Manifestações clínicas na dengue: diagnóstico laboratorial / Clinical manifestations in dengue: laboratory diagnosis

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.

Early molecular markers predictive of dengue hemorrhagic fever

The management of acute dengue patients during outbreaks is a challenging problem. Most of the dengue fever cases are benign, but some cases develop into a severe and possibly lethal vasculopathy, known as dengue hemorrhagic fever. Early symptoms of dengue and hemorrhagic fever are very similar. An early differential diagnosis is needed to predict which of these two clinical presentations is crucial to proper patient care and public health management. This study evaluates the predictive potential of specific mRNA expression markers of dengue hemorrhagic fever using quantitative real-time PCR assays. Six candidate "dengue hemorrhagic fever specific signature genes" were evaluated and all showed good correlation among their transcription levels at early days of infection and the later development of severe vasculopathy. The markers selected were able to indicate, at early stages of infection, the evolution of a dengue-infected patient to the severe form of the illness. Despite the fact that these results grant further validation studies, the panel of candidate prognostic markers obtained demonstrated the potential to be useful for clinical use in the form of a fast assay based in blood samples.

O manejo de pacientes infectados pelo dengue ainda é um problema desafiador. A maioria dos casos de dengue é benigna mas parte desses casos pode evoluir para o desenvolvimento de vasculopatia severa conhecida como dengue hemorrágica, que pode ser letal. Os sintomas iniciais da dengue e sua forma hemorrágica são bastante similares. O desenvolvimento de um teste diagnóstico que seja rápido e capaz de diferenciar as duas formas clínicas da dengue é crucial para o cuidado adequado de pacientes. O presente estudo avalia, através da PCR quantitativa em tempo real, o potencial preditivo dos níveis de expressão de RNAm candidatos a marcadores da dengue hemorrágica, previamente identificados por estudos genômicos funcionais. Um conjunto de seis marcadores moleculares para a dengue hemorrágica foi avaliado e apresentou correlação entre seus níveis de transcrição e o posterior desenvolvimento da vasculopatia severa. Os marcadores selecionados foram capazes de indicar, nos momentos iniciais dos sintomas, a evolução de um paciente infectado pelo dengue para a forma severa da doença. O painel de candidatos a marcadores de prognóstico obtido demonstrou um bom potencial para uso clínico na forma de um ensaios rápido baseado em amostras de sangue.

Miocarditis en niños con fiebre por dengue hemorrágico en un hospital universitario de Colombia / Myocarditis in children affected by dengue hemorrhagic fever in a teaching hospital in Colombia

Objetivo Determinar la frecuencia de miocarditis en niños con fiebre por Dengue hemorrágico-FDH, en el Huila, Colombia. Materiales y Métodos Se realizó un estudio descriptivo de observación prospectiva, entre Marzo del 2005 y Octubre de 2006. Se observaron 102 pacientes con diagnóstico de FDH, basado en los criterios de la OMS, para identificar la frecuencia de miocarditis. Resultados Un 10,7 por ciento de los niños presentaron miocarditis. Solo un caso con miocarditis fue clasificado como dengue II; los otros diez casos fueron dengue III y IV. La diferencia en la presentación de miocarditis en los estadíos más severos de dengue fue estadísticamente significativa, con un p=0.0004. Diez de los pacientes tuvieron miocarditis que respondió al soporte inotrópico temprano. En el electrocardiograma (EKG), dos pacientes presentaron taquiarritmias, uno tipo supraventricular y otro ventricular, el resto mostró bradicardia sinusal con trastornos de repolarización y bajos voltajes. El ecocardiograma se realizó en 50 por ciento de los niños, encontrándose derrame pericárdico grado I-II en dos pacientes y uno con la fracción de eyección muy disminuida. La estancia promedio fue de 7 días. Un paciente presentó desenlace fatal. Conclusión La presentación de miocarditis alerta sobre la presencia de disfunción miocárdica como una patología a considerarse en pacientes con FDH.

Objective To determining myocarditis frequency in children suffering from DHF in the Huila region of Colombia. Methods This was a descriptive and prospective study which was carried out between March 2005 and October 2005 involving 102 patients suffering from DHF, based on WHO criteria. These children were followed-up to identify signs of myocarditis. Results 10.7 percent of the children had signs of myocarditis; one of them was classified as having dengue II and the other ten were classified as suffering form dengue III and IV. This difference was statistically significant (p=0.0004). 10 patients had fulminant myocarditis and required early inotropic support. Two patients had tachyarrythmias in the EKG (one SV and one ventricular); the others had sinusal bradichardia and low voltages. Echocardiograms were perfomed on 50 percent of the children, revealing pericardial leakage grade I and II in two patients, one with very diminished EF and AF. Average hospital stay was 7 days. 10 had satisfactory outcome whereas one died. Conclusion This series of cases in children reinforces the association between myocarditis and dengue viral infection.

Caracterización clínica y epidemiológica de los casos de dengue: experiencia del Hospital General de Culiacán, Sinaloa, México / Clinical and epidemiologic characteristics of dengue cases: the experience of a general hospital in Culiacan, Sinaloa, Mexico

OBJETIVO: Documentar las características clínicas y epidemiológicas de los pacientes con dengue atendidos en un hospital de Culiacán, Sinaloa, México. MÉTODOS: Estudio transversal, observacional y analítico realizado en el Hospital General Dr. Bernardo J. Gastélum de Culiacán entre el 1 de octubre y el 2 de diciembre de 2003. Se evaluó la asociación entre las variables independientes (las características clínicas y epidemiológicas de los pacientes) y la variable dependiente (diagnóstico confirmado de dengue hemorrágico) mediante el análisis de regresión simple. Las variables que mostraron una relación significativa (P < 0,05) se incluyeron en el análisis de regresión logística multifactorial. RESULTADOS: En los 241 casos que cumplieron los criterios de inclusión para este estudio (207 de dengue y 34 de dengue hemorrágico), la edad promedio fue de 34,7 ± 15,1 años. Según los resultados del análisis multifactorial ajustado por la edad, el sexo y la presencia de casos de dengue en la localidad, las variables con valor predictivo de una mayor gravedad de la enfermedad fueron: la presencia de ascitis (OR = 22,12; IC95 por ciento: 5,00 a 97,87), la gingivorragia (OR = 7,35; IC95 por ciento: 2,11 a 25,61), la hematemesis (OR = 7,40; IC95 por ciento: 1,04 a 52,42), la trombocitopenia (plaquetas entre 40 001/mm³ y 60 000/mm³) (OR = 5,43; IC95 por ciento: 1,58 a 18,72), la hiperemia conjuntival (OR = 4,27; IC95 por ciento: 1,37 a 13,28), los vómitos persistentes (OR = 3,04; IC95 por ciento: 1,05 a 8,80) y la ausencia de congestión nasal (OR = 0,015; IC95 por ciento: 0,0004 a 0,473). CONCLUSIONES: Se confirmó el valor de la presencia de ascitis, gingivorragia, hematemesis, trombocitopenia (con valores de plaquetas entre 40 001/mm³ y 60 000/mm³) y vómitos persistentes como signos de alarma que anuncian la inminencia del choque por dengue. Se observaron conteos plaquetarios > 100 000/mm3 en casos con cuadros clínicos graves (fuga capilar) que no se...

OBJECTIVES: To document the clinical and epidemiological characteristics present in dengue patients served by a hospital in Culiacan, Sinaloa, Mexico. METHODS: A cross-sectional, observational, and analytical study was carried out at the Hospital General Dr. Bernardo J. Gastélum de Culiacan from 1 October to 2 December 2003. Associations between the independent variables (the patients' clinical and epidemiological characteristics) and the dependent variable (confirmed hemorrhagic dengue) were determined through simple regression analysis. The variables that were significantly associated (P < 0.05) were submitted to multifactorial logistic regression analysis. RESULTS: Of the only 241 cases that met the study's inclusion criteria (207 dengue and 34 hemorrhagic dengue), the mean age was 34.7 ± 15.1 years. According to the results of the multifactorial analysis (adjusted by age, sex, and the presence of dengue cases at the geographic location), the variables predictive of major complications of the disease were: the presence of ascites (odds ration [OR] = 22.12; 95 percent confidence interval [95 percentCI]: 5.00-97.87), gingivorrhagia (OR = 7.35; 95 percentCI: 2.11-25.61), hematemesis (OR = 7.40; 95 percentCI: 1.04-52.42), thrombocytopenia (platelets from 40001/mm³- 60000/mm³) (OR = 5.43; 95 percentCI: 1.58-18.72), conjunctival hyperemia (OR = 4.27; 95 percentCI: 1.37-13.28), persistent vomiting (OR = 3.04; 95 percentCI: 1.05-8.80), and the absence of nasal congestion (OR = 0.015; 95 percentCI: 0.0004-0.473). CONCLUSIONS: The presence of ascites, gingivorrhagia, hematemesis, thrombocytopenia (with platelet values from 40001/mm³-60000/mm³), and persistent vomiting were confirmed as warning signs of an imminent dengue attack. Platelet counts of > 100000/mm3 were confirmed in cases with acute clinical symptoms (capillary leak) that were not classified as hemorrhagic dengue due to falling short of the criteria established by WHO.

Manifestações mucocutâneas da dengue / Mucocutaneous manifestations of dengue

Dengue é doença viral sistêmica que ocorre de forma epidêmica em áreas tropicais e subtropicais da Asia, Américas e Africa. O vírus da dengue pertence ao gênero Flavivirus e à família Flaviviridae (arbovírus do grupo B). Aedes aegypti é o principal vetor e verdadeiro reservatório. A febre na dengue clássica persiste por período de dois a cinco dias com cefaléia intensa, mialgia, artralgia e dor retro-orbital. Alterações cutâneas incluem diversos achados como erupção morbiliforme que pode ser pruriginosa e que gera descamação residual, algumas manifestações hemorrágicas discretas como epistaxe, petéquias e sangramento gengival. Extravasamento capilar de plasma é responsável pela hemoconcentração e trombocitopenia observadas e que caracterizam a dengue hemorrágica. Manifestações cutâneas da dengue hemorrágica incluem lesões hemorrágicas disseminadas como petéquias e equimoses, mas também instabilidade hemodinâmica com pulso filiforme, pressão arterial convergente, extremidades frias, confusão mental e choque.

Dengue fever is a systemic viral disease that occurs epidemically in tropical and subtropical regions of Asia, Americas and Africa. The dengue virus belongs to the genus Flavivirus of the family Flaviviridae (group B arbovirus). Aedes aegypti is the major vector and the true reservoir for the virus. Classic dengue fever lasts for two-five days, with severe headache, intense myalgia, arthralgia and retro-orbital pain. Cutaneous alterations include several findings such as a diffuse morbilliform rash that may be pruritic and heals with desquamation, and minor bleeding phenomena such as epistaxis, petechiae, and gingival bleeding. Diffuse capillary leakage of plasma is responsible for the hemoconcentration and thrombocytopenia that characterize dengue hemorrhagic fever. Cutaneous manifestations of dengue hemorrhagic fever include many disseminated hemorrhagic lesions such as petechiae and ecchymoses, but also hemodynamic instability with filiform pulse, narrowing of pulse pressure, cold extremities, mental confusion, and shock.