Dengue Virus Net is the web resource for anyone interested in dengue. The objectives of Dengue Virus Net are to be the public and professional information resource for dengue and to serve as a network in the exchange of information and news related to dengue.
Dengue is a mosquito-borne infection that causes a severe flu-like illness (dengue fever), and sometimes a potentially lethal complication called dengue haemorrhagic fever. Global incidence of dengue has grown dramatically in recent decades. About two fifths of the world's population are now at risk. Dengue is found in tropical and sub-tropical climates worldwide, mostly in urban and semi-urban areas. Dengue is transmitted to humans by the Aedes aegypti or more rarely the Aedes albopictus mosquito, which feed during the day. Dengue haemorrhagic fever is a leading cause of serious illness and death among children in some Asian countries. There is currently no specific treatment for dengue.
- Dengue Awareness Week - The News International
Thu, 17 Apr 2014 12:42:
- Dengue Fever Hits Asylum Detention Centre In Nauru - Bernama
Thu, 17 Apr 2014 07:53:
- Don't get dengue for Easter - Newsport Daily
Thu, 17 Apr 2014 05:18:
- Dengue outbreak at Australia's Pacific island refugee detention centre sparks ... - South China Morning Post
Thu, 17 Apr 2014 04:35:
- Dengue prevention: 'Public support, awareness a must' - The Express Tribune
Thu, 17 Apr 2014 03:54:
- Nauru dengue fever outbreak sparks fresh concerns about detention centre - The Guardian
Thu, 17 Apr 2014 03:43:
- Anti-dengue seminar - The Nation
Thu, 17 Apr 2014 02:01:
- Dengue fever outbreak hits Nauru sparking calls for restoration of health ... - Sydney Morning Herald
Thu, 17 Apr 2014 01:53:
- Doctors renew call to visit Nauru detention centre after dengue fever outbreak - SBS
Wed, 16 Apr 2014 23:51:
- Move Nauru asylum centre dengue patients to Australia - activists - Radio Australia
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- National dengue surveillance in the Lao People's Democratic Republic, 2006-2012: epidemiological and laboratory findings.
Khampapongpane B, Lewis HC, Ketmayoon P, et al. National dengue surveillance in the Lao People's Democratic Republic, 2006-2012: epidemiological and laboratory findings. [Journal Article]Western Pac Surveill Response J 2014 Jan; 5(1):7-13.Although dengue has been a public health problem for several decades in the Lao People's Democratic Republic, the magnitude of the disease burden and epidemiological trends remain poorly understood. We analysed national dengue surveillance and laboratory data from 2006 to 2012 by person, place and time. Between 2006 and 2012, the annual dengue notification rate ranged between 62 and 367 cases per 100 000 population with an apparent geographical expansion of transmission throughout the country in recent years and concurrent co-circulation of all four dengue virus subtypes. An electronic database, called Lao People's Democratic Republic Early Warning Alert and Response Network, was introduced in 2008 to provide automated early warning for outbreaks and epidemics. Village outbreaks continue to be notified primarily through event-based surveillance, whereas the weekly indicator-based system provides systematic assessment of annual epidemic cycles. The dengue case data indicate a high and increasing burden of disease. Efforts now need to focus on using available data to prompt more effective outbreak response and to guide the design and implementation of intervention strategies.
- Larval Competition Extends Developmental Time and Decreases Adult Size of wMelPop Wolbachia-Infected Aedes aegypti.
Ross PA, Endersby NM, Yeap HL, et al. Larval Competition Extends Developmental Time and Decreases Adult Size of wMelPop Wolbachia-Infected Aedes aegypti. [JOURNAL ARTICLE]Am J Trop Med Hyg 2014 Apr 14.AbstractPublisher Full TextThe intracellular endosymbiont Wolbachia has been artificially transinfected into the dengue vector Aedes aegypti, where it is being investigated as a potential dengue biological control agent. Invasion of Wolbachia in natural populations depends upon the fitness of Wolbachia-infected Ae. aegypti relative to uninfected competitors. Although Wolbachia infections impose fitness costs on the adult host, effects at the immature stages are less clear, particularly in competitive situations. We look for effects of two Wolbachia infections, wMel and wMelPop, on intra-strain and inter-strain larval competition in Ae. aegypti. Development of Wolbachia-infected larvae is delayed in mixed cohorts with uninfected larvae under crowded-rearing conditions. Slow developing wMelPop-infected larvae have reduced adult size compared with uninfected larvae, and larvae with the wMel infection are somewhat larger and have greater viability relative to uninfected larvae when in mixed cohorts. Implications for successful invasion by these Wolbachia infections under field conditions are considered.
- Severe Neutropenia in Dengue Patients: Prevalence and Significance.
Thein TL, Lye DC, Leo YS, et al. Severe Neutropenia in Dengue Patients: Prevalence and Significance. [JOURNAL ARTICLE]Am J Trop Med Hyg 2014 Apr 14.AbstractPublisher Full TextStudies on severe neutropenia in dengue are scarce, and its clinical significance is uncertain. We analyzed a cohort of 1,921 reverse transcription polymerase chain reaction-confirmed adult dengue patients admitted to the Communicable Disease Center in Singapore between 2005 and 2008. Time trend analyses for daily absolute neutrophil counts (ANCs) were done using Bayesian hierarchical and Markov models. We found that severe neutropenia, defined as ANC ≤ 0.5 × 10(9)/L, was found in 11.8% with a median duration of 1 day. ANC nadir occurred on illness day 5. Severe neutropenia was not predictive of more severe disease and not associated with secondary bacterial infections, prolonged hospital stay, prolonged fever, or fatal outcome. We concluded that prophylactic antibiotics are not indicated in patients with severe neutropenia without indication for bacterial infection.
- Dengue NS1 and prM antibodies increase the sensitivity of acute dengue diagnosis test and differentiate from Japanese encephalitis infection.
Gowri Sankar S, Balaji T, Venkatasubramani K, et al. Dengue NS1 and prM antibodies increase the sensitivity of acute dengue diagnosis test and differentiate from Japanese encephalitis infection. [JOURNAL ARTICLE]J Immunol Methods 2014 Apr 11.AbstractPublisher Full TextAccurate and early diagnosis of dengue infection is essential for dengue case management. In outbreak conditions, it is essential to include two different tests to diagnose dengue and the choice depends on number of days after the onset of illness in which sample is collected. During the laboratory diagnosis of dengue in late acute and convalescent phase by MAC-ELISA, it is necessary to rule out possible cross reactions of closely related flavivirus, such as Japanese encephalitis virus which is commonly co-circulating. In the present investigation, the usefulness of dengue virus NS1 and prM antibodies in diagnosing and differentiating dengue from Japanese encephalitis infection was assessed using samples collected during out-breaks. It was shown here that, detection of antibodies against dengue NS1 and prM proteins increases the sensitivity of dengue diagnosis until 15days. Moreover, detection of antibodies against both proteins was able to differentiate dengue from Japanese encephalitis infection.
- A novel approach to propagate flavivirus infectious cDNA clones in bacteria by introducing tandem repeat sequences upstream of virus genome.
Pu SY, Wu RH, Tsai MH, et al. A novel approach to propagate flavivirus infectious cDNA clones in bacteria by introducing tandem repeat sequences upstream of virus genome. [JOURNAL ARTICLE]J Gen Virol 2014 Apr 11.AbstractPublisher Full TextDespite tremendous efforts to improve the methodology for constructing flavivirus infectious cDNAs, the manipulation of flavivirus cDNAs remains a difficult task in bacteria. Here, we successfully propagated DNA-launched type 2 dengue virus (DENV2) and Japanese encephalitis virus (JEV) infectious cDNAs by introducing seven repeats of the tetracycline-response element (7XTRE) and a minimal cytomegalovirus (CMVmin) promoter upstream of the viral genome. Insertion of the 7XTRE-CMVmin sequence upstream of the DENV2 or JEV genome decreased the cryptic E. coli promoter (ECP) activity of the viral genome in bacteria, as measured using fusion constructs containing DENV2 or JEV segments and the reporter gene Renilla luciferase in an empty vector. The growth kinetics of recombinant viruses derived from DNA-launched DENV2 and JEV infectious cDNAs were similar to those of parental viruses. Similarly, RNA-launched DENV2 infectious cDNAs were generated by inserting 7XTRE-CMVmin, five repeats of the GAL4 upstream activating sequence (5XGAL4), or five repeats of BamHI linkers (5XBamHI) upstream of the DENV2 genome. All three tandem repeat sequences decreased the ECP activity of the DENV2 genome in bacteria. Notably 7XTRE-CMVmin stabilized RNA-launched JEV infectious cDNAs and reduced the ECP activity of the JEV genome in bacteria. The growth kinetics of recombinant viruses derived from RNA-launched DENV2 and JEV infectious cDNAs displayed patterns similar to those of the parental viruses. These results support a novel methodology for constructing flavivirus infectious cDNAs, which will facilitate research in virology, viral pathogenesis, and vaccine development of flaviviruses and other RNA viruses.
- Hemophagocytic Lymphohistiocytosis Syndrome in Dengue Hemorrhagic Fever.
Raju S, Kalyanaraman S, Swaminathan K, et al. Hemophagocytic Lymphohistiocytosis Syndrome in Dengue Hemorrhagic Fever. [JOURNAL ARTICLE]Indian J Pediatr 2014 Apr 15.AbstractPublisher Full TextHemophagocytic lymphohistiocytosis (HLH) is a life threatening florid activation of macrophages of the lymphoreticular system. It is reported to be associated with dengue in children in India and carries a high mortality. Patients present with high fever, worsening blood cell counts, splenomegaly, abnormal liver enzymes with features of liver failure, coagulopathy and neurological complications. The diagnosis is according to "Diagnostic Guidelines for HLH 2004", based on a triad of clinical, blood parameters and bone marrow cytology. In the present study, data of 212 children admitted with dengue were analyzed. Of 212 children, 31 children were classified as suspect HLH and advised bone marrow evaluation; of whom 23 children had marrow evidence of HLH. Worsening of blood cell counts were recorded in all children with a mean platelet count of 58,303.03 cells/cumm, low hematocrit in 95.65 %, low mean hemoglobin level of 8.37 g/dL, high erythrocyte sedimentation rate (ESR) and prolonged pro-thrombin time/international normalization ratio (PT/INR). Serum triglycerides, ferritin and transaminases were high. Of the 23 children, 19 patients received intravenous immunoglobulin (IVIG) and all of these children recovered. Dengue with multi-organ dysfunction is commonly concurrent to HLH in the marrow and hence, an early diagnosis based on clinical, laboratory and bone marrow evaluation is significant. A bone marrow evaluation confirms the diagnosis of HLH.
- A Meta-Analysis of the Diagnostic Accuracy of Two Commercial NS1 Antigen ELISA Tests for Early Dengue Virus Detection.
Costa VG, Marques-Silva AC, Moreli ML A Meta-Analysis of the Diagnostic Accuracy of Two Commercial NS1 Antigen ELISA Tests for Early Dengue Virus Detection. [Journal Article]PLoS One 2014; 9(4):e94655.AbstractPMC Free Full TextPublisher Full TextDengue virus (DENV) NS1 antigen detection is regarded as an early diagnostic marker. Accordingly, several studies have evaluated the performance of tests that utilize NS1 capture, but the results of individual studies may be limited due to the restricted sample size of the patients recruited. Therefore, our objective was to perform a meta-analysis of the diagnostic accuracy of two commercial NS1 ELISAs (Panbio and Platelia).Studies of interest were found in PubMed, Embase and Google Scholar databases using defined inclusion/exclusion criteria. A total of 30 studies containing 12,105 total enrolled patients were included. The results were as follows: 1) Panbio assays showed low overall performance, sensitivity 66% (95% confidence interval (CI) 61-71), specificity 99% (95% CI 96-100), positive likelihood ratio (LR+) 98 (95% CI 20-464), negative likelihood ratio (LR-) 0.3 (95% CI 0.2-0.4), diagnostic odds ratio (DOR) 289 (95% CI 59-1412); 2) Platelia assays showed high overall performance, sensitivity 74% (95% CI 63-82), specificity 99% (95% CI 97-100), LR+ 175 (95% CI 28-1099), LR- 0.3 (95% CI 0.2-0.4), DOR 663 (95% CI 98-4478). The lowest sensitivity values were for secondary infections (57% [95% CI 47-67] and 66% [95% CI 53-77] for Panbio and Platelia, respectively) and for the detection of DENV4. Regarding clinical manifestations, the sensitivity of Platelia was 69% (95% CI 43-86) and 60% (95% CI 48-70) for fever and dengue hemorrhagic fever, respectively. In addition, the sensitivity of both tests was slightly lower for samples from Southeast Asia and Oceania.DENV1 samples gave higher sensitivity results for both tests. We observed that factors negatively influencing the tests, such as the type of infection, geographical origins of samples and viral serotypes, require further investigation to optimize the diagnostic accuracy.
- Ribosomal Protein S29 Regulates Metabolic Insecticide Resistance through Binding and Degradation of CYP6N3.
Yu J, Hu S, Ma K, et al. Ribosomal Protein S29 Regulates Metabolic Insecticide Resistance through Binding and Degradation of CYP6N3. [Journal Article]PLoS One 2014; 9(4):e94611.AbstractPMC Free Full TextPublisher Full TextMany diseases are transmitted by mosquitoes, including malaria, dengue fever, yellow fever, filariasis, and West Nile fever. Chemical control plays a major role in managing mosquito-borne diseases. However, excessive and continuous application of insecticides has caused the development of insecticide resistance in many species including mosquito, and this has become the major obstacle to controlling mosquito-borne diseases. Insecticide resistance is the result of complex polygenic inheritance, and the mechanisms are not well understood. Ribosomal protein RPS29 was found to be associated with DM resistance in our previous study. In this study, we aim to further investigate the involvement of RPS29 in deltamethrin resistance.In this study, tandem affinity purification was used to identify proteins that can interact with RPS29. Among the candidate proteins, CYP6N3, a member of the CYP450 superfamily, was identified, and binding to RPS29 was confirmed in vitro and in vivo by GST pull-down and immunofluorescence. CCK-8 assay was used to investigate the RPS29-CTP6N3 interaction in relation to DM resistance. CYP6N3 overexpression significantly enhanced DM resistance and insect cell viability, but this was reversed by RPS29 overexpression. Western blot was used to study the mechanism of interaction between RPS29 and CYP6N3. RPS29 increases CYP6N3 protein degradation through the proteasome.These observations indicate that CYP6N3, a novel RPS29-interacting partner, could stimulate deltamethrin resistance in mosquito cells and RPS29 overexpression targeted CYP6N3 for proteosomal degradation, abrogating the CYP6N3-associated resistence to deltamethrin. Our findings provide a novel mechanism associated with CYP450s mediated DM resistance.
- Lack of clinical manifestations in asymptomatic dengue infection is attributed to broad down-regulation and selective up-regulation of host defence response genes.
Yeo AS, Azhar NA, Yeow W, et al. Lack of clinical manifestations in asymptomatic dengue infection is attributed to broad down-regulation and selective up-regulation of host defence response genes. [Journal Article]PLoS One 2014; 9(4):e92240.AbstractPMC Free Full TextPublisher Full TextDengue represents one of the most serious life-threatening vector-borne infectious diseases that afflicts approximately 50 million people across the globe annually. Whilst symptomatic infections are frequently reported, asymptomatic dengue remains largely unnoticed. Therefore, we sought to investigate the immune correlates conferring protection to individuals that remain clinically asymptomatic.We determined the levels of neutralizing antibodies (nAbs) and gene expression profiles of host immune factors in individuals with asymptomatic infections, and whose cognate household members showed symptoms consistent to clinical dengue infection.We observed broad down-regulation of host defense response (innate, adaptive and matrix metalloprotease) genes in asymptomatic individuals as against symptomatic patients, with selective up-regulation of distinct genes that have been associated with protection. Selected down-regulated genes include: TNF α (TNF), IL8, C1S, factor B (CFB), IL2, IL3, IL4, IL5, IL8, IL9, IL10 and IL13, CD80, CD28, and IL18, MMP8, MMP10, MMP12, MMP15, MMP16, and MMP24. Selected up-regulated genes include: RANTES (CCL5), MIP-1α (CCL3L1/CCL3L3), MIP-1β (CCL4L1), TGFβ (TGFB), and TIMP1.Our findings highlight the potential association of certain host genes conferring protection against clinical dengue. These data are valuable to better explore the mysteries behind the hitherto poorly understood immunopathogenesis of subclinical dengue infection.
- Optimization of dengue immunoassay by label-free interferometric optical detection method.
Laguna MF, Holgado M, Sanza FJ, et al. Optimization of dengue immunoassay by label-free interferometric optical detection method. [Journal Article]Sensors (Basel) 2014; 14(4):6695-700.AbstractPublisher Full TextIn this communication we report a direct immunoassay for detecting dengue virus by means of a label-free interferometric optical detection method. We also demonstrate how we can optimize this sensing response by adding a blocking step able to significantly enhance the optical sensing response. The blocking reagent used for this optimization is a dry milk diluted in phosphate buffered saline. The recognition curve of dengue virus over the proposed surface sensor demonstrates the capacity of this method to be applied in Point of Care technology.