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 to go off the radar by December 15 - Times of India
  Fri, 06 Dec 2013 22:10:
• Invincible dengue… Anti-dengue spray ineffective, Reveals Report - PakistanToday.com.pk
  Fri, 06 Dec 2013 19:39:
• 23 get dengue, two die - PakistanToday.com.pk
  Fri, 06 Dec 2013 18:15:
• Dengue Fever: Another Formidable World Cup Opponent - Huffington Post
  Fri, 06 Dec 2013 13:36:
• 18 more test positive for dengue in city - The News International
  Fri, 06 Dec 2013 09:54:
• Dengue situation in Orchard Rd stabilises - Channel News Asia
  Thu, 05 Dec 2013 13:42:
• Dengue Fever rocks Khmer vibe - The Desert Sun
  Fri, 06 Dec 2013 01:52:
• Dengue vaccine to be tested in India: reports - Business Recorder
  Thu, 05 Dec 2013 23:39:
• 18 more dengue fever cases - Pakistan Daily Times
  Thu, 05 Dec 2013 20:59:
• Dengue problem over in Islamabad - The News International
  Thu, 05 Dec 2013 05:53:

• PRO/EDR> Chikungunya (51): Singapore, Philippines
  Thu, 05 Dec 2013 20:09:22
  Chikungunya -- Singapore
  The mosquito-borne chikungunya virus appears to have become endemic in Singapore, after it had seemingly been eradicated.
  The dengue-like disease took hold in April [2013] and there have been 924 cases this year [2013] -- of which 881 were locally transmitted. Last week [week of 25 Nov 2013], there were 36 new cases.
  The National Environment Agency (NEA) said the bulk of the infections have been in the Sungei Kadut and Bukit Timah/Holland areas, although 4 of last week's cases were in
• PRO/EDR> Chikungunya (51): Singapore, Philippines
  Thu, 05 Dec 2013 20:09:22
  Chikungunya -- Philippines
  The mosquito-borne chikungunya virus appears to have become endemic in Singapore, after it had seemingly been eradicated.
  The dengue-like disease took hold in April [2013] and there have been 924 cases this year [2013] -- of which 881 were locally transmitted. Last week [week of 25 Nov 2013], there were 36 new cases.
  The National Environment Agency (NEA) said the bulk of the infections have been in the Sungei Kadut and Bukit Timah/Holland areas, although 4 of last week's cases were in

• Dengue virus type 2: protein binding and active replication in human central nervous system cells.
  Salazar MI, Pérez-García M, Terreros-Tinoco M, et al. Dengue virus type 2: protein binding and active replication in human central nervous system cells. [Journal Article]ScientificWorldJournal 2013.:904067.AbstractPublisher Full TextAn increased number of dengue cases with neurological complications have been reported in recent years. The lack of reliable animal models for dengue has hindered studies on dengue virus (DENV) pathogenesis and cellular tropism in vivo. We further investigate the tropism of DENV for the human central nervous system (CNS), characterizing DENV interactions with cell surface proteins in human CNS cells by virus overlay protein binding assays (VOPBA) and coimmunoprecipitations. In VOPBA, three membrane proteins (60, 70, and 130 kDa) from the gray matter bound the entire virus particle, whereas only a 70 kDa protein bound in white matter. The coimmunoprecipitation assays revealed three proteins from gray matter consistently binding virus particles, one clearly distinguishable protein (~32 kDa) and two less apparent proteins (100 and 130 kDa). Monoclonal anti-NS3 targeted the virus protein in primary cell cultures of human CNS treated with DENV-2, which also stained positive for NeuH, a neuron-specific marker. Thus, our results indicate (1) that DENV-2 exhibited a direct tropism for human neurons and (2) that human neurons sustain an active DENV replication as was demonstrated by the presence of the NS3 viral antigen in primary cultures of these cells treated with DENV-2.
• West nile virus drug discovery.
  Lim SP, Shi PY West nile virus drug discovery. [Journal Article]Viruses 2013; 5(12):2977-3006.AbstractPublisher Full TextThe outbreak of West Nile virus (WNV) in 1999 in the USA, and its continued spread throughout the Americas, parts of Europe, the Middle East and Africa, underscored the need for WNV antiviral development. Here, we review the current status of WNV drug discovery. A number of approaches have been used to search for inhibitors of WNV, including viral infection-based screening, enzyme-based screening, structure-based virtual screening, structure-based rationale design, and antibody-based therapy. These efforts have yielded inhibitors of viral or cellular factors that are critical for viral replication. For small molecule inhibitors, no promising preclinical candidate has been developed; most of the inhibitors could not even be advanced to the stage of hit-to-lead optimization due to their poor drug-like properties. However, several inhibitors developed for related members of the family Flaviviridae, such as dengue virus and hepatitis C virus, exhibited cross-inhibition of WNV, suggesting the possibility to re-purpose these antivirals for WNV treatment. Most promisingly, therapeutic antibodies have shown excellent efficacy in mouse model; one of such antibodies has been advanced into clinical trial. The knowledge accumulated during the past fifteen years has provided better rationale for the ongoing WNV and other flavivirus antiviral development.
• Aedes albopictus (Skuse) males in laboratory and semi-field cages: Release ratios and mating competitiveness.
  Madakacherry O, Lees RS, Gilles JR Aedes albopictus (Skuse) males in laboratory and semi-field cages: Release ratios and mating competitiveness. [JOURNAL ARTICLE]Acta Trop 2013 Nov 30.AbstractPublisher Full TextTo control the container-breeding mosquito and major vector of dengue and chikungunya Aedes albopictus, the sterile insect technique (SIT) is proposed as a component of integrated vector management programs in endemic areas. For the technique to be successful released males, sterilized with 35Gy of ionizing radiation during the pupal stage, must be able to compete for mating opportunities with wild counterparts and successfully copulate with wild females to induce sterility in the population. Any reduction in competitiveness can be compensated for by increasing the ratio of released sterile to wild males, a ratio which must be optimized for effectiveness and efficiency. Fruit fly SIT programs use field enclosures to test the competitiveness of sterile males to monitor the quality of the colony and adjust release ratios. This is laborious and time consuming, and for mosquito programs it would be advantageous if similarly useful results could be obtained by smaller scale laboratory tests, conducted on a more regular basis. In the present study we compared the competitiveness, as measured by hatching rate of resulting egg batches, of irradiated males measured in small and large laboratory cages and semi-field enclosures in a greenhouse setting, when competing in a 1:1, 3:1 and 5:1 ratio with fertile males. The sterile males were found to be equally competitive when compared to unirradiated counterparts, and a 5:1 ratio was sufficient to reduce, but not eliminate, the fertility of the female populations, irrespective of cage size. Variability in hatch rate in eggs laid by individual females and so-called indeterminate matings, when we could not be certain whether a female had mated a fertile or a sterile male, could be investigated by closer investigation of mating status and the frequency of multiple matings in Ae. albopictus. The laboratory results are encouraging for the effectiveness of the SIT using irradiated males of this species, and we support further assessment in the field.
• Differential transcription profiles in Aedes aegypti detoxification genes after temephos selection.
  Saavedra-Rodriguez K, Strode C, Flores AE, et al. Differential transcription profiles in Aedes aegypti detoxification genes after temephos selection. [JOURNAL ARTICLE]Insect Mol Biol 2013 Dec 3.AbstractPublisher Full TextThe mosquito Aedes aegypti is the main vector of Dengue and Yellow Fever flaviviruses. The organophosphate insecticide temephos is a larvicide that is used globally to control Ae. aegypti populations; many of which have in turn evolved resistance. Target site alteration in the acetylcholine esterase of this species has not being identified. Instead, we tracked changes in transcription of metabolic detoxification genes using the Ae. aegypti 'Detox Chip' microarray during five generations of temephos selection. We selected for temephos resistance in three replicates in each of six collections, five from Mexico, and one from Peru. The response to selection was tracked in terms of lethal concentrations. Uniform upregulation was seen in the epsilon class glutathione-S-transferase (eGST) genes in strains from Mexico prior to laboratory selection, while eGSTs in the Iquitos Peru strain became upregulated after five generations of temephos selection. While expression of many carboxyl/cholinesterase esterase (CCE) genes increased with selection, no single esterase was consistently upregulated and this same pattern was noted in the cytochrome P450 monooxygenase (CYP) genes and in other genes involved in reduction or oxidation of xenobiotics. Bioassays using glutathione-S-transferase (GST), CCE and CYP inhibitors suggest that various CCEs instead of GSTs are the main metabolic mechanism conferring resistance to temephos. We show that temephos-selected strains show no cross resistance to permethrin and that genes associated with temephos selection are largely independent of those selected with permethrin in a previous study.
• Development of clinical decision rules to predict recurrent shock in dengue.
  Huy NT, Thao NT, Ha TT, et al. Development of clinical decision rules to predict recurrent shock in dengue. [JOURNAL ARTICLE]Crit Care 2013 Dec 2; 17(6):R280.AbstractPublisher Full TextMortality from dengue infection is mostly due to shock. Among dengue patients with shock, approximately 30% have recurrent shock that requires a treatment change. Here, we report development of a clinical rule for use during a patient's first shock episode to predict a recurrent shock episode.The study was conducted in Center for Preventive Medicine in Vinh Long province and the Children's Hospital No. 2 in Ho Chi Minh City, Vietnam. We included 444 dengue patients with shock, 126 of whom had recurrent shock (28%). Univariate and multivariate analyses and a preprocessing method were used to evaluate and select 14 clinical and laboratory signs recorded at shock onset. Five variables including admission day, purpura/ecchymosis, ascites/pleural effusion, blood platelet count, and pulse pressure was finally trained and validated by a 10-fold validation strategy with 10 times of repetition, using a logistic regression model.Results showed that shorter admission day (fever days prior to admission), purpura/ecchymosis, ascites/pleural effusion, low platelet count, and narrow pulse pressure were independently associated with recurrent shock. Our logistic prediction model was capable of predicting recurrent shock when compared to the null method (p < 0.05) and was not outperformed by other prediction models. Our final scoring rule provided relatively good accuracy (AUC, 0.73; sensitivity and specificity, 68%). Score points derived from the logistic prediction model revealed identical accuracies with AUCs at 0.73. Using a cutoff value > -154.5, our simple scoring rule showed a sensitivity of 68.3% and a specificity of 68.2%.Our simple clinical rule is not to replace clinical judgment but to help clinicians to predict recurrent shock during a patient's first dengue shock episode.
• Synthesis, Activity, and QSAR Studies of Tryptamine Derivatives on Third-instar Larvae of Aedes aegypti Linn.
  Oliveira RR, Brito TB, Nepel A, et al. Synthesis, Activity, and QSAR Studies of Tryptamine Derivatives on Third-instar Larvae of Aedes aegypti Linn. [JOURNAL ARTICLE]Med Chem 2013 Dec 2.Special attention has been given to the mosquito Aedes aegypti Linn. (Diptera: Culicidae) owing to numerous dengue epidemic outbreaks worldwide. Failure to control vector spreading is accounted for unorganized urban growth and resistance to larvicides and insecticides. Therefore, researchers are currently searching for new and more efficient larvicides and insecticides to aid dengue control measures. Triptamine is known to affect insect behavior, development, and physiology. Expression of this compound in plants has reduced the growth rate of herbivore insects. In view of these facts, it was of our interest to synthesize triptamine amide derivatives as potential larvicides against Ae. aegypti, establishing an Structure-Activity Relationship. Eleven amide derivatives of triptamine were synthesized, characterized, and evaluated for their larvicidal activity against third-instar Ae. aegypti larvae. N-(2-(1H-indol-3-yl)ethyl)-2,2,2-trichloroacetamide exhibited the highest overall larvicidal potency, while N-(2-(1H-Indol-3-yl)ethyl) acetamide displayed the lowest larvicidal potency. A regression equation correlating the larvicidal activity with Log P was obtained. We have found a clear relationship between the larvicidal activity of non-chlorinated compounds and Log P. Analysis of the relationship between Log P and larvicidal activity against Ae. aegypti may be useful in the evaluation of potential larvicidal compounds.
• Role of Vascular Endothelial Growth Factor (VEGF) in the Neurological Manifestations of Dengue: A Preliminary Study.
  Misra UK, Kalita J, Singh AP Role of Vascular Endothelial Growth Factor (VEGF) in the Neurological Manifestations of Dengue: A Preliminary Study. [JOURNAL ARTICLE]Inflammation 2013 Dec 1.AbstractPublisher Full TextThis study reports on vascular endothelial growth factor (VEGF) in dengue patients with neurological manifestations. Their bleeding diathesis, hypotension, edema, flushing, and hepatosplenomegaly were noted. Complete blood counts, serum chemistry, coagulation profile, liver and kidney function tests, creatine kinase (CK), and MRI in encephalopathic patients were carried out. Serum VEGF was estimated by ELISA in 21 dengue patients and 14 controls. Twelve patients had dengue fever (DF), eight dengue hemorrhagic fever (DHF), and one dengue shock syndrome (DSS). Fifteen patients had neurological manifestation, 12 had muscle involvement (raised CK with or without weakness), and 3 had encephalopathy. The VEGF level in dengue patients was 50.0 ± 56.1 pg/mL and in the controls, 60.6 ± 20.3 pg/mL. The VEGF level neither correlated with the severity nor with the neurological involvement. Thrombocytopenia, however, correlated with the severity of dengue and neurological manifestations. The VEGF level is not related to the severity of dengue and neurological syndrome.
• Dengue infection in dhaka city, bangladesh.
  Sharmin R, Tabassum S, Mamun KZ, et al. Dengue infection in dhaka city, bangladesh. [Journal Article]Mymensingh Med J 2013 Oct; 22(4):781-6.Dengue fever (DF) and dengue haemorrhagic fever (DHF) are now endemic in Bangladesh with outbreaks being reported quite frequently. This cross sectional study was done clinically suspected dengue patients were selected from different hospitals of Dhaka city, Bangladesh, from January 2008 to December 2008. The clinical features, risk factors and laboratory findings associated with dengue infection were investigated among 201 clinically suspected patients. Antibodies were detected in 137(68.2%) cases. Of these, 80(58.4%) were primary and 57(41.6%) as secondary dengue cases according to presence of dengue-specific IgM and/or IgG antibodies. Among primary cases, 70(87.5%) were DF and 10(12.5%) were DHF cases, in contrast to secondary cases, where 10(18.1%) were DF and 47(81.9%) were DHF cases. Majority (57.9%) of patients presented with Grade I and 42.1% had Grade II disease. Patients between 16-30 years were the most vulnerable age group (81.3% DF and 71.9% DHF patients). Males out-numbered females with 72.5% male vs. 27.5% female patients having DF and 68.4% male vs. 31.6% female patients having DHF. The monsoon period was the peak season for dengue infection. Headache and arthralgia were the most frequent symptoms in both DF and DHF, but vomiting was more common in DHF. The Tourniquet test was significantly positive among DHF than DF cases (p = 0.001). Platelet count was the only laboratory parameter that showed significantly higher values among DHF than DF cases (p = 0.001).
• Projecting the impact of climate change on dengue transmission in Dhaka, Bangladesh.
  Banu S, Hu W, Guo Y, et al. Projecting the impact of climate change on dengue transmission in Dhaka, Bangladesh. [JOURNAL ARTICLE]Environ Int 2013 Nov 28.:137-142.AbstractPublisher Full TextWeather variables, mainly temperature and humidity influence vectors, viruses, human biology, ecology and consequently the intensity and distribution of the vector-borne diseases. There is evidence that warmer temperature due to climate change will influence the dengue transmission. However, long term scenario-based projections are yet to be developed. Here, we assessed the impact of weather variability on dengue transmission in a megacity of Dhaka, Bangladesh and projected the future dengue risk attributable to climate change. Our results show that weather variables particularly temperature and humidity were positively associated with dengue transmission. The effects of weather variables were observed at a lag of four months. We projected that assuming a temperature increase of 3.3°C without any adaptation measure and changes in socio-economic condition, there will be a projected increase of 16,030 dengue cases in Dhaka by the end of this century. This information might be helpful for the public health authorities to prepare for the likely increase of dengue due to climate change. The modelling framework used in this study may be applicable to dengue projection in other cities.
• Complex behavior in a dengue model with a seasonally varying vector population.
  McLennan-Smith TA, Mercer GN Complex behavior in a dengue model with a seasonally varying vector population. [JOURNAL ARTICLE]Math Biosci 2013 Nov 27.AbstractPublisher Full TextIn recent decades, dengue fever and dengue hemorrhagic fever have become a substantial public health concern in many subtropical and tropical countries throughout the world. Many of these regions have strong seasonal patterns in rainfall and temperature which are directly linked to the transmission of dengue through the mosquito vector population. Our study focuses on the development and analysis of a strongly seasonally forced, multi-subclass dengue model. This model is a compartment-based system of first-order ordinary differential equations with seasonal forcing in the vector population and also includes host population demographics. Our analysis of this model focuses particularly on the existence of deterministic chaos in regions of the parameter space which potentially hinders application of the model to predict and understand future outbreaks. The numerically efficient 0-1 test for deterministic chaos suggested by Gottwald and Melbourne (2004) is used to analyze the long-term behavior of the model as an alternative to Lyapunov exponents. Various solutions types were found to exist within the studied parameter range. Most notable are the existence of isola n-cycle solutions before the onset of deterministic chaos. Analysis of the seasonal model with the 0-1 test revealed the existence of three disconnected regions in parameter space where deterministic chaos exists in the single subclass model. Knowledge of these regions and how they relate to the parameters of the model gives greater confidence in the predictive power of the seasonal model.