Summary
Objective To evaluate the existing WHO dengue classification across all age groups and a wide geographical range and to develop a revised evidence‐based classification that would better ...reflect clinical severity.
Methods We followed suspected dengue cases daily in seven countries across South‐east Asia and Latin America and then categorised them into one of three intervention groups describing disease severity according to the overall level of medical and nursing support required. Using a pre‐defined analysis plan, we explored the clinical and laboratory profiles characteristic of these intervention categories and presented the most promising options for a revised classification scheme to an independent group of WHO dengue experts for consideration. Potential warning signs were also evaluated by comparing contemporaneous data of patients who progressed to severe disease with the data of those who did not.
Results A total of 2259 patients were recruited during 2006–2007 and 230 (13%) of the 1734 laboratory‐confirmed patients required major intervention. Applying the existing WHO system, 47/210 (22%) of patients with shock did not fulfil all the criteria for dengue haemorrhagic fever. However, no three‐tier revision adequately described the different severity groups either. Inclusion of readily discernible complications (shock/severe vascular leakage and/or severe bleeding and/or severe organ dysfunction) was necessary to devise a system that identified patients requiring major intervention with sufficient sensitivity and specificity to be practically useful. Only a small number of subjects (5%) progressed to severe disease while under observation; several warning signs were identified, but much larger studies are necessary to fully characterize features associated with disease progression.
Conclusions Based on these results, a revised classification system comprised of two entities, ‘Dengue’ and ‘Severe Dengue’, was proposed and has now been incorporated into the new WHO guidelines.
Objectif: Evaluer la classification actuelle de l’OMS pour la dengue dans tous les groupes d’âge et sur une vaste étendue géographique et élaborer une classification révisée, fondée sur des preuves permettant de mieux tenir compte de la sévérité clinique.
Méthodes: Nous avons suivi quotidiennement des cas suspects de dengue dans 7 pays d’Asie du sud‐est et d’Amérique latine, puis les avons classé en trois groupes d’intervention décrivant la sévérité de la maladie en fonction du niveau général du soutien médical et infirmier nécessaire. En utilisant un plan d’analyse prédéfini, nous avons exploré les profils cliniques et de laboratoire, caractéristiques de ces catégories d’intervention et avons soumis pour avis, les options les plus prometteuses pour un système révisé de classification, à un groupe d’experts indépendants de l’OMS pour la dengue. Les signes avant‐coureurs potentiels ont également étéévalués en comparant les données contemporaines de patients qui ont évolué vers une maladie sévère avec les données de ceux qui n’ont pas évolué de cette façon.
Résultats: 2259 patients ont été recrutés en 2006–2007 et 230 (13%) des 1734 patients avec une confirmation de laboratoire ont nécessité une intervention majeure. En appliquant le système actuel de l’OMS, 47/210 (22%) patients atteints de choc ne remplissaient pas tous les critères de dengue hémorragique. Toutefois, aucune révision tertiaire non plus n’a pu décrire adéquatement les différents groupes de sévérité. L’inclusion de complications facilement reconnaissables (choc/pertes vasculaires sévères et/ou saignements sévères et/ou dysfonctionnement sévère d’un organe) a été nécessaire pour concevoir un système permettant d’identifier les patients nécessitant une intervention majeure, avec une sensibilité et une spécificité suffisantes pour être utiles dans la pratique. Seul un petit nombre de sujets (5%) a progressé vers une maladie sévère alors qu’ils étaient sous observation; plusieurs signes d’alerte ont été identifiés, mais beaucoup plus d’études sont nécessaires pour caractériser complètement les caractéristiques associées à la progression de la maladie.
Conclusions: Sur base de ces résultats, un système de classification révisé, composé de deux entités, “Dengue” et “ dengue sévère “, a été proposé et a été intégré dans les nouvelles directives de l’OMS.
Early diagnosis of dengue can assist patient triage and management and prevent unnecessary treatments and interventions. Commercially available assays that detect the dengue virus protein NS1 in the ...plasma/serum of patients offers the possibility of early and rapid diagnosis.
The sensitivity and specificity of the Pan-E Dengue Early ELISA and the Platelia Dengue NS1 Ag assays were compared against a reference diagnosis in 1385 patients in 6 countries in Asia and the Americas. Platelia was more sensitive (66%) than Pan-E (52%) in confirmed dengue cases. Sensitivity varied by geographic region, with both assays generally being more sensitive in patients from SE Asia than the Americas. Both kits were more sensitive for specimens collected within the first few days of illness onset relative to later time points. Pan-E and Platelia were both 100% specific in febrile patients without evidence of acute dengue. In patients with other confirmed diagnoses and healthy blood donors, Platelia was more specific (100%) than Pan-E (90%). For Platelia, when either the NS1 test or the IgM test on the acute sample was positive, the sensitivity versus the reference result was 82% in samples collected in the first four days of fever. NS1 sensitivity was not associated to disease severity (DF or DHF) in the Platelia test, whereas a trend for higher sensitivity in DHF cases was seen in the Pan-E test (however combined with lower overall sensitivity).
Collectively, this multi-country study suggests that the best performing NS1 assay (Platelia) had moderate sensitivity (median 64%, range 34-76%) and high specificity (100%) for the diagnosis of dengue. The poor sensitivity of the evaluated assays in some geographical regions suggests further assessments are needed. The combination of NS1 and IgM detection in samples collected in the first few days of fever increased the overall dengue diagnostic sensitivity.
Rhythm disturbances occured in 52% of the patients, and included bradyarrhytmias (29%), atrial and ventricular ectopic beats, tachyarrhytmias including atrial fibrillation, ectopic atrial tachycardia ...ventricular tachycardia and sudden death Conclusion: Chikungunya myocarditis can be fatal.
Dengue virus infections are a major cause of morbidity in tropical countries. Early detection of dengue hemorrhagic fever (DHF) may help identify individuals that would benefit from intensive ...therapy. Predictive modeling was performed using 11 laboratory values of 51 individuals (38 DF and 13 DHF) obtained on initial presentation using logistic regression. We produced a robust model with an area under the curve of 0.9615 that retained IL-10 levels, platelets, and lymphocytes as the major predictive features. A classification and regression tree was developed on these features that were 86% accurate on cross-validation. The IL-10 levels and platelet counts were also identified as the most informative features associated with DHF using a Random Forest classifier. In the presence of polymerase chain reaction-proven acute dengue infections, we suggest a complete blood count and rapid measurement of IL-10 can assist in the triage of potential DHF cases for close follow-up or clinical intervention improving clinical outcome.
► We examine the population structure of dengue viruses in Venezuela, 2006–2007. ► Phylogenetic trees show that only one genotype was circulating for each serotype. ► Extensive viral genetic ...diversity indicates significant in situ evolution. ► Particularly, variations in non-structural proteins appear to have a major role. ► These results on dengue evolution are relevant in the context of vaccine design.
During the past three decades there has been a notable increase in dengue disease severity in Venezuela. Nevertheless, the population structure of the viruses being transmitted in this country is not well understood. Here, we present a molecular epidemiological study on dengue viruses (DENV) circulating in Aragua State, Venezuela during 2006–2007. Twenty-one DENV full-length genomes representing all of the four serotypes were amplified and sequenced directly from the serum samples. Notably, only DENV-2 was associated with severe disease. Phylogenetic trees constructed using Bayesian methods indicated that only one genotype was circulating for each serotype. However, extensive viral genetic diversity was found in DENV isolated from the same area during the same period, indicating significant in situ evolution since the introduction of these genotypes. Collectively, the results suggest that the non-structural (NS) proteins may play an important role in DENV evolution, particularly NS1, NS2A and NS4B proteins. The phylogenetic data provide evidence to suggest that multiple introductions of DENV have occurred from the Latin American region into Venezuela and vice versa. The implications of the significant viral genetic diversity generated during hyperendemic transmission, particularly in NS protein are discussed and considered in the context of future development and use of human monoclonal antibodies as antivirals and tetravalent vaccines.
Secondary dengue viral infection can produce capillary leakage associated with increased mortality known as dengue hemorrhagic fever (DHF). Because the mortality of DHF can be reduced by early ...detection and intensive support, improved methods for its detection are needed. We applied multidimensional protein profiling to predict outcomes in a prospective dengue surveillance study in South America. Plasma samples taken from initial clinical presentation of acute dengue infection were subjected to proteomics analyses using ELISA and a recently developed biofluid analysis platform. Demographics, clinical laboratory measurements, nine cytokines, and 419 plasma proteins collected at the time of initial presentation were compared between the DF and DHF outcomes. Here, the subject's gender, clinical parameters, two cytokines, and 42 proteins discriminated between the outcomes. These factors were reduced by multivariate adaptive regression splines (MARS) that a highly accurate classification model based on eight discriminant features with an area under the receiver operator curve (AUC) of 0.999. Model analysis indicated that the feature–outcome relationship were nonlinear. Although this DHF risk model will need validation in a larger cohort, we conclude that approaches to develop predictive biomarker models for disease outcome will need to incorporate nonparametric modeling approaches. Clin Trans Sci 2012; Volume #: 1–13
Objective To evaluate the existing WHO dengue classification across all age groups and a wide geographical range and to develop a revised evidence-based classification that would better reflect ...clinical severity. Methods We followed suspected dengue cases daily in seven countries across South-east Asia and Latin America and then categorised them into one of three intervention groups describing disease severity according to the overall level of medical and nursing support required. Using a pre-defined analysis plan, we explored the clinical and laboratory profiles characteristic of these intervention categories and presented the most promising options for a revised classification scheme to an independent group of WHO dengue experts for consideration. Potential warning signs were also evaluated by comparing contemporaneous data of patients who progressed to severe disease with the data of those who did not. Results A total of 2259 patients were recruited during 2006-2007 and 230 (13%) of the 1734 laboratory-confirmed patients required major intervention. Applying the existing WHO system, 47/210 (22%) of patients with shock did not fulfil all the criteria for dengue haemorrhagic fever. However, no three-tier revision adequately described the different severity groups either. Inclusion of readily discernible complications (shock/severe vascular leakage and/or severe bleeding and/or severe organ dysfunction) was necessary to devise a system that identified patients requiring major intervention with sufficient sensitivity and specificity to be practically useful. Only a small number of subjects (5%) progressed to severe disease while under observation; several warning signs were identified, but much larger studies are necessary to fully characterize features associated with disease progression. Conclusions Based on these results, a revised classification system comprised of two entities, 'Dengue' and 'Severe Dengue', was proposed and has now been incorporated into the new WHO guidelines.Original Abstract: Objectif: Evaluer la classification actuelle de l'OMS pour la dengue dans tous les groupes d'age et sur une vaste etendue geographique et elaborer une classification revisee, fondee sur des preuves permettant de mieux tenir compte de la severite clinique. Methodes: Nous avons suivi quotidiennement des cas suspects de dengue dans 7 pays d'Asie du sud-est et d'Amerique latine, puis les avons classe en trois groupes d'intervention decrivant la severite de la maladie en fonction du niveau general du soutien medical et infirmier necessaire. En utilisant un plan d'analyse predefini, nous avons explore les profils cliniques et de laboratoire, caracteristiques de ces categories d'intervention et avons soumis pour avis, les options les plus prometteuses pour un systeme revise de classification, a un groupe d'experts independants de l'OMS pour la dengue. Les signes avant-coureurs potentiels ont egalement eteevalues en comparant les donnees contemporaines de patients qui ont evolue vers une maladie severe avec les donnees de ceux qui n'ont pas evolue de cette facon. Resultats: 2259 patients ont ete recrutes en 2006-2007 et 230 (13%) des 1734 patients avec une confirmation de laboratoire ont necessite une intervention majeure. En appliquant le systeme actuel de l'OMS, 47/210 (22%) patients atteints de choc ne remplissaient pas tous les criteres de dengue hemorragique. Toutefois, aucune revision tertiaire non plus n'a pu decrire adequatement les differents groupes de severite. L'inclusion de complications facilement reconnaissables (choc/pertes vasculaires severes et/ou saignements severes et/ou dysfonctionnement severe d'un organe) a ete necessaire pour concevoir un systeme permettant d'identifier les patients necessitant une intervention majeure, avec une sensibilite et une specificite suffisantes pour etre utiles dans la pratique. Seul un petit nombre de sujets (5%) a progresse vers une maladie severe alors qu'ils etaient sous observation; plusieurs signes d'alerte ont ete identifies, mais beaucoup plus d'etudes sont necessaires pour caracteriser completement les caracteristiques associees a la progression de la maladie. Conclusions: Sur base de ces resultats, un systeme de classification revise, compose de deux entites, "Dengue" et " dengue severe ", a ete propose et a ete integre dans les nouvelles directives de l'OMS.
Objective: To evaluate the existing WHO dengue classification across all age groups and a wide geographical range and to develop a revised evidence-based classification that would better reflect ...clinical severity. Methods: We followed suspected dengue cases daily in seven countries across South-east Asia and Latin America and then categorized them into one of three intervention groups describing disease severity according to the overall level of medical and nursing support required. Using a pre-defined analysis plan, we explored the clinical and laboratory profiles characteristic of these intervention categories and presented the most promising options for a revised classification scheme to an independent group of WHO dengue experts for consideration. Potential warning signs were also evaluated by comparing contemporaneous data of patients who progressed to severe disease with the data of those who did not. Results: A total of 2259 patients were recruited during 2006-2007 and 230 (13%) of the 1734 laboratory-confirmed patients required major intervention. Applying the existing WHO system, 47/210 (22%) of patients with shock did not fulfil all the criteria for dengue hemorrhagic fever. However, no three-tier revision adequately described the different severity groups either. Inclusion of readily discernible complications (shock/severe vascular leakage and/or severe bleeding and/or severe organ dysfunction) was necessary to devise a system that identified patients requiring major intervention with sufficient sensitivity and specificity to be practically useful. Only a small number of subjects (5%) progressed to severe disease while under observation; several warning signs were identified, but much larger studies are necessary to fully characterize features associated with disease progression. Conclusions: Based on these results, a revised classification system comprised of two entities, 'Dengue' and 'Severe Dengue', was proposed and has now been incorporated into the new WHO guidelines. PUBLICATION ABSTRACT
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