Dengue and dengue hemorrhagic fever

Stochastic two-strain epidemic model with saturated incidence rates driven by Lévy noise

In this paper, we introduce a stochastic two-strain epidemic model driven by Lévy noise describing the interaction between four compartments; susceptible, infected individuals by the first strain, infected ones by the second strain and the recovered individuals. The forces of infection, for both strains, are represented by saturated incidence rates. Our study begins with the investigation of unique global solution of the suggested mathematical model. Then, it moves to the determination of sufficient conditions of extinction and persistence in mean of the two-strain disease. In order to illustrate the theoretical findings, we give some numerical simulations.

Discovery of Potent Degraders of the Dengue Virus Envelope Protein

Targeted protein degradation has been widely adopted as a new approach to eliminate both established and previously recalcitrant therapeutic targets. Here, it is reported that the development of small molecule degraders of the envelope (E) protein of dengue virus. Two classes of bivalent E-degraders are developed by linking two previously reported E-binding small molecules, GNF-2, and CVM-2-12-2, to a glutarimide-based recruiter of the CRL4CRBN ligase to effect proteosome-mediated degradation of the E protein. ZXH-2-107 (based on GNF-2) is an E-degrader with ABL inhibitory activity while ZXH-8-004 (based on CVM-2-12-2) is a selective and potent E-degrader. These two compounds provide proof of concept that difficult-to-drug targets such as a viral envelope protein can be effectively eliminated using a bivalent degrader and provide starting points for the future development of a new class of direct-acting antiviral drugs.

Arbovirus Transmission in Australia from 2002 to 2017

Arboviruses pose a significant global public health threat, with Ross River virus (RRV), Barmah Forest virus (BFV), and dengue virus (DENV) being among the most common and clinically significant in Australia. Some arboviruses, including those prevalent in Australia, have been reported to cause transfusion-transmitted infections. This study examined the spatiotemporal variation of these arboviruses and their potential impact on blood donation numbers across Australia. Using data from the Australian Department of Health on eight arboviruses from 2002 to 2017, we retrospectively assessed the distribution and clustering of incidence rates in space and time using Geographic Information System mapping and space-time scan statistics. Regression models were used to investigate how weather variables, their lag months, space, and time affect case and blood donation counts. The predictors' importance varied with the spatial scale of analysis. Key predictors were average rainfall, minimum temperature, daily temperature variation, and relative humidity. Blood donation number was significantly associated with the incidence rate of all viruses and its interaction with local transmission of DENV, overall. This study, the first to cover eight clinically relevant arboviruses at a fine geographical level in Australia, identifies regions at risk for transmission and provides valuable insights for public health intervention.

Utility of the WHO dengue guidelines in pediatric immunological studies

Dengue is a significant health problem due to the high burden of critical infections during outbreaks. In 1997, the World Health Organization (WHO) classified dengue as dengue fever (DF), dengue hemorrhagic fever (DHF), and dengue shock syndrome (DSS). It was revised in 2009 (updated in 2015), and the new guidelines recommended classifying patients as dengue without warning signs (DNS), dengue with warning signs (DWS), and severe dengue (SD). Although the utility of the revised 2009 classification for clinical studies is accepted, for immunological studies it needs to be clarified. We determined the usefulness of the 2009 classification for pediatric studies that analyze the circulating interleukin (IL)-6 and IL-8, two inflammatory cytokines. Plasma levels of IL-6 and IL-8 were evaluated in the acute and convalescent phases by flow cytometry in children with dengue classified using the 1997 and 2009 WHO guidelines. The plasma levels of IL-6 and IL-8 were elevated during the acute and decreased during convalescence, and both cytokines served as a good marker of acute dengue illness compared to convalescence. There were no differences in the plasma level of the evaluated cytokines among children with different clinical severity with any classification, except for the IL-8, which was higher in DWS than DNS. Based on the levels of IL-8, the 2009 classification identified DWS plus SD (hospital-treated children) compared to the DNS group [area under the curve (AUC): 0.7, p = 0.028]. These results support the utility of the revised 2009 (updated in 2015) classification in studies of immune markers in pediatric dengue.

A Cross-Sectional Study on Bedside Abdominal Ultrasound Findings as a Diagnostic and Prognostic Tool in Dengue Fever in Manipal Hospital, Bengaluru, India

Background Dengue fever poses a significant health burden globally, particularly in tropical and subtropical regions. Early diagnosis and effective management are crucial in reducing morbidity and mortality associated with the disease. Bedside abdominal ultrasound has emerged as a promising tool for assessing dengue patients, providing real-time imaging of abdominal organs, and aiding clinical decision-making. Materials and methods This cross-sectional study was conducted in 55 adult emergency departments of Manipal Hospital, Bengaluru, from March 2017 to March 2018. Adult patients presenting with signs and symptoms suggestive of dengue fever were included. Clinical data, laboratory investigations, and bedside abdominal ultrasound findings were systematically recorded and analyzed using appropriate statistical methods. Results Descriptive statistics revealed characteristic clinical measurements and symptom ratings observed in dengue fever patients. Frequency distributions highlighted common symptoms encountered, while statistical analyses demonstrated significant associations between ultrasonic parameters, disease severity, and outcomes. The study found notable correlations between ultrasonic findings and dengue severity levels, emphasizing the potential of bedside ultrasound as a diagnostic and prognostic tool. Conclusion Bedside abdominal ultrasound shows promise as a valuable adjunctive tool in assessing dengue fever patients. The significant associations between ultrasonic parameters and disease severity suggest its utility in risk stratification and guiding clinical management decisions. Incorporating bedside ultrasound into routine practice may improve patient care and outcomes in dengue fever management. Further research is warranted to validate these findings and explore additional bedside ultrasound applications in dengue fever diagnosis and prognosis.

In-silico screening and identification of potential drug-like compounds for dengue-associated thrombocytopenia from Carica papaya leaf extracts

Dengue virus is a mosquito-borne pathogen that causes a variety of illnesses ranging from mild fever to severe and fatal dengue haemorrhagic fever or dengue shock syndrome. One of the major clinical manifestations of severe dengue infection is thrombocytopenia. The dengue non-structural protein 1 (NS1) is the primary protein that stimulates immune cells via toll-like receptor 4 (TLR4), induces platelets, and promotes aggregation, which could result in thrombocytopenia. The leaf extracts of Carica papaya seem to have therapeutic benefits in managing thrombocytopenia associated with dengue. The present study focuses on understanding the underlying mechanism of the use of papaya leaf extracts in treating thrombocytopenia. We have identified 124 phytocompounds that are present in the papaya leaf extract. The pharmacokinetics, molecular docking, binding free energy calculations, and molecular dynamic simulations were performed to investigate the drug-like properties, binding affinities, and interaction of phytocompounds with NS1 protein as well as the interactions of NS1 with TLR4. Three phytocompounds were found to bind with the ASN130, a crucial amino acid residue in the active site of the NS1 protein. Thus, we conclude that Rutin, Myricetin 3-rhamnoside, or Kaempferol 3-(2''-rhamnosylrutinoside) may serve as promising molecules by ameliorating thrombocytopenia in dengue-infected patients by interfering the interaction of NS1 with TLR4. These molecules can serve as drugs in the management of dengue-associated thrombocytopenia after verifying their effectiveness and assessing the drug potency, through additional in-vitro assays.Communicated by Ramaswamy H. Sarma.

Local Transmission of Dengue in South Florida: A Case Report

Dengue is a significant global health concern, primarily prevalent in tropical and subtropical regions, affecting approximately 400 million people annually worldwide. This case report highlights the emergence of dengue in South Florida and raises concerns about the possibility of a local transmission. Unlike most cases, the patients discussed had not recently traveled, prompting the need for further investigation into the local transmission of dengue. In October 2023, two adult brothers presented to the Emergency Department (ED) with symptoms including fever, chills, nausea, vomiting, rash, severe headache, and syncope. Laboratory tests revealed thrombocytopenia, atypical lymphocytes, and elevated liver enzymes. With this clinical picture, dengue was suspected, and management was initiated accordingly. Both patients denied recent travel and had no known dengue infections in the past but had been exposed to mosquitoes a week prior. Both patients were managed with supportive treatment and platelet transfusions, which led to clinical improvement. However, the laboratory tests for dengue diagnosis had to be sent to a third-party laboratory, resulting in delayed confirmation of the disease. We received confirmation of a positive dengue serology approximately a week after the first patient was discharged. Two suspected cases of dengue virus were confirmed. The availability of local laboratory tests is crucial for the early diagnosis and management of dengue. The study calls for increased awareness of the disease's severity and its risk factors, emphasizing early recognition, judicious use of intravenous fluids, and the need for accessible local diagnostic resources to facilitate timely patient care.

The Looming Threat of Dengue Fever: The Africa Context

In Africa, compared to 2019, dengue infections have surged ninefold by December 2023, with over 270 000 cases and 753 deaths reported across 18 African Union (AU) Member States. This commentary synthesises the context of dengue outbreaks in Africa and provides recommendations for sustainable control. In 2023, 18 African Union Member States reported outbreaks of dengue, among which seven had ongoing armed conflicts. These countries were amongst the top 15 African countries contributing to the most displaced persons on the continent and accounted for 98% of all dengue cases reported in the continent in 2023. Climate change remains an important driver, both through the displacement of people and global warming. The continent continues to face several challenges in detection, reporting and management, such as the lack of local laboratory capacity, misclassification of dengue cases and lack of medical countermeasures. Solutions targeting the strengthening of cross-border surveillance and early warning systems using a multisectoral one-health approach, local research and development for therapeutics and diagnostics and community engagement empowering communities to protect themselves and understand the gravity of the threat could help curb the spread of the disease in Africa.

Unraveling Dengue Virus Diversity in Asia: An Epidemiological Study through Genetic Sequences and Phylogenetic Analysis

Dengue virus (DENV) is the causative agent of dengue. Although most infected individuals are asymptomatic or present with only mild symptoms, severe manifestations could potentially devastate human populations in tropical and subtropical regions. In hyperendemic regions such as South Asia and Southeast Asia (SEA), all four DENV serotypes (DENV-1, DENV-2, DENV-3, and DENV-4) have been prevalent for several decades. Each DENV serotype is further divided into multiple genotypes, reflecting the extensive diversity of DENV. Historically, specific DENV genotypes were associated with particular geographical distributions within endemic regions. However, this epidemiological pattern has changed due to urbanization, globalization, and climate change. This review comprehensively traces the historical and recent genetic epidemiology of DENV in Asia from the first time DENV was identified in the 1950s to the present. We analyzed envelope sequences from a database covering 16 endemic countries across three distinct geographic regions in Asia. These countries included Bangladesh, Bhutan, India, Maldives, Nepal, Pakistan, and Sri Lanka from South Asia; Cambodia, Laos, Myanmar, Thailand, and Vietnam from Mainland SEA; and Indonesia, the Philippines, Malaysia, and Singapore from Maritime SEA. Additionally, we describe the phylogenetic relationships among DENV genotypes within each serotype, along with their geographic distribution, to enhance the understanding of DENV dynamics.

Population-specific thermal responses contribute to regional variability in arbovirus transmission with changing climates

Temperature is increasing globally, and vector-borne diseases are particularly responsive to such increases. While it is known that temperature influences mosquito life history traits, transmission models have not historically considered population-specific effects of temperature. We assessed the interaction between Culex pipiens population and temperature in New York State (NYS) and utilized novel empirical data to inform predictive models of West Nile virus (WNV) transmission. Genetically and regionally distinct populations from NYS were reared at various temperatures, and life history traits were monitored and used to inform trait-based models. Variation in Cx. pipiens life history traits and population-dependent thermal responses account for a predicted 2.9°C difference in peak transmission that is reflected in regional differences in WNV prevalence. We additionally identified genetic signatures that may contribute to distinct thermal responses. Together, these data demonstrate how population variation contributes to significant geographic variability in arbovirus transmission with changing climates.

Microclimate factors related to dengue virus burden clusters in two endemic towns of Mexico

In dengue-endemic areas, transmission control is limited by the difficulty of achieving sufficient coverage and sustainability of interventions. To maximize the effectiveness of interventions, areas with higher transmission could be identified and prioritized. The aim was to identify burden clusters of Dengue virus (DENV) infection and evaluate their association with microclimatic factors in two endemic towns from southern Mexico. Information from a prospective population cohort study (2·5 years of follow-up) was used, microclimatic variables were calculated from satellite information, and a cross-sectional design was conducted to evaluate the relationship between the outcome and microclimatic variables in the five surveys. Spatial clustering was observed in specific geographic areas at different periods. Both, land surface temperature (aPR 0·945; IC95% 0·895-0·996) and soil humidity (aPR 3·018; IC95% 1·013-8·994), were independently associated with DENV burden clusters. These findings can help health authorities design focused dengue surveillance and control activities in dengue endemic areas.

Vascular dysfunction in hemorrhagic viral fevers: opportunities for organotypic modeling

The hemorrhagic fever viruses (HFVs) cause severe or fatal infections in humans. Named after their common symptom hemorrhage, these viruses induce significant vascular dysfunction by affecting endothelial cells, altering immunity, and disrupting the clotting system. Despite advances in treatments, such as cytokine blocking therapies, disease modifying treatment for this class of pathogen remains elusive. Improved understanding of the pathogenesis of these infections could provide new avenues to treatment. While animal models and traditional 2D cell cultures have contributed insight into the mechanisms by which these pathogens affect the vasculature, these models fall short in replicatingin vivohuman vascular dynamics. The emergence of microphysiological systems (MPSs) offers promising avenues for modeling these complex interactions. These MPS or 'organ-on-chip' models present opportunities to better mimic human vascular responses and thus aid in treatment development. In this review, we explore the impact of HFV on the vasculature by causing endothelial dysfunction, blood clotting irregularities, and immune dysregulation. We highlight how existing MPS have elucidated features of HFV pathogenesis as well as discuss existing knowledge gaps and the challenges in modeling these interactions using MPS. Understanding the intricate mechanisms of vascular dysfunction caused by HFV is crucial in developing therapies not only for these infections, but also for other vasculotropic conditions like sepsis.

Discovery of Potent Degraders of the Dengue Virus Envelope Protein

Targeted protein degradation has been widely adopted as a new approach to eliminate both established and previously recalcitrant therapeutic targets. Here we report the development of small molecule degraders of the envelope (E) protein of dengue virus. We developed two classes of bivalent E-degraders, linking two previously reported E-binding small molecules, GNF-2 and CVM-2-12-2, to a glutarimide-based recruiter of the CRL4CRBN ligase to effect proteosome-mediated degradation of the E protein. ZXH-2-107 (based on GNF-2) is an E degrader with ABL inhibition while ZXH-8-004 (based on CVM-2-12-2) is a selective and potent E-degrader. These two compounds provide proof-of-concept that difficult-to-drug targets such as a viral envelope protein can be effectively eliminated using a bivalent degrader and provide starting points for the future development of a new class antiviral drugs.

Is there an overestimation of dengue compared with that of other acute febrile syndromes in childhood?

A group of children with clinical suspicion of dengue were assessed to determine if there was an overestimation of dengue compared with that of leptospirosis and leishmaniasis. This descriptive and analytical cross-sectional study, based on the active search of participants with acute febrile illness, was conducted at two pediatric hospitals. The collection of clinical and epidemiological data was performed using questionnaires, and laboratory tests specific for dengue were performed using immunochromatographic, serological, and molecular methods. Dengue-negative samples were assessed for Leptospira and Leishmania spp. using molecular tests. Data were assessed using analysis of variance (ANOVA), the chi-square test, and Fisher's exact test. In total, 86 participants were evaluated, of whom 39 (45%) were positive for dengue fever, 4 (5%) for leptospirosis, and 1 (1%) for leishmaniasis. Forty-two participants (49%) presented dengue-like symptoms. The predominant age range for the virus was 3-10 years. Most clinical manifestations were nonspecific, with frequent concomitant gastrointestinal and respiratory symptoms. Furthermore, we found that the acute febrile syndrome in childhood persists as a challenge for health professionals, especially in the early days of the disease, due to a plurality of diagnostic hypotheses, associated with the difficulty of establishing well-defined symptoms in children, especially in infants. Dengue fever continues to be a frequent pathology with acute febrile infections in childhood; however, there is an overestimation of the disease, especially in endemic regions, when one considers only the clinical epidemiological diagnosis.

Quantitative detection of chikungunya, Zika, and dengue viruses by one-step real-time PCR in different cell substrates

Chikungunya (CHIKV), Zika (ZIKV), and dengue viruses (DENV) are vector-borne pathogens that cause emerging and re-emerging epidemics throughout tropical and subtropical countries. The symptomatology is similar among these viruses and frequently co-circulates in the same areas, making the diagnosis arduous. Although there are different methods for detecting and quantifying pathogens, real-time reverse transcription-polymerase chain reaction (real-time RT-qPCR) has become a leading technique for detecting viruses. However, the currently developed assays frequently involve probes and high-cost reagents, limiting access in low-income countries. Therefore, this study aims to design and evaluate a quantitative one-step RT-qPCR assay to detect CHIKV, ZIKV, and DENV with high specificity, reproducibility, and low cost in multiple cell substrates. We established a DNA intercalating green dye-based RT-qPCR test that targets nsP1 of CHIKV, and NS5 gene of ZIKV, and DENV for the amplification reaction. The assay exhibited a high specificity confirmed by the melting curve analysis. No cross-reactivity was observed between the three viruses or unspecific amplification of host RNA. The sensitivity of the reaction was evaluated for each virus assay, getting a limit of detection of one RNA copy per virus. Standard curves were constructed, obtaining a reaction efficiency of ~ 100%, a correlation coefficient (R2) of ~ 0.97, and a slope of -3.3. The coefficient of variation (CV) ranged from 0.02 to 1.43. In addition, the method was optimized for viral quantification and tested in Vero, BHK-21, C6/36, LULO, and the Aedes cell lines. Thus, the DNA intercalating green dye-based RT-qPCR assay was a highly specific, sensitive, reproducible, and effective method for detecting and quantifying CHIKV, ZIKV, and DENV in different cell substrates that could also be applied in clinical samples.

Immunization against dengue virus infection is coercive: A timely call

Background

In context, the dengue virus causes dengue fever, which is spread by mosquito bites. About 22,000 people every year lose their lives as a direct result of it. Dengue fever has been on the rise recently, and its spread has alarmed health officials throughout the world.

Discussion

Vaccination is essential for the prevention and management of dengue cases because there is currently no particular cure against dengue virus. The current dengue epidemic calls for urgent action in the form of immunization. However, there are serious drawbacks to using existing vaccines like Dengvaxia. Besides, the Qdenga vaccine has not yet been approved by the FDA in the United States. On the other hand, positive results from a phase II randomized and controlled clinical study of the TV005 tetravalent live-attenuated dengue vaccine were recently reported in Bangladesh. Only an effective vaccination can drastically lower dengue infection and mortality rates.

Conclusion

The development of safe and effective vaccination, as well as their correct dissemination, is an essential requirement for the people of Bangladesh and the rest of the globe, and we concentrated on this critical problem in this article.

Integrated One Health strategies in Dengue

Zoonoses have rapidly spread globally, necessitating the implementation of vaccination strategies as a control measure. Emerging and re-emerging vector-borne diseases are among the major global public health concerns. Dengue, a zoonotic viral infection transmitted to humans by a vector, the Aedes mosquito, is a severe global health problem. Dengue is a serious tropical infectious disease, second only to malaria, causing around 25,000 deaths each year. The resurgence of Dengue is mainly due to climate change, demographic transitions and evolving social dynamics. The development of an effective vaccine against Dengue has proven to be a complex undertaking due to four different viral serotypes with distinct antigenic profiles. This review highlights the urgent need to address the dengue threat by exploring the application of biotechnological and -OMICS sciences.

Introduction of New Dengue Virus Lineages of Multiple Serotypes after COVID-19 Pandemic, Nicaragua, 2022

Major dengue epidemics throughout Nicaragua's history have been dominated by 1 of 4 dengue virus serotypes (DENV-1-4). To examine serotypes during the dengue epidemic in Nicaragua in 2022, we performed real-time genomic surveillance in-country and documented cocirculation of all 4 serotypes. We observed a shift toward co-dominance of DENV-1 and DENV-4 over previously dominant DENV-2. By analyzing 135 new full-length DENV sequences, we found that introductions underlay the resurgence: DENV-1 clustered with viruses from Ecuador in 2014 rather than those previously seen in Nicaragua; DENV-3, which last circulated locally in 2014, grouped instead with Southeast Asia strains expanding into Florida and Cuba in 2022; and new DENV-4 strains clustered within a South America lineage spreading to Florida in 2022. In contrast, DENV-2 persisted from the formerly dominant Nicaragua clade. We posit that the resurgence emerged from travel after the COVID-19 pandemic and that the resultant intensifying hyperendemicity could affect future dengue immunity and severity.

Addressing the Dengue fever challenges in Nigeria: A narrative review and recommendations for control

Dengue fever is a mosquito-borne viral infection that continues to pose a significant public health threat globally, including Nigeria. Here, we provided a review of dengue fever outbreaks in Nigeria from 1972 to 2023, examining the epidemiology, prevention strategies, challenges faced in combating the disease, and recommendations to mitigate its spread and transmission. We utilized scholarly databases such as PubMed and Google Scholar in writing this paper. The search keywords like, "dengue fever", "break-bone fever", "dengue fever virus" "outbreak", "Nigeria", "prevalence", and "epidemiology", were used to get appropriate published articles about the subject areas. Over the past five decades, Nigeria has experienced intermittent outbreaks of dengue fever, with varying degrees of severity and geographic distribution. Factors such as urbanization, climate change, and inadequate healthcare infrastructure have contributed to the resurgence and spread of the disease in the country. Despite efforts to control dengue transmission through vector control measures and public health interventions, challenges persist, including limited surveillance capacity, diagnostic delays, and gaps in vector control strategies. The emergence of new dengue virus serotypes and the potential for co-circulation with other arboviruses further complicate control efforts. This review highlights the importance of strengthening surveillance systems, enhancing vector control measures, improving diagnostic capabilities, and increasing public awareness to effectively mitigate the burden of dengue fever in Nigeria. Collaboration between government agencies, healthcare providers, researchers, and international partners is crucial in addressing the growing threat of dengue fever and reducing its impact on public health in Nigeria.

Occupational exposure to malaria, leishmaniasis and arbovirus vectors in endemic regions: A systematic review

Vector-borne diseases, including dengue, leishmaniasis and malaria, may be more common among individuals whose occupations or behaviours bring them into frequent contact with these disease vectors outside of their homes. A systematic review was conducted to ascertain at-risk occupations and situations that put individuals at increased risk of exposure to these disease vectors in endemic regions and identify the most suitable interventions for each exposure. The review was conducted in accordance with PRISMA guidelines on articles published between 1945 and October 2021, searched in 16 online databases. The primary outcome was incidence or prevalence of dengue, leishmaniasis or malaria. The review excluded ecological and qualitative studies, abstracts only, letters, commentaries, reviews, and studies of laboratory-acquired infections. Studies were appraised, data extracted, and a descriptive analysis conducted. Bite interventions for each risk group were assessed. A total of 1170 articles were screened and 99 included. Malaria, leishmaniasis and dengue were presented in 47, 41 and 24 articles, respectively; some articles presented multiple conditions. The most represented populations were soldiers, 38% (43 of 112 studies); refugees and travellers, 15% (17) each; migrant workers, 12.5% (14); miners, 9% (10); farmers, 5% (6); rubber tappers and missionaries, 1.8% (2) each; and forest workers, 0.9% (1). Risk of exposure was categorised into round-the-clock or specific times of day/night dependent on occupation. Exposure to these vectors presents a critical and understudied concern for outdoor workers and mobile populations. When devising interventions to provide round-the-clock vector bite protection, two populations are considered. First, mobile populations, characterized by their high mobility, may find potential benefits in insecticide-treated clothing, though more research and optimization are essential. Treated clothing offers personal vector protection and holds promise for economically disadvantaged individuals, especially when enabling them to self-treat their clothing to repel vectors. Secondly, semi-permanent and permanent settlement populations can receive a combination of interventions that offer both personal and community protection, including spatial repellents, suitable for extended stays. Existing research is heavily biased towards tourism and the military, diverting attention and resources from vulnerable populations where these interventions are most required like refugee populations as well as those residing in sub-Saharan Africa.

Identifying villages and breeding habitats for dengue transmission in Thailand: insights from long-term larval surveys

BACKGROUND

In Thailand, the Department of Disease Control (DDC) regularly performs visual larval surveys throughout the country to monitor dengue fever outbreaks. Since 2016, the DDC switched from a paper-based to a digital-based larval survey process. The significant amount of larval survey data collected digitally presents a valuable opportunity to precisely identify the villages and breeding habitats that are vulnerable to dengue transmission.

METHODS

The study used digitally collected larval survey data from 2017 to 2019. It employed larval indices to evaluate the risk of dengue transmission in villages based on seasonal, regional, and categorical perspectives. Furthermore, the study comprehensively scrutinized each container category by employing different measures to determine its breeding preference ratio.

RESULTS

The result showed that villages with a very high-risk of dengue transmission were present year-round in all regions, with the highest proportion during the rainy season. The Southern region had more high-risk villages during the winter season due to rainfall. Slums and residential communities were more vulnerable to dengue than commercial areas. All container categories could potentially serve as breeding habitats for dengue-carrying mosquitoes, with abandoned containers being the most significant breeding sites.

CONCLUSIONS

The risk of dengue transmission was present year-round throughout Thailand. This underscores the importance of community and government initiatives, along with sustained public awareness campaigns and active community engagement, to efficiently and permanently eradicate mosquito breeding habitats. It should be noted that larval indices may not strongly correlate with dengue cases, as indicated by the preliminary analysis. However, they offer valuable insights into potential breeding sites for targeted preventive measures.

Epidemiological Trends of Dengue in One of the Western Hilly Areas of Himachal Pradesh

Background

Dengue is one of the neglected tropical diseases, with a wide spectrum of diseases, ranging from acute febrile illness dengue fever to life-threatening dengue hemorrhagic fever or dengue shock syndrome. In recent years, it has become a major public health concern in many nonendemic areas as well.

Materials and Methods

A secondary data analysis of records available with district Integrated Disease Surveillance Programme cell was conducted to study distribution (time, place, and person) of dengue from 2017 to 2022 in Kangra, a sub-Himalayan district of Himachal Pradesh (HP).

Results

In the evaluated period (2017-2022), a total of 6008 cases suspected of dengue were tested and test positivity of 7% (441) with male gender predominance was found. Mean age of the diagnosed cases was 37.7 ± 16.8 years. A seasonal trend was observed starting from late August to November in all study years.

Conclusion

Dengue is still a neglected disease, but it has shown its presence especially in this part of HP, indicating the need for better preparation and sensitization of vector-borne disease control program activities, especially in post-monsoon, to prevent future epidemics.

Dengue: A review of laboratory diagnostics in the vaccine age

Background. Dengue is an important arboviral infection of considerable public health significance. It occurs in a wide global belt within a variety of tropical regions. The timely laboratory diagnosis of Dengue infection is critical to inform both clinical management and an appropriate public health response. Vaccination against Dengue virus is being introduced in some areas.Discussion. Appropriate diagnostic strategies will vary between laboratories depending on the available resources and skills. Diagnostic methods available include viral culture, the serological detection of Dengue-specific antibodies in using enzyme immunoassays (EIAs), microsphere immunoassays, haemagglutination inhibition or in lateral flow point of care tests. The results of antibody tests may be influenced by prior vaccination and exposure to other flaviviruses. The detection of non-structural protein 1 in serum (NS1) has improved the early diagnosis of Dengue and is available in point-of-care assays in addition to EIAs. Direct detection of viral RNA from blood by PCR is more sensitive than NS1 antigen detection but requires molecular skills and resources. An increasing variety of isothermal nucleic acid detection methods are in development. Timing of specimen collection and choice of test is critical to optimize diagnostic accuracy. Metagenomics and the direct detection by sequencing of viral RNA from blood offers the ability to rapidly type isolates for epidemiologic purposes.Conclusion. The impact of vaccination on immune response must be recognized as it will impact test interpretation and diagnostic algorithms.

Optimising the surveillance of Aedes aegypti in Brazil by selecting smaller representative areas within an endemic city

OBJECTIVES

Arboviruses, such as dengue (DENV), zika (ZIKV), and chikungunya (CHIKV), constitute a growing urban public health threat. Focusing on Aedes aegypti mosquitoes, their primary vectors, is crucial for mitigation. While traditional immature-stage mosquito surveillance has limitations, capturing adult mosquitoes through traps yields more accurate data on disease transmission. However, deploying traps presents logistical and financial challenges, demonstrating effective temporal predictions but lacking spatial accuracy. Our goal is to identify smaller representative areas within cities to enhance the early warning system for DENV outbreaks.

METHODS

We created Sentinel Geographic Units (SGUs), smaller areas of 1 km2 within each stratum, larger areas, with the aim of aligning the Trap Positivity Index (TPI) and Adult Density Index (ADI) with their respective strata. We conducted a two-step evaluation of SGUs. First, we examined the equivalence of TPI and ADI between SGUs and strata from January 2017 to July 2022. Second, we assessed the ability of SGU's TPI and ADI to predict DENV outbreaks in comparison to Foz do Iguaçu's Early-Warning System, which forecasts outbreaks up to 4 weeks ahead. Spatial and temporal analyses were carried out, including data interpolation and model selection based on Akaike information criteria (AIC).

RESULTS

Entomological indicators produced in small SGUs can effectively replace larger sentinel areas to access dengue outbreaks. Based on historical data, the best predictive capability is achieved 2 weeks after infestation verification. Implementing the SGU strategy with more frequent sampling can provide more precise space-time estimates and enhance dengue control.

CONCLUSIONS

The implementation of SGUs offers an efficient way to monitor mosquito populations, reducing the need for extensive resources. This approach has the potential to improve dengue transmission management and enhance the public health response in endemic cities.

Transmission dynamics of a reaction-advection-diffusion dengue fever model with seasonal developmental durations and intrinsic incubation periods

In this paper, we propose a reaction-advection-diffusion dengue fever model with seasonal developmental durations and intrinsic incubation periods. Firstly, we establish the well-posedness of the model. Secondly, we define the basic reproduction number ℜ 0 for this model and show that ℜ 0 is a threshold parameter: ifℜ 0 < 1 , then the disease-free periodic solution is globally attractive; ifℜ 0 > 1 , the system is uniformly persistent. Thirdly, we study the global attractivity of the positive steady state when the spatial environment is homogeneous and the advection of mosquitoes is ignored. As an example, we use the model to investigate the dengue fever transmission case in Guangdong Province, China, and explore the impact of model parameters on ℜ 0 . Our findings indicate that ignoring seasonality may underestimate ℜ 0 . Additionally, the spatial heterogeneity of transmission may increase the risk of disease transmission, while the increase of seasonal developmental durations, intrinsic incubation periods and advection rates can all reduce the risk of disease transmission.

Exploring the therapeutic potential of DV-B-120 as an inhibitor of dengue virus infection

Dengue fever, an infectious disease prevalent in subtropical and tropical regions, currently lacks effective small-molecule drugs as treatment. In this study, we used a fluorescence peptide cleavage assay to screen seven compounds to assess their inhibition of the dengue virus (DENV) NS2B-NS3 protease. DV-B-120 demonstrated superior inhibition of NS2B-NS3 protease activity and lower toxicity compared to ARDP0006. The selectivity index of DV-B-120 was higher than that of ARDP0006. In vivo assessments of the antiviral efficacy of DV-B-120 against DENV replication demonstrated delayed mortality of suckling mice treated with the compound, with 60-80% protection against life-threatening effects, compared to the outcomes of DENV-infected mice treated with saline. The lower clinical scores of DENV-infected mice treated with DV-B-120 indicated a reduction in acute-progressive illness symptoms, underscoring the potential therapeutic impact of DV-B-120. Investigations of DV-B-120's ability to restore the antiviral type I IFN response in the brain tissue of DENV-infected ICR suckling mice demonstrated its capacity to stimulate IFN and antiviral IFN-stimulated gene expression. DV-B-120 not only significantly delayed DENV-2-induced mortality and illness symptoms but also reduced viral numbers in the brain, ultimately restoring the innate antiviral response. These findings strongly suggest that DV-B-120 holds promise as a therapeutic agent against DENV infection and highlight its potential contribution in addressing the current lack of effective treatments for this infectious disease.IMPORTANCEThe prevalence of dengue virus (DENV) infection in tropical and subtropical regions is escalating due to factors like climate change and mosquito vector expansion. With over 300 million annual infections and potentially fatal outcomes, the urgent need for effective treatments is evident. While the approved Dengvaxia vaccine has variable efficacy, there are currently no antiviral drugs for DENV. This study explores seven compounds targeting the NS2B-NS3 protease, a crucial protein in DENV replication. These compounds exhibit inhibitory effects on DENV-2 NS2B-NS3, holding promise for disrupting viral replication and preventing severe manifestations. However, further research, including animal testing, is imperative to assess therapeutic efficacy and potential toxicity. Developing safe and potent treatments for DENV infection is critical in addressing the rising global health threat posed by this virus.

A 2D-proteomic analysis identifies proteins differentially regulated by two different dengue virus serotypes

The mosquito transmitted dengue virus (DENV) is a major public health problem in many tropical and sub-tropical countries around the world. Both vaccine development and drug development are complex as the species Dengue virus consist of four distinct viruses (DENV 1 to DENV 4) each of which is composed of multiple lineages and strains. To understand the interaction of DENV with the host cell machinery, several studies have undertaken in vitro proteomic analysis of different cell lines infected with DENV. Invariably, these studies have utilized DENV 2. In this study we sought to define proteins that are differentially regulated by two different DENVs, DENV 2 and DENV 4. A 2-dimensional proteomic analysis identified some 300 protein spots, of which only 11 showed differential expression by both DENVs. Of these, only six were coordinately regulated. One protein, prohibitin 1 (PHB1) was downregulated by infection with both DENVs. Overexpression of PHB1 increased DENV protein expression, level of infection and genome copy number. DENV E protein colocalized with PHB, and there was a direct interaction between DENV 2 E protein and PHB1, but not between DENV 4 E protein and PHB1. The low number of proteins showing coordinate regulation after infection by different DENVs is a cause for concern, particularly in determining new druggable targets, and suggests that studies should routinely investigate multiple DENVs.

Glycolysis is reduced in dengue virus 2 infected liver cells

Infections with dengue virus (DENV) remain a worldwide public health problem. A number of bona fide cellular targets of DENV have been identified including liver cells. Despite the many lines of evidence confirming the involvement of hepatocytes during DENV infection, only a few studies have used proteomic analysis to understand the modulation of the cellular proteome occurring upon DENV infection. We utilized a 2D-gel electrophoresis analysis to identify proteins that were differentially regulated by DENV 2 infection of liver (Hep3B) cells at 12 h post infection (hpi) and at 48 hpi. The analysis identifies 4 proteins differentially expressed at 12 hpi, and 14 differentially regulated at 48 hpi. One candidate protein identified as downregulated at 48 hpi in the proteomic analysis (GAPDH) was validated in western blotting in Hep3B cells, and subsequently in induced pluripotent stem cell (iPSC) derived human hepatocytes. The reduced expression of GAPDH was coupled with an increase in NADH, and a significantly reduced NAD + /NADH ratio, strongly suggesting that glycolysis is down regulated in response to DENV 2 infection. Metformin, a well characterized drug used in the treatment of diabetes mellitus, is an inhibitor of hepatic gluconeogenesis was shown to reduce the level of DENV 2 infection and new virus production. Collectively these results show that although glycolysis is reduced, glucose is still required, possibly for use by the pentose phosphate pathway to generate nucleosides required for viral replication.

Repurposing of drugs targeting heparan sulphate binding site of dengue virus envelope protein: an in silico competitive binding study

Dengue virus, an arbovirus, leads to millions of infections every year ultimately leading to a high rate of mortality. Highly effective and specific therapeutic option is not available till date to combat viral infection. One of the first stages in the virus lifecycle encompasses the viral entry into the host cell which is mediated by the interaction between heparan sulphate and the Dengue virus envelope protein in turn leading to the interaction between the envelope protein receptor binding domain and host cell receptors. The heparan sulphate binding site on the envelope protein was established using literature survey and the result validated using ColDock simulations. We have performed virtual screening against the heparan sulphate binding site using DrugBank database and short-listed probable inhibitors based on binding energy calculation following Molecular Dynamics (MD) simulations in this study. Two compounds (PubChem IDS 448062 and 656615) were selected for further analyses on which RAMD simulations were performed to quantitate the binding stability of both the molecules in the protein binding pocket which ultimately led to the selection of ZK-806450 molecule as the final selected compound. Competitive binding MD simulation against dengue virus envelope protein was performed for this molecule and heparan sulphate in order to ascertain the efficiency of binding of this molecule to the dengue virus envelope protein in the presence of its natural ligand molecule and found that this molecule has a higher affinity for the dengue virus envelope protein GAG binding site than heparan sulphate. This study may help in the use of this inhibitor molecule to combat dengue virus infection in foreseeable future and open a new avenue for drug repurposing methodology using competitive binding MD simulation.

Dengue vector control in high-income, city settings: A scoping review of approaches and methods

BACKGROUND

Dengue virus (DENV) is endemic to many parts of the world and has serious health and socioeconomic effects even in high-income countries, especially with rapid changes in the climate globally. We explored the literature on dengue vector control methods used in high-income, city settings and associations with dengue incidence, dengue prevalence, or mosquito vector densities.

METHODS

Studies of any design or year were included if they reported effects on human DENV infection or Aedes vector indices of dengue-specific vector control interventions in high-income, city settings.

RESULTS

Of 24 eligible sources, most reported research in the United States (n = 8) or Australia (n = 5). Biocontrol (n = 12) and chemical control (n = 13) were the most frequently discussed vector control methods. Only 6 sources reported data on the effectiveness of a given method in reducing human DENV incidence or prevalence, 2 described effects of larval and adult control on Aedes DENV positivity, 20 reported effectiveness in reducing vector density, using insecticide, larvicide, source reduction, auto-dissemination of pyriproxyfen and Wolbachia, and only 1 described effects on human-vector contact.

CONCLUSIONS

As most studies reported reductions in vector densities, rather than any effects on human DENV incidence or prevalence, we can draw no clear conclusions on which interventions might be most effective in reducing dengue in high-income, city areas. More research is needed linking evidence on the effects of different DENV vector control methods with dengue incidence/prevalence or mosquito vector densities in high-income, city settings as this is likely to differ from low-income settings. This is a significant evidence gap as climate changes increase the global reach of DENV. The importance of community involvement was clear in several studies, although it is impossible to tease out the relative contributions of this from other control methods used.

Genetic variants associated with dengue hemorrhagic fever. A systematic review and meta-analysis

Dengue hemorrhagic fever (DHF) is a severe condition resulting from the dengue virus, with four serotypes known as DEN-1, DEN-2, DEN-3, and DEN-4. Genetic variations play a crucial role in influencing susceptibility to DHF. Therefore, this investigation conducted a meta-analysis to uncover genetic changes that might have remained undetected in individual studies due to small sample sizes or methodological differences. Among 2212 initially identified studies, 23 were deemed suitable for analysis based on PRISMA guidelines. Toll-like receptors (TLR) and CD209 showed significant association with DHF (odds ratios: TLR=0.56, CD209 =0.55), indicating protective effects. However, tumor necrosis factor (TNF) and human leukocyte antigen (HLA) did not exhibit a statistically significant relationship with DHF. This study emphasizes the relevance of TLR and CD209 in DHF susceptibility and resistance across diverse geographical locations.

Mosquito E-20-Monooxygenase Gene Knockout Increases Dengue Virus Replication in Aedes aegypti Cells

E-20-monooxygenase (E20MO) is an enzymatic product of the shade (shd) locus (cytochrome p450, E20MO). Initially discovered in Drosophila, E20MO facilitates the conversion of ecdysone (E) into 20-hydroxyecdysone (20E) and is crucial for oogenesis. Prior research has implicated 20E in growth, development, and insecticide resistance. However, little attention has been given to the association between the E20MO gene and DENV2 infection. The transcriptome of Ae. aegypti cells (Aag2 cells) infected with DENV2 revealed the presence of the E20MO gene. The subsequent quantification of E20MO gene expression levels in Aag2 cells post-DENV infection was carried out. A CRISPR/Cas9 system was utilized to create an E20MO gene knockout cell line (KO), which was then subjected to DENV infection. Analyses of DENV2 copies in KO and wild-type (WT) cells were conducted at different days post-infection (dpi). Plasmids containing E20MO were constructed and transfected into KO cells, with pre- and post-transfection viral copy comparisons. Gene expression levels of E20MO increased after DENV infection. Subsequently, a successful generation of an E20MO gene knockout cell line and the verification of code-shifting mutations at both DNA and RNA levels were achieved. Furthermore, significantly elevated DENV2 RNA copies were observed in the mid-infection phase for the KO cell line. Viral RNA copies were lower in cells transfected with plasmids containing E20MO, compared to KO cells. Through knockout and plasmid complementation experiments in Aag2 cells, the role of E20MO in controlling DENV2 replication was demonstrated. These findings contribute to our understanding of the intricate biological interactions between mosquitoes and arboviruses.

Potential of several triazene derivatives against DENGUE viruses

Dengue fever is an infectious disease caused by the dengue virus (DENV), an RNA Flavivirus transmitted by the mosquitoes Aedes aegypti and Aedes albopictus widespread in tropical, subtropical and also temperate regions. Symptoms range from a simple cold to a severe, life-threatening haemorrhagic fever. According to the WHO, it affects around 390 million people per year. No antiviral treatment for DENV is available, and the Dengvaxia vaccine is only intended for people over 9 years of age who have contracted dengue one time in the past, and shows serotype-specific effectiveness. There is therefore a crying need to discover new molecules with antiviral power against flaviviruses. The present study was carried out to evaluate the anti-DENV activities and cytotoxicity of triazenes obtained by diazocopulation. Some triazenes were highly cytotoxic (16, and 25) to hepatocarcinoma Huh7 cells, whereas others displayed strong anti-DENV potential. The antiviral activity ranged from EC50 = 7.82 µM to 48.12 µM in cellulo, with a selectivity index (CC50/EC50) greater than 9 for two of the compounds (10, and 20). In conclusion, these new triazenes could serve as a lead to develop and optimize drugs against DENV.

"Seven-Plus-One Model": A Move Toward Dengue Free Community

Dengue is a wide spectrum of diseases creating menace in the community. This vector-born disease alone has a significant impact on global public health and the economy. Resources need to be mobilized to tackle the situation. The present article focused on the novice concept of "Seven-Plus-One models" as an approach to dengue prevention with vector management through community participation. A multidisciplinary approach along with exemplifying effective methods of inspectorial coordination and community participation is much required. The implementation of the Seven-Plus-One model has a positive impact on reducing dengue cases, indicating acceptance and effectiveness of the concept among the public. Dengue morbidity rate can be reduced through early detection and mobilizing the community for active participation in dengue prevention and control.

Spatial analysis of Dengue through the reproduction numbers relating to socioeconomic features: Case studies on two Brazilian urban centers

The study of the propagation of infectious diseases in urban centers finds a close connection with their population's social characteristics and behavior. This work performs a spatial analysis of dengue cases in urban centers based on the basic reproduction numbers, R0, and incidence by planning areas (PAs), as well as their correlations with the Human Development Index (HDI) and the number of trips. We analyzed dengue epidemics in 2002 at two Brazilian urban centers, Belo Horizonte (BH) and Rio de Janeiro (RJ), using PAs as spatial units. Our results reveal heterogeneous spatial scenarios for both cities, with very weak correlations between R0 and both the number of trips and the HDI; in BH, the values of R0 show a less spatial heterogeneous pattern than in RJ. For BH, there are moderate correlations between incidence and both the number of trips and the HDI; meanwhile, they weakly correlate for RJ. Finally, the absence of strong correlations between the considered measures indicates that the transmission process should be treated considering the city as a whole.

Polyubiquitin protein of Aedes aegypti as an interacting partner of dengue virus envelope protein

Dengue virus (DENV) is an arbovirus that comprises four antigenically different serotypes. Aedes aegypti (Diptera: Culicidae) acts as the principal vector for DENV transmission, and vector control is crucial for dengue fever epidemic management. To design effective vector control strategies, a comprehensive understanding of the insect vector and virus interaction is required. Female Ae. aegypti ingests DENV during the acquisition of a blood meal from an infected human. DENV enters the insect midgut, replicates inside it and reaches the salivary gland for transmitting DENV to healthy humans during the subsequent feeding cycles. DENV must interact with the proteins present in the midgut and salivary glands to gain entry and accomplish successful replication and transmission. Ae. aegypti midgut cDNA library was prepared, and yeast two-hybrid screening was performed against the envelope protein domain III (EDIII) protein of DENV-2. The polyubiquitin protein was selected from the various candidate proteins for subsequent analysis. Polyubiquitin gene was amplified, and the protein was purified in a heterologous expression system for in vitro interaction studies. In vitro pull-down assay presented a clear interaction between polyubiquitin protein and EDIII. To further confirm this interaction, a dot blot assay was employed, and polyubiquitin protein was found to interact with DENV particles. Our results enable us to suggest that polyubiquitin plays an important role in DENV infection within mosquitoes.

Association Between Leucopenia, Transaminitis, Nonstructural Protein One Antigen (Ns1Ag) Level, and Thrombocytopenia in Adult Dengue Patients in a Tertiary Care Hospital: A Cross-Sectional Study

BACKGROUND

The dengue virus is present throughout the tropics. Thrombocytopenia is one of the severe manifestations of the dengue virus. We studied the association of thrombocytopenia with serum transaminase level, leucopenia, and nonstructural protein one antigen (Ns1Ag) level.

METHODS

Data were taken retrospectively from hospital records after obtaining ethical committee approval. In the study, we included 102 patients with acute febrile illness with clinical features suggestive of dengue fever (dengue Ns1Ag positive, dengue IgM positive, or both). We excluded patients with thrombocytopenia due to other causes. Patients' demographic, clinical, and laboratory parameters were collected. We also noted episodes of bleeding or the need for a platelet transfusion. We did a statistical analysis to find out the correlation between age, sex, leucopenia, transaminitis, Ns1Ag level, and thrombocytopenia and its severity.

RESULTS

Multiple regression analysis was used to find thrombocytopenia predictors among aspartate transaminase (AST), alanine transaminase (ALT), Ns1Ag level, and leucopenia. AST and ALT correlated inversely with thrombocytopenia, with p-values of 0.012 and 0.027, respectively. Ns1Ag and leucopenia were not associated with thrombocytopenia, with p-values of 0.802 and 0.532, respectively (p-values significant at 0.01<= p<=0.05).

CONCLUSION

Serum AST and ALT levels correlate with thrombocytopenia in dengue fever.

Integration of population-level data sources into an individual-level clinical prediction model for dengue virus test positivity

The differentiation of dengue virus (DENV) infection, a major cause of acute febrile illness in tropical regions, from other etiologies, may help prioritize laboratory testing and limit the inappropriate use of antibiotics. While traditional clinical prediction models focus on individual patient-level parameters, we hypothesize that for infectious diseases, population-level data sources may improve predictive ability. To create a clinical prediction model that integrates patient-extrinsic data for identifying DENV among febrile patients presenting to a hospital in Thailand, we fit random forest classifiers combining clinical data with climate and population-level epidemiologic data. In cross-validation, compared to a parsimonious model with the top clinical predictors, a model with the addition of climate data, reconstructed susceptibility estimates, force of infection estimates, and a recent case clustering metric significantly improved model performance.

Dengue Cases Presenting to the Emergency Department of a Tertiary Care Hospital in Late 2021: A Cross-Sectional Study in Karachi

Objectives: Dengue Fever (DF) is an arboviral disease caused by the Dengue virus (DENV). This study aims to assess the association of dengue prevalence with patients' residential areas and hematological laboratory findings (Total platelet count, immunoglobulins, and dengue antigens) during COVID-19 pandemic. Methods: A retrospective study was conducted at the Emergency department of Jinnah Postgraduate Medical Center, Karachi from October to December 2021. All the patients irrespective of their ages presenting to the ED with either of the following complaints: fever; GIT problems; vomiting; body ache; bleeding were included in our study. Results: Our study comprised 189 patients in total in which the females (n = 172) outnumbered the males (n = 17). Out of all, 84.7% of the patients were febrile having a low-grade fever on average. Korangi district had the most dengue cases, while Keamari had the fewest. There was no significant association reported between mean platelet count, mean TLC, and mean hemoglobin levels with dengue positivity. Conclusion: There is a concerning rise in DF cases in Karachi, particularly in the Korangi district. Despite the COVID-19 pandemic, DF demands urgent attention.

Sofosbuvir Suppresses the Genome Replication of DENV1 in Human Hepatic Huh7 Cells

Dengue virus (DENV) causes dengue fever and dengue hemorrhagic fever, and DENV infection kills 20,000 people annually worldwide. Therefore, the development of anti-DENV drugs is urgently needed. Sofosbuvir (SOF) is an effective drug for HCV-related diseases, and its triphosphorylated metabolite inhibits viral RNA synthesis by the RNA-dependent RNA polymerase (RdRp) of HCV. (2'R)-2'-Deoxy-2'-fluoro-2'-methyluridine (FMeU) is the dephosphorylated metabolite produced from SOF. The effects of SOF and FMeU on DENV1 replication were analyzed using two DENV1 replicon-based methods that we previously established. First, a replicon-harboring cell assay showed that DENV1 replicon replication in human hepatic Huh7 cells was decreased by SOF but not by FMeU. Second, a transient replicon assay showed that DENV1 replicon replication in Huh7 cells was decreased by SOF; however, in hamster kidney BHK-21 cells, it was not suppressed by SOF. Additionally, the replicon replication in Huh7 and BHK-21 cells was not affected by FMeU. Moreover, we assessed the effects of SOF on infectious DENV1 production. SOF suppressed infectious DENV1 production in Huh7 cells but not in monkey kidney Vero cells. To examine the substrate recognition of the HCV and DENV1 RdRps, the complex conformation of SOF-containing DENV1 RdRp or HCV RdRp was predicted using AlphaFold 2. These results indicate that SOF may be used as a treatment for DENV1 infection.

Investigating Lycotoxin-An1a (An1a), a defense antiviral peptide from Alopecosa nagpag venom as prospective anti-dengue agent against DENV-2 NS2B-NS3 protease

Dengue fever is a global health concern with no effective therapy. Screening synthetic chemicals, animal-originated compounds, and phytocompounds against Dengue virus (DENV) targets has failed to find dengue antivirals. The current study examines animal drugs as antagonists against NS2B-NS3Pro, one of DENV's most promising therapeutic targets for dengue fever. Antiviral-Lycotoxin-An1a (An1a), a defence antiviral peptide isolated from the venom of Alopecosa nagpag, a toxic spider. Based on prior in vitro research, it was discovered that the venom peptide suppresses the action of DENV-2 NS2B-NS3Pro. An1a peptide with NS2B-NS3Pro wild type (WT) and two mutants (H51N and S135A) was tested for anti-dengue characteristics using in silico analysis. The WT NS2B-NS3Pro has a catalytic triad of His51, Asp75, and Ser135 in the active site, but the mutants have N51 instead of His51 and Ala135 instead of Ser135. The dynamic sites of the three proteases (WT, H51N, S135A) and the peptide toxin (An1a) were taken into account to achieve molecular docking of An1a with WT NS2B-NS3Pro in conjunction with H51N and S135A. Cluspro-2 performs rigid-flexible docking to predict peptide binding affinity, effectiveness, and inhibitory consistency. Since the ligand had a higher binding affinity, docking score, and molecular interaction network, MD simulations and MM-GBSA free energy calculations were used to investigate the stability of the three protein-peptide complexes. The computer-aided screening and manufacture of spider venom-based anti-dengue medicines yielded intriguing results in the preliminary studies. This study is significant in defining the ideal therapeutic candidate against dengue infections.

First report on evaluation of commercial eugenol and piperine against Aedes aegypti L (Diptera: Culicidae) larvae: Mortality, detoxifying enzyme, and histopathological changes in the midgut

Dengue fever is a worldwide public health problem, and efforts to eradicate it have focused on controlling the dengue vector, Aedes aegypti. This study aims to assess the toxicity and effect of commercial eugenol and piperine on Ae. aegypti larvae through enzyme detoxification and histopathological changes in the midgut. Laboratory-reared Ae. aegypti larvae were treated with various concentrations of commercial eugenol and piperine and observed after 24, 48, and 72 h. Biochemical methods were used to assess detoxification enzyme activity for acetylcholinesterase, glutathione S-transferase, and oxidase, and changes in the midgut were examined using routine histological examination. In terms of larvicidal activity, piperine exceeded eugenol. Piperine and eugenol had LC50 and LC90 values of 3.057 and 5.543 μM, respectively, and 6.421 and 44.722 μM at 24 h. Piperine and eugenol reduced oxidase activity significantly (p < 0.05), but increased acetylcholinesterase and glutathione S-transferase activity significantly (p < 0.05). After being exposed to piperine and eugenol, the food bolus and peritrophic membrane ruptured, the epithelial layer was interrupted and irregular, the epithelial cells shrank and formed irregularly, and the microvilli became irregular in shape. Commercial piperine and eugenol behave as potential larvicides, with processes involving altered detoxifying enzymes, specifically decreased oxidase function and increased GST activity, as well as midgut histological abnormalities.

[Clinical Update on Diagnosis, Treatment and Prevention of Dengue]

Dengue is a vector-borne disease that has a significant impact on global public health. The vector mosquito belongs to the genus Aedes. Two species play a key role in human transmission: Ae. aegypti, which has adapted to the urban environment of highly populated areas in tropical and subtropical countries, leading to a dramatic increase in dengue cases over the years, and Ae. albopictus, which poses a potential threat to temperate climate countries due to its ability to adapt to colder climates. The disease is widespread across the world, posing a risk to nearly half of the world's population. Although most cases are asymptomatic, dengue causes a burden on healthcare systems and mainly affects the younger population. The disease is also spreading to temperate climate countries, thus becoming a global threat. Vector control measures and vaccine development have been the main prevention strategies, as there is still no effective treatment for the disease.

Dengue and chikungunya: future threats for Northern Europe?

Arthropod-borne viral diseases are likely to be affected by the consequences of climate change with an increase in their distribution and intensity. Among these infectious diseases, chikungunya and dengue viruses are two (re)emergent arboviruses transmitted by Aedes species mosquitoes and which have recently demonstrated their capacity for rapid expansion. They most often cause mild diseases, but they can both be associated with complications and severe forms. In Europe, following the establishment of invasive Aedes spp, the first outbreaks of autochtonous dengue and chikungunya have already occurred. Northern Europe is currently relatively spared, but climatic projections show that the conditions are permissive for the establishment of Aedes albopictus (also known as the tiger mosquito) in the coming decades. It is therefore essential to question and improve the means of surveillance in northern Europe, at the dawn of inevitable future epidemics.

Emerging and re-emerging pediatric viral diseases: a continuing global challenge

The twenty-first century has been marked by a surge in viral epidemics and pandemics, highlighting the global health challenge posed by emerging and re-emerging pediatric viral diseases. This review article explores the complex dynamics contributing to this challenge, including climate change, globalization, socio-economic interconnectedness, geopolitical tensions, vaccine hesitancy, misinformation, and disparities in access to healthcare resources. Understanding the interactions between the environment, socioeconomics, and health is crucial for effectively addressing current and future outbreaks. This scoping review focuses on emerging and re-emerging viral infectious diseases, with an emphasis on pediatric vulnerability. It highlights the urgent need for prevention, preparedness, and response efforts, particularly in resource-limited communities disproportionately affected by climate change and spillover events. Adopting a One Health/Planetary Health approach, which integrates human, animal, and ecosystem health, can enhance equity and resilience in global communities. IMPACT: We provide a scoping review of emerging and re-emerging viral threats to global pediatric populations This review provides an update on current pediatric viral threats in the context of the COVID-19 pandemic This review aims to sensitize clinicians, epidemiologists, public health practitioners, and policy stakeholders/decision-makers to the role these viral diseases have in persistent pediatric morbidity and mortality.

Increasing transmission of dengue virus across ecologically diverse regions of Ecuador and associated risk factors

The distribution and intensity of viral diseases transmitted by Aedes aegypti mosquitoes, including dengue, have rapidly increased over the last century. Here, we study dengue virus (DENV) transmission across the ecologically and demographically distinct regions or Ecuador. We analyzed province-level age-stratified dengue incidence data from 2000-2019 using catalytic models to estimate the force of infection of DENV over eight decades. We found that provinces established endemic DENV transmission at different time periods. Coastal provinces with the largest and most connected cities had the earliest and highest increase in DENV transmission, starting around 1980 and continuing to the present. In contrast, remote and rural areas with reduced access, like the northern coast and the Amazon regions, experienced a rise in DENV transmission and endemicity only in the last 10 to 20 years. The newly introduced chikungunya and Zika viruses have age-specific distributions of hospital-seeking cases consistent with recent emergence across all provinces. To evaluate factors associated with geographic differences in DENV transmission potential, we modeled DENV vector risk using 11,693 Aedes aegypti presence points to the resolution of 1 hectare. In total, 56% of the population of Ecuador, including in provinces identified as having increasing DENV transmission in our models, live in areas with high risk of Aedes aegypti, with population size, trash collection, elevation, and access to water as important determinants. Our investigation serves as a case study of the changes driving the expansion of DENV and other arboviruses globally and suggest that control efforts should be expanded to semi-urban and rural areas and to historically isolated regions to counteract increasing dengue outbreaks.

Leptospirosis and Dengue Coinfection-Associated Multi-Organ Dysfunction Syndrome: A Case Report

Dengue and leptospirosis are frequently discussed separately, with dengue causing rash and leptospirosis causing jaundice. Currently, there are more and more reports of coinfections. The comparable clinical symptoms of both infections make it challenging to distinguish between leptospirosis and dengue. Differentiating between leptospirosis and dengue is crucial since leptospirosis has a more favorable prognosis with early antibiotic therapy, whereas dengue does not have a specific treatment, although early detection is essential for close monitoring and cautious fluid management. Here, we highlight a case of dengue virus and leptospirosis coinfection in a female who presented with acute febrile illness, dyspnea, and altered sensorium, which progressed to multiorgan dysfunction syndrome, involving the neurological, respiratory, hepatic, and hematological systems.