Background and Objectives: Dengue is an arbovirosis caused by the dengue virus with 04 serotypes. The aim of the study was to characterise the four serotypes (DENV-1, DENV-2, DENV-3 and DENV-4) of the dengue virus cir...Background and Objectives: Dengue is an arbovirosis caused by the dengue virus with 04 serotypes. The aim of the study was to characterise the four serotypes (DENV-1, DENV-2, DENV-3 and DENV-4) of the dengue virus circulating in Ouagadougou, Burkina Faso. Methods: This was a descriptive analytical study that included 2833 patients and was carried out from January 2021 to December 2022. Rapid diagnosis of dengue was performed using the “Dengue Duo (AgNS1/IgM/IgG)” kit (SD Bioline, Korea). Viral RNA was extracted using the QIAGEN RNA RNeasy Plus Mini Kit (Quiagen, Germany) and virus serotypes were identified using the DENGUE Real-TM Genotype PCR kit (Sacace biotechnologies, Italy). Platelet counts were also performed using the XN-1500 Sysmex. Results: The prevalence of acute infections (NS1Ag positive) by TDR was 5.7% (162/2833), with the peak of dengue virus infection occurring between October and November. On the other hand, the AgNS1+ samples tested by RT-PCR were 53.7% positive for dengue virus;this shows the extent of probable cross-reactions with rapid diagnostic tests and false positives. Serotype 1 accounted for 52.6%, 28.4% had serotype 3, 16.8% had serotype 2 and 2.1% had serotype 4. We found cases of co-infection with DENV-1 and DENV-2 in two patients, co-infection with DENV-1 and DENV-3 in three patients, co-infection with DENV-1 and DENV-4 in one patient, co-infection with DENV-3 and DENV-4 in one patient and co-infection with three serotypes, DENV-1, DENV-2 and DENV-3 in one patient. Conclusion: The study showed that all four serotypes of the dengue virus were circulating in Ouagadougou. Serotype 1 was predominant.展开更多
Objective: To investigate the inhibitory effects against dengue virus serotype 2(DENV-2) by five different fractions(extracted by methanol, ethanol, benzene, chloroform and n-hexane) of Rumex dentatus, Commelina bengh...Objective: To investigate the inhibitory effects against dengue virus serotype 2(DENV-2) by five different fractions(extracted by methanol, ethanol, benzene, chloroform and n-hexane) of Rumex dentatus, Commelina benghalensis, Ajuga bracteosa and Ziziphus mauritiana, as well as their constituents(gallic acid, emodin, and isovanillic acid). Methods: All the samples were tested for cytotoxicity on baby hamster kidney cells by MTT assay and for anti-DENV-2 activity by plaque reduction neutralization assay using two DENV-2 doses(45 and 90 plaqueforming units or PFU). Results: All the samples except isovanillic acid exhibited significant prophylactic effects against DENV-2 infectivity(without cytotoxicity) when administered to cells before infection, but were not effective when given 6 h post-infection. The methanol extract of Rumex dentatus demonstrated the highest antiviral efficacy by inhibiting DENV-2 replication, with IC_(50) of 0.154 μg/mL and 0.234 μg/mL, when added before infection with 45 and 90 PFU of virus, respectively. Gallic acid also exhibited significant antiviral effects by prophylactic treatment prior to virus adsorption on cells, with IC_(50) of 0.191 μg/mL and 0.522 μg/mL at 45 and 90 PFU of DENV-2 infection, respectively. Conclusions: The highly potent activities of the extracts and constituent compounds of these plants against DENV-2 infectivity highlight their potential as targets for further research to identify novel antiviral agents against dengue.展开更多
Dengue is a significant public health concern across tropical and subtropical regions worldwide,principally causing disease in children.Very young children are at increased risk of severe manifestations of dengue infe...Dengue is a significant public health concern across tropical and subtropical regions worldwide,principally causing disease in children.Very young children are at increased risk of severe manifestations of dengue infection.The mechanism of dengue disease in this population is not fully understood.In this study,we present a murine model of dengue virus primary infection in suckling C57BL/6 and BALB/c mice in order to investigate disease pathogenesis.Three-day-old C57BL/6 mice intraperitoneally infected with DENV-2 NGC were more susceptible to infection than BALB/c mice,showing increased liver enzymes,extended viremia,dissemination to organs and histological alterations in liver and small intestine.Furthermore,the immune response in DENV-infected C57BL/6 mice exhibited a marked Th1 bias compared to BALB/c mice.These findings highlight the possibility of establishing an immunocompetent mouse model of DENV-2 infection in suckling mice that reproduces certain signs of disease observed in humans and that could be used to further study agerelated mechanisms of dengue pathogenesis.展开更多
Dengue virus(DENV)is one of the most important arboviral pathogens in the tropics and subtropics,and nearly one-third of the world's population is at risk of infection.The transmission of DENV involves a sylvatic ...Dengue virus(DENV)is one of the most important arboviral pathogens in the tropics and subtropics,and nearly one-third of the world's population is at risk of infection.The transmission of DENV involves a sylvatic cycle between nonhuman primates(NHP)and Aedes genus mosquitoes,and an endemic cycle between human hosts and predominantly Aedes aegypti.DENV belongs to the genus Flavivirus of the family Flaviviridae and consists of four antigenically distinct serotypes(DENV-1-4).Phylogenetic analyses of DENV have revealed its origin,epidemiology,and the drivers that determine its molecular evolution in nature.This review discusses how phyloge-netic research has improved our understanding of DENV evolution and how it affects viral ecology and improved our ability to analyze and predict future DENV emergence.展开更多
Dengue virus(DENV) nonstructural protein 1(NS1) is a highly conserved 46-kDa protein that contains 2 glycosylation sites(Asn-130 and Asn-207) and 12 conserved cysteine(Cys) residues. Here, we performed site-directed m...Dengue virus(DENV) nonstructural protein 1(NS1) is a highly conserved 46-kDa protein that contains 2 glycosylation sites(Asn-130 and Asn-207) and 12 conserved cysteine(Cys) residues. Here, we performed site-directed mutagenesis to generate systematic mutants of viral strain TSV01. The results of the subsequent analysis showed that an alanine substitution at the second N-linked glycan Asn-207 in NS1 delayed viral RNA synthesis, reduced virus plaque size, and weakened the cytopathic effect. Three mutants at Cys sites(Cys-4, Cys-55, Cys-291) and a C-terminal deletion(ΔC) mutant significantly impaired RNA synthesis, and consequently abolished viral growth, whereas alanine mutations at Asn-130 and Glu-173 resulted in phenotypes that were similar to the wild-type(WT) virus. Further analysis showed that the Asn-207 mutation slightly delayed viral replication. These results suggest that the three conserved disulfide bonds and the second N-linked glycan in NS1 are required for DENV-2 replication.展开更多
Dear Editor,Dengue virus(DENV,family Flaviviridae,genus Flavivirus)serotypes 1 to 4(DENV-1,-2,-3,and-4)are responsible for more than 100 million infections per year worldwide.Symptoms of DENV infection can be diverse,...Dear Editor,Dengue virus(DENV,family Flaviviridae,genus Flavivirus)serotypes 1 to 4(DENV-1,-2,-3,and-4)are responsible for more than 100 million infections per year worldwide.Symptoms of DENV infection can be diverse,reaching from an acute febrile illness to the more severe,sometimes fatal dengue haemorrhagic fever/dengue shock syndrome.展开更多
Objective: To identify the changes in the proteome of U937 cells infected with dengue virus(DENV).Methods: In this study, differentiated U937 cultures were infected with two DENV-2strains, one of which was associated ...Objective: To identify the changes in the proteome of U937 cells infected with dengue virus(DENV).Methods: In this study, differentiated U937 cultures were infected with two DENV-2strains, one of which was associated with dengue(DENV-2/NG) and the other one with severe dengue(DENV-2/16681), with the aim of determining the cellular proteomic profiles under different infection conditions. Cellular proteins were extracted and separated by two-dimensional electrophoresis, and those proteins with differential expression profiles were identified by mass spectrometry. The obtained results were correlated with cellular viability, the number of infectious viral particles, and the viral DNA/protein quantity.Results: In comparison with non-infected cultures, in the cells infected with the DENV-2/NG strain, nine proteins were expressed differentially(five were upregulated and four were downregulated); in those cultures infected with the DENV-2/16681 strain, six proteins were differentially expressed(two were downregulated and four were upregulated). The downregulated proteins included fatty acid-binding protein, heterogeneous nuclear ribonucleoprotein 1, protein disulfide isomerase, enolase 1, heat shock 70 k Da protein 9, phosphotyrosyl phosphatase, and annexin IV. The upregulated proteins included heat shock 90 k Da protein AA1, tubulin beta, enolase 1, pyruvate kinase,transaldolase and phospholipase C-alpha.Conclusions: Because the monocyte/macrophage lineage is critical for disease pathogenicity, additional studies on these proteins could provide a better understanding of the cellular response to DENV infection and could help identify new therapeutic targets against infection.展开更多
To express and characterize NS1 of Indonesian-specific DENV2 virus in Pichia pastoris (P. pastoris).MethodsA codon optimized synthetic gene derived from the DENV-2 NS1 amino acid sequences was synthesized commerc...To express and characterize NS1 of Indonesian-specific DENV2 virus in Pichia pastoris (P. pastoris).MethodsA codon optimized synthetic gene derived from the DENV-2 NS1 amino acid sequences was synthesized commercially and inserted into the P. pastoris pPICZαA expression vector. The recombinant DENV-2 NS1 protein was purified by Ni-NTA affinity chromatography, and its antigenicity was tested.ResultsThe recombinant DENV-2 NS1 protein was secreted as a protein with a molecular weight of ∼45 kDa, and the optimal expression condition was achieved by induction with 2% (v/v) methanol for 72 h. The purified recombinant DENV-2 NS1 protein was able to interact with a monoclonal antibody of NS1 in a commercial rapid test.ConclusionsThe resulting recombinant DENV-2 NS1 protein produced in P. pastoris KM71 is a potential candidate for use in the development of a dengue diagnostic kit and vaccine.展开更多
Objective:To understand the cause for the differences between potentially mild Southeast Asian and the more pathogenic ZIKV in South America.Methods:A comparative genomic analysis was performed to determine putative c...Objective:To understand the cause for the differences between potentially mild Southeast Asian and the more pathogenic ZIKV in South America.Methods:A comparative genomic analysis was performed to determine putative causations stemming from ZIKV.Results:Phylogcnctic analyses integrating geographical and time factors revealed that Southeast Asian ZIKV might not be the direct source of South American outbreaks as previously speculated.Amino acid residues unique to South American ZIKV isolates at the envelope,pr and NS1 proteins are listed and shown in the structural context.These unique residues on external viral proteins are not found in Southeast Asian ZIKV and could be responsible for the ongoing outbreak either via an intrinsic property of the virus or interactions with human immunity.Only a selected few primer/probe sets currently in clinical use were identified of being capable of detecting ZIKV strains worldwide.The envelope proteins of dengue virus(DENV) and ZIKV also showed a remarkable degree of similarity especially at the surface residues.Conclusions:findings that may help explain the cross-reactivity of DENV antibodies to ZIKV.Thus,major caveats must be exercised in using existing diagnostic tools for ZIKV.展开更多
Objective:To investigate the involvement of Ca^(2+)in dengue virus(DENV)-infected human umbilical vein endothelial cells(HUVECs)and the disruption of endothelial integrity.Methods:HUVECs were infected with DENV-2 in t...Objective:To investigate the involvement of Ca^(2+)in dengue virus(DENV)-infected human umbilical vein endothelial cells(HUVECs)and the disruption of endothelial integrity.Methods:HUVECs were infected with DENV-2 in the presence of intracellular Ca^(2+)or endoplasmic reticulum Ca^(2+)chelators.Virus infectivity was measured by focus-forming assay and quantitative RT-PCR.Intracellular Ca^(2+)was measured using Fluo-4-AM dye.VE-cadherin and focal adhesion kinase(FAK)expressions were investigated by immunofluorescence and immunoblotting assays,respectively.Results:DENV infection increased intracellular cytosolic Ca^(2+)levels and caused disassembly of the adherens junction protein,VEcadherin as evidenced by decreased VE-cadherin expression at the periphery of DENV-2 infected HUVECs.Depletion of intracellular Ca^(2+)stores,particularly those of the endoplasmic reticulum Ca^(2+),significantly decreased DENV yield in HUVECs.Decreased virus yield following the depletion of intracellular Ca^(2+)was caused by the inhibition of viral entry into HUVECs and not the inhibition of viral binding or attachment.DENV-2 infection also resulted in Ca^(2+)-dependent activation of FAK.Conclusions:Intracellular Ca^(2+)is required for the early phases of DENV infection in endothelial cells.Increased cytosolic Ca^(2+)levels in endothelial cells during DENV infection activated FAK,disrupted adherens junctions and compromised barrier integrity.Thus,Ca^(2+)plays an important role in DENV infection in endothelial cells.展开更多
Objective: To evaluate the expression of DNA plasmid-harboring modified antibody gene that produces neutralizing human monoclonal antibodies against four serotypes of dengue virus(DENV) without enhancing activity in B...Objective: To evaluate the expression of DNA plasmid-harboring modified antibody gene that produces neutralizing human monoclonal antibodies against four serotypes of dengue virus(DENV) without enhancing activity in BALB/c mice. Methods: We constructed pFUSE-based vectors(pFUSE1 G7 C2hVH and pFUSE1 G7 C2hVL) containing genes encoding the variable domains of the heavy or light chain of the anti-dengue virus antibody 1 G7 C2, a human IgG1 that has been characterized for its neutralizing activity to DENV-1-4. Leucine(L) at positions 234 and 235 on the Fc CH2 domain in pFUSE1 G7 C2hVH was mutated to alanine(A)(LALA mutation) by site direct mutagenesis, and the new plasmid was termed pFUSE1 G7 C2hVHLALA. An equal amount of pFUSE1 G7 C2hVL and 1 G7 C2hG1-LALA plasmids were co-transfected into Chinese hamster ovary cells(CHO-K1) and a single dose of 100 μg 1 G7 C2hG1-LALA plasmid was intramuscularly injected, followed by electroporation in BALB/c mice. The secreted 1 G7 C2hG1-LALA antibodies in cell culture supernatant and mouse serum were examined for their biological functions, neutralization and enhancing activity. Results: The co-transfection of heavy-and light-chain 1 G7 C2hG1-LALA plasmids in CHO-K1 cells produced approximately 3 900 ng/mL human IgG and neutralized 90%-100% all four DENV, with no enhancing activity. Furthermore, the modified human IgG was produced more than 1 000 ng/mL in mouse serum on day 7 post plasmid injection and showed cross-neutralization to four DENV serotypes. Subsequently, antibody production and neutralization decreased rapidly. Nevertheless, the secreted neutralizing 1 G7 C2hG1-LALA in mouse serum demonstrated complete absence of enhancing activities to all DENV serotypes. Conclusions: These findings reveal that a new modified 1 G7 C2h G1-LALA expressing plasmid based on gene transfer is a possible therapeutic antibody candidate against DENV infection.展开更多
The PSV?NS3, an expressing recombinant plasmid of dengue virus type 2 NS3 protein, was injected directly into the quadriceps of Balb/C mice to explore whether it could inducing immune response. The splenic T cell subs...The PSV?NS3, an expressing recombinant plasmid of dengue virus type 2 NS3 protein, was injected directly into the quadriceps of Balb/C mice to explore whether it could inducing immune response. The splenic T cell subsets of two groups was analysed by flow cytometry. It was found that the percentage of CD4+ and CD8+ T cells of experimental group were significantly higher than those of the control group. The titer of IgG antibody was as high as 1∶5 120 in experimental group, but it couldn’t be detected in control group by ELISA. The western blot further proved that the IgG antibody was specific for NS3 protein. Those results Suggested that inoculation Balb/C mice with PSV?NS3 could inducing immune response, and the NS3 protein might be used as the candidate protein of DNA vaccine of dengue virus.展开更多
Dengue virus infections are increasing worldwide generally and in Asia,Central and South America and Africa,particularly.It poses a serious threat to the children population.The rapid and accurate diagnostic systems a...Dengue virus infections are increasing worldwide generally and in Asia,Central and South America and Africa,particularly.It poses a serious threat to the children population.The rapid and accurate diagnostic systems are essentially required due to lack of effective vaccine against dengue virus and the progressive spread of the dengue virus infection.The recent progress in developing micro-and nano-fabrication techniques has led to low cost and scale down the biomedical point-of-care devices.Starting from the conventional and modern available methods for the diagnosis of dengue infection,this review examines several emerging rapid and point-of-care diagnostic devices that hold significant potential for the progress in smart diagnosis tools.The given review revealed that an effective vaccine is required urgently against all the dengue virus serotypes.However,the rapid detection methods of dengue virus help in early treatment and significantly reduce the dengue virus outbreak.展开更多
Objectives: Dengue virus (DENV) infection is a mosquito-borne disease that stands out as one of the major public health issues and has a wide-ranging geographical distribution throughout the tropics and subtropics. Th...Objectives: Dengue virus (DENV) infection is a mosquito-borne disease that stands out as one of the major public health issues and has a wide-ranging geographical distribution throughout the tropics and subtropics. The general alarming increase in the number of cases over the last two decades can be attributed to an extent by the change in national practices to keeping records and reporting dengue to the Ministries of Health, and WHO. Dengue diagnosis is routinely carried out by detection of dengue virus (DENV) antigen NS1 (Non-structural Antigen 1) and/or anti-DENV IgM/IgG antibodies using enzyme-linked immunosorbent assays (ELISAs) and rapid diagnostic tests (RDTs). This study compared the performance of three RDTs and one ELISA used for dengue diagnosis in southeastern, Nigeria. Design: This study adopted a cross-sectional design that included prospective hospital-based surveillance of cases among febrile participants attending two major health facilities within the southeastern region of Nigeria. In this study, 338 HIV-infected participants from two teaching hospitals in Nigeria’s southeast were systematically tested for Dengue with four methods: NS1 RDT, IgG RDT, IgM RDT, and NS1 ELISA. Their specificities and sensitivities were compared, as well as their level of concordance. Their respective performances were also evaluated using the Receivers Operational curve (ROC). Results: Out of the 338 patients, the dengue prevalence from the four dengue diagnostic methods Dengue virus NS1 ELISA, NS1 RDT, IgM and IgG seropositivity were 8.9%, 0.6%, 5.6%, and 8.0%, respectively. The Dengue IgM RDT test indicated 36.8% sensitivity, 92.8% specificity, the IgG anti-dengue specific test indicated 29.6% sensitivity, 92.9% specificity and the dengue NS1 RDT test indicated 3.3% sensitivity, 99.4% specificity when compared with the Dengue NSI Elisa test method as a reference method. Conclusion: The use of NSI ELISA for DENV diagnosis showed good performance and the RDTs showed, to an extent, reliable results compared with ELISA. However, diagnostic laboratories should be aware of performance variations across tests and the possibilities of cross-reactivity that may affect results.展开更多
Obejective The domainⅢof dengue virus type 2 envelope was cloned and expressed in Escherichia coli and the inhibited effects of recombinant protein on virus was detected. Methods In this study, the domainⅢ(DⅢ) pro...Obejective The domainⅢof dengue virus type 2 envelope was cloned and expressed in Escherichia coli and the inhibited effects of recombinant protein on virus was detected. Methods In this study, the domainⅢ(DⅢ) protein of the dengue virus type-2 (DENV-2) envelope (E) antigen was expressed in Escherichia coli by fusion with a carrier protein. The protein was puriifed using enzymatic cleavage and afifnity puriifcation. Rabbit immunization and antibody detection was carried out. Inhibition of DENV-2 infection was observed by DENV-2 EDⅢprotein and its immunity rabbits serum. Results The recombinant expression DENV-2 EDⅢ protein plasmid was constructed successfully. After isopropyl thiogalactoside induction, a speciifc soluble 29 kD protein was obtained, and the expression product accounted for 68.87%of the total protein of the cell lysate. Western blot demonstrated the reactivity of the recombinant protein with his-tag and DENV (Ⅰ-Ⅳ) monoclonal antibodies. The protein was puriifed using enzymatic cleavage and affinity purification. The purified recombinant EDⅢ protein inhibited the entry of DENV-2 into BHK-21 cells. DENV-2 plaque neutralization assays were carried out using serially diluted antibodies against EDⅢprotein. At a 1︰16 dilution, the antibodies produced at least 90%neutralization of the DENV-2 virus. Furthermore, the antibodies continued to exhibit high neutralization effects (approximately 80%) until the anti-EDⅢantibody titer reached 1︰1 024. Conclusions DENV-2 EDⅢwas cloned and expressed successfully. DENV-2 EDⅢprotein could be useful in the development of inexpensive dengue vaccine. The data also suggested that DENV-2 employed an attachment molecule or receptor for its entry into C6/36 mosquito cells.展开更多
Rationale: Malaria and dengue are the most prevalent vector-borne diseases in tropical countries. Plasmodium parasite and dengue virus(DENV) concurrent infection is possible and often under-recognized in geographical ...Rationale: Malaria and dengue are the most prevalent vector-borne diseases in tropical countries. Plasmodium parasite and dengue virus(DENV) concurrent infection is possible and often under-recognized in geographical areas where these infections are both endemic.Patients concern and diagnosis: We describe the first two cases of Plasmodium falciparum and DENV-3 co-infection in travelers returning to northeastern Italy from Burkina Faso during 2013-2014.Interventions: Malaria infection in both patients was treated with mefloquine. Due to the persistence of symptoms despite of the antimalaria treatment, dengue was also investigated;the treatment of dengue was symptomatic.Outcomes: The patients were discharged in good general condition.Lessons: The need for surveillance of potential malaria and dengue co-infection in travelers returning to Europe from endemic areas is highlighted, as infection with Plasmodium does not exclude arboviral co-infection.展开更多
Objective:To identify the residue determinants of the serospecificity and sero-cross-reactivity of dengue virus(DENV)envelope protein domain 3(ED3),which contains two major putative epitopes of DENV.Methods:We constru...Objective:To identify the residue determinants of the serospecificity and sero-cross-reactivity of dengue virus(DENV)envelope protein domain 3(ED3),which contains two major putative epitopes of DENV.Methods:We constructed ED3 from DENV3(3ED3)and DENV4(4ED3),and six epitope-grafted variants,where we transferred epitope 1(L304I,K305D,V309M,and S310A)and/or epitope 2(D383N,K384S,K387T,and N389H)of 4ED3 onto 3ED3 and vice-versa.Swiss albino mice aged 3-4 weeks were immunized against wildtype and epitope-grafted ED3 variants and anti-ED3 IgG antibody responses were determined using ELISA.Results:Mouse immunization using 3ED3 and 4ED3 generated serotype-specific antisera,as expected.Similarly,most epitope-grafted ED3s produced antisera serospecific to the template ED3 with little or no cross-recognition of ED3 of the serotype from which the epitopes were taken.These indicated that a mere grafting of the epitope was not sufficient to transfer serospecificity,contrary to our expectations.However,one epitope-grafted ED3 mutant,where epitope 1 of 3ED3 was grafted onto 4ED3(4ED3^(epi1)),generated antisera that was serospecific to both 4ED3 and 3ED3.Conclusions:The 4ED3^(epi1)is a chimeric ED3 that produces antisera possessing serospecificity to both 3ED3 and 4ED3 onto a common 4ED3 scaffold.The 4ED3^(epi1),therefore,provides a unique tool for analyzing serospecificity and sero-cross-reactivity in dengue.We believe that chimeric ED3 may provide a template for future recombinant ED3 possessing serospecificity of multiple DENVs onto a single scaffold and may pave a way developing tri-and/or tetravalent anti-DENV antisera.展开更多
<strong>Introduction: </strong>Most febrile illnesses in Ghana are often misdiagnosed and presumptively treated as malaria. This situation may be due to the inappropriate diagnostic tool, clinical oversigh...<strong>Introduction: </strong>Most febrile illnesses in Ghana are often misdiagnosed and presumptively treated as malaria. This situation may be due to the inappropriate diagnostic tool, clinical oversight and lack of awareness of some of the disease conditions that might have been present in the country. This study sought to investigate the seroprevalence of dengue virus, geographical location of participants with circulating antibodies and finally evaluate the diagnostic accuracy of a Rapid diagnostic kit (RDT) using Enzyme Linked Immuno-Sorbent Assay (ELISA) as a gold standard for confirmation. <strong>Method: </strong>A hospital-based cross-sectional study was conducted among adults (≥18) attending the University of Cape Coast Hospital. From each participant, 3 - 4 ml of venous blood was drawn and serum was tested for IgG and IgM using RDT methods. Positive samples were selected for ELISA confirmation. Statistical analysis was performed using SPSS (v.20) and STATA (v.14) software. <strong>Results: </strong>A total of 270 participants were enrolled in the study. The geometric mean age was 32 years. Overall, Dengue virus (DENV) IgG seroprevalence by RDT was 10 (3.7%). Seroprevalence of IgG and IgM by the ELISA method was 34 (12.6%) and 6 (2.2%) respectively. Females recorded a high seroprevalence (7.4%) than males (5.2%) in terms of past exposure (IgG). On current exposure (IgM), females recorded a high seroprevalence (1.5%) than males (0.7%). Seroprevalence of individuals with dual positivity ((IgG + IgM+) (acute secondary infection) was 1.9%. Those with primary and recent infection (IgM+ only) were 0.4% whiles those with past and probably secondary infection (IgG+ only) were 10.7%. The odds of dengue exposure were significantly high among participants with ages 50 - 59 as compared to their other counterparts (AOR = 3.5, p = 0.03). Diagnostic accuracy of RDT kit was poor (Kappa value = 0.373 and 0.0001). Elmina was noted to record the highest seroprevalence values for both anti-dengue IgG (3.3%) and IgM (1.85%). <strong>Conclusion:</strong> The seroprevalence of anti-dengue IgG and IgM among participants suggests that dengue virus is in circulation in Cape Coast Metropolis and Komenda Edina Eguafo Abirem Municipality.展开更多
Rationale:Dengue fever is a viral infection that is spread through the bites of infected female Aedes mosquitos.It can cause life threatening complications,including dengue haemorrhagic fever(DHF)and dengue shock synd...Rationale:Dengue fever is a viral infection that is spread through the bites of infected female Aedes mosquitos.It can cause life threatening complications,including dengue haemorrhagic fever(DHF)and dengue shock syndrome.Patient concerns:A 15-year-old male presented with fever and petechiae and later developed hemoptysis.Diagnosis:Dengue fever with DHF with diffuse alveolar hemorrhage.Interventions:Invasive ventilation with high positive end expiratory pressure,multiple transfusions of packed red blood cells,fresh frozen plasma,single donor platelets and inotropic support Outcomes:The patient was stabilized and discharged on minimal supplemental oxygen.Lessons:Diffuse alveolar hemorrhage,although very rare,should be considered in a patient with dengue who presents with hemoptysis.The treatment is directed at providing respiratory and circulatory support,and preventing the progression of microcirculation damage.展开更多
Dengue is the most prevalent arthropod-borne viral diseases in terms of morbidity and mortality in the recent decade with the classic symptoms of high fever,headache as well as muscle and joint pain.Nilavembu Kudineer...Dengue is the most prevalent arthropod-borne viral diseases in terms of morbidity and mortality in the recent decade with the classic symptoms of high fever,headache as well as muscle and joint pain.Nilavembu Kudineer(NK)is one among the 32 types of internal medicines described in the ancient Siddha system of medicine in south India which reduces fever and relieves body aches.NK,a polyherbal formulation made up of eight traditional herbs in equal parts,is also recommended for prevention and management of all types of viral infections including Dengue/Chikugunya.Exploration of bioactive compounds in the plants is the primary step for the standardization and bioactivity screening of plants and formulations.So the current study aims at recording the chemical constituents and medicinal activities of each ingredient of NK.The anti-pyretic,anti-inflammatory,analgesic and immunostimulant effects of NK have been attributed to more than one ingredient in NK.The medicinal property of the NK can be also attributed to the combined effect of all phytochemicals present in these eight herbs.The current study encompasses the various chemicals and the activities of individual herbs but a thorough stereoscopic and chromatographic investigation is required to trace out the major phytochemical entities which are retained once the NK is prepared by the traditional methods.展开更多
文摘Background and Objectives: Dengue is an arbovirosis caused by the dengue virus with 04 serotypes. The aim of the study was to characterise the four serotypes (DENV-1, DENV-2, DENV-3 and DENV-4) of the dengue virus circulating in Ouagadougou, Burkina Faso. Methods: This was a descriptive analytical study that included 2833 patients and was carried out from January 2021 to December 2022. Rapid diagnosis of dengue was performed using the “Dengue Duo (AgNS1/IgM/IgG)” kit (SD Bioline, Korea). Viral RNA was extracted using the QIAGEN RNA RNeasy Plus Mini Kit (Quiagen, Germany) and virus serotypes were identified using the DENGUE Real-TM Genotype PCR kit (Sacace biotechnologies, Italy). Platelet counts were also performed using the XN-1500 Sysmex. Results: The prevalence of acute infections (NS1Ag positive) by TDR was 5.7% (162/2833), with the peak of dengue virus infection occurring between October and November. On the other hand, the AgNS1+ samples tested by RT-PCR were 53.7% positive for dengue virus;this shows the extent of probable cross-reactions with rapid diagnostic tests and false positives. Serotype 1 accounted for 52.6%, 28.4% had serotype 3, 16.8% had serotype 2 and 2.1% had serotype 4. We found cases of co-infection with DENV-1 and DENV-2 in two patients, co-infection with DENV-1 and DENV-3 in three patients, co-infection with DENV-1 and DENV-4 in one patient, co-infection with DENV-3 and DENV-4 in one patient and co-infection with three serotypes, DENV-1, DENV-2 and DENV-3 in one patient. Conclusion: The study showed that all four serotypes of the dengue virus were circulating in Ouagadougou. Serotype 1 was predominant.
基金support of the National University of SingaporeQuaid-i-Azam University
文摘Objective: To investigate the inhibitory effects against dengue virus serotype 2(DENV-2) by five different fractions(extracted by methanol, ethanol, benzene, chloroform and n-hexane) of Rumex dentatus, Commelina benghalensis, Ajuga bracteosa and Ziziphus mauritiana, as well as their constituents(gallic acid, emodin, and isovanillic acid). Methods: All the samples were tested for cytotoxicity on baby hamster kidney cells by MTT assay and for anti-DENV-2 activity by plaque reduction neutralization assay using two DENV-2 doses(45 and 90 plaqueforming units or PFU). Results: All the samples except isovanillic acid exhibited significant prophylactic effects against DENV-2 infectivity(without cytotoxicity) when administered to cells before infection, but were not effective when given 6 h post-infection. The methanol extract of Rumex dentatus demonstrated the highest antiviral efficacy by inhibiting DENV-2 replication, with IC_(50) of 0.154 μg/mL and 0.234 μg/mL, when added before infection with 45 and 90 PFU of virus, respectively. Gallic acid also exhibited significant antiviral effects by prophylactic treatment prior to virus adsorption on cells, with IC_(50) of 0.191 μg/mL and 0.522 μg/mL at 45 and 90 PFU of DENV-2 infection, respectively. Conclusions: The highly potent activities of the extracts and constituent compounds of these plants against DENV-2 infectivity highlight their potential as targets for further research to identify novel antiviral agents against dengue.
基金Consejo Nacional de Investigaciones Científicas y Técnicas,Grant/Award Number:PIP0118UBS Optimus Foundation,Grant/Award Number:ID 2007-00206+1 种基金Fundación Bunge y BornFondo para la Investigación Científica y Tecnológica,Grant/Award Number:PICT2008-1073。
文摘Dengue is a significant public health concern across tropical and subtropical regions worldwide,principally causing disease in children.Very young children are at increased risk of severe manifestations of dengue infection.The mechanism of dengue disease in this population is not fully understood.In this study,we present a murine model of dengue virus primary infection in suckling C57BL/6 and BALB/c mice in order to investigate disease pathogenesis.Three-day-old C57BL/6 mice intraperitoneally infected with DENV-2 NGC were more susceptible to infection than BALB/c mice,showing increased liver enzymes,extended viremia,dissemination to organs and histological alterations in liver and small intestine.Furthermore,the immune response in DENV-infected C57BL/6 mice exhibited a marked Th1 bias compared to BALB/c mice.These findings highlight the possibility of establishing an immunocompetent mouse model of DENV-2 infection in suckling mice that reproduces certain signs of disease observed in humans and that could be used to further study agerelated mechanisms of dengue pathogenesis.
基金National Key Research and Development Plan of China,Grant/Award Number:2018YFA0507202,2020YFC1200100 and 2021YFC2300200National Natural Science Foundation of China,Grant/Award Number:31825001,32188101,81730063,81961160737 and 82102389+5 种基金Provincial Innovation Team for the Prevention and Control of Highly Pathogenic Pathogens,Institute of Medical Biology,Chinese Academy of Medical Sciences,Grant/Award Number:202105AE160020Shenzhen San-Ming Project for Prevention and Research on Vector-borne Diseases,Grant/Award Number:SZSM201611064Shenzhen Science and Technology Project,Grant/Award Number:JSGG20191129144225464Tsinghua University Spring Breeze Fund,Grant/Award Number:2020Z99CFG017Young Elite Scientists Sponsorship Program,Grant/Award Number:2021QNRC001Yunnan Cheng Gong Expert Work-Station,Grant/Award Number:202005AF150034。
文摘Dengue virus(DENV)is one of the most important arboviral pathogens in the tropics and subtropics,and nearly one-third of the world's population is at risk of infection.The transmission of DENV involves a sylvatic cycle between nonhuman primates(NHP)and Aedes genus mosquitoes,and an endemic cycle between human hosts and predominantly Aedes aegypti.DENV belongs to the genus Flavivirus of the family Flaviviridae and consists of four antigenically distinct serotypes(DENV-1-4).Phylogenetic analyses of DENV have revealed its origin,epidemiology,and the drivers that determine its molecular evolution in nature.This review discusses how phyloge-netic research has improved our understanding of DENV evolution and how it affects viral ecology and improved our ability to analyze and predict future DENV emergence.
基金supported by Important National Science & Technology Specific Projects (2012ZX10004219, 2012ZX10004403)the National Natural Scientific Fund of China (81072675)the Wuhan Key Laboratory on Emerging Infectious Diseases and Biosafety
文摘Dengue virus(DENV) nonstructural protein 1(NS1) is a highly conserved 46-kDa protein that contains 2 glycosylation sites(Asn-130 and Asn-207) and 12 conserved cysteine(Cys) residues. Here, we performed site-directed mutagenesis to generate systematic mutants of viral strain TSV01. The results of the subsequent analysis showed that an alanine substitution at the second N-linked glycan Asn-207 in NS1 delayed viral RNA synthesis, reduced virus plaque size, and weakened the cytopathic effect. Three mutants at Cys sites(Cys-4, Cys-55, Cys-291) and a C-terminal deletion(ΔC) mutant significantly impaired RNA synthesis, and consequently abolished viral growth, whereas alanine mutations at Asn-130 and Glu-173 resulted in phenotypes that were similar to the wild-type(WT) virus. Further analysis showed that the Asn-207 mutation slightly delayed viral replication. These results suggest that the three conserved disulfide bonds and the second N-linked glycan in NS1 are required for DENV-2 replication.
基金Supported by the German Research Foundation (JO 1276/5-1)the Federal Ministry of Education and Research of Germany (BMBF) under the project NEED (01Kl2022).
文摘Dear Editor,Dengue virus(DENV,family Flaviviridae,genus Flavivirus)serotypes 1 to 4(DENV-1,-2,-3,and-4)are responsible for more than 100 million infections per year worldwide.Symptoms of DENV infection can be diverse,reaching from an acute febrile illness to the more severe,sometimes fatal dengue haemorrhagic fever/dengue shock syndrome.
基金Supported by the Administrative Department of Science,Technology,and Research-COLCIENCIAS(Projects 111549326092 and 111549326083)
文摘Objective: To identify the changes in the proteome of U937 cells infected with dengue virus(DENV).Methods: In this study, differentiated U937 cultures were infected with two DENV-2strains, one of which was associated with dengue(DENV-2/NG) and the other one with severe dengue(DENV-2/16681), with the aim of determining the cellular proteomic profiles under different infection conditions. Cellular proteins were extracted and separated by two-dimensional electrophoresis, and those proteins with differential expression profiles were identified by mass spectrometry. The obtained results were correlated with cellular viability, the number of infectious viral particles, and the viral DNA/protein quantity.Results: In comparison with non-infected cultures, in the cells infected with the DENV-2/NG strain, nine proteins were expressed differentially(five were upregulated and four were downregulated); in those cultures infected with the DENV-2/16681 strain, six proteins were differentially expressed(two were downregulated and four were upregulated). The downregulated proteins included fatty acid-binding protein, heterogeneous nuclear ribonucleoprotein 1, protein disulfide isomerase, enolase 1, heat shock 70 k Da protein 9, phosphotyrosyl phosphatase, and annexin IV. The upregulated proteins included heat shock 90 k Da protein AA1, tubulin beta, enolase 1, pyruvate kinase,transaldolase and phospholipase C-alpha.Conclusions: Because the monocyte/macrophage lineage is critical for disease pathogenicity, additional studies on these proteins could provide a better understanding of the cellular response to DENV infection and could help identify new therapeutic targets against infection.
基金"Penelitian Unggulan Strategis Nasional 2013" under the contract number of 0400/I1/B04/SPK-WRRI/VI/2014,Ministry of Research,Technology,and Higher Education of Indonesia,for funding this work
文摘To express and characterize NS1 of Indonesian-specific DENV2 virus in Pichia pastoris (P. pastoris).MethodsA codon optimized synthetic gene derived from the DENV-2 NS1 amino acid sequences was synthesized commercially and inserted into the P. pastoris pPICZαA expression vector. The recombinant DENV-2 NS1 protein was purified by Ni-NTA affinity chromatography, and its antigenicity was tested.ResultsThe recombinant DENV-2 NS1 protein was secreted as a protein with a molecular weight of ∼45 kDa, and the optimal expression condition was achieved by induction with 2% (v/v) methanol for 72 h. The purified recombinant DENV-2 NS1 protein was able to interact with a monoclonal antibody of NS1 in a commercial rapid test.ConclusionsThe resulting recombinant DENV-2 NS1 protein produced in P. pastoris KM71 is a potential candidate for use in the development of a dengue diagnostic kit and vaccine.
基金supported by Thailand Research Fund-Mahidol University(RSA5880062)by the Office of the Higher Education Commission and Mahidol University under the National Research Universities Initiativesupported by the Royal Golden Jubilee Ph.D.Program (Grant No.PHD/0204/2552)
文摘Objective:To understand the cause for the differences between potentially mild Southeast Asian and the more pathogenic ZIKV in South America.Methods:A comparative genomic analysis was performed to determine putative causations stemming from ZIKV.Results:Phylogcnctic analyses integrating geographical and time factors revealed that Southeast Asian ZIKV might not be the direct source of South American outbreaks as previously speculated.Amino acid residues unique to South American ZIKV isolates at the envelope,pr and NS1 proteins are listed and shown in the structural context.These unique residues on external viral proteins are not found in Southeast Asian ZIKV and could be responsible for the ongoing outbreak either via an intrinsic property of the virus or interactions with human immunity.Only a selected few primer/probe sets currently in clinical use were identified of being capable of detecting ZIKV strains worldwide.The envelope proteins of dengue virus(DENV) and ZIKV also showed a remarkable degree of similarity especially at the surface residues.Conclusions:findings that may help explain the cross-reactivity of DENV antibodies to ZIKV.Thus,major caveats must be exercised in using existing diagnostic tools for ZIKV.
基金funding from the Ministry of Higher Education Malaysia via the Higher Institution Centre of Excellence(HICo E)program(MO002-2019)Development of Research Institute for Excellent Enterprises(ATC+)Project,Republic of Korea(IF001-2021)
文摘Objective:To investigate the involvement of Ca^(2+)in dengue virus(DENV)-infected human umbilical vein endothelial cells(HUVECs)and the disruption of endothelial integrity.Methods:HUVECs were infected with DENV-2 in the presence of intracellular Ca^(2+)or endoplasmic reticulum Ca^(2+)chelators.Virus infectivity was measured by focus-forming assay and quantitative RT-PCR.Intracellular Ca^(2+)was measured using Fluo-4-AM dye.VE-cadherin and focal adhesion kinase(FAK)expressions were investigated by immunofluorescence and immunoblotting assays,respectively.Results:DENV infection increased intracellular cytosolic Ca^(2+)levels and caused disassembly of the adherens junction protein,VEcadherin as evidenced by decreased VE-cadherin expression at the periphery of DENV-2 infected HUVECs.Depletion of intracellular Ca^(2+)stores,particularly those of the endoplasmic reticulum Ca^(2+),significantly decreased DENV yield in HUVECs.Decreased virus yield following the depletion of intracellular Ca^(2+)was caused by the inhibition of viral entry into HUVECs and not the inhibition of viral binding or attachment.DENV-2 infection also resulted in Ca^(2+)-dependent activation of FAK.Conclusions:Intracellular Ca^(2+)is required for the early phases of DENV infection in endothelial cells.Increased cytosolic Ca^(2+)levels in endothelial cells during DENV infection activated FAK,disrupted adherens junctions and compromised barrier integrity.Thus,Ca^(2+)plays an important role in DENV infection in endothelial cells.
基金supported by the Faculty of Tropical Medicine,Mahidol University,Thailand,Research Fund through a Research and Researcher for Industry(RRi,Grant Number PHD59I0063 for SB)TRF Grant for New Researcher(TRG,Grant Number TRG5980015 for CP)the Office of the National Research Council of Thailand-Japan Society for the Promotion of Science(JSPS)or NRCT-JSPS
文摘Objective: To evaluate the expression of DNA plasmid-harboring modified antibody gene that produces neutralizing human monoclonal antibodies against four serotypes of dengue virus(DENV) without enhancing activity in BALB/c mice. Methods: We constructed pFUSE-based vectors(pFUSE1 G7 C2hVH and pFUSE1 G7 C2hVL) containing genes encoding the variable domains of the heavy or light chain of the anti-dengue virus antibody 1 G7 C2, a human IgG1 that has been characterized for its neutralizing activity to DENV-1-4. Leucine(L) at positions 234 and 235 on the Fc CH2 domain in pFUSE1 G7 C2hVH was mutated to alanine(A)(LALA mutation) by site direct mutagenesis, and the new plasmid was termed pFUSE1 G7 C2hVHLALA. An equal amount of pFUSE1 G7 C2hVL and 1 G7 C2hG1-LALA plasmids were co-transfected into Chinese hamster ovary cells(CHO-K1) and a single dose of 100 μg 1 G7 C2hG1-LALA plasmid was intramuscularly injected, followed by electroporation in BALB/c mice. The secreted 1 G7 C2hG1-LALA antibodies in cell culture supernatant and mouse serum were examined for their biological functions, neutralization and enhancing activity. Results: The co-transfection of heavy-and light-chain 1 G7 C2hG1-LALA plasmids in CHO-K1 cells produced approximately 3 900 ng/mL human IgG and neutralized 90%-100% all four DENV, with no enhancing activity. Furthermore, the modified human IgG was produced more than 1 000 ng/mL in mouse serum on day 7 post plasmid injection and showed cross-neutralization to four DENV serotypes. Subsequently, antibody production and neutralization decreased rapidly. Nevertheless, the secreted neutralizing 1 G7 C2hG1-LALA in mouse serum demonstrated complete absence of enhancing activities to all DENV serotypes. Conclusions: These findings reveal that a new modified 1 G7 C2h G1-LALA expressing plasmid based on gene transfer is a possible therapeutic antibody candidate against DENV infection.
基金Supported by Foundation of American Chinese Medicine
文摘The PSV?NS3, an expressing recombinant plasmid of dengue virus type 2 NS3 protein, was injected directly into the quadriceps of Balb/C mice to explore whether it could inducing immune response. The splenic T cell subsets of two groups was analysed by flow cytometry. It was found that the percentage of CD4+ and CD8+ T cells of experimental group were significantly higher than those of the control group. The titer of IgG antibody was as high as 1∶5 120 in experimental group, but it couldn’t be detected in control group by ELISA. The western blot further proved that the IgG antibody was specific for NS3 protein. Those results Suggested that inoculation Balb/C mice with PSV?NS3 could inducing immune response, and the NS3 protein might be used as the candidate protein of DNA vaccine of dengue virus.
基金supported by the Scientific Research Fund of the Shenzhen International cooperation projects under Grant Nos.(GJHZ20190819151403615)the Natural Science Youth Foundation of China(61801307).
文摘Dengue virus infections are increasing worldwide generally and in Asia,Central and South America and Africa,particularly.It poses a serious threat to the children population.The rapid and accurate diagnostic systems are essentially required due to lack of effective vaccine against dengue virus and the progressive spread of the dengue virus infection.The recent progress in developing micro-and nano-fabrication techniques has led to low cost and scale down the biomedical point-of-care devices.Starting from the conventional and modern available methods for the diagnosis of dengue infection,this review examines several emerging rapid and point-of-care diagnostic devices that hold significant potential for the progress in smart diagnosis tools.The given review revealed that an effective vaccine is required urgently against all the dengue virus serotypes.However,the rapid detection methods of dengue virus help in early treatment and significantly reduce the dengue virus outbreak.
文摘Objectives: Dengue virus (DENV) infection is a mosquito-borne disease that stands out as one of the major public health issues and has a wide-ranging geographical distribution throughout the tropics and subtropics. The general alarming increase in the number of cases over the last two decades can be attributed to an extent by the change in national practices to keeping records and reporting dengue to the Ministries of Health, and WHO. Dengue diagnosis is routinely carried out by detection of dengue virus (DENV) antigen NS1 (Non-structural Antigen 1) and/or anti-DENV IgM/IgG antibodies using enzyme-linked immunosorbent assays (ELISAs) and rapid diagnostic tests (RDTs). This study compared the performance of three RDTs and one ELISA used for dengue diagnosis in southeastern, Nigeria. Design: This study adopted a cross-sectional design that included prospective hospital-based surveillance of cases among febrile participants attending two major health facilities within the southeastern region of Nigeria. In this study, 338 HIV-infected participants from two teaching hospitals in Nigeria’s southeast were systematically tested for Dengue with four methods: NS1 RDT, IgG RDT, IgM RDT, and NS1 ELISA. Their specificities and sensitivities were compared, as well as their level of concordance. Their respective performances were also evaluated using the Receivers Operational curve (ROC). Results: Out of the 338 patients, the dengue prevalence from the four dengue diagnostic methods Dengue virus NS1 ELISA, NS1 RDT, IgM and IgG seropositivity were 8.9%, 0.6%, 5.6%, and 8.0%, respectively. The Dengue IgM RDT test indicated 36.8% sensitivity, 92.8% specificity, the IgG anti-dengue specific test indicated 29.6% sensitivity, 92.9% specificity and the dengue NS1 RDT test indicated 3.3% sensitivity, 99.4% specificity when compared with the Dengue NSI Elisa test method as a reference method. Conclusion: The use of NSI ELISA for DENV diagnosis showed good performance and the RDTs showed, to an extent, reliable results compared with ELISA. However, diagnostic laboratories should be aware of performance variations across tests and the possibilities of cross-reactivity that may affect results.
基金supported by grants from the National Natural Science Foundation of China (30872198 30972566)
文摘Obejective The domainⅢof dengue virus type 2 envelope was cloned and expressed in Escherichia coli and the inhibited effects of recombinant protein on virus was detected. Methods In this study, the domainⅢ(DⅢ) protein of the dengue virus type-2 (DENV-2) envelope (E) antigen was expressed in Escherichia coli by fusion with a carrier protein. The protein was puriifed using enzymatic cleavage and afifnity puriifcation. Rabbit immunization and antibody detection was carried out. Inhibition of DENV-2 infection was observed by DENV-2 EDⅢprotein and its immunity rabbits serum. Results The recombinant expression DENV-2 EDⅢ protein plasmid was constructed successfully. After isopropyl thiogalactoside induction, a speciifc soluble 29 kD protein was obtained, and the expression product accounted for 68.87%of the total protein of the cell lysate. Western blot demonstrated the reactivity of the recombinant protein with his-tag and DENV (Ⅰ-Ⅳ) monoclonal antibodies. The protein was puriifed using enzymatic cleavage and affinity purification. The purified recombinant EDⅢ protein inhibited the entry of DENV-2 into BHK-21 cells. DENV-2 plaque neutralization assays were carried out using serially diluted antibodies against EDⅢprotein. At a 1︰16 dilution, the antibodies produced at least 90%neutralization of the DENV-2 virus. Furthermore, the antibodies continued to exhibit high neutralization effects (approximately 80%) until the anti-EDⅢantibody titer reached 1︰1 024. Conclusions DENV-2 EDⅢwas cloned and expressed successfully. DENV-2 EDⅢprotein could be useful in the development of inexpensive dengue vaccine. The data also suggested that DENV-2 employed an attachment molecule or receptor for its entry into C6/36 mosquito cells.
文摘Rationale: Malaria and dengue are the most prevalent vector-borne diseases in tropical countries. Plasmodium parasite and dengue virus(DENV) concurrent infection is possible and often under-recognized in geographical areas where these infections are both endemic.Patients concern and diagnosis: We describe the first two cases of Plasmodium falciparum and DENV-3 co-infection in travelers returning to northeastern Italy from Burkina Faso during 2013-2014.Interventions: Malaria infection in both patients was treated with mefloquine. Due to the persistence of symptoms despite of the antimalaria treatment, dengue was also investigated;the treatment of dengue was symptomatic.Outcomes: The patients were discharged in good general condition.Lessons: The need for surveillance of potential malaria and dengue co-infection in travelers returning to Europe from endemic areas is highlighted, as infection with Plasmodium does not exclude arboviral co-infection.
基金This research was supported by a GARE project grant(MOE,Bangladesh,grant no.LS201615)a Chittagong University Revenue Budget Grant(6160/2018)to MMI.
文摘Objective:To identify the residue determinants of the serospecificity and sero-cross-reactivity of dengue virus(DENV)envelope protein domain 3(ED3),which contains two major putative epitopes of DENV.Methods:We constructed ED3 from DENV3(3ED3)and DENV4(4ED3),and six epitope-grafted variants,where we transferred epitope 1(L304I,K305D,V309M,and S310A)and/or epitope 2(D383N,K384S,K387T,and N389H)of 4ED3 onto 3ED3 and vice-versa.Swiss albino mice aged 3-4 weeks were immunized against wildtype and epitope-grafted ED3 variants and anti-ED3 IgG antibody responses were determined using ELISA.Results:Mouse immunization using 3ED3 and 4ED3 generated serotype-specific antisera,as expected.Similarly,most epitope-grafted ED3s produced antisera serospecific to the template ED3 with little or no cross-recognition of ED3 of the serotype from which the epitopes were taken.These indicated that a mere grafting of the epitope was not sufficient to transfer serospecificity,contrary to our expectations.However,one epitope-grafted ED3 mutant,where epitope 1 of 3ED3 was grafted onto 4ED3(4ED3^(epi1)),generated antisera that was serospecific to both 4ED3 and 3ED3.Conclusions:The 4ED3^(epi1)is a chimeric ED3 that produces antisera possessing serospecificity to both 3ED3 and 4ED3 onto a common 4ED3 scaffold.The 4ED3^(epi1),therefore,provides a unique tool for analyzing serospecificity and sero-cross-reactivity in dengue.We believe that chimeric ED3 may provide a template for future recombinant ED3 possessing serospecificity of multiple DENVs onto a single scaffold and may pave a way developing tri-and/or tetravalent anti-DENV antisera.
文摘<strong>Introduction: </strong>Most febrile illnesses in Ghana are often misdiagnosed and presumptively treated as malaria. This situation may be due to the inappropriate diagnostic tool, clinical oversight and lack of awareness of some of the disease conditions that might have been present in the country. This study sought to investigate the seroprevalence of dengue virus, geographical location of participants with circulating antibodies and finally evaluate the diagnostic accuracy of a Rapid diagnostic kit (RDT) using Enzyme Linked Immuno-Sorbent Assay (ELISA) as a gold standard for confirmation. <strong>Method: </strong>A hospital-based cross-sectional study was conducted among adults (≥18) attending the University of Cape Coast Hospital. From each participant, 3 - 4 ml of venous blood was drawn and serum was tested for IgG and IgM using RDT methods. Positive samples were selected for ELISA confirmation. Statistical analysis was performed using SPSS (v.20) and STATA (v.14) software. <strong>Results: </strong>A total of 270 participants were enrolled in the study. The geometric mean age was 32 years. Overall, Dengue virus (DENV) IgG seroprevalence by RDT was 10 (3.7%). Seroprevalence of IgG and IgM by the ELISA method was 34 (12.6%) and 6 (2.2%) respectively. Females recorded a high seroprevalence (7.4%) than males (5.2%) in terms of past exposure (IgG). On current exposure (IgM), females recorded a high seroprevalence (1.5%) than males (0.7%). Seroprevalence of individuals with dual positivity ((IgG + IgM+) (acute secondary infection) was 1.9%. Those with primary and recent infection (IgM+ only) were 0.4% whiles those with past and probably secondary infection (IgG+ only) were 10.7%. The odds of dengue exposure were significantly high among participants with ages 50 - 59 as compared to their other counterparts (AOR = 3.5, p = 0.03). Diagnostic accuracy of RDT kit was poor (Kappa value = 0.373 and 0.0001). Elmina was noted to record the highest seroprevalence values for both anti-dengue IgG (3.3%) and IgM (1.85%). <strong>Conclusion:</strong> The seroprevalence of anti-dengue IgG and IgM among participants suggests that dengue virus is in circulation in Cape Coast Metropolis and Komenda Edina Eguafo Abirem Municipality.
文摘Rationale:Dengue fever is a viral infection that is spread through the bites of infected female Aedes mosquitos.It can cause life threatening complications,including dengue haemorrhagic fever(DHF)and dengue shock syndrome.Patient concerns:A 15-year-old male presented with fever and petechiae and later developed hemoptysis.Diagnosis:Dengue fever with DHF with diffuse alveolar hemorrhage.Interventions:Invasive ventilation with high positive end expiratory pressure,multiple transfusions of packed red blood cells,fresh frozen plasma,single donor platelets and inotropic support Outcomes:The patient was stabilized and discharged on minimal supplemental oxygen.Lessons:Diffuse alveolar hemorrhage,although very rare,should be considered in a patient with dengue who presents with hemoptysis.The treatment is directed at providing respiratory and circulatory support,and preventing the progression of microcirculation damage.
文摘Dengue is the most prevalent arthropod-borne viral diseases in terms of morbidity and mortality in the recent decade with the classic symptoms of high fever,headache as well as muscle and joint pain.Nilavembu Kudineer(NK)is one among the 32 types of internal medicines described in the ancient Siddha system of medicine in south India which reduces fever and relieves body aches.NK,a polyherbal formulation made up of eight traditional herbs in equal parts,is also recommended for prevention and management of all types of viral infections including Dengue/Chikugunya.Exploration of bioactive compounds in the plants is the primary step for the standardization and bioactivity screening of plants and formulations.So the current study aims at recording the chemical constituents and medicinal activities of each ingredient of NK.The anti-pyretic,anti-inflammatory,analgesic and immunostimulant effects of NK have been attributed to more than one ingredient in NK.The medicinal property of the NK can be also attributed to the combined effect of all phytochemicals present in these eight herbs.The current study encompasses the various chemicals and the activities of individual herbs but a thorough stereoscopic and chromatographic investigation is required to trace out the major phytochemical entities which are retained once the NK is prepared by the traditional methods.