Fluid management for dengue in children

Updates in the Management of Dengue Shock Syndrome: A Comprehensive Review

Dengue is a very serious public health problem that can manifest a wide range of symptoms from asymptomatic to fatal conditions, such as dengue shock syndrome (DSS). It is a life-threatening mosquito-borne viral infection widely spread in tropical areas. Dengue virus transmission occurs from an infected Aedes mosquito to humans. Various factors are responsible for the occurrence of the disease, such as viral load, age of the host, immune status of the host, and genetic variability. Dengue infection occurs in three phases: febrile, critical, and recovery. The febrile phase lasts for seven days and manifests symptoms such as high-grade fever, headache, arthralgia, and backache, and in some cases, the upper respiratory tract and gastrointestinal tract are also involved. Severe dengue is characterized by endothelial dysfunction that causes vascular permeability and plasma leakage. The fundamental mechanisms of these immune pathologies are not yet known. Dengue manifests various complications such as dengue encephalopathy, encephalitis, stroke, ocular involvement, acute transverse myelitis, myalgia, and cerebellar syndrome, but the most commonly seen is liver involvement. Dengue is managed supportively because there are no proven curative treatments. The cornerstone of care during the critical period of dengue is prudent fluid resuscitation. The first fluid of preference is a crystalloid. Prophylactic transfusion of platelets is not advised. The occurrence of four antigenically different dengue virus serotypes, each able to elicit a cross-reactive and disease-enhancing antibody response against the other three serotypes, has made the creation of the dengue vaccine a difficult undertaking. The development of a dengue vaccine has faced significant challenges due to a lack of the best animal models and a variety of immunological conditions in people, particularly in endemic locations. Dengvaxia is a live attenuated vaccine, which was developed by Sanofi. It is made up of four chimeric vaccine viruses produced by Vero cells.

Fluid management in children with severe dengue: a narrative review

Dengue is a mosquito-borne arboviral infection of increasing public health importance. Globally, children account for a significant proportion of infections. No pathogen-specific treatment currently exists, and the current approach to reducing disease burden is focused on preventative strategies such as vector control, epidemiological interventions, and vaccination in selected populations. Once infected, the mainstay of treatment is supportive, of which appropriate fluid management is a cornerstone. The timely provision of fluid boluses has historically been central to the management of septic shock. However, in patients with dengue shock, particular emphasis is placed on judicious fluid administration. Certain colloids such as hydroxyethyl starches and dextran, despite no longer being used routinely in intensive care units due to concerns of acute kidney injury and impairment of coagulation, are still commonly used in dengue shock syndrome. Current guidelines recommend initial crystalloid therapy, with consideration of colloids for severe or recalcitrant shock in patients with dengue. In this review, we discuss the pathophysiology of septic shock, and consider whether any differences in dengue exist that may warrant a separate approach to fluid therapy. We critically review the available evidence for fluid management in dengue, including the role of colloids. In dengue, there is increasing recognition of the importance of tailoring fluid therapy to phases of disease, with attention to the need for fluid "deresuscitation" once the critical phase of vascular leak passes.

Soluble Notch ligand DLL1 is associated with bleeding complication in patients with dengue fever infection

Bleeding associated with endothelial damage is one key feature of severe dengue fever. Here, we investigated whether Notch ligands are associated with bleeding in 115 patients with confirmed dengue infection in Vietnam. Soluble Notch ligands were determined by ELISA. 14.8% (17/115) experienced bleeding manifestations. High soluble DLL1 (sDLL1) plasma levels was associated with bleeding (median 15674 pg/ml vs 7117 pg/ml; p<0.001). ROC analysis demonstrated that sDLL1 had the best test performance (AUC=0.852), with 88% sensitivity and 84% specificity. The combination with ALT/AST slightly increased DLL1 performance. sDLL1 may be useful to guide clinical management of dengue patients in endemic settings.

Dengue virus entry/fusion inhibition by small bioactive molecules; A critical review

Many flaviviruses are remarkable human pathogens that can be transmitted by mosquitoes and ticks. Despite the availability of vaccines for viral infections such as yellow fever, Japanese encephalitis, and tick-borne encephalitis, flavivirus-like dengue is still a significant life-threatening illness worldwide. To date, there is no antiviral treatment for dengue therapy. Industry and the research community have been taking ongoing steps to improve anti-flavivirus treatment to meet this clinical need. The successful activity has been involved in the inhibition of the virus entry fusion process in the last two decades. In this study, the latest understanding of the use of small molecules used as fusion inhibitors has been comprehensively presented. We summarized the structure, the process of fusion of dengue virus E protein (DENV E), and the amino acids involved in the fusion process. Special attention has been given to small molecules that allow conformational changes to DENV E protein viz. blocking the pocket of βOG, which is important for fusion.

Microvascular Fluid Exchange: Implications of the Revised Starling Model for Resuscitation of Dengue Shock Syndrome

Dengue is the most common mosquito-borne viral infection in the world. The most feared complication is a poorly understood vasculopathy that occurs in only a small minority of symptomatic individuals, especially children and young adults, but can result in potentially fatal dengue shock syndrome (DSS). Based mainly on expert opinion, WHO management guidelines for DSS recommend prompt infusion of a crystalloid fluid bolus followed by a tapering crystalloid fluid regimen, supplemented if necessary by boluses of synthetic colloid solutions. However, following publication of a number of major trials undertaken in other, primarily adult, critical care scenarios, use of both synthetic colloid solutions and of fluid boluses for volume expansion have become controversial. Synthetic colloids tend to be used for severe DSS cases in order to boost intravascular oncotic pressure, based on the classic Starling hypothesis in which opposing hydrostatic and oncotic forces determine fluid flow across the microvascular barrier. However, the revised Starling model emphasizes the critical contribution of the endothelial glycocalyx layer (EGL), indicating that it is the effective oncotic pressure gradient across the EGL not endothelial cells per se that opposes filtration. Based on several novel concepts that are integral to the revised Starling model, we review the clinical features of DSS and discuss a number of implications that are relevant for fluid management. We also highlight the need for context-specific clinical trials that address crucially important questions around the management of DSS.

Role of Immunoinformatics in Accelerating Epitope-Based Vaccine Development against Dengue Virus

Dengue Fever (DF) has emerged as a significant public health problem of international concern with its high prevalence in the tropic and subtropical regions. Dengue Virus (DENV), which is the cause of DF, consists of four serotypes of antigenically distinct viruses. The immense variation and limited identity similarity at the amino acid level lead to a problematic challenge in the development of an efficacious vaccine. Fortunately, the extensively available immunological data, the advance in antigenic peptide prediction, and the incorporation of molecular docking and dynamics simulation in immunoinformatics have directed the vaccine development towards the rational design of the epitope-based vaccine. Here, we point out the current state of dengue epidemiology and the recent development in vaccine development. Subsequently, we provide a systematic review of our validated method and tools for B- and T-cell epitope prediction as well as the use of molecular docking and dynamics in evaluating epitope affinity and stability in the discovery of a new tetravalent dengue vaccine through computational epitope-based vaccine design.

Dengue Virus and Its Inhibitors: A Brief Review

The global occurrence of viral infectious diseases poses a significant threat to human health. Dengue virus (DENV) infection is one of the most noteworthy of these infections. According to a WHO survey, approximately 400 million people are infected annually; symptoms deteriorate in approximately one percent of cases. Numerous foundational and clinical investigations on viral epidemiology, structure and function analysis, infection source and route, therapeutic targets, vaccines, and therapeutic drugs have been conducted by both academic and industrial researchers. At present, CYD-TDV or Dengvaxia^® is the only approved vaccine, but potent inhibitors are currently under development. In this review, an overview of the viral life circle and the history of DENVs is presented, and the most recently reported antiviral candidates and newly discovered promising targets are focused and summarized. We believe that these successes and failures have enabled progress in anti-DENV drug discovery and hope that our review will stimulate further innovation in this area.

Personal Protection of Permethrin-Treated Clothing against Aedes aegypti, the Vector of Dengue and Zika Virus, in the Laboratory

BACKGROUND

The dengue and Zika viruses are primarily transmitted by Aedes aegypti mosquitoes, which are most active during day light hours and feed both in and outside of the household. Personal protection technologies such as insecticide-treated clothing could provide individual protection. Here we assessed the efficacy of permethrin-treated clothing on personal protection in the laboratory.

METHODS

The effect of washing on treated clothing, skin coverage and protection against resistant and susceptible Ae. aegypti was assessed using modified WHO arm-in-cage assays. Coverage was further assessed using free-flight room tests to investigate the protective efficacy of unwashed factory-dipped permethrin-treated clothing. Clothing was worn as full coverage (long sleeves and trousers) and partial coverage (short sleeves and shorts). Residual permethrin on the skin and its effect on mosquitoes was measured using modified WHO cone assays and quantified using high-pressure liquid chromatography (HPLC) analysis.

RESULTS

In the arm-in-cage assays, unwashed clothing reduced landing by 58.9% (95% CI 49.2-66.9) and biting by 28.5% (95% CI 22.5-34.0), but reduced to 18.5% (95% CI 14.7-22.3) and 11.1% (95% CI 8.5-13.8) respectively after 10 washes. Landing and biting for resistant and susceptible strains was not significantly different (p<0.05). In free-flight room tests, full coverage treated clothing reduced landing by 24.3% (95% CI 17.4-31.7) and biting by 91% (95% CI 82.2-95.9) with partial coverage reducing landing and biting by 26.4% (95% CI 20.3-31.2) and 49.3% (95% CI 42.1-59.1) respectively with coverage type having no significant difference on landing (p<0.05). Residual permethrin was present on the skin in low amounts (0.0041mg/cm2), but still produced a KD of >80% one hour after wearing treated clothing.

CONCLUSION

Whilst partially covering the body with permethrin-treated clothing provided some protection against biting, wearing treated clothing with long sleeves and trousers provided the highest form of protection. Washing treated clothing dramatically reduced protection provided. Permethrin-treated clothing could provide protection to individuals from Ae. aegypti that show permethrin resistance. Additionally, it could continue to provide protection even after the clothing has been worn. Field trials are urgently needed to determine whether clothing can protect against dengue and Zika.

Colloids for the Initial Management of Severe Sepsis and Septic Shock in Pediatric Patients: A Systematic Review

AIM

The goal of this study was to perform a systematic review of the literature assessing the use of colloids for the initial treatment of severe sepsis and septic shock in pediatric patients.

DESIGN

The PICO [Patient, Intervention, Comparison, Outcome] method was used for the selection of studies, and the Cochrane Bias Tool was used to analyze the quality of the selected studies.

DATA SEARCH

Relevant studies were sought using the following databases: EMBASE (1980 to March 2014), PubMed (1970 to March 2014), Cochrane (1980 to March 2014), Web of Science, and Scopus. Searches used the following key words: isotonic solution, crystalloid, saline solution, colloid, resuscitation, fluid therapy, sepsis and septic shock, starch, and gelatin. The filters children and clinical trial were used when possible.

REVIEW METHOD

Study selection was performed by 1 examiner. The selected articles were analyzed by 2 examiners who validated the articles according to the Cochrane Bias Tool. Discrepancies were resolved by consensus or by a third examiner.

RESULT

A total of 110 articles were selected based on the key words. Of these, 99 were excluded because they assessed postoperative follow-up, burn cases, cardiac surgery, or nutritional therapy or were review articles, guidelines, or editorials. One study was included after an analysis of previous reviews. A total of 12 articles were selected for analysis because they were reports of clinical trials conducted with prospective cohorts and they analyzed the use of crystalloids and colloids or colloids only in the initial treatment of severe sepsis or septic shock in children and adolescents. The total number of patients was 4375, and they ranged in age from 2 months to 15 years, with most patients between 5 and 15 years. Five studies assessed patients diagnosed with malaria, 5 assessed patients with dengue shock syndrome, 1 studied febrile diseases, and 1 examined the progression of patients with septic shock caused by various causes.

CONCLUSIONS

The studies analyzed did not find evidence to suggest that the use of colloids is superior to crystalloids. In some studies, the fluid volume needed to achieve initial stabilization was smaller in the group given colloids. Crystalloids are the preferred therapeutic option because of their effectiveness, low cost, and wide availability. Colloids may be the first choice in cases of malaria when the central nervous system is affected.

Host biomarkers are associated with progression to dengue haemorrhagic fever: a nested case-control study

OBJECTIVES

Dengue represents the most important arboviral infection worldwide. Onset of circulatory collapse can be unpredictable. Biomarkers that can identify individuals at risk of plasma leakage may facilitate better triage and clinical management.

DESIGN

Using a nested case-control design, we randomly selected subjects from a prospective cohort study of dengue in Colombia (n=1582). Using serum collected within 96 hours of fever onset, we tested 19 biomarkers by ELISA in cases (developed dengue hemorrhagic fever or dengue shock syndrome (DHF/DSS); n=46), and controls (uncomplicated dengue fever (DF); n=65) and healthy controls (HC); n=15.

RESULTS

Ang-1 levels were lower and angptl3, sKDR, sEng, sICAM-1, CRP, CXCL10/IP-10, IL-18 binding protein, CHI3L1, C5a and Factor D levels were increased in dengue compared to HC. sICAM-1, sEng and CXCL10/IP-10 were further elevated in subjects who subsequently developed DHF/DSS (p=0.008, p=0.028 and p=0.025, respectively). In a logistic regression model, age (odds ratio (OR) (95% CI): 0.95 (0.92-0.98), p=0.001), hyperesthesia/hyperalgesia (OR; 3.8 (1.4-10.4), p=0.008) and elevated sICAM-1 (>298ng/mL: OR; 6.3 (1.5-25.7), p=0.011) at presentation were independently associated with progression to DHF/DSS.

CONCLUSIONS

These results suggest that inflammation and endothelial activation are important pathways in the pathogenesis of dengue and sICAM-1 levels may identify individuals at risk of plasma leakage.