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Abstract Background A major challenge in dengue management in resource limited settings is the confirmation of diagnosis. Clinical features of dengue often overlap with other infections and molecular diagnostic tools are not readily accessible to clinicians at hospitals. In addition, the prediction of plasma leakage in dengue is also difficult. Hematocrit level and ultrasound scans (combined with clinical parameters) are helpful to detect plasma leakage once it has happened, not before. Methods Colombo Dengue Study (CDS) is a prospective cohort study of clinically suspected adult dengue patients recruited from the National hospital of Sri Lanka (within the first 3 days of fever) that aimed to a) identify clinical and basic laboratory test parameters to differentiate dengue from non-dengue fever, b) evaluate the comparative efficacy of loop-mediated isothermal amplification (LAMP) for dengue diagnosis (vs. NS1 antigen test and RT-qPCR) and c) identify early associations that are predictive of plasma leakage or severe dengue. The basic laboratory tests considered here included hematological parameters, serum biochemistry and inflammatory markers. Results Only 70% of clinically suspected patients were confirmed as having dengue by either the NS1 antigen test or RT-qPCR. On a Bayesian latent class model which assumes no “gold standard”, LAMP performed equally or better than RT-qPCR and NS1 antigen test respectively. When confirmed dengue patients were compared with others, the earlier group had significantly lower lymphocyte counts and higher aspartate aminotransferase levels (AST) within the first 3 days of fever. Confirmed dengue patients with plasma leakage had a lower mean age and a higher median baseline AST level compared to those without plasma leakage (p

Dengue is a global health problem, caused by the dengue virus (DENV), which belongs to the Flaviviridae family of viruses. The transmission of DENV occurs through vectors, Ae. aegypti and Ae. Albopictus mosquitoes, to the human host, classifying it as a vector-borne disease. The disease incidence is increasing at an alarming rate and needs to be tackled to reduce the morbidity and mortality caused by the disease. Environmental and clinical surveillance, detection of the virus, and diagnostics are critical tools to address this issue. In this comprehensive review, we explore various diagnostic techniques and the associated challenges within the context of dengue. While we briefly touch upon dengue's epidemiology, serotypes, and pathogenesis, our primary emphasis remains on diagnostics. We delve into the intricacies of these diagnostic methods, considering both the challenges they entail and the potential they hold in terms of accuracy and accessibility. It's important to note that the review does not extensively cover clinical aspects or regional variations of the disease. [ABSTRACT FROM AUTHOR]

Objective: Accurate laboratory testing is a critical component of dengue surveillance and control. The objective of this programme was to assess dengue diagnostic proficiency among national-level public health laboratories in the World Health Organization (WHO) Western Pacific Region. Methods: Nineteen national-level public health laboratories performed routine dengue diagnostic assays on a proficiency testing panel consisting of two modules: one containing commercial serum samples spiked with cultured dengue viruses for the detection of nucleic acid and non-structural protein 1 (NS1) (Module A) and one containing human serum samples for the detection of anti-dengue virus antibodies (Module B). A review of logistics arrangements was also conducted. Results: All 16 laboratories testing Module A performed reverse transcriptase polymerase chain reaction (RT-PCR) for both RNA and serotype detection. Of these, 15 had correct results for RNA detection and all 16 correctly serotyped the viruses. All nine laboratories performing NS1 antigen detection obtained the correct results. Sixteen of the 18 laboratories using IgM assays in Module B obtained the correct results as did the 13 laboratories that performed IgG assays. Detection of ongoing/recent dengue virus infection by both molecular (RT-PCR) and serological methods (IgM) was available in 15/19 participating laboratories. Discussion: This first round of external quality assessment of dengue diagnostics was successfully conducted in national-level public health laboratories in the WHO Western Pacific Region, revealing good proficiency in both molecular and serological testing. Further comprehensive diagnostic testing for dengue virus and other priority pathogens in the Region will be assessed during future rounds.

Dengue fever is a mosquito-borne viral disease estimated to cause about 230 million infections worldwide every year, of which 25,000 are fatal. Global incidence has risen rapidly in recent decades with some 3.6 billion people, over half of the world's population, now at risk, mainly in urban centres of the tropics and subtropics. Demographic and societal changes, in particular urbanization, globalization, and increased international travel, are major contributors to the rise in incidence and geographic expansion of dengue infections. Major research gaps continue to hamper the control of dengue. The European Commission launched a call under the 7th Framework Programme with the title of ‘Comprehensive control of Dengue fever under changing climatic conditions’. Fourteen partners from several countries in Europe, Asia, and South America formed a consortium named ‘DengueTools’ to respond to the call to achieve better diagnosis, surveillance, prevention, and predictive models and improve our understanding of the spread of dengue to previously uninfected regions (including Europe) in the context of globalization and climate change.The consortium comprises 12 work packages to address a set of research questions in three areas: Research area 1: Develop a comprehensive early warning and surveillance system that has predictive capability for epidemic dengue and benefits from novel tools for laboratory diagnosis and vector monitoring. Research area 2: Develop novel strategies to prevent dengue in children. Research area 3: Understand and predict the risk of global spread of dengue, in particular the risk of introduction and establishment in Europe, within the context of parameters of vectorial capacity, global mobility, and climate change.In this paper, we report on the rationale and specific study objectives of ‘DengueTools’. DengueTools is funded under the Health theme of the Seventh Framework Programme of the European Community, Grant Agreement Number: 282589 Dengue Tools.

Abstract: Dengue is a mosquito-transmitted infection that poses significant global health risks for travelers and individuals living in the tropics and subtropics. The reported global incidence has increased dramatically in the past century, with dengue now ranking as the most common cause of febrile illness in travelers. While sporadic cases have been reported within the southern United States since 1980, autochthonous outbreaks have now been described in Hawaii, St. Croix (US Virgin Islands), along the Texas–Mexico border, and, most recently, in Key West, Florida. Although many infections are mild or asymptomatic, 5–10% of patients may experience hemorrhagic disease, with shock and even death. Laboratory identification commonly involves serologic and nucleic acid amplification methods. Due to rising incidence worldwide, physicians should be familiar with the clinical manifestations, laboratory diagnosis, and management of this illness. [Copyright &y& Elsevier]

Dengue fever is a mosquito-borne viral disease estimated to cause about 230 million infections worldwide every year, of which 25,000 are fatal. Global incidence has risen rapidly in recent decades with some 3.6 billion people, over half of the world's population, now at risk, mainly in urban centres of the tropics and subtropics. Demographic and societal changes, in particular urbanization, globalization, and increased international travel, are major contributors to the rise in incidence and geographic expansion of dengue infections. Major research gaps continue to hamper the control of dengue. The European Commission launched a call under the 7th Framework Programme with the title of 'Comprehensive control of Dengue fever under changing climatic conditions'. Fourteen partners from several countries in Europe, Asia, and South America formed a consortium named 'DengueTools' to respond to the call to achieve better diagnosis, surveillance, prevention, and predictive models and improve our understanding of the spread of dengue to previously uninfected regions (including Europe) in the context of globalization and climate change. The consortium comprises 12 work packages to address a set of research questions in three areas: Research area 1: Develop a comprehensive early warning and surveillance system that has predictive capability or epidemic dengue and benefits from novel tools for laboratory diagnosis and vector monitoring. Research area 2: Develop novel strategies to prevent dengue in children. Research area 3: Understand and predict the risk of global spread of dengue, in particular the risk of introduction and establishment in Europe, within the context of parameters of vectorial capacity, global mobility, and climate change. In this paper, we report on the rationale and specific study objectives of 'DengueTools'. DengueTools is funded under the Health theme of the Seventh Framework Programme of the European Community, Grant Agreement Number: 282589 Dengue Tools. [ABSTRACT FROM AUTHOR]

Abstract: Dengue is a rapidly spreading mosquito-borne viral disease prevalent in over a hundred countries around the world. A definitive identification of dengue infection depends on reliable dengue diagnostic tests. This study describes the design, expression and purification of an in vivo biotinylated chimeric dengue antigen to exploit the high affinity of biotin–streptavidin interaction to detect anti-dengue antibodies. This chimeric antigen incorporates the envelope domain III (EDIII) of the four dengue virus serotypes. A biotin acceptor peptide was fused with the chimeric dengue antigen for in vivo biotinylation in Escherichia coli through simultaneous co-expression of the biotin ligase, BirA. Despite the localization of the chimeric dengue antigen to the insoluble fraction of induced E. coli cells, it was found to be biotinylated in vivo. It was purified to near homogeneity using affinity chromatography with final yields of 20mg protein of ∼95% purity, from 1L of induced E. coli shake flask culture, and the efficiency of biotinylation was estimated to be ∼85%. Mouse antibodies specific to recombinant EDIII of each of the four dengue serotypes, captured on microtiter wells sensitized with anti-mouse immunoglobulin antibodies, were recognized specifically and with high efficiency by the biotinylated antigen in conjunction with streptavidin–enzyme conjugate. An evaluation of the biotinylated antigen against a panel of pre-characterized dengue-positive and dengue-negative human sera (n =164), in an antibody capture ELISA format, showed that it manifested 100% specificity, but also suggested that additional epitopes may need to be included in its design to enhance sensitivity. [ABSTRACT FROM AUTHOR]

Transforming the structural and functional properties of carbon nanostructures are highly beneficial for healthcare diagnostics. This research demonstrates the functionalization of opto-electrochemically active ruthenium bipyridine complex (Ru(II)) on the surface of graphene oxide (GO), enabling a dual-functional immunoprobe for the detection of non-structural 1 (NS1) protein, a dengue biomarker. Structural investigations reveals that Ru(II) has intermolecular bonding with functional groups of GO. Ultraviolet photoelectron spectral readouts display the changes in the work function and ionization energy of GO, supporting the functionalization of Ru(II). Bio-affinity layers of protein-G (Pro-G) at GO-Ru(II) electrode interface promotes the localization of monoclonal antibodies (mAb) selective for binding the epitopes of NS1 antigen. The chronoamperometric and fluorescence quenching-based immunoassays showed a linear response with a lowest detection limit of 0.38 and 0.48 ng/mL, respectively. Under optimal condition, the developed immunosensor studied to have retained stability/sensitivity toward NS1 without impact from interferents. The dual functional immuno-bioprobe translated from GO-Ru(II) conjugated nanostructures offers new insights for further studies in on-site diagnosis. • Dual functional immunoprobe for NS1 detection based on GO-Ru(II) nanocomposite. • Monoclonal antibodies modified GO-Ru(II)/protein-G enable selective probing of NS1 protein, sensitivity of 0.14 mA/ng mL-1. • Ru(II)-localized GO composite exhibit selective fluorescence quenching against NS1 protein immunocomplex formation. • GO-Ru(II) immunosensor platform shows interferent-free specificity to NS1 in patient serum samples. [ABSTRACT FROM AUTHOR]

Background: Dengue diagnostics currently relies on serum and plasma tests. Although the proof of concept for detecting dengue virus (DENV) RNA and nonstructural protein 1 (NS1) antigen from urine and saliva has been demonstrated, few studies have explored their use in diagnostics., Objectives: To investigate the occurrence, excretion kinetics, and diagnostic potential of DENV-RNA and NS1 antigen in the urine and saliva of dengue patients., Study Design: We examined serial serum, urine (n=50) and saliva (n=48) samples of 14 Finnish travelers with dengue. All samples were analyzed by NS1 ELISA and DENV RT-PCR, and the first and last serum specimens were tested for DENV IgG and IgM. In addition, biochemical parameters were studied from the urine and clinical and laboratory data of the patients were collected., Results: DENV-NS1 protein and RNA proved detectable from saliva and urine using tests developed for serum samples. RNA/NS1 detection showed a diagnostic sensitivity of 64%/54% and 60%/56% for urine and saliva, respectively. RNA analyses performed on days 7-13 after onset of symptoms revealed the sensitivity for urine (72%) to be greater than for serum (31%) or saliva (50%). The concentration of urine samples had no impact on RNA detection., Conclusions: Noninvasive sampling enables an alternative approach to dengue diagnostics. The performance of the NS1 antigen assay may be improved by optimizing it for urine and saliva samples. The prolonged excretion of DENV-RNA in urine extends the sampling time window for molecular diagnostics and surveillance., (Copyright © 2014 Elsevier B.V. All rights reserved.)