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The association between tropical cyclones and dengue fever in the Pearl River Delta, China during 2013-2018: A time-stratified case-crossover study.

BACKGROUND: Studies have shown that tropical cyclones are associated with several infectious diseases, while very few evidence has demonstrated the relationship between tropical cyclones and dengue fever. This study aimed to examine the potential impact of tropical cyclones on dengue fever incidence in the Pearl River Delta, China. METHODS: Data on daily dengue fever incidence, occurrence of tropical cyclones and meteorological factors were collected between June and October, 2013-2018 from nine cities in the Pearl River Delta. Multicollinearity of meteorological variables was examined via Sp…

T cell and memory B cell responses in tetravalent DNA, tetravalent inactivated and tetravalent live-attenuated prime-boost dengue vaccines in rhesus macaques.

We previously reported the efficacy of prime-boost vaccination using three tetravalent (T) dengue vaccines, DNA (TDNA), purified inactivated vaccine (TPIV), and live attenuated vaccine (TLAV). We demonstrated that the TPIV/TLAV prime-boost vaccination yielded the highest and most durable neutralizing antibodies and 100% protection to all 4 serotypes of dengue virus in rhesus macaques. This study compares gene transcription, T and B cell responses elicited by these prime-boost combinations in rhesus macaques. This study shows that the TLAV vaccine increased the expression of the innate immune g…

Brazilian Dengue Virus Type 2-Associated Renal Involvement in a Murine Model: Outcomes after Infection by Two Lineages of the Asian/American Genotype.

Dengue virus type 2 (DENV-2) is, traditionally, the most studied serotype due to its association with explosive outbreaks and severe cases. In Brazil, almost 20 years after the first introduction in the 1990s, a new lineage (Lineage II) of the DENV-2 Asian/American genotype emerged and caused an epidemic with severe cases and hospitalizations. Severe dengue includes multiple organ failure, and renal involvement can be potentially related to increased mortality. In order to better understand the role of DENV infection in renal injury, here we aimed to investigate the outcomes of infection with …

Ivermectin Accelerates Circulating Nonstructural Protein 1 (NS1) Clearance in Adult Dengue Patients: A Combined Phase 2/3 Randomized Double-blinded Placebo Controlled Trial.

BACKGROUND: Dengue is the most significant mosquito-borne viral disease; there are no specific therapeutics. The antiparasitic drug ivermectin efficiently inhibits the replication of all 4 dengue virus serotypes in vitro. METHODS: We conducted 2 consecutive randomized, double-blind, placebo-controlled trials in adult dengue patients to evaluate safety and virological and clinical efficacies of ivermectin. After a phase 2 trial with 2 or 3 days of 1 daily dose of 400 µg/kg ivermectin, we continued with a phase 3, placebo-controlled trial with 3 days of 400 µg/kg ivermectin. RESULTS: The phase…

Performance evaluation of machine learning-based infectious screening flags on the HORIBA Medical Yumizen H550 Haematology Analyzer for vivax malaria and dengue fever.

BACKGROUND: Automated detection of malaria and dengue infection has been actively researched for more than two decades. Although many improvements have been achieved, these solutions remain too expensive for most laboratories and clinics in developing countries. The low range HORIBA Medical Haematology Analyzer, Yumizen H550, now provides dedicated flags 'vivax malaria' and 'dengue fever' in routine blood testing, developed through machine learning methods, to be used as a screening tool for malaria and dengue fever in endemic areas. This study sought to evaluate the effectiveness of these fla…

ERG-Associated lncRNA (ERGAL) Promotes the Stability and Integrity of Vascular Endothelial Barrier During Dengue Viral Infection via Interaction With miR-183-5p.

Dengue virus (DENV) continues to be a major public health problem. DENV infection will cause mild dengue and severe dengue. Severe dengue is clinically manifested as serious complications, including dengue hemorrhagic fever and/or dengue shock syndrome (DHF/DSS), which is mainly characterized by vascular leakage. Currently, the pathogenesis of severe dengue is not elucidated thoroughly, and there are no known therapeutic targets for controlling the disease effectively. This study aimed to further reveal the potential molecular mechanism of severe dengue. In this study, the long non-coding RNA,…

Prophylactic platelet transfusion plus supportive care versus supportive care alone in adults with dengue and thrombocytopenia: a multicentre, open-label, randomised, superiority trial.

BACKGROUND: Dengue is the commonest vector-borne infection worldwide. It is often associated with thrombocytopenia, and prophylactic platelet transfusion is widely used despite the dearth of robust evidence. We aimed to assess the efficacy and safety of prophylactic platelet transfusion in the prevention of bleeding in adults with dengue and thrombocytopenia. METHODS: We did an open-label, randomised, superiority trial in five hospitals in Singapore and Malaysia. We recruited patients aged at least 21 years who had laboratory-confirmed dengue (confirmed or probable) and thrombocytopenia (≤20 …

Yellow Fever Virus, but Not Zika Virus or Dengue Virus, Inhibits T-Cell Receptor-Mediated T-Cell Function by an RNA-Based Mechanism.

The Flavivirus genus within the Flaviviridae family is comprised of many important human pathogens including yellow fever virus (YFV), dengue virus (DENV), and Zika virus (ZKV), all of which are global public health concerns. Although the related flaviviruses hepatitis C virus and human pegivirus (formerly named GBV-C) interfere with T-cell receptor (TCR) signaling by novel RNA and protein-based mechanisms, the effect of other flaviviruses on TCR signaling is unknown. Here, we studied the effect of YFV, DENV, and ZKV on TCR signaling. Both YFV and ZKV replicated in human T cells in vitro; howe…

Source and Purity of Dengue-Viral Preparations Impact Requirement for Enhancing Antibody to Induce Elevated IL-1β Secretion: A Primary Human Monocyte Model.

Dengue virus is a major global health threat and can lead to life-threatening hemorrhagic complications due to immune activation and cytokine production. Cross-reactive antibodies to an earlier dengue virus infection are a recognized risk factor for severe disease. These antibodies bind heterologous dengue serotypes and enhance infection into Fc-receptor-bearing cells, a process known as antibody-dependent enhancement of infection. One crucial cytokine seen elevated in severe dengue patients is IL-1β, a potent inflammatory cytokine matured by the inflammasome. We used a highly-physiologic syst…

Eugenol, α-pinene and β-caryophyllene from Plectranthus barbatus essential oil as eco-friendly larvicides against malaria, dengue and Japanese encephalitis mosquito vectors.

Mosquito-borne diseases represent a deadly threat for millions of people worldwide. Eco-friendly mosquitocides are a priority. In Ayurvedic medicine, Plectranthus species have been used to treat heart disease, convulsions, spasmodic pain and painful urination. In this research, we evaluated the acute toxicity of essential oil from Plectranthus barbatus and its major constituents, against larvae of the malaria vector Anopheles subpictus, the dengue vector Aedes albopictus and the Japanese encephalitis vector Culex tritaeniorhynchus. The chemical composition of P. barbatus essential oil was anal…

Larvicidal activity of the leaf extracts of Spondias mombin Linn. (Anacardiaceae) from various solvents against malarial, dengue and filarial vector mosquitoes (Diptera: Culicidae).

BACKGROUND & OBJECTIVES: Aedes aegypti, Anopheles gambiae and Culex quinquefasciatus are vector mosquitoes of dengue, malaria, and filariasis, respectively. Since no vaccine is available to treat these diseases, the control of the main mosquito vectors is essential. As conventional insecticides have limited success, plants may be alternative larvicidal agents, since they contain a rich source of bioactive chemicals. The aim of this study was to evaluate the larvicidal activity of methanol crude extract, hexane, dichloromethane, acetone, ethyl acetate and methanol fractions of Spondias mombin l…

Dengue virus 4 (DENV-4) re-emerges after 30 years in Brazil: cocirculation of DENV-2, DENV-3, and DENV-4 in Bahia.

Dengue fever (DF) is a mosquito-borne viral disease of great concern in tropical and subtropical regions of the world. One important cause of the increase in DF is rapid development and urbanization has led to proliferation of the Aedes aegypti mosquito, the vector responsible for transmission of the illness. Surveillance of dengue virus (DENV) infection in Brazil shows the predominance of DENV-1, DENV-2, and DENV-3 until 2010. This study reports the reappearance of DENV-4 in Brazil for the first time in 30 years. Serum samples were collected from individuals (n = 214) exhibiting fever and mus…

Co-existence of major and minor viral populations from two different origins in patients secondarily infected with dengue virus serotype 2 in Bangkok.

Generally, RNA viruses exhibit significant genetic diversity that sometimes effect viral fitness in infected hosts and probably also pathogenesis. Dengue viruses (DENVs) consist of four antigenically distinct serotypes. All the serotypes of DENV can cause mild to severe dengue illnesses. In this study, we examined the sequence variation of DENV in plasma obtained from four patients living in Bangkok who had been secondarily infected with serotype 2 (DENV-2) in 2010. The plasma-derived RNA was directly subjected to reverse transcriptase (RT)-polymerase chain reaction (PCR) at a region including…

A mouse-passaged dengue virus strain with reduced affinity for heparan sulfate causes severe disease in mice by establishing increased systemic viral loads.

The four serotypes of dengue virus (DENV1 to DENV4) cause extensive morbidity and mortality. A major obstacle to studying disease pathogenesis and developing therapies has been the lack of a small-animal model. We previously reported isolation of a DENV2 strain, obtained by passaging a clinical isolate between mosquito cells and mice, that caused severe DENV disease in mice and contained multiple mutations, including many in domain II of the envelope (E) protein. Here, we describe a recombinant virus, differing from the non-mouse-passaged virus by two mutations in the E protein, that induces v…

Dengue in Vietnamese infants--results of infection-enhancement assays correlate with age-related disease epidemiology, and cellular immune responses correlate with disease severity.

The pathogenesis of severe dengue is not well understood. Maternally derived subneutralizing levels of dengue virus-reactive IgG are postulated to be a critical risk factor for severe dengue during infancy. In this study, we found that, in healthy Vietnamese infants, there was a strong temporal association between the Fc-dependent, dengue virus infection-enhancing activity of neat plasma and the age-related epidemiology of severe dengue. We then postulated that disease severity in infants with primary infections would be associated with a robust immune response, possibly as a consequence of hi…

Гетерологический венесуэльский энцефалитный репликонный репликонный режим вакцины денге обеспечивает полную защиту от вирусного вызова в циномольгусе.

Потенциальная вакцина (D1ME-VRP), содержащая вирус денге типа 1 премембрана и белки конвертов в венесуэльской системе репликонных частиц (VRP), была построена и испытана в сочетании с плазмидной вакциной ДНК (D1ME-DNA), содержащей идентичные последовательности вирусов денге. Циномольгузные макаки были привиты тремя дозами ДНК (ДДД), тремя дозами ВРП (группа VVV) или гетерологическим редукционным режимом ДНК (DDV) с использованием двух доз вакцины ДНК и третьей дозы вакцины ВРП. Через четыре недели после окончательной иммунизации группа DDV произвела самые высокие вирусные вирусы денге типа 1,

Совпадение в аннотации оригинала
A candidate vaccine (D1ME-VRP) expressing dengue virus type 1 premembrane and envelope proteins in a Venezuelan equine encephalitis (VEE) virus replicon particle (VRP) system was constructed and tested in conjunction with a plasmid DNA vaccine (D1ME-DNA) expressing identical dengue virus sequences. Cynomolgus macaques were vaccinated with three doses of DNA …

[Development of multiplex reverse translation-polymerase chain reaction methods for detection of dengue virus type 1-4 and its application in clinical use].

OBJECTIVE: To develop multiplex reverse translation-polymerase chain reaction (RT-PCR) method for detection of dengue virus type 1-4. METHODS: Based on the genomes sequence analysis of dengue virus type 1-4, four-pair of primers were designed. The specificity of the primers was primarily tested by searching the GenBank DNA sequence database. The optimal reaction conditions of the multiplex RT-PCR were then established. The specificity of RT-PCR was tested using the homologous yellow fever virus and Japanese encephalitis virus. 30 serum samples of dengue virus from suspected sufferers in the p…

Иммуномасса, направленная на неструктурный белок 5, чтобы отличить вирусную инфекцию Западного Нила от лихорадки денге и св. Заражение вирусом энцефалита Луиса и вакцинация от флавивируса.

Вирус Западного Нила (ВНВ) — формирующийся аромат, вызывающий частые эпидемии с 1996 года. Помимо естественной передачи от комаров, ВНВ может также передаваться путем переливания крови и трансплантации органов, что повышает неотложность разработки конкретного и быстрого серологического анализа инфекции ВНВ. Нынешним иммуномассиям не хватает конкретности, поскольку они основаны на обнаружении антител против структурных белков ВНВ и на иммунной реакции на структурные белки среди флавивирусов, реагирующих друг на друга. Здесь мы описываем микросферные иммунассаи, обнаруживающие антитела к неструк

Совпадение в аннотации оригинала
West Nile virus (WNV) is an emerging flavivirus that has caused frequent epidemics since 1996. Besides natural transmission by mosquitoes, W … nvelope and NS3 proteins, the NS5-based assay (i) reliably discriminates between WNV infections and dengue virus or St. Louis encephalitis virus infections, (ii) differentiates between flavivirus vaccination and natural WNV infection, and (iii) indicates recent infections. These unique features of the NS5-based immunoassay will be very useful for both cl …

Plasma levels of tumour necrosis factor alpha and transforming growth factor beta-1 in children with dengue 2 virus infection in French Polynesia.

The pathogenesis of dengue haemorrhagic fever (DHF) is not well understood. In the absence of predictive clinical or biological criteria, the management of DHF patients remains difficult. The role played by cytokines in the occurrence of DHF has been suggested by several authors. In this study, we determined the plasma levels of tumour necrosis factor alpha (TNF alpha) and transforming growth factor beta-1 (TGF beta-1) in 52 children with laboratory-confirmed dengue virus infection admitted to hospital during the recent dengue 2 outbreak in French Polynesia. Thirty-three children were classifi…

Cross-protection between group B arboviruses: resistance in mice to Japanese B encephalitis and St. Louis encephalitis viruses induced by Dengue virus immunization.

Albino Swiss mice, immunized with any of several types and strains of dengue viruses, were afforded substantial protection against peripheral Japanese B encephalitis or St. Louis encephalitis virus challenge. Dengue-2 (New Guinea "C")-immunized mice showed, 10 and 20 weeks after immunization, undiminished resistance with concomitant cyclophosphamide treatment and virus challenge. Examination of the effects of immunization on Japanese B encephalitis virus pathogenesis, after virus challenge with concomitant cyclophosphamide treatment, indicated that protection was associated with decreased vire…