las alteraciones bioquímicas pueden utilizarse como herramientas predictoras de gravedad del dengue. Objetivo. Evaluar las alteraciones bioquímicas como posibles marcadores predictores de gravedad del dengue. Materiales y métodos. Se llevó a cabo un estudio de casos y controles anidado en una cohorte. Se seleccionaron al azar 125 casos con dengue grave y 120 controles con dengue no grave para evaluar los niveles séricos de lactato-deshidrogenasa (LDH), creatina cinasa (CK), proteína C reactiva (PCR) y albúmina, en sueros obtenidos en las primeras horas de la enfermedad. Para evaluar el valor diagnóstico de cada biomarcador, se establecieron puntos de corte con una sensibilidad del 90 % en la detección de casos graves. Resultados. Se observó una asociación entre los niveles de PCR por debajo de 9,8 mg/l (OR=0,04; IC 95% =0,02-0,08 ; p=0,000), de LDH inferiores a 400 U/L (OR=0,49; IC 95% =0,24-1,02; p=0,053) y de albúmina menor de 4 mg/dl (OR=3,46; IC 95% =1,96-6,12; p=0,000), con la gravedad del dengue. En contraste, los niveles de la CK no mostraron asociación con la gravedad de la enfermedad. Conclusiones. Los hallazgos de nuestro estudio sugieren una asociación de los niveles de PCR, LDH y albúmina con la gravedad del dengue. Estas pruebas bioquímicas podrían ser utilizadas como herramientas predictoras del curso clínico de la infección.

Introduction: Dengue is the most important mosquito-borne infection in the world. There is evidence supporting the use of biochemical alterations as prediction tools for severity of illness in dengue. Objective: To evaluate biochemical alterations as potential prediction markers for severity in dengue. Materials and methods: This was a case-control study nested in a cohort. We randomly selected 125 severe dengue cases and 120 controls with non-severe dengue for measuring LDH, CK, CRP and albumin serum levels using acute phase sera. To evaluate the predictive value for each biomarker, we established cut-off points with 90% sensitivity in detecting severe cases. Results: There was association among the CRP levels < 9.8 mg/L (OR=0.04; 95%CI=0.02-0.08; p=0.000), <400 U/L LDH levels (OR=0.49; 95%CI=0.24-1.02; p=0.053) and <4 mg/dl albumin levels (OR=3.46; 95%CI=1.96-6.12; p=0.000) with the severity of dengue. In contrast, the CK levels showed no association with the severity of the disease. Conclusions: Our findings suggest an association of CRP, LDH and albumin levels with the severity of dengue. These biochemical tests could be used as predictive tools in the clinical course of the infection.

Biomarcadores pronósticos de gravedad del dengue / Biomarkers for the prognosis of severe dengue

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Introduction: There are very few strategies for the early detection of the patients who might develop the severe form of the illness. Objective: To evaluate the utility of serum levels of some immune response mediators as early biomarkers for the severe dengue prognosis during the early phase of the illness. Materials and methods: Using a case-control design nested in a multicenter cohort from the AEDES network (a Colombian multicenter study), we compared TNF a, ST2, TRAIL and IDO levels in samples which were obtained during the early phase of the illness. Results: ST2, TRAIL and TNF a levels were higher in severe dengue patients compared with uncomplicated patients (p<0.0001), as follows: OR=24.8, CI95%= 6.1- 98.0; OR=18.0, CI95%= 4.6-69.1; OR=NC, CI95%= NC, respectively. We did not find statistically significant differences between IDO levels in severe dengue and uncomplicated dengue (p=1.000, OR=1.0, CI95%= 0.2-6.1). Conclusions: In the early phase of the dengue infection (96 hours), ST2, TRAIL and TNF a quantifications could contribute to the prediction of complications of the illness.

Clinical and laboratory findings in patients with dengue associated with hepatopathy / Achados clínicos e laboratoriais em pacientes com dengue associada à hepatopatia

INTRODUCTION: Hepatic disorders caused by dengue infection may progress to severe manifestations, including mortality and morbidity. Cytokines are involved in it, such as the migration inhibitory factor of macrophages (MIF), tumor necrosis factor (TNF), natural killer cells (NK), B lymphocytes, and macrophages. METHODS: This study was carried out from January to April 2007 at a public hospital from the Federal University of Mato Grosso do Sul, Campo Grande, Brazil. Sixty-eight patients were studied concerning hepatic alterations, with 56 reported having classic dengue, 6 with hemorrhagic dengue grade I, and 6 with hemorrhagic dengue grade II. RESULTS: Among the 56 with classic dengue, 83.3 percent had aspartate aminotransferase (AST) alterations, and 69.6 percent had altered alanine aminotransferase (ALT). For those with hemorrhagic dengue grade I, 100 percent had AST alterations, and 83.3 percent had altered ALT. All the patients with hemorrhagic dengue grade II had AST and ALT alterations. AST variations reached 22.0 and 907.0, with an average value of 164.6. For ALT, we found variations between 25.0 and 867.0, with an average value of 166.07. There had been statistical significance between dengue clinical shapes and hepatic function markers. CONCLUSIONS: We conclude that the infection was predominant in adults, females, and in those with low income and education. The liver enzymes were of larger amount in hemorrhagic dengue, but there was weak statistical evidence of the clinical manifestations and transaminases. Major signs and clinical symptoms were fever, headache, myalgia, arthralgia, weakness, severe pain behind the eyes, and rashes.

INTRODUÇÃO: Afecções hepáticas causadas pela infecção da dengue podem evoluir para quadro grave, incluindo mortalidade e morbidade. O mecanismo de lesão do fígado está relacionado com a exacerbação da resposta imune. As citocinas estão envolvidas nele como fator inibidor da migração de macrófagos (MIF), fator de necrose tumoral (TNF), células natural killer (NK), B linfócitos e macrófagos. MÉTODOS: Este estudo foi realizado em um hospital público da Universidade Federal do Mato Grosso do Sul. As alterações hepáticas pelo dengue podem evoluir com quadros graves e potencialmente letais. Foram avaliados exames de 68 pacientes atendidos e confirmados com dengue, onde 56 foram classificados como dengue clássico, seis, como dengue hemorrágico grau I e seis como dengue hemorrágico grau II. RESULTADOS: Do dengue clássico, 83,3 por cento tiveram alterações de aspartato aminotransferase (AST) e 69,6 por cento alterações para alanino aminotransferase (ALT). No dengue hemorrágico grau I, AST elevou-se 100 por cento e para ALT 83,3 por cento. No dengue hemorrágico grau II observou-se 100 por cento de alterações tanto para AST, quanto para ALT. A variação de AST ficou entre 22,0 e 907,0 com média de 164,6. A alanino aminotransferase variou entre 25,0 e 867,0 com média de 166,07. Houve significância entre formas clínicas do dengue e marcadores de função hepática. CONCLUSÕES: Conclui-se que a infecção predominou em adultos do sexo feminino, de baixa renda e escolaridade. As enzimas hepáticas elevam-se mais no dengue hemorrágico, fraca evidência estatística entre as manifestações clínicas e as transaminases. Os mais prevalentes sinais/sintomas clínicos foram febre, cefaléia, mialgia, artralgia, fraqueza, dor retrorbitária e exantema.

Alterações hematológicas em pacientes com dengue / Hematological abnormalities in patients with dengue

Dengue é uma doença negligenciada de alta morbidade e mortalidade em crianças e adultos, ocorrendo principalmente em regiões tropicais e subtropicais. O objetivo desse trabalho foi avaliar as alterações hematológicas de pacientes com quadro clínico de dengue. Foram estudados 543 prontuários de atendimentos referentes à epidemia pelo vírus tipo 3, ocorrida no ano de 2007, em Campo Grande, Mato Grosso do Sul. Houve predomínio de casos de dengue clássico (90,2 por cento), com quadro clínico leve sem complicações. As principais alterações hematológicas observadas foram a leucopenia (68,3 por cento), plaquetopenia (66,5 por cento), linfocitopenia (67,2 por cento) e presença de linfócitos atípicos (67 por cento). A febre hemorrágica do dengue apresentou plaquetopenia mais prolongada e maior número de linfócitos atípicos, as demais alterações hematológicas apresentaram evolução diária semelhante às encontradas no dengue clássico. As alterações hematológicas observadas no dengue apresentaram-se de acordo com a evolução clínica e gravidade da doença.

Dengue is a neglected disease with high morbidity and mortality among children and adults that occurs mainly in tropical and subtropical regions. The objective of this study was to evaluate hematological changes in patients with clinical manifestations of dengue. Medical records relating to 543 cases of dengue virus 3 that occurred during the 2007 epidemic in Campo Grande, Mato Grosso do Sul, were studied. Cases of classic dengue predominated (90.2 percent), with mild clinical manifestations lacking complications. The main hematological findings were leukopenia (68.3 percent), thrombocytopenia (66.5 percent), lymphocytopenia (67.2 percent) and atypical lymphocytes (67 percent). In dengue hemorrhagic fever, thrombocytopenia was more prolonged and the number of atypical lymphocytes was higher, while the other hematological abnormalities presented daily evolution similar to those in classic dengue. The hematological changes observed in dengue present according to the clinical course of the disease and its severity.

Es la prueba del lazo un buen predictor de complicaciones hemorrágicas en pacientes con dengue? / Is the test of the tie a good predictor of hemorragic complication in patients with dengue?

Introducción: El dengue es una enfermedad que puede cursar con complicaciones hemorragicas. La prueba del lazo es un método recomendado como criterio diagnóstico de Fiebre Hemorrágica Dengue. Objetivos: Describir las manifestaciones hemorrágicas más frecuentes, hallar la sensibilidad y especificidad de la prueba del lazo, en relación al recuento de plaquetas y a la presencia de manifestaciones hemorrágicas espontáneas. Metodología: diseño observacional descriptivo, retrospectivo, de corte transverso, con componentes analíticos. Población de estudio: se estudiaron 245 pacientes, 170 mujeres (69%) y 75 varones (31%), con cuadro clínico compatible con dengue, que consultaron entre diciembre 2006 abril 2007 en el Hospital Nacional. Muestreo: no probabilístico, de casos consecutivos. Resultados:Las manifestaciones hemorrágicas espontáneas más frecuentes fueron las petequias 18 casos (7,3 %) , gingivorrágias 14 casos (5,7%) y epistaxis 11 casos (4,5 %) La sensibilidad y especificidad de la prueba del lazo, en relación con el recuento de plaquetas , fue del 27,7% y 84,5%. La prueba del lazo, en relación a la presencia de manifestaciones hemorrágicas, presentó una sensibilidad del 30,7% y especificidad del 85,4%. Conclusiones: La prueba del lazo no fue un buen método predictor de aparición de manifestaciones hemorrágicas por su baja sensibilidad. Sin embargo, cunado está ausente, ungran porcentaje de los pacientes no presentaron manifestaciones hemorrágicas, lo que dió una alta espeficidad...

Serum ferritin levels in children with dengue infection.

The purpose of this study was to evaluate the levels of ferritin, an acute-phase reactant, in predicting the risk of dengue hemorrhagic fever (DHF) in patients with dengue infection. One hundred seventy-seven Thai children (100 males, 77 females) 4-16 years old (median age 11 years) with DF (n = 44) and DHF (n = 133) were enrolled in the study. All patients had serologic confirmation of dengue infection. Each had a venous blood sample drawn daily during hospitalization and at the outpatient clinic 2-4 weeks after discharge from the hospital, to determine serum ferritin levels. The median serum ferritin levels (ng/ml) in children with DHF (Day 2, 974; Day 3, 624; Day 4, 1,136; Day 5, 1,912; Day 6, 2, 105; Day 7, 1,840; Day 8, 1,478 and Day 9, 1,144 of illness) were higher than those with DF (Day 2, 25.4; Day 3, 45.6; Day 4, 655; Day 5, 1,050; Day 6, 1,075; Day 7, 615; Day 8, 764 and Day 9, 600 of illness) with p-values of 0.013, 0.001 and 0.013 on Days 5, 6 and 7 of illness, respectively. A cutoff level of serum ferritin of 1,200 ng/ml was used to calculate sensitivity and specificity for DHF. The results reveal the sensitivities on Days 5, 6 and 7 of illness were 81.5, 84.4 and 89.9%, respectively, and the specificities were 42.4, 39.0 and 36.4%, respectively. High serum ferritin levels > or = 1,200 ng/ml may be a predictor of dengue hemorrhagic fever.

Blood zinc levels and clinical severity of dengue hemorrhagic fever in children.

The aims of the study were to investigate the relationship between blood zinc levels and the severity of DHF. A cross-sectional study was conducted involving 51 children at Budhi Asih Hospital, Jakarta, from March to May, 2005. Blood zinc levels were measured with a colorimeter using 5-BR-PAPS. The diagnosis and grading of DHF was determined according to WHO criteria. On analyzing the data, z test, ANNOVA, chi-square, linear regression and coefficient of correlation, were applied appropriately with p < or = 0.05. Forty-five samples were obtained consisting of 15 boys and 30 girls, age 75 +/- 35 months, body mass index of 15.1 +/- 3.2, pre-admission fever for 4.4 +/- 1.6 days, a hematocrit of 38.4 +/- 5.1%, a thrombocyte count of 77,200 +/- 32,100/dl, and a zinc level of 6.4 +/- 6.3 micromol/l, of with 34 had low and 11 were high zinc level cases (cutoff point: 9.18 micromol/l). The clinical severity in the low and high zinc groups were not significantly different. The blood zinc level in DHF grade 4 was not significantly lower than in the other three grades (p>0.05). The numbers of lymphocytes in the four grades were significantly different (p<0.01), between the low and high zinc groups (p<0.05). The association between lymphocytes and zinc levels showed a linear regression of Yc: 42.04+1.30X, p<0.05 and a coefficient correlation of r: 0.47. Therefore, no association was found between zinc levels and clinical severity of DHF in children.

Serum levels of interleukin-6, tumor necrosis factor-alpha and interferon-gama in infants with and without dengue

This study compared the serum levels of IL-6, TNF-alpha and IFN-gamma, in children under 1 year of age with and without dengue. Sera were collected from a total of 41 children living in the Department of Antioquia, Colombia (27 patients with dengue and 14 controls). The results showed higher cytokine levels in children with dengue than without dengue, with statistically significant differences for IL-6 and IFN-gamma. No statistically significant differences were found between clinical forms, although IL-6 and IFN-gamma levels were higher in dengue fever cases than in dengue hemorrhagic fever cases. On the other hand, TNF-alpha levels were higher in dengue hemorrhagic fever than in dengue fever. The levels of IL-6 and TNF-alpha were higher in secondary infection than in primary infection, although IFN-gamma levels were higher in primary infection. These results suggest that IL-6, TNF-alpha and IFN-gamma are involved in dengue infection independently of the clinical form.

Este estudo comparou os níveis séricos de IL-6, TNF-alfa e IFN-gama, em crianças menores de um ano com e sem dengue. Os soros foram coletados de um total de 41 crianças residentes no Departamento de Antioquia, Colômbia (27 pacientes com dengue e 14 controles). Os resultados mostraram níveis de citoquinas mais elevadas em crianças com dengue do que naquelas sem dengue, com diferenças estatisticamente significativas para IL-6 and IFN-gama. Não houve diferenças estatisticamente significativas entre formas clínicas, embora os níveis de IL-6 e IFN-gama estivessem mais elevados nos casos de febre do dengue que nos casos de febre hemorrágica do dengue. Por outro lado, os níveis de TNF-alfa estavam mais elevados na febre hemorrágica do dengue que na febre do dengue. Os níveis de IL-6 and TNF-alfa estavam mais elevados em infecções secundárias que em infecções primarias, embora os níveis de IFN-gama estivessem mais elevados em infecções primárias. Estes resultados sugerem que IL-6, TNF-alfa e IFN-gama estejam envolvidos na infecção do dengue, independentemente da forma clínica.

Hematological and biochemical indicators for the early diagnosis of dengue viral infection

To determine the haematological and biochemical indicators for the early diagnosis of dengue viral infection. A case series. At Medical Unit-III, Ward 7, Jinnah Postgraduate Medical Centre and referred cases from Faiz-e-Rehman Hospital, Metroville, Karachi from September to November 2007. Patients presenting with a fever of less than 2 weeks duration, generalized morbiliform rash and bleeding manifestations were included. Clinical history was recorded and patients were placed on fluid and haematological support. Diagnosis was established by Polymerase Chain Reaction [PCR] for dengue virus or detection of dengue virus specific IgM and IgG. Results: One hundred and four patients met the inclusion criteria during the study period. Sixty six patients had clinical and haematological features suggestive of grade I Dengue Hemorrhagic Fever [DHF]; 34 patients had grade II DHF and 4 had grade III DHF out of whom 3 progressed to grade IV DHF. All the patients presented with fever followed by generalized morbiliform rash [81.73%], vomiting [79.8%], abdominal pain [65.38%], backache [62.5%], depression [60.6%] and mucosal bleeding manifestations [34.6%]. Clinically, conjunctival infection was present in 93 patients [89.4%], hepatomegaly 59 [56.7%], lymphadenopathy in 17 [16.3%], splenomegaly in 13 [12.5%], pleural effusion in 11 [10.5%] and ascites in 8 [7.6%]. Common laboratory findings were thrombocytopenia in 100% patients, leucopenia in 55 [52.8%], raised hematocrit in 52 [50%], and elevated aminotransferases, gamma GT in 100 [96%] patients. The overall mortality was 2.88%. In this series clinical history and examination supported by the triad of thrombocytopenia, raised hematocrit and elevated liver enzymes was sufficient for the early diagnosis of dengue hemorrhagic fever without waiting for dengue serology

Effect of pretreatment with chromium picolinate on haematological parameters during dengue virus infection in mice.

BACKGROUND & OBJECTIVE: Dengue virus (DV) has caused severe epidemics of dengue fever (DF) and dengue haemorrhagic fever (DHF) and is endemic all over India. We have earlier reported that exposure of mice to hexavalent chromium [Cr(VI)] compounds increased the severity of dengue virus infection. Trivalent chromium picolinate (CrP) is used worldwide as micronutrient and nutritional supplement. The present study was therefore, carried out to investigate the effects of CrP on various haematological parameters during DV infection of mice. METHODS: The Swiss Albino smice were inoculated with dengue virus (1000 LD50, intracerebrally) and fed with chromium picolinate (CrP) in drinking water (100 and 250 mg/l) for 24 wk. Peripheral blood leucocytes and other haematological parameters, and spleens were studied on days 4 and 8 after virus inoculations and the findings were compared with those given only CrP and the normal control age matched mice. RESULTS: CrP in drinking water for 24 wk had no significant effects on peripheral blood cells of mice. On the other hand, there was significant decrease in different haematological parameters following inoculation of normal mice with DV. In CrP fed mice the effects of DV infection were abolished on most of the haematological parameters. INTERPRETATION & CONCLUSION: The findings of present study showed that the adverse effects of DV infection, specially on platelets and leucocytes, were abrogated by pretreatment of mice with CrP. The therapeutic utility of CrP in viral infections including dengue needs to be studied in depth.

Evidência de alterações de permeabilidade vascular na dengue: quando a dosagem de albumina sérica define o quadro? / Plasma leakage detection in severe dengue: when serum albumin quantification plays a role?

Evidência de extravasamento vascular decorrente do aumento da permeabilidade capilar caracteriza e diferencia febre hemorrágica da dengue. Este artigo avalia o valor de albumina sérica na detecção de alterações de permeabilidade vascular em casos de dengue. Quatorze pacientes diagnosticados com febre hemorrágica da dengue em dois hospitais privados em Recife, Brasil, entre janeiro e maio de 2002 foram seguidos com dosagens diárias de hematócrito e albumina sérica. Ultra-son e Raio X de tórax foram realizados. Oito (57 por cento) casos apresentaram hemoconcentração de 20 por cento ou mais. Hipoalbuminemia foi detectado em dez (71 por cento) pacientes. Dosagem de albumina sérica aumentou a detecção de alterações de permeabilidade em seis (43 por cento) casos na qual a hemoconcentração foi inferior a 20 por cento e os sintomas foram compatíveis com um a resposta imune exacerbada. Raio-X foi normal em todos os casos. A utilização, portanto, de dosagem de albumina sérica aumenta a sensibilidade de detecção de casos de febre hemorrágica da dengue.

Evidence of vascular leakage due to increased capillary permeability characterizes and differentiates dengue hemorrhagic fever. This article assesses the value of serum albumin for detecting vascular permeability abnormalities in dengue cases. Fourteen patients diagnosed with dengue hemorrhagic fever at two private hospitals in Recife, Brazil, between January and May 2002 were followed up with daily hematocrit and serum albumin assays. Ultrasound scans and chest X-rays were also performed. Eight (57 percent) of the cases presented hemoconcentration of 20 percent or more. Hypoalbuminemia was detected in ten patients (71 percent). Serum albumin assays increased the detection of permeability abnormalities in six cases (43 percent) in which the hemoconcentration was less than 20 percent and the symptoms were compatible with an exacerbated immune response. The X-rays were normal in all cases. Thus, the use serum albumin quantification increased the sensitivity of dengue hemorrhagic fever detection.

Seroprevalence of dengue virus antibodies in asymptomatic Costa Rican children, 2002-2003: a pilot study / La seroprevalencia de anticuerpos contra el virus del dengue en niños costarricenses asintomáticos, 2002-2003: estudio piloto

OBJECTIVES: Since 1993 dengue has become more frequent in Costa Rica. Adults have been the most affected population, while children have remained virtually unharmed. So far no studies have investigated how many asymptomatic children have been affected by this virus. This pilot study documents the seroprevalence, measured as the presence of IgG antibodies, of dengue virus in asymptomatic children from two different geographical areas. METHODS: This descriptive, prospective epidemiologic study compared the presence of antibodies in children who live in a coastal region of a tropical country where dengue is endemic, and an inland area where dengue is not endemic. An enzyme-linked immunosorbent assay was used to test the serum for dengue virus IgG antibodies. None of the children had a prior history of dengue, fever, immunosuppressive therapy or underlying disease. RESULTS: During the period from July 2002 to July 2003, 103 children were recruited from each area. In the costal region we found a seroprevalence of 36.9 percent. In the inland area seroprevalence was 2.9 percent CONCLUSIONS: We found a substantial number of asymptomatic infections in Costa Rican children. This greatly increases the risk of dengue hemorrhagic fever or dengue shock syndrome in these children, in whom previous dengue infection had gone undetected. Preventive efforts should be targeted at the costal region due to the higher prevalence in this area.

OBJETIVOS: Desde 1993, la frecuencia de dengue en Costa Rica ha venido aumentando. La población de adultos ha sido la más afectada, mientras que en los niños apenas se han presentado casos. Hasta el momento no se han realizado estudios para determinar cuántos niños asintomáticos se han visto afectados por el virus de la enfermedad. Este estudio piloto documenta la seroprevalencia de anticuerpos de tipo IgG contra el virus del dengue en niños asintomáticos procedentes de dos zonas geográficas distintas. MÉTODOS: En este estudio epidemiológico descriptivo y prospectivo se comparó la presencia de anticuerpos en niños que vivían en la zona costera de un país tropical donde el dengue es endémico, y en una zona del interior donde no lo es. Se usó inmunoadsorción enzimática para detectar IgG en el suero. Ninguno de los niños tenía antecedentes de dengue, enfermedad febril, tratamiento inmunosupresor o enfermedad subyacente. RESULTADOS: Durante el período transcurrido desde julio de 2003 hasta julio de 2003, se reunió a 103 niños de cada área. En la zona costera encontramos una seroprevalencia de IgG de 36,9 por ciento; en el interior, de 2,9 por ciento. CONCLUSIONES: Encontramos muchos casos de infección asintomática por el virus del dengue en niños costarricenses. Esto conlleva un riesgo elevado de fiebre hemorrágica del dengue o de síndrome de choque por dengue en estos niños en quienes la infección había pasado inadvertida. Es necesario tomar medidas preventivas en la región del litoral debido a la mayor prevalencia de la enfermedad en ella.

Double infection of heteroserotypes of dengue viruses in field populations of Aedes aegypti and Aedes albopictus (Diptera: Culicidae) and serological features of dengue viruses found in patients in southern Thailand.

In order to understand more about the epidemiology of DHF, a study of the type of dengue viruses and vectors under natural conditions was carried out. Mosquito vectors in the field and the serum of DHF patients in southern Thailand were examined. The two mosquito species are abundant and DHF incidence remains high in this region. Dengue viruses were examined in field-caught mosquitoes by RT-PCR technique. The mosquitoes were caught in 4 provinces: Krabi, Phuket, Phang-Nga and Surat Thani during the late dry season until the early rainy season in 2005. Three dengue serotypes (DEN-2, DEN-3, DEN-4) were detected in Ae. aegypti males and females, and 2 (DEN-2, DEN-3) were detected in Ae. albopictus females. Double infection with 2 serotypes of dengue viruses (DEN-2 and DEN-3) were detected in Ae. aegypti males and females and Ae. albopictus females. DEN-2 and DEN-1 were the most prevalent serotypes found in the serum of the patients in this area, followed by DEN-4 and DEN-3. The prevalence of the predominant dengue serotype varied from province to province. Detection of viruses in adult male mosquitoes reveals the role of transovarial transmission of dengue viruses in field populations of DHF vectors and elucidates circulation of dengue viruses in vectors in the natural environment of endemic areas. The incidence of multiple serotypes of dengue virus in Ae. aegypti and Ae. albopictus in the same area points toward a high risk for an epidemic of DHF. These findings provide greater understanding of the relationship among mosquito vectors, virus transmission and DHF epidemiology in endemic areas.

A reappraisal of the criteria to diagnose plasma leakage in dengue hemorrhagic fever.

A study was undertaken to analyze the usefulness of radiographic and ultrasonographic findings and area specific hematocrit cut off values in Dengue Hemorrhagic Fever (DHF). Of the 65 cases, 35 were DHF and 30 were Dengue Fever as per the WHO case definition. Among the DHF cases, hemoconcentration (>20%) was detected in 20 cases (57.14%), hypoproteinemia in 11 (31.42%) and clinical evidence of pleural effusion and or ascites in 25 (71.42%). Hemoconcentration based on area specific hematocrit cut off values was observed in 32 cases (91.42%). Ultrasonographic evidence of plasma leakage was seen in 32 cases (91.42%). In detecting plasma leakage, area specific hematocrit cut off values and ultrasonography had the highest sensitivity (91.42%), while ultrasonography had the highest negative predictive value of 84.21%. Clinical evidence of plasma leakage was more frequent than hemoconcentration or hypoproteinuria. Ultrasonography is an ideal non-invasive investigation to detect plasma leakage and area specific hematocrit values are useful as evidence of plasma leakage.