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The Transmission Cycles of Dengue Virus (DENV). The transmission cycles of DENV, depicting the sylvatic origins and the ‘zone of emergence’ where sylvatic cycles contact human populations in rural areas in West Africa and Southeast Asia. Image courtesy of Shannan Rossi, Department of Pathology, UTMB.
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Dengue viruses (DENV) are by far the most important arboviral pathogens in the tropics around the world, putting at risk of infection nearly a third of the global human population. DENV are members of the genus Flavivirus in the Family Flaviviridae and comprise four antigenically distinct serotypes (DENV-1-4). Although they share almost identical e...
Contexts in source publication
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... utilize Aedes (Stegomyia) spp., primarily Ae. aegypti and Ae. albopictus, as vectors for domestic and peridomestic transmission, and arboreal Aedes mosquitoes as vectors for enzootic transmission (Figure 1). All DENV group into four genetically related but antigenically distinct serotypes (DENV-1, -2, -3 and -4) within the dengue (DEN) antigenic complex [1]. ...
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... and domestic (Ae. aegypti aegypti) mosquitoes and switching of reservoir hosts from non-human primates to humans (Figure 1). Furthermore, the emergence of the extant, distinct human DENV strains from the sylvatic transmission cycle was most likely facilitated by the allopatric and perhaps ecological partitioning of ancestral sylvatic DENV strains in different species of non-human primate populations. ...
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... four DENV serotypes are maintained in two distinct transmission cycles: (a) sylvatic and (b) human (Figure 1). ...
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... Africa, the principal vectors include Ae. (Stegomyia) luteocephalus, Ae. (Diceromyia) furcifer, and Ae. (Diceromyia) taylori (Figure 1) [95,96,[105][106][107]. Although Ae. furcifer are primarily canopy-dwelling enzootic mosquitoes, they are known to descend to ground level to feed on humans [105]. ...
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... species are also known to descend to the ground to feed on humans. The Asian primate reservoir hosts include, cynomolgus monkeys (Macaca fascicularis), Southern pig-tailed macaques (Macaca nemestrina) and silvered leaf monkeys (Presbytis cristata) and possibly green-mitered leaf monkeys (Presbytis melaphos) [2,109] (Figure 1). Although only two documented foci of sylvatic DENV transmission have been recognized, if one considers the extent of the geographic range of either vectors and primate reservoir hosts, it is probable that sylvatic DENV transmission occurs, yet undiscovered, in other locations of tropical Africa and Asia [94,110]. ...
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... opportunistic feeding behavior of the arboreal mosquito vectors described above could facilitate transfer of sylvatic DENV from the forest to peridomestic environments (Figure 1). Indeed, in rural areas of Africa and Asia where enzootic vector(s) often reach high densities, DENV is known to transfer between non-human primates and humans. ...
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... in rural areas of Africa and Asia where enzootic vector(s) often reach high densities, DENV is known to transfer between non-human primates and humans. The moist savannahs surrounding sylvan environments in rural areas of Africa and Asia are defined as the 'zone of emergence' [114] (Figure 1). In Asia, the studies of Rudnick demonstrated that zoonotic Ae. niveus vectors descend to the ground to feed on humans, where Ae. albopictus are also abundant, thus allowing the transfer of virus into human habitats [115]. ...
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... this human cycle, Ae. aegypti aegypti mosquitoes transmit DENV [116], while other Aedes spp. (for example, Ae. albopictus, Ae. polynesiensis) serve as secondary vectors [7,99,117,118] (Figure 1). As described above (see Section 4), although Ae. albopictus may have been the original vector for human transmission, DENV have fully exploited the highly anthropophilic Ae. aegypti aegypti for sustained human transmission. ...
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... transmission (TOT) has also been suggested as a mechanism of DENV maintenance in both transmission cycles (Figure 1), especially during protracted dry seasons or interepidemic periods. The involvement of TOT in DENV maintenance was demonstrated in nature with the isolation of presumably sylvatic DENV-2 from a pool of Ae. taylori in 1980 in Côte d'Ivoire [96], and a year later in Senegal from a pool of Ae. furcifer mosquitoes [3]. ...
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Abstract: Dengue fever is caused by dengue virus (DENV), a member of the genus Flavivirus, family Flaviviridae. The
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Dengue fever is one of the most important re-emerging arboviral disease, more than half of the world’s populatio...
Background:
At the present time, dengue is one of the most important arboviruses affecting man, becoming a serious global public health problem, especially in subtropical and tropical countries, where environmental conditions favor the development and proliferation of the mosquito Aedes aegypti. Dengue is caused by a type of flavivírus, which is a...
A series of tritylated and dimethoxytritylated analogues of selected pyrimidine and purine nucleosides were synthesized and evaluated for their in vitro inhibitory activity against two important members of the genus Flavivirus in the Flaviviridae family, the yellow fever (YFV) and dengue viruses (DENV). Among all compounds tested, the 5′-O-tritylat...
Background: Dengue fever is caused by dengue virus (DENV), a member of the genus Flavivirus of the family Flaviviridae. The virus is transmitted by the infected female of the primary vector Aedes Aegyptus mosquitoes. Dengue fever is the world's most important re-emerging arboviral disease with over 50% of the world's population at risk of the disea...
Dengue viruses are the most widespread arboviruses (transmitted mainly by Aedes aegypti and Ae. albopictus mosquitoes), which have shown an unexpected geographic expansion. There are four dengue virus serotypes: DENV-1, DENV-2, DENV-3, and DENV-4. Subsequent infections increase the risk of developing severe dengue fever.
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Citations
... Frontiers in Genetics frontiersin.org endemic settings (Chen and Vasilakis, 2011). Empirical data has shown that turnover of DENV lineages is often associated with enhanced transmission and outbreaks (Chen et al., 2008;Lambrechts et al., 2012;Tan et al., 2022), emphasizing the importance of genetically characterizing circulating and emerging lineages in affected regions. ...
... All four serotypes co-circulated at any time, confirming the hyperendemic status of dengue in Malaysia (Mia et al., 2013;Mohd-Zaki et al., 2014). Interestingly, the mean nucleotide substitution rate (subs/site/year) of each serotype did not differ substantially and were comparable to empirical data (Chen and Vasilakis, 2011), suggesting that DENV serotypes tend to evolve at a comparable rate, despite temporal fluctuations in their abundance. Besides non-uniformity in sampling that affects the observed heterogeneity in surveillance data, apparently "fixed" rate of evolution among serotypes may also be due to the strong purifying selection acting on DENV populations (Holmes, 2003;Lequime et al., 2016) that may mask the true heterogeneity of natural populations. ...
Dengue has been one of the major public health problems in Malaysia for decades. Over 600,000 dengue cases and 1,200 associated fatalities have been reported in Malaysia from 2015 to 2021, which was 100% increase from the cumulative total of dengue cases reported during the preceding 07-year period from 2008 to 2014. However, studies that describe the molecular epidemiology of dengue in Malaysia in recent years are limited. In the present study, we describe the genetic composition and dispersal patterns of Dengue virus (DENV) by using 4,004 complete envelope gene sequences of all four serotypes (DENV-1 = 1,567, DENV-2 = 1,417, DENV-3 = 762 and DENV-4 = 258) collected across Malaysia from 2015 to 2021. The findings revealed that DENV populations in Malaysia were highly diverse, and the overall heterogeneity was maintained through repetitive turnover of genotypes. Phylogeography analyses suggested that DENV dispersal occurred through an extensive network, mainly among countries in South and East Asia and Malaysian states, as well as among different states, especially within Peninsular Malaysia. The results further suggested Selangor and Johor as major hubs of DENV emergence and spread in Malaysia.
... 1 Dengue virus is an enveloped virus with a genome composed by a positive-sense single-stranded RNA with approximately 11.000 nucleotides, 2,3 transmitted mainly through of blood repast by infected species of Aedes aegypti and A albopictus. 4 The virus is further classified according to the distinction of their antigenic and genetic characteristics into 4 serotypes 5 DENV-1, DENV-2, DENV-3, and DENV-4, each one being subdivided into genotypes. 6,7 Dengue virus serotypes with the highest rates of reported infections in Brazil are DENV-1 and DENV-2. ...
Background
Dengue virus (DENV) causes an important disease and directly affects public health, being the arbovirus that presents the highest number of infections and deaths in the Western Brazilian Amazon. This virus is divided into 4 serotypes that have already circulated in the region.
Methodology
Molecular characterization of a cohort containing 841 samples collected from febrile patients between 2021 and 2023 was analyzed using a commercial kit to detect the main arboviruses circulating in Brazil: Zika, DENV-1, DENV-2, DENV-3, DENV-4 and, Chikungunya. Subsequently, Sanger sequencing was performed for positive samples.
Results
The cohort detected 162 positive samples, 12 for DENV-1 and 150 identified as DENV-2, indicating co-circulation of serotypes. The samples were subjected to sequencing and the analysis of the sequences that obtained good quality revealed that 5 samples belonged to the V genotype of DENV-1 and 46 were characterized as DENV-2 Cosmopolitan genotype—lineage 5.
Conclusion
The results allowed us to identify for the first time the Cosmopolitan genotype in Rondônia, Brazilian Western Amazon, and its fast spread dispersion.
... Dengue is a well-recognized vector-borne infectious disease exceedingly endemic to tropical and subtropical in many countries and is progressively spreading to the entire world (Khetarpal & Khanna et al., 2016;Chen & Vasilakis et al., 2011). This infection, takes hold of approximately 390 million people annually across the globe, out of which 96 million present with clinical symptoms (Kalita et al., 2020). ...
Managing dengue effectively is crucial due to four virus serotypes causing varying infection severities. Dengue fever has becoming more prevalent. Cases of haemorrhagic fever place a significant cost on society and its survivors. This study analyses prevalent serotypes during an endemic situation for severity and community transmission.
During a dengue outbreak in 2022, 514 samples were included in this study, and various diagnostic tests were employed. Dengue viral NS1 antigen gene, IgM antibody detection were executed using ELISA tests, while dengue RT-PCR for molecular confirmation using single-tube dengue multiplex RT-PCR assays to detect the presence of viral RNA and determine the infecting serotype. Data suggested that 108 were highly positive for dengue viral NS1Ag. Sensitivity and specificity of single-tube RT-PCR for dengue were found to be 79.41 and 100% respectively. Among the samples tested with the dengue Multiplex Real-Time PCR assay, 50.60% (n=41) were positive with DENV-2 being the most prevalent serotype followed by DENV-1 (32.10%, n=26) and DENV-3 (12.3%, n= 10).
Dengue fever is a global health challenge, especially in India. Serotyping identifies circulating serotypes. RT-PCR multiplexing assay can be a promising molecular diagnostic method, proving highly sensitive, specific, and rapid. It holds great promise for swift and reliable dengue virus detection and serotyping, enhancing future identification of cases for vaccine development.
... With global dengue cases surging, there is a critical need for enhanced genomic surveillance to track the emergence and spread of dengue virus lineages [4]. These lineages consist of four antigenically distinct serotypes (DENV1-4) which can be further subdivided into genetically diverse genotypes [5,6]. Additionally, the rollout of novel vaccines and other biological interventions, such as the release of mosquitoes carrying the virus-inhibiting Wolbachia bacterium, warrant close monitoring of changes in dengue virus genetic diversity that may impact or reflect the effectiveness of these strategies [7,8]. ...
Background
The increasing burden of dengue virus on public health due to more explosive and frequent outbreaks highlights the need for improved surveillance and control. Genomic surveillance of dengue virus not only provides important insights into the emergence and spread of genetically diverse serotypes and genotypes, but it is also critical to monitor the effectiveness of newly implemented control strategies. Here, we present DengueSeq, an amplicon sequencing protocol, which enables whole-genome sequencing of all four dengue virus serotypes.
Results
We developed primer schemes for the four dengue virus serotypes, which can be combined into a pan-serotype approach. We validated both approaches using genetically diverse virus stocks and clinical specimens that contained a range of virus copies. High genome coverage (>95%) was achieved for all genotypes, except DENV2 (genotype VI) and DENV 4 (genotype IV) sylvatics, with similar performance of the serotype-specific and pan-serotype approaches. The limit of detection to reach 70% coverage was 10-100 RNA copies/μL for all four serotypes, which is similar to other commonly used primer schemes. DengueSeq facilitates the sequencing of samples without known serotypes, allows the detection of multiple serotypes in the same sample, and can be used with a variety of library prep kits and sequencing instruments.
Conclusions
DengueSeq was systematically evaluated with virus stocks and clinical specimens spanning the genetic diversity within each of the four dengue virus serotypes. The primer schemes can be plugged into existing amplicon sequencing workflows to facilitate the global need for expanded dengue virus genomic surveillance.
... Hematological parameter evaluation revealed a significant incidence of leukopenia in the patient population. The mean WBC count in leukopenic individuals was markedly reduced, paralleling findings from Chaloemwong, J., Tantiworawit The study also reported significant thrombocytopenia, a common abnormality in dengue patients, echoing the research by Anwar, F., Ahmad, S., Haroon, M., Haq, I. U. et al., from the Mardan district, and findings from Nandwani, S., Bhakhri, B. K., Singh, N., Rai, R.et al., who documented reduced platelet counts in a pediatric cohort (26,27). The implications of these hematological changes are profound, as they not only signal the infection's progression but also assist clinicians in stratifying patients based on the severity of their symptoms. ...
Background: Dengue fever continues to pose significant challenges in public health, particularly within developing countries where it remains endemic. The ability to distinguish dengue infection from other febrile illnesses and assess its severity is crucial. The analysis of hematological parameters and inflammatory biomarkers, particularly C-reactive protein (CRP), offers valuable insights into the disease's progression.
... En cambio, el ciclo de transmisión en áreas boscosas tiene lugar en pág. 313 los ambientes selváticos del sudeste asiatico y áfrica occidetal y sus vectores principales son Ae. luteocéfalo, Ae. furcifer y Ae. taylori(4). En zonas urbanas, la transmisión del DENV ocurre entre humanos, mientras que en áreas boscosas la transmisión es dada entre primates no humanos con efectos indirectos de manera ocasional en las poblaciones humanas(5).Diferencias entre las diferentes formas de transmisión del dengue ...
El dengue y la desnutrición son dos problemas de salud significativos que afectan a comunidades en todo el mundo, especialmente en regiones tropicales y subtropicales. El dengue es una enfermedad viral transmitida por mosquitos, siendo el Aedes aegypti el principal vector. Sus síntomas varían desde fiebre y dolores musculares hasta complicaciones graves, como el dengue grave o hemorrágico. Por otro lado, la desnutrición se refiere a la falta de nutrientes esenciales en el organismo, comprometiendo el desarrollo y funcionamiento adecuado del cuerpo. Ambos problemas de salud pueden estar interrelacionados, ya que la desnutrición puede debilitar el sistema inmunológico, aumentando la vulnerabilidad a enfermedades como el dengue.
... The sequences from human serum from dengue cases found in Borbon are similar to those within this clade and have been actively circulating in the area [30,31]. Due to human migration and high mutation rate, the dengue virus undergoes constant evolutionary changes, increasing the likelihood of new variants emerging, particularly in the study area where there is high mobility between the populations from Colombia, Ecuador and lately from Venezuela [32]. ...
Ecuador is a tropical country reporting Dengue virus (DENV) outbreaks with areas of hyperendemic viral transmission. Entomo-virological surveillance and monitoring effort conducted in the Northwestern border province of Esmeraldas in April 2022, five pools of female Aedes aegypti mosquitoes from a rural community tested positive for DENV serotype 2 by RT-qPCR. One pool was sequenced by Illumina MiSeq, and it corresponded to genotype III Southern Asian-American. Comparison with other genomes revealed genetic similarity to a human DENV genome sequenced in 2021, also from Esmeraldas. Potential introduction events to the country could have originated from Colombia, considering the vicinity of the collection sites to the neighboring country and high human movement. The inclusion of genomic information complements entomo-virological surveillance, providing valuable insights into genetic variants. This contribution enhances our understanding of Dengue virus (DENV) epidemiology in rural areas and guides evidence-based decisions for surveillance and interventions.
Author Summary
In this study, the complete genetic information of the dengue virus isolated from the mosquito vector Aedes aegypti was characterized using molecular biology, sequencing, and bioinformatics analysis. The isolation of the virus from the vector has contributed significantly to our understanding of the transmission dynamics of the disease and its genetic relationship with human cases. Identifying the serotypes and genotypes circulating in Ecuador has enabled us to comprehend the evolution of the virus from 2014 to 2023. Therefore, surveillance of genetic variability would aid in adapting precise prevention and control strategies to the genetic variants present in a specific geographical area. Entomo-virological surveillance is essential for assessing changes in risk and the impact of control measures.
... Aedes aegypti and Aedes albopictus are the main vectors for urban transmission. In contrast, Aedes luteocephalus, Aedes furcifer and Aedes taylor are the main vectors for sylvatic transmission [48]. Infected mosquitoes transmit the virus vertically to their offspring via transovarial transmission, which is an essential factor in the maintenance of transmission cycles in both humans and wildlife [49]. ...
... It can survive away from populated areas, thanks to its capacity to adapt to colder weather and broad diet, which includes food from various animals and birds. Aedes albopictus is becoming a big issue for dengue transmission in cooler regions, such as some Eastern European and Mediterranean nations [8]. ...
Neurological problems are more frequently linked to dengue, a mosquito-transmitted virus common in tropical areas. This review study thoroughly examines the effects of dengue on adult males' neurological systems. Dengue hemorrhagic fever (DHF) or dengue shock syndrome (DSS) can develop in severe cases of dengue fever caused by the dengue virus (DENV). Unsettlingly, it is thought that a sizable portion of DENV infections impact the central nervous system (CNS), which calls into question the former theory that the DENV is not neurotropic. This review dissects the many neurological manifestations of dengue, spanning from encephalopathy, encephalitis, and other CNS implications to peripheral neuromuscular issues, through the systematic analysis of publications gathered from PubMed. The essay emphasizes the immunological reactions brought on by DENV infections and offers a deeper understanding of the pathophysiology. Given that they exhibit similar first symptoms, Zika and chikungunya are two more illnesses that must be distinguished from dengue. The mainstay of current diagnostic methods is serum and cerebrospinal fluid (CSF) tests, although supportive care is still used. This review highlights the importance of tracking neurological symptoms in dengue patients and encourages more studies in this area.
... Currently, dengue is reported as the most prevalent mosquitoborne viral infection worldwide, with substantial human health and economic costs (Guzman et al., 2010). Dengue is caused by any of the dengue serotypes (Chen et al., 2011). Dengue is mainly a tropical disease transmitted by mosquitoes of the genus Aedes (Ong et al., 2021). ...
... Classical dengue fever is the most prevalent type of the disease and, is manifested by sudden onset of headache, malaise, fever, anorexia, muscle and joint pains, lymphadenopathy, and rash (Kularatne et al., 2015). aggravated dengue is characterized by dengueshocked disease leakage of plasma, hemorrhage, and signs of severe organ dysfunction, such as elevated hepatic enzymes and impaired consciousness (Chen et al., 2011). The case fatality rate of aggravated dengue can exceed 5% and figures as high as 44% have been documented (Withana et al., 2014). ...
Background: The mosquito borne dengue fever and malaria -; are major public health concerns in tropical settings. They are highly prevalent and considered one of the main etiology of febrile illnesses in Sudan. Aim: This study aimed to determine seroprevalence of dengue virus among febrile malaria positive and negative patients in Nyala city, Western Sudan by using Enzyme linked immuno sorbent assay (ELISA) to detect dengue virus IgM and IgG antibodies. It also aimed to study possible risk factors that may be associated with dengue virus and malaria infections. Methods: This cross sectional study, which was undertaken in different Hospitals in Nyala city, South Darfur state Sudan during June to December 2021. A total of 93 blood samples from febrile patients were collected in EDTA containers. Plasma was obtained by centrifugation and tested by ELISA (EUROIMMUN, Germany) according to manufactures instructions for dengue virus IgG and IgM antibodies. Malaria parasites were detected using microscopy of stained blood smears. Generated data was analyzed using the statistical package (SPSS) version 21. Results: Forty six (49.5%) out of 93 febrile patients were found infected with malaria parasites using blood smear microscopy. Among these malaria infected patients, the prevalence of dengue anti-virus IgG (49 .5%) was higher than that of IgM (16.1%) but was statistically insignificant (p>0.05). In the present study dengue infection was higher in males than in females but was statistically insignificant (P> 0.05) and the Age group 21-40 years was the most affected with dengue virus infection. Conclusion: The present study showed higher prevalance rate of dengue IgG among the participants of study more than IgM but was statistically insignificant There was no association between age and gender with seroplevance of dengue virus among febrile patients with and without malaria. The frequent existence of infections of DENV requires improved surveillance and control measures to combat this disease in Nyala, Sudan.
