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.
- Hukumpet witnesses outbreak of dengue - Deccan Chronicle
Tue, 23 Sep 2014 00:41:
- Pvt hospitals' dengue report card does not reach UT - Times of India
Tue, 23 Sep 2014 00:26:
- Dengue on the rise, 100 down in Bandra alone - Daily News & Analysis
Mon, 22 Sep 2014 23:53:
- No sweat: Threat of dengue-fever minimal this year say experts - The Express Tribune
Mon, 22 Sep 2014 23:48:
- Sahakarnagar high-risk zone for dengue: Survey - Times of India
Mon, 22 Sep 2014 23:17:
- 'Put dengue preventive measures in place' - Times of India
Mon, 22 Sep 2014 22:50:
- 62-yr-old tests positive for dengue in Noida - Times of India
Mon, 22 Sep 2014 22:35:
- DRG experts say no fear of dengue outbreak this year - Daily Times
Mon, 22 Sep 2014 22:16:
- President Maduro creates committee against dengue fever and chikungunya - El Universal
Mon, 22 Sep 2014 21:16:
- No fear of dengue outbreak this year: PU experts - Pakistan Today
Mon, 22 Sep 2014 20:24:
- Genetic Diversity of Brazilian Aedes aegypti: Patterns following an Eradication Program.
Monteiro FA, Shama R, Martins AJ, et al. Genetic Diversity of Brazilian Aedes aegypti: Patterns following an Eradication Program. [Journal Article]PLoS Negl Trop Dis 2014 Sep; 8(9):e3167.AbstractPublisher Full TextAedes aegypti is the most important vector of dengue fever in Brazil, where severe epidemics have recently taken place. Ae. aegypti in Brazil was the subject of an intense eradication program in the 1940s and 50s to control yellow fever. Brazil was the largest country declared free of this mosquito by the Pan-American Health Organization in 1958. Soon after relaxation of this program, Ae. aegypti reappeared in this country, and by the early 1980s dengue fever had been reported. The aim of this study is to analyze the present-day genetic patterns of Ae. aegypti populations in Brazil.We studied the genetic variation in samples of 11 widely spread populations of Ae. aegypti in Brazil based on 12 well-established microsatellite loci. Our principal finding is that present-day Brazilian Ae. aegypti populations form two distinct groups, one in the northwest and one in the southeast of the country. These two groups have genetic affinities to northern South American countries and the Caribbean, respectively. This is consistent with what has been reported for other genetic markers such as mitochondrial DNA and allele frequencies at the insecticide resistance gene, kdr.We conclude that the genetic patterns in present day populations of Ae. aegypti in Brazil are more consistent with a complete eradication of the species in the recent past followed by re-colonization, rather than the alternative possibility of expansion from residual pockets of refugia. At least two colonizations are likely to have taken place, one from northern South American countries (e.g., Venezuela) that founded the northwestern group, and one from the Caribbean that founded the southeastern group. The proposed source areas were never declared free of Ae. aegypti.
- [Exanthems and fever in travellers returning from the tropics.]
Fischer M, Schliemann S [Exanthems and fever in travellers returning from the tropics.] [JOURNAL ARTICLE]Hautarzt 2014 Sep 18.AbstractPublisher Full TextDengue fever with its subtle rash is today more common than malaria in travellers returning to Europe from the tropics (meta-analysis Geo Sentinel network). Up to 5 % of all safari tourists experience African tick bite fever during or soon after their journey; it is caused by rickettsiae and clinically presents with exanthems, focal necrotizing vasculitis (eschar, tache noir), lymphadenopathy and moderate fever. Typhoid fever is a severe infectious disease is which is difficult to diagnosis at first assessment. The presence of rose spots, which may be found in up to 33 % of patients with typhoid fever, can lead the way to diagnosis. Exanthems can be subtle and may occur weeks after infection without any other distinctive clinical sign. Particular importance in travel medicine has to be paid to acute HIV infection and secondary syphilis after exposition and infection in the tropics. Also the highly contagious infectious diseases of childhood as measles and rubeola have to be taken into account in adults with no or insufficient vaccination after a stay in tropical countries.
- Molecular mimicry between dengue virus and coagulation factors induces antibodies to inhibit thrombin activity and enhance fibrinolysis.
Chuang YC, Lin YS, Liu HS, et al. Molecular mimicry between dengue virus and coagulation factors induces antibodies to inhibit thrombin activity and enhance fibrinolysis. [JOURNAL ARTICLE]J Virol 2014 Sep 17.AbstractPublisher Full TextDengue virus (DENV) is the most common cause of viral hemorrhagic fever, and it may lead to life-threating dengue hemorrhagic fever and shock syndrome (DHF/DSS). Because most cases of DHF/DSS occur in patients with secondary DENV infection, anti-DENV antibodies are generally considered to play a role in the pathogenesis of DHF/DSS. Previously, we have found that anti-thrombin antibodies (ATAs) with both anti-thrombotic and profibrinolytic activities are present in the sera of dengue patients. However, the mechanism by which these autoantibodies are induced is unclear. In this study, we demonstrated that antibodies induced by DENV immunization in mice and rabbits could bind to DENV antigens as well as to human thrombin and plasminogen (Plg). The binding of anti-DENV antibodies to thrombin and Plg was inhibited by pre-adsorption with DENV nonstructural protein 1. In addition, affinity-purified ATAs from DENV-immunized rabbit sera could inhibit thrombin activity and enhance Plg activation both in vitro and in vivo. Taken together, our results suggest that molecular mimicry between DENV and coagulation factors can induce the production of autoantibodies with biological effects similar to those of ATAs found in dengue patients. These coagulation factor cross-reactive anti-DENV antibodies can interfere with the balance of coagulation and fibrinolysis, which may lead to the tendency of DHF/DSS patients to bleed.Dengue virus (DENV) infection is the most common mosquito-borne viral disease in tropical and sub-tropical areas. Over 50 million DENV infection cases develop each year, and more than 2.5 billion people are at risk of dengue-induced hemorrhagic fever and shock syndrome. Currently, there is no vaccine or drug treatment for DENV. In the present study, we demonstrated that DENV immunization could induce thrombin and plasminogen (Plg) cross-reactive antibodies, which were able to inhibit thrombin activity and enhance Plg activation. These results suggest that molecular mimicry between DENV antigens, thrombin, and Plg may elicit antibodies that disturb hemostasis. The selection of appropriate candidate antigens for use in DENV vaccines should prevent these potentially dangerous autoimmune responses.
Guzman MG, Harris E Dengue. [REVIEW]Lancet 2014 Sep 12.Dengue viruses have spread rapidly within countries and across regions in the past few decades, resulting in an increased frequency of epidemics and severe dengue disease, hyperendemicity of multiple dengue virus serotypes in many tropical countries, and autochthonous transmission in Europe and the USA. Today, dengue is regarded as the most prevalent and rapidly spreading mosquito-borne viral disease of human beings. Importantly, the past decade has also seen an upsurge in research on dengue virology, pathogenesis, and immunology and in development of antivirals, vaccines, and new vector-control strategies that can positively impact dengue control and prevention.
- Multiobjective Genetic Algorithm applied to dengue control.
Florentino HO, Cantane DR, Santos FL, et al. Multiobjective Genetic Algorithm applied to dengue control. [REVIEW]Math Biosci 2014 Sep 13.AbstractPublisher Full TextDengue fever is an infectious disease caused by a virus of the Flaviridae family and transmitted to the person by a mosquito of the genus Aedes aegypti. This disease has been a global public health problem because a single mosquito can infect up to 300 people and between 50 and 100 million people are infected annually on all continents. Thus, dengue fever is currently a subject of research, whether in the search for vaccines and treatments for the disease or efficient and economical forms of mosquito control. The current study aims to study techniques of multiobjective optimization to assist in solving problems involving the control of the mosquito that transmits dengue fever. The population dynamics of the mosquito is studied in order to understand the epidemic phenomenon and suggest strategies of multiobjective programming for mosquito control. A Multiobjective Genetic Algorithm (MGA_DENGUE) is proposed to solve the optimization model treated here and we discuss the computational results obtained from the application of this technique.
- FALSE-NEGATIVE DENGUE CASES IN RORAIMA, BRAZIL: AN APPROACH REGARDING THE HIGH NUMBER OF NEGATIVE RESULTS BY NS1 AG KITS.
Acosta PO, Granja F, Meneses CA, et al. FALSE-NEGATIVE DENGUE CASES IN RORAIMA, BRAZIL: AN APPROACH REGARDING THE HIGH NUMBER OF NEGATIVE RESULTS BY NS1 AG KITS. [JOURNAL ARTICLE]Rev Inst Med Trop Sao Paulo 2014 Sep; 56(5):447-450.Serum samples from 150 NS1-negative (Platelia ELISA) patients presumptively diagnosed with dengue were analyzed by the TaqMan probed real-time reverse transcription PCR (TaqMan qRT-PCR) method. The qRT-PCR positive samples were tested for serotype by semi-nested RT-PCR and a qualitative immunochromatographic assay for IgG and IgM. Molecular detection methods showed 33 (22%) positive samples out of 150 NS1-antigen negative samples. Of these, 72% were collected up to day 2 after the onset of symptoms, when diagnostic sensitivity of NS1-antigen test assays is significantly enhanced. Most of the cases were not characterized as secondary infection. Twenty-eight samples were successfully serotyped, 75% of which for DENV-4, 14% for DENV-2, 7% for DENV-3 and 4% for DENV-1. These findings reaffirm the hyperendemic situation of the state of Roraima and suggest a lower sensitivity of the NS1 test, mainly when DENV-4 is the predominant serotype. Health care providers should therefore be aware of samples tested negative by NS1 antigen assays, especially when clinical symptoms and other laboratory data results show evidence of dengue infection.
- LABORATORY EVALUATION OF THE DEVELOPMENT OF Aedes aegypti IN TWO SEASONS: INFLUENCE OF DIFFERENT PLACES AND DIFFERENT DENSITIES.
Lopes TF, Holcman MM, Barbosa GL, et al. LABORATORY EVALUATION OF THE DEVELOPMENT OF Aedes aegypti IN TWO SEASONS: INFLUENCE OF DIFFERENT PLACES AND DIFFERENT DENSITIES. [Journal Article]Rev Inst Med Trop Sao Paulo 2014 Sep; 56(5):369-74.AbstractPublisher Full TextAedes aegypti is an important vector in Brazil being the main vector of the dengue-fever. This paper employs survival curves to describe the time in days from larvae to adult forms of Aedes aegypti raised, individually and collectively, and compares it during winter and spring when positioned inside and outside a laboratory. The study was conducted in São Vicente, a coastal city in Southeastern Brazil. The lowest water temperature in winter and in spring was 20 °C and the highest was 26 °C in spring. Higher and more stable temperatures were measured in the intra compared to the peri in both seasons. Consequently, larvae positioned in the intra resulted in the lowest median time to develop in the individual and collective experiment (nine and ten days, respectively). At least 25% of the larvae positioned in the intra in the individual experiment in the spring took only seven days to reach adulthood. Sex ratios and the median time development by sex did not show significant differences. These results indicate that efforts to control Aedes aegypti must be continuous and directed mainly to prevent the intra-domiciliary sites that can be infested in a week in order to reduce the human-vector contact.
- [A possible fifth dengue virus serotype].
da Silva Voorham JM [A possible fifth dengue virus serotype]. [English Abstract, Journal Article]Ned Tijdschr Geneeskd 2014; 158(0):A7946.Sylvatic dengue viruses are both evolutionarily and ecologically distinguishable from the human dengue virus (DENV). Sporadic episodes of sylvatic human infections in West Africa and Southeast Asia suggest that sylvatic DENV regularly come into contact with human beings. Following a study on the sylvatic transmission cycle in Malaysia in 2007, researchers announced that a new DENV serotype, DENV-5, had been discovered. Scientists are still sceptical about these new findings, and indicate that more data is necessary to determine whether this 'new' virus really is a different serotype or whether it is a variant of one of the four DENV serotypes already known. The good news is that this new variant has not yet established itself in the human transmission cycle. However, if it really is a new serotype this will have implications for the long-term control of dengue using vaccines currently under development.
- Synthesis of silver nanoparticles from Azadirachta indica-a most effective method for mosquito control.
Poopathi S, De Britto LJ, Praba VL, et al. Synthesis of silver nanoparticles from Azadirachta indica-a most effective method for mosquito control. [JOURNAL ARTICLE]Environ Sci Pollut Res Int 2014 Sep 18.AbstractPublisher Full TextMosquitoes transmit major communicable diseases such as dengue, malaria, filariasis, Japanese encephalitis, chikungunya, and so on. Vector control is important in epidemic disease situations as there is an urgent need to develop new and improved mosquito control methods that are economical and effective yet safe for non-targeted organisms. In the present study, silver nanoparticles (AgNPs) were synthesized from the aqueous leaf extract of neem plant (Azadirachta indica), and their effects on mosquito vectors (Aedes aegypti and Culex quinquefasciatus) were assessed. The synthesised AgNPs were characterized by UV-vis spectroscopy, scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FT-IR), and X-ray diffraction analysis (XRD). The nanoparticles have maximum absorption at 442 ± 1.5 nm with an average size of 41-60 nm. The XRD data showed six well-defined diffraction peaks, corresponding to a relative intensity of the crystal structure of metallic silver 36.42, 100.00, 53.70, 14.20, 16.05, and 6.79, respectively. The FT-IR data showed strong prominent peaks in different ranges, reflecting its complex nature. The mosquito larvae were exposed to varying concentrations of AgNPs synthesized from the neem leaves under investigation (0.07-25 mg/l) for 24 h; this revealed larvicidal activity of AgNPs with LC50 and LC90 values of 0.006 and 0.04 mg/l for A. aegypti, respectively. Further, the LC50 and LC90 values were also identified as 0.047 and 0.23 mg/l for Cx. quinquefasciatus, respectively. The result obtained from this study presents biosynthesized silver nanoparticle from A. indica as the biolarvicidal agent with the most potential for mosquito control.
- Crossing the border.
Nuzback K Crossing the border. [Journal Article]Tex Med 2014; 110(9):41-4.Hot, humid locations like Southeast Texas provide the perfect environment for the spread of viruses travelers typically bring back to the United States after a trip to the tropics. For instance, dengue and other diseases that travel via mosquito can make their way to the U.S. Gulf Coast. According to the Texas Department of State Health Services (DSHS), 23 Texas patients acquired dengue locally in 2013 - a fourfold increase from the prior 10 years combined. And, dengue is not the only tropical disease to emerge in the United States. DSHS officials identified the first case of chikungunya, a virus also transmitted by mosquitoes, in Texas in July.