The global distribution and burden of dengue

Ponatinib and other clinically approved inhibitors of Src and Rho-A kinases abrogate dengue virus serotype 2- induced endothelial permeability

Severe dengue often presents as shock syndrome with enhanced vascular permeability and plasma leakage into tissue spaces. In vitro studies have documented the role of Src family kinases (SFKs) and RhoA-kinases (ROCK) in dengue virus serotype 2 (DENV2)-induced endothelial permeability. Here, we show that the FDA-approved SFK inhibitors Bosutinib, Vandetanib and Ponatinib, as well as the ROCK inhibitors, Netarsudil and Ripasudil significantly inhibit DENV2-induced endothelial permeability. In cultured telomerase immortalized human microvascular endothelial cells (HMEC-1), treatment with these inhibitors reduced the phosphorylation of VE-Cadherin, Src and myosin light chain 2 (MLC2) proteins that were upregulated during DENV2 infection. It also prevented the loss of VE-Cadherin from the inter-endothelial cell junctions induced by viral infection. In in-vivo studies using DENV2-infected AG129 IFN receptor-α/β/γ deficient mice, ponatinib, when administered 24 h post-infection onwards, demonstrated significant benefits in improving body weight, clinical outcomes, and survival rates. While all virus-infected, untreated mice died by day-10 post-infection, 80% of the ponatinib-treated mice survived, and approximately 60% were still alive at the end of the 15-day observation period. The treatment also significantly reduced disease severity factors such as vascular leakage, thrombocytopenia; mRNA transcript levels of proinflammatory cytokines such as IL-1β and TNF-α; and restored liver function. Comparable effects were observed even when ponatinib treatment was initiated after symptom onset. The results highlight ponatinib as an effective therapeutic option in severe dengue; and also a similar potential for other FDA- approved SFK and ROCK inhibitors.

Identification of novel inhibitors of dengue viral NS5 RNA-dependent RNA polymerase through molecular docking, biological activity evaluation and molecular dynamics simulations

The DENV-NS5 RNA-dependent RNA polymerase (RdRp) is essential for viral replication, and one of the targets of anti-virus. In this study, the Uni-VSW module was used to virtual screen 1.6 million compounds in the ChemDiv and TargetMol (USA) database, 27 candidates were obtained. Thereby 23 candidates were selected based on their binding free energies by 50 ns MD simulations. The biological activity of the candidates and the reference compounds (BCX4430 and Compound 27) were evaluated on their IC50 values against DENV-NGC, CC50 values, and selectivity index. Among these, the IC50 values of D1 and D8 were 13.06 ± 1.17 μM and 14.79 ± 7.76 μM, respectively, which were better than that of Compound 27 (IC50 =19.67 ± 1.12 μM). The comprehensive MD simulations were performed on the candidates to assess the stability behaviour and binding mechanisms. The density functional theory (DFT) analysis was also conducted to explore the structural and electronic properties.

Travel medicine providers' opinions on the dengue vaccine TAK-003 as a travel vaccine and the need for decision-support information and materials before its launch in Japan

TAK-003 is a dengue vaccine introduced in dengue-endemic countries and considered for travelers. Although not yet approved in Japan, inquiries from travelers are increasing. With limited evidence about vaccine use for travelers, consolidated expert opinions would aid in vaccination decision-making. Therefore, this study examined the opinions on TAK-003 and the need for decision-support information and materials among travel medicine providers before its launch in Japan. Participants recruited from the Japanese Society of Travel and Health were assessed on their intention to receive TAK-003 themselves when visiting dengue-endemic areas, and their intention to recommend it to travelers, with responses provided separately for short- and long-term travels. Participants who did not recommend TAK-003 provided reasons using multiple-choice questions. All participants were asked about their need for supporting information to aid in vaccination decision-making. Among the 154 respondents, over half intended to receive (55% for short-term, 75% for long-term) and recommend (53% for short-term, 75% for long-term) the vaccination. The primary reasons for not recommending it were concerns about efficacy and safety, which were also the most requested support information. These findings suggest that many travel medicine providers have positive opinions on TAK-003 as a travel vaccine and need decision-support information and materials.

Impact of human mobility and weather conditions on Dengue mosquito abundance during the COVID-19 pandemic in Hong Kong

Background

While Aedes mosquitoes, the Dengue vectors, are expected to expand due to climate change, the impact of human mobility on them is largely unclear. Changes in human mobility, such as staying at home during the pandemic, likely affect mosquito abundance.

Objectives

We aimed to assess the influence of human mobility on the abundance and extensiveness of Aedes albopictus, taking account of the nonlinear lagged effects of weather, during the COVID-19 pandemic in Hong Kong.

Methods

Google human mobility indices (including residential, parks, and workplaces) and weather conditions (total rainfall and mean temperature) along with Aedes albopictus abundance and extensiveness, monitored using Gravidtrap were collected between April 2020 and August 2022. Distributed lag non-linear models with mixed-effects models were used to explore their influence in three areas of Hong Kong.

Results

Time spent at home (i.e., residential mobility) was negatively associated with mosquito abundance. The model projected that if residential mobility in 2022 was returned to the pre-pandemic level, the mosquito abundance would increase by an average of 80.49 % compared to actual observation. The relative risk (RR) of mosquito abundance was associated with low rainfall (<50 mm) after 4.5 months, peaking at 1.73, compared with 300 mm. Heavy rainfall (>500 mm) within 3 months was also associated with a peak RR of 1.41. Warm conditions (21-30 °C, compared with 20 °C) were associated with a higher RR of 1.47 after half a month.

Discussion

Human mobility is a critical factor along with weather conditions in mosquito prediction, and a stay-at-home policy may be an effective intervention to control Aedes albopictus.

Cytokine storm and vascular leakage in severe dengue: insights from single-cell RNA profiling

Severe dengue is characterized by vascular leakage triggered by a hyperinflammatory response, though the underlying mechanisms remain unclear. Our previous mouse model study highlighted the importance of small intestine in severe disease and identified key cytokines (IL-17A, TNF-α, and IL-6) involved. Here, we used a Fixed RNA Profiling assay to characterize key cytokine- and effector-producing cells, along with their receptor expression. Type 3 innate lymphoid cells (ILC3), Th17 cells, and γδ T cells emerged as pathologically relevant IL-17A/F-producing cells. These cells expressed IL-1β and IL-23 receptors, underscoring the significance of these signaling pathways. IL-1β was produced by M2-like macrophages, dendritic cells, and neutrophils, whereas M1-like macrophages, which differentiated post-infection, produced IL-23, TNF-α, and IL-6, acting as initiators and amplifiers of the cytokine storm. Newly differentiated neutrophils produced IL-1β and effector molecule matrix metalloprotease-8, suggesting a dual role in exacerbating the cytokine storm and directly mediating vascular leakage. Identified macrophages and neutrophils exhibited atypical characteristics. These findings provide new pathological insights into severe dengue and broader mechanism underlying cytokine storm-related diseases.

A one health approach for integrated vector management monitoring and evaluation

The French Agency for Food, Environmental and Occupational Health & Safety (Anses) has set up a multidisciplinary working group (WG) to develop an innovative One Health approach for the monitoring and evaluation of an integrated vector management system (IVMS) on a territorial scale. Four existing evaluation guidelines and methods have been combined into a semi-quantitative evaluation approach that takes into account all the dimensions of an integrated process. We propose a set of 34 criteria divided into three sections (objectives and management, implementation, integration) that correspond to the main functional components of an IVMS. Each criterion is assigned a score based on the results of a scoring questionnaire completed by the system's stakeholders, and two graphical outputs are generated using a specific combination of these scores. An overview of the system's performance is provided through a series of pie charts synthesizing the scores for each of the three sections and the corresponding eleven subsections. A radar chart further combines the results according to eight attributes chosen to characterize the qualities of the system. Our approach was tested for the invasive mosquito Aedes albopictus, a main vector of arboviruses, in two French territories with contrasting dengue epidemiology. This approach is intended to be generic and usable in all territories that are at risk of being affected by arboviruses, whether in tropical or temperate regions. Beyond a conventional assessment of the various components of an IVMS, our interdisciplinary and multisectoral approach aims to gain a better understanding of such a system in its environment, its overall functioning and its mechanisms for adapting to contextual change. It also aims to identify avenues for improvement as part of a continuous quality process, and to facilitate comparisons between territories and the cross-fertilization of knowledge between stakeholders.

Wolbachia: A bacterial weapon against dengue fever- a narrative review of risk factors for dengue fever outbreaks

Arboviruses constitute the largest known group of viruses and are responsible for various infections that impose significant socioeconomic burdens worldwide, particularly due to their link with insect-borne diseases. The increasing incidence of dengue fever in non-endemic regions underscores the urgent need for innovative strategies to combat this public health threat. Wolbachia, a bacterium, presents a promising biological control method against mosquito vectors, offering a novel approach to managing dengue fever. We systematically investigated biomedical databases (PubMed, Web of Science, Google Scholar, Science Direct, and Embase) using "AND" as a Boolean operator with keywords such as "dengue fever," "dengue virus," "risk factors," "Wolbachia," and "outbreak." We prioritized articles that offered significant insights into the risk factors contributing to the outbreak of dengue fever and provided an overview of Wolbachia's characteristics and functions in disease management, considering studies published until December 25, 2024. Field experiments have shown that introducing Wolbachia-infected mosquitoes can effectively reduce mosquito populations and lower dengue transmission rates, signifying its potential as a practical approach for controlling this disease.

Soluble tumour necrosis factor receptor 1 predicts hospitalization in children and young adults with dengue virus infection in the Philippines

BACKGROUND

Dengue fever is a common cause of acute febrile illness in the tropics and requires hospitalization for intravenous (IV) fluid therapy in a minority of patients. Predicting which patients will progress to severe disease is challenging. Soluble tumour necrosis factor receptor 1 (sTNFR1) is associated with severe dengue and may have prognostic value.

METHODS

Prospective cohort study of outpatients in the Philippines with dengue fever, confirmed by NS1 antigenemia or IgM seropositivity. sTNFR1 was measured at presentation and patients were followed for 14-21 days for hospitalization (primary outcome), duration of stay, IV fluid resuscitation, hemoconcentration, and thrombocytopenia (secondary outcomes).

RESULTS

244 patients (median age 9 years, 40 % female, 26 % uncomplicated dengue, 73 % dengue with warning signs, 0.82 % severe dengue) were included. The median sTNFR1 plasma concentration was 3000pg/mL (IQR 2400-3700) at clinic presentation, decreasing to 1800 (IQR 1600-2100) after recovery. 181 patients (74 %) required hospitalization. Plasma sTNFR1 concentration > 2800 pg/mL, measured at clinic presentation, was associated with subsequent hospitalization (relative risk 1.5, 95 %CI 1.2-1.7, p < 0.0001). Elevated sTNFR1 was also associated with longer duration of stay, IV fluid requirement, hemoconcentration, and thrombocytopenia. sTNFR1 was also associated with a marker of systemic inflammation (procalcitonin), and circulating markers of endothelial activation (Ang2, sTie-2, sVCAM-1, and endoglin).

CONCLUSION

Elevated sTNFR1 is predictive of subsequent hospitalization among outpatients with DENV infection. It shows promise as a marker that could guide triage to reduce the large healthcare burden of dengue in resource-constrained settings.

Development and Validation of a Prediction Score for Critical Admission in Children With Dengue

OBJECTIVES

This study aimed to develop and validate a clinical score for the prediction of critical care entrance in children with dengue.

METHODS

We conducted a retrospective cohort study using admissions from January 2019 to August 2021, at Hospital Infantil Napoleón Franco Pareja, in Cartagena, Colombia. We included all children 18 years or younger, with a positive immunoglobulin M or nonstructural protein 1 laboratory test and admitted for follow-up at the emergency department. We selected variables retrospectively collected on emergency admission for feature selection. We assessed discrimination and calibration in the development dataset, using 1000 bootstrap replications for internal validation. Data from 2019 to 2020 were used for development and 2021 for temporal validation. We report the c-statistic for discrimination with 95% confidence intervals (CIs), as well as the calibration intercept and slope.

RESULTS

One thousand three hundred eighty-five patients were included for development and internal validation. In temporal validation with 519 additional patients, the c-statistic was 0.82 (95% CI: 0.77-0.87), with a calibration slope of 0.98 (95% CI: 0.77-1.18). We selected the 50th percentile of the distribution of predicted probability of critical care entrance (5%) as a threshold value for increased alert at emergency admission, missing 10% of all cases that need to enter critical care (sensitivity of 90% with 95% CI of 82-95, and specificity of 48% with 95% CI of 41-50).

CONCLUSIONS

Our validated model can be useful to predict critical care entrance in children with dengue. We recommend the validation and potential recalibration of our score in other clinical settings.

Quantifying temporal differences in the induction of interferon-mediated signalling observed in a dengue virus 1 human infection model: insights from longitudinal proteome analysis

BACKGROUND

According to WHO, dengue is one of the top ten global health threats, with almost half of the world's population at risk of being infected. Most of the annual 400 million dengue virus (DENV) infections manifest asymptomatically or in a mild form, causing symptoms such as fever and headache. Nevertheless, every year 500,000 dengue cases require hospitalization and up to 25,000 patients die. Despite the high incidence, the DENV-elicited proteome response remains insufficiently understood.

METHODS

Therefore, we evaluated the proteome dynamics of nine dengue-naïve individuals experimentally infected with the underattenuated DENV-1 strain 45AZ5 via the Proximity Extension Assay technology of Olink®.

FINDINGS

Using Olink Explore, a total of ∼3000 proteins were quantified simultaneously in serum samples at 8, 10, 14, and 28 days after the viral inoculation. We identified the top ten significant proteins via linear mixed effects models, i.e., interferons (IFNs), IFN-related proteins, and members of the CCL and CXCL chemokine family. In all participants, an increase in IFN-λ1 levels was observed after peak viral load, whereas in one participant an IFN-γ response was not detected. Interestingly, both the onset and peak viral load of this participant were, on average, delayed 4 days compared to other participants. To gain a detailed kinetic overview of the DENV-elicited proteome response, we designed a smaller, targeted Olink® panel to evaluate serum protein levels at multiple time points throughout the infection. Here, we revealed that type I/III IFN response precedes the type II IFN response.

INTERPRETATION

In conclusion, our analyses provided detailed insights into the temporal dynamics of the different IFN responses upon a primary DENV-1 infection. These insights might aid in better understanding dengue pathogenesis.

FUNDING

Funding for this research was provided by Johnson and Johnson, the State of New York, and the Congressionally Directed Medical Research Programs.

Global dengue fever management in health systems: identifying strategies, challenges and solutions - a scoping review protocol

INTRODUCTION

Dengue fever, the fastest-spreading mosquito-borne viral disease, poses a significant global public health challenge. Over the past two decades, its rapid spread has been driven by urbanisation, climate change and international travel, particularly affecting tropical and subtropical regions. Despite its considerable economic burden, effective antiviral treatments and vaccines remain unavailable. This study aims to bridge gaps in dengue fever management by systematically identifying and analysing strategies, challenges and solutions adopted within health systems worldwide.

METHODS AND ANALYSIS

This scoping review will adopt the methodological framework of Arksey and O'Malley. A comprehensive search will be conducted across databases including PubMed, Scopus, Web of Science, Embase and Cochrane Library, along with grey literature sources and manual reference list searches, covering the period from 2003 to 2024, limited to English-language publications. Search strategies will be developed using controlled vocabulary and key terms associated with various components of dengue fever management. Two independent reviewers will screen titles and abstracts based on predefined inclusion and exclusion criteria, followed by full text screening to determine final eligibility. A descriptive numerical analysis will summarise the characteristics of included studies, while a thematic analysis will provide an overview of the literature, encompassing strategies, challenges and solutions.

ETHICS AND DISSEMINATION

This study, approved by the Medical Ethics Committee of Mashhad University of Medical Sciences (IR.MUMS.REC.1403.142), adheres to ethical guidelines for handling publicly available data. All findings will be transparently reported and disseminated through peer-reviewed journals, relevant conferences and stakeholder engagement.

Investigating how dengue virus-induced metabolic changes affect the host immune response and how to develop Immunomodulatory strategies

Dengue virus (DENV) infection imposes a significant global health burden, driven by its ability to manipulate host cellular processes to facilitate replication and evade immune defenses. This review explores the complex interplay between DENV, host immunometabolism, and signaling pathways. DENV induces metabolic reprogramming, including glycolytic upregulation, lipid droplet utilization through lipophagy, and alterations in amino acid metabolism, to fulfill its energy and biosynthetic needs. The virus also disrupts mitochondrial dynamics, leading to increased reactive oxygen species (ROS) production, which modulates immune responses but may also contribute to oxidative stress and severe pathology. Concurrently, DENV hijacks host signaling pathways, including PI3K/Akt, NF-κB, and JAK/STAT, to suppress apoptosis, evade type I interferon responses, and drive pro-inflammatory cytokine production. The interplay between these signaling and metabolic pathways highlights a dual role of host processes: enabling viral replication while activating antiviral immune responses. The review also examines potential therapeutic strategies targeting metabolic and signaling pathways to combat DENV infection, including glycolysis inhibitors, lipid metabolism modulators, and host-directed therapies. While significant progress has been made in understanding DENV-induced immunometabolism, further research is needed to elucidate the precise molecular mechanisms and translate these findings into clinical applications. This study underscores the importance of integrating metabolic and signaling insights to identify novel therapeutic targets against DENV and related flaviviruses, addressing the critical need for effective antiviral interventions.

Increased thermal suitability elevates the risk of dengue transmission across the mid hills of Nepal

The burden of climate-sensitive, mosquito-borne diseases, including dengue, has significantly increased in recent years. Understanding the temporal and spatial variations of these diseases is essential for effectively controlling potential outbreaks. In this study, we utilized Moderate Resolution Imaging Spectroradiometer (MODIS) satellite land surface temperature (LST) data (MOD11A2) and a temperature-dependent mechanistic model (R0) to predict the monthly suitability for dengue transmission in Nepal from 2001 to 2020 for both mosquito vectors, Aedes aegypti and Ae. albopictus. We divided the study period into two episodes: 2001-2010, which we characterized as the period of dengue emergence, and 2011-2020, identified as the period of rapid expansion. We compared the thermal suitability across these two time periods. The results indicated that approximately half of Nepal is thermally suitable for dengue transmission for at least one month, with the maximum transmission risk lasting up to nine months each year, a trend that has more or less remained stable over the past 20 years. However, strong temporal dynamics were observed in the hilly regions and around major urban centers such as Kathmandu and Pokhara, where the length of thermal suitability extended up to six months for both vector species. Consequently, the population exposed to thermal suitability increased significantly on a monthly basis. Compared to the emergence period, the proportion of the population exposed to a suitable thermal environment for six months or longer each year increased by 18% for Ae. aegypti and 20% for Ae. albopictus. These findings provide evidence-based insights that could assist health authorities in the control and management of dengue in Nepal.

Integrating meteorological data and hybrid intelligent models for dengue fever prediction

BACKGROUND

Dengue fever is a globally prevalent arbovirus disease that poses a serious challenge to global health. Therefore, analyzing the relationship between dengue fever incidence and meteorological factors and developing a more effective prediction model based on this relationship can provide a theoretical basis for public health departments to formulate reasonable prevention strategies.

METHODS

We collected dengue fever cases and meteorological data, including temperature, humidity, sunshine duration, etc., from Guangdong and Zhejiang Provinces in China from 2005-2024. A distributed lag nonlinear model (DLNM) was used to analyze the exposure-response relationship between meteorological factors and dengue incidence. Moreover, the raw case data were classified into dengue warning levels using a fuzzy clustering algorithm. The improved horned lizard optimization algorithm (IHLOA) was then combined with support vector machine (SVM), random forest (RF) and k-nearest neighbor (KNN) for dengue prediction. The average accuracy (Avg acc ), average fitness value (Avg fit ), average feature reduction rate (Avg feature ), standard deviation (STD) andF 1 _ s c o r e micro were used to evaluate prediction performance.

RESULTS

The incidence risk of dengue fever was positively correlated with temperature, relative humidity, sunshine duration and the vegetation index but negatively correlated with visibility, wind speed and sea level pressure. Meteorological factors had a lag effect on the risk of dengue fever, and the magnitude of the effect varies dynamically with lag time. Compared with the other prediction models, our proposed hybrid prediction models exhibited relatively lowAvg feature values and relatively high Avg acc values, indicating the best prediction results.

CONCLUSION

Our experiment revealed the correlation and lag effect between meteorological factors and the incidence of dengue fever, indicating that meteorological factors have important value in predicting dengue fever. In addition, the hybrid prediction models constructed in this article can accurately predict outbreaks of dengue fever, which can lay a theoretical foundation for the construction of monitoring and early warning systems and improve the ability of relevant government departments to detect and identify dengue fever outbreaks in a timely manner.

Potential of coconut oil as a mosquito repellent

BACKGROUND

Naturally derived products have become popular as a mosquito repellent in addition to mosquito nets and chemical repellents. Coconut-derived fatty acids have demonstrated repellent properties against various blood-feeding arthropods, including mosquitoes. Daily use moisturizers and body soaps containing coconut have displayed some repellent effect against mosquitoes. However, no studies have been conducted on coconut oil specifically, and the effects of pure coconut oil still remain unknown in the western Kenya region.

METHODS

In this study, we investigated the effect of coconut oil on decreasing mosquito bites in a laboratory and field setting. Using Anopheles stephensi mosquitoes, the laboratory experiment compared coconut oil treated and non-treated membranes on a Hemotek blood feeding device. In the cross-sectional study in western Kenya, we investigated bite counts among 490 children, 5 years and under. Descriptive analysis, simple, multiple and mixed regression models were employed. The outcome was the number of mosquito bite marks, the primary explanatory variable was skin cream types, in addition to demographic, environmental, behavioral and socio-economic variables.

RESULTS

Coconut oil significantly reduced mosquito blood feeding, with a pooled Mantel-Haenszel odds ratio of 0.06, a Mantel-Haenszel chi-square statistic of 79.82 (p = 0.01), and an average blood-feeding rate of 1% compared to 31% in the control group. The mixed model identified significant factors influencing mosquito bite counts while accounting for village-level random effects. Coconut oil users experienced 15% reduction in bites (p = 0.01) compared to synthetic creams users. High and medium cream application frequencies reduced bites by 57% (p < 0.001) and 17% (p = 0.007), respectively. Late cream application and late net entry significantly increased bite counts by 41% (p < 0.001) and 53% (p < 0.001), respectively. In addition, higher temperatures from the preceding 2 weeks in the region was associated with a 26% (p = 0.003) increase in bite counts.

CONCLUSIONS

These findings underscore the protective impact of cream application and timing and net use timing, as well as environmental temperature influences on bite outcomes. Particularly, the effect of coconut oil in decreasing mosquito bites and its potential as an alternative repellent has been observed in both laboratory and field settings.

Molecular epidemiology of dengue in Southeast Asia (SEA): Protocol of systematic review and meta-analysis

INTRODUCTION

Dengue fever is a major global public health challenge caused by the Arbovirus and transmitted by Aedes mosquitoes. The increasing incidence of dengue, particularly in the Southeast Asia (SEA) region, including Malaysia, highlights the urgent need for a comprehensive understanding of dengue molecular epidemiology. This study aims to systematically review various aspects of dengue molecular epidemiology to gain insights into the disease's dynamics, transmission and circulation. Providing evidence-based insights is crucial for the prevention and control of dengue.

METHODS AND ANALYSIS

A systematic review and meta-analysis will be conducted following the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols guidelines. Eligible studies will include observational designs from the inception of time to 31 December 2024, in the SEA region. The review will encompass various molecular epidemiology domains as the exposures and assess the outcomes, such as confirmed dengue cases and severity. Descriptive and meta-analytical methods will determine prevalence, genetic changes and associations. Grading of Recommendations Assessment, Development, and Evaluation methodology will evaluate the quality of evidence, and reporting biases will be addressed. This review aims to bridge the gap in dengue molecular epidemiology in the SEA region by providing comprehensive insights crucial for effective dengue prevention and control.

ETHICS AND DISSEMINATION

No primary data will be collected; thus, the ethical exemption was obtained from Medical Research Ethics Committee with reference number 23-03212-AE6 and ethics approval from the IMU University Joint Committee. The results will be disseminated through a peer-reviewed publication and conference presentation.

PROSPERO REGISTRATION NUMBER

CRD42023480417.

Infectivity and Dissemination of Dengue Virus-1 in Different Aedes aegypti Populations Throughout Brazil

Dengue virus, one of the most prevalent mosquito-borne flaviviruses affecting humans globally, is primarily transmitted by the Aedes aegypti mosquito, which thrives in densely populated urban environments. Dengue incidence has surged in recent decades, becoming a major public health concern in many regions, particularly in Brazil, which has experienced recurrent outbreaks and reported over 6.6 million probable cases in the year of 2024. While the link between the mosquito vector and dengue transmission is well understood, the effects of different DENV types and their interactions with the vector capacity of natural mosquito populations are crucial for understanding disease dynamics. Here we report findings from experiments designed to analyze and compare the infectivity and dissemination of the DENV-1 strain among five Ae. aegypti populations collected from different regions of Brazil. When exposed to DENV-infected AG129 mice for blood feeding, these populations exhibited variations in infection rates and dissemination efficiency. Eight days post-infection, all populations demonstrated high infection rates, underscoring the substantial capacity of Brazilian Ae. aegypti populations to support the locally circulating DENV-1 strain. Our results demonstrate variation in Ae. aegypti vector competence across Brazil, revealing distinct patterns of DENV transmission efficiency. These findings highlight the necessity for geographically tailored control strategies, particularly in high-risk urban areas where outbreak potential is greatest.

Fitness compatibility and dengue virus Inhibition in a Bangladeshi strain of Aedes aegypti infected with the Wolbachia strain wAlbB

Dengue cases in Bangladesh have surged in recent years. The existing insecticide-based control program is challenged by issues of insufficient household coverage and high levels of insecticide resistance in the primary dengue virus (DENV) vector, Aedes aegypti. A more sustainable, effective alternative could be the implementation of a Wolbachia-mediated disease management strategy. Hence, we created and characterised a Wolbachia-infected Ae. aegypti strain with a Dhaka wild-type genetic background, and compared its reproductive compatibility, maternal inheritance, fitness, and virus-blocking ability to the parental strains (Dhaka wild-type and wAlbB2-F4). The new Ae. aegypti strain wAlbB2-Dhaka demonstrated complete cytoplasmic incompatibility with the wild-type and complete maternal transmission, retaining levels of pyrethroid resistance of the Dhaka wild-type. No significant fitness costs were detected during laboratory comparison. Compared to the wild-type, wAlbB2-Dhaka mosquitoes demonstrated a significantly reduced genome copies of DENV in the bodies (44.4%, p = 0.0034); a two-fold reduction in dissemination to legs and wings (47.6%, p < 0.0001); and > 13-fold reduction of DENV in saliva expectorates (proxy of transmission potential) (92.7%, p < 0.0001) 14 days after ingesting dengue-infected blood. Our work indicates that the wAlbB2-Dhaka strain could be used for Ae. aegypti suppression or replacement strategies for dengue management in Bangladesh.

Haemoconcentration in diagnosing dengue haemorrhagic fever: evidence from a rural Sri Lankan observational study

BACKGROUND

One of the World Health Organization criteria for dengue haemorrhagic fever (DHF) is a 20% increase in haematocrit. This study on dengue hospitalised patients compares haematocrit levels at baseline, at the onset of the critical phase and the maximum during the critical phase in rural Sri Lanka.

METHODS

This observational study included patients with dengue in the febrile phase who progressed to the critical phase. Haematocrit was recorded and ultrasound scans were performed thrice daily when the platelet count dropped to <100 000/μl. The onset of the critical phase was confirmed by ultrasound-detected plasma leakage.

RESULTS

Forty-three patients were included in the final analysis. The mean haematocrit at baseline and at the onset of the critical phase was 40.6% (standard deviation [SD] 4.7) and 41.3% (SD 5.1), respectively, with no difference (p=0.14, paired t-test). None of the participants showed a 20% increase in haematocrit at the onset of the critical phase, with the maximum observed increase being 17.0%.

CONCLUSION

A 20% increase in haematocrit was not observed during the critical phase, suggesting that haemoconcentration is unreliable for diagnosing DHF in hospitalised patients. This study recommends revisiting the WHO criterion of a 20% haematocrit increase for diagnosing plasma leakage in dengue patients. It suggests that frequent ultrasound scans may be a more reliable method for early detection of plasma leakage.

Influence of air pollution and climate variability on dengue in Singapore: a time-series analysis

The associations between respiratory and cardiovascular health outcomes with air quality have been well examined. Less conclusive are the studies assessing the relationship between air quality and dengue, a mosquito-borne illness which continues to pose risk to more than half the world's population. We examined this relationship in Singapore, a tropical city-state located in the South-East Asian region where the burden of dengue is among the highest across the globe. We analyzed the short-term associations between all laboratory-confirmed dengue reports and variations in PM2.5, PM10, CO, O3, NO2 and SO2 in Singapore from 2009 to 2019 using the Distributed Lag Non-linear Model (DLNM) framework. PM2.5 (RR90th percentile: 1.28, 95% CI 1.11,1.49), PM10 (RR90th percentile: 1.30, 95% CI 1.12, 1.51), and CO (RR90th percentile: 1.30, 95% CI 1.06, 1.61), were positively associated with dengue up to a period of 48 days with observed maximum threshold effects, while O3 and NO2 were negatively associated with dengue. There was a positive, non-linear association between ambient temperature and dengue. We observed strong evidence of ambient temperature modifying the association between particulate matter and dengue risk. Variations in the concentrations of these air pollutant types may inform short-term dengue control resource augmentation plans.

Identification of visible and near-infrared signature peaks for arboviruses and Plasmodium falciparum

Arbovirus and malaria infections affect more than half of the world's population causing major financial and physical burden. Current diagnostic tools such as microscopy, molecular and serological techniques are technically demanding, costly, or time consuming. Near-infrared spectroscopy has recently been demonstrated as a potential diagnostic tool for malaria and Dengue virus and as a screening tool for disease vectors. However, pathogen specific absorption peaks that allow detection of these infections are yet to be described. In this study, we identified unique visible and near-infrared peaks from existing laboratory strains of four major arboviruses including Barmah Forest virus, Dengue virus, Ross River virus, Sindbis virus and Plasmodium falciparum. Secondly, to determine the diagnostic ability of these peaks, we developed machine learning algorithms using artificial neural networks to differentiate arboviruses from media in which they were grown. Signature peaks for BFV were identified within the visible region at 410, 430, 562 and 588 nm and the near-infrared region at, 946, 958, 1130, 1154 and 1780 nm. DENV related peaks were seen at 410nm within the visible region and 1130 nm within the near-infrared region. Signature peaks for Ross River virus were observed within the visible region at 410 and 430 nm and within the near-infrared region at 1130 and 1780 nm, while Sindbis virus had a prominent peak at 410 nm within the visible region. Peaks at 514, 528, 547, 561, 582, and 595 nm and peaks at 1388, 1432, 1681, 1700, 1721, 1882, 1905, 2245, 2278, 2300 nm were unique for P. falciparum. Near-infrared spectroscopy predictive sensitivity defined as the ability to predict an arbovirus as an infection was 90% (n=20) for Barmah Forest virus, 100% (n=10) for Ross River virus and 97.5% (n=40) for Dengue virus, while infection specificity defined as the ability to predict media as not-infected was 100% (n=10). Our findings indicate that spectral signatures obtained by near-infrared spectroscopy are potential biomarkers for diagnosis of arboviruses and malaria.

Arboviruses in UK Armed Forces: a review of historical cases and identification of future threats

INTRODUCTION

Arboviruses are a diverse group of arthropod-borne pathogens and are emerging global public health threats with no approved therapeutics. Arboviruses are spreading rapidly, posing a health threat to UK Armed Forces (UKAF) service personnel (SP) through deployment to endemic regions. There are limited data on the burden of arboviral infections in UKAF SP.

METHODS

A retrospective service evaluation of UKAF electronic healthcare records (eHRs) and statutory notifications to the Defence Public Health Unit was conducted. Cases with possible/confirmed dengue, chikungunya or Zika virus infections between 2005 and 2023 were included. eHRs were interrogated and trends analysed.

RESULTS

Of 107 suspected infections between 2005 and 2023, 49 (45.8%) were laboratory-confirmed. Dengue fever was the most common (45/49) followed by chikungunya (3/49) and Zika (1/49) virus infections. The average yearly incidence of reported dengue infection increased from 0.51 cases per 100 000 UKAF SP per year in 2009-2011 to 3.85 cases per 100 000 SP per year in 2021-2023. 19/45 (42.2%) cases occurred during operational deployments and 24/45 (53.3%) during non-military activity. Dengue infection was most frequently acquired in Southeast Asia.Using WHO clinical severity criteria, 33/45 (73.3%) had dengue with warning signs and 5 (11.1%) had severe dengue. 23/45 (51.1%) dengue cases were hospitalised (median length of stay 5 days, IQR 3, range 1-9). No dengue fatalities or medical discharges occurred. Occupational impact was significant, with a median of 11 days stood down (IQR 10, range 0-45); 3/19 (15.8%) cases on operations required aeromedical evacuation (AEROMED). One deployed case of chikungunya required AEROMED and a 35-day downgrade.

CONCLUSIONS

Reports of arboviral infections, particularly dengue, are increasing in UKAF personnel, presenting an emerging health threat. This has implications for UKAF provision of deployed diagnostics and dengue vaccination policy. The rapid spread of arboviruses outside their traditional geographical areas, including into Europe, necessitates further surveillance and requires diagnostic and therapeutic research.

SHMT, SHMTML and PRPS1 synergize to regulate blood digestion and nutrient metabolism in Aedes aegypti mosquitoes

Mosquitoes rely on vertebrate blood for nutrients vital for ovarian development. The enzyme serine hydroxymethyltransferase (SHMT) is crucial for amino acid and one‑carbon metabolism, playing a significant role in blood digestion and nutrient use in mosquitoes, though its functional mechanism remains further investigation. Using CRISPR/Cas9 to knock out the SHMT gene, we observed impaired blood digestion, delayed ovarian development, and inability to fly in mosquitoes. Multi-omics analysis revealed that SHMT deletion affected genes and metabolites related to amino acid metabolism. Knocking down SHMT-responsive genes mitochondrial-like serine hydroxymethyltransferase (SHMTML) and ribose-phosphate pyrophosphokinase 1 (PRPS1) also hindered blood digestion and ovarian development, mirroring SHMT-deficient mosquitoes. The interaction between SHMT, SHMTML, and PRPS1 was confirmed through various experiments, including Co-IP, GST pull-down, immunofluorescence colocalization, BiFC, molecular docking, and functional studies. Further research reveals that missing any of these proteins in mosquitoes results in ammonia and reactive oxygen species buildup, leading to mitochondrial problems, midgut cell damage, and abnormal enzyme expression. This study highlights a new molecular mechanism of SHMT and emphasizes its crucial interaction with SHMTML and PRPS1 in blood digestion and nutrient metabolism in vector mosquitoes. These findings may offer a strategic foundation for the development of innovative mosquito control measures.

Stabilized dengue virus 2 envelope subunit vaccine redirects the neutralizing antibody response to all E-domains

The four dengue virus (DENV) serotypes cause several hundred million infections annually. Several live-attenuated tetravalent dengue vaccines (LAVs) are at different stages of clinical testing and regulatory approval. A major hurdle faced by the two leading LAVs is uneven replication of vaccine serotypes stimulating a dominant response to one serotype at the expense of the other three, leading to the potential for vaccine antibody (Ab)-enhanced, more severe infections by wild-type (WT) DENV serotypes that fail to replicate in the vaccine. Protein subunit vaccines are a promising alternative since antigen dosing can be precisely controlled. However, DENV envelope (E) protein subunit vaccines have not performed well to date, possibly due to differences between the monomeric structure of soluble E and the E homodimer of the viral surface. Previously, we have combined structure-guided computational and experimental approaches to design and produce DENV2 E antigens that are stable homodimers at 37℃ and stimulate higher levels of neutralizing Abs (NAbs) than the WT E antigen in mice. The goal of this study was to evaluate if DENV2 E homodimers stimulate NAbs that target different epitopes on E protein compared to the WT E monomer. Using DENV4/2 chimeric viruses and Ab depletion methods, we mapped the WT E-elicited NAbs to simple epitopes on domain III of E. In contrast, the stable E homodimer stimulated a more complex response toward all three surface-exposed domains of the E protein. Our findings highlight the impact of DENV2 E oligomeric state on the quality and specificity of DENV NAbs and the promise of DENV E homodimers as subunit vaccines.IMPORTANCEThe ideal dengue virus (DENV) vaccine should elicit a balanced and highly protective immune response against all four DENV serotypes. Current tetravalent live-attenuated DENV vaccines have faced challenges due to uneven replication of vaccine virus strains stimulating a strong immune response to one serotype and weak responses to the other three. Protein subunit vaccines provide novel opportunities to stimulate a balanced response because dosing can be precisely controlled and independent of vaccine virus replication. Here, we compare immune responses elicited by a new DENV serotype 2 protein vaccine designed to match the structure of proteins on the viral surface. We find that proteins designed to match the viral surface stimulate better immune responses targeting multiple sites on the viral surface compared to previous protein vaccines. Our results justify further testing and development of these second-generation DENV protein subunit vaccines.

Structural dynamics of the dengue virus non-structural 5 (NS5) interactions with promoter stem-loop A (SLA)

The dengue virus (DENV) NS5 protein, essential for viral RNA synthesis, is an attractive antiviral drug target. DENV NS5 interacts with the stem-loop A (SLA) promoter at the 5'-untranslated region of the viral genome to initiate negative-strand synthesis. However, the conformational dynamics of this interaction remains unclear. Our study explores the structural dynamics of DENV serotype 2 NS5 (DENV2 NS5) in complex with SLA, employing surface plasmon resonance (SPR), hydrogen-deuterium exchange mass spectrometry (HDX-MS), computational modeling, and cryoEM. Our findings reveal that DENV2 NS5 binds SLA in a closed conformation, with interdomain cooperation between its methyltransferase (MTase) and RNA-dependent RNA polymerase (RdRp) domains, critical for the interaction. SLA binding induces conformational changes in both domains, highlighting NS5's multifunctional role in viral replication. Our cryoEM results visualizes the DENV2 NS5-SLA complex, confirming a conserved SLA binding across DENV serotypes and provides key insights for antiviral strategies targeting NS5's conformational states.

Concordance of dengue viral load with disease severity and different clinical manifestations: A systematic review and meta-analysis

INTRODUCTION

Dengue is a common arboviral disease of tropical and sub-tropical regions of the globe with high prevalence rate in South-East Asian region. Association of viral load with dengue disease severity is dependent on various factors like dengue serotype, primary or secondary infection and immune response of an individual. The objective of the study was to evaluate the association of dengue viral load with dengue disease severity like dengue fever (DF), dengue haemorrhagic fever/dengue shock syndrome (DHF/DSS), dengue serotypes and different clinical manifestations detected during dengue like thrombocytopenia, leukopenia and increased liver enzymes.

MATERIALS AND METHODS

The systematic review and meta-analysis [PROSPERO (CRD42024601682)] is prepared by abiding to PRISMA checklist. It includes twenty-nine observational cross-sectional studies, which has compared association of dengue viral load with dengue disease severity, dengue serotypes and different clinical manifestations in dengue patients.

RESULT

A total of 3983 dengue patients were included in the studies out of which 1758 were diagnosed with DF and 2225 were diagnosed with DHF/DSS. Most of the studies were from South-East Asian countries followed by America and Europe. Meta-analysis of the studies revealed that, high viral load was mostly detected in DHF/DSS as compared to DF. Regarding co-relation of viral load, chances of high viral load was more in female patients than male patients. On comparing viral load with different clinical manifestations, it was seen that, the odds of high viral load were more in patients diagnosed with thrombocytopenia and leukopenia, whereas the odds of high viral load were lower in patients diagnosed with increased secretion of liver enzymes.

CONCLUSION

High Viral load had significant association with dengue disease severity. Female patients had high viral load as compared to male patients. Therefore, viral load may be regarded a potential prognostic tool in detecting dengue severity in patients, and studies need to be conducted with sufficient sample size, abiding to a single classification system and measure of outcome to prevent heterogeneity.

Prognosis and mortality risk in elderly patients with dengue virus infection: Excess fatality and the urgent need for revising current WHO criteria for elderly patients

BACKGROUND

The World Health Organization (WHO) reports a rising global incidence of dengue and severe outcomes among the elderly. This study investigates the differences in dengue characteristics between elderly and non-elderly patients and identifies mortality risk factors among elderly dengue patients.

METHODS

We conducted a retrospective study of adults (≥20 years) with dengue virus (DENV) infection at two medical centers from 2002 to 2018. Participants were divided into non-elderly (20-64 years) and elderly (≥65 years) groups.

RESULTS

A total of 1274 patients with laboratory-confirmed dengue were included in the study, of whom 373 (29.3 %) were classified as elderly. The majority of patients (67.5 %) were infected with DENV-2. In the overall cohort, age ≥65 years was identified as an independent predictor of mortality. Compared with non-elderly patients, elderly individuals exhibited significantly lower frequencies of classical dengue symptoms (e.g., fever, myalgia, bone pain, rash), but experienced higher rates of severe dengue, longer hospital stays, and more frequent complications, including acute kidney injury, severe hepatitis, bacteremia, pneumonia, and acute respiratory failure. The mortality rate was significantly higher among elderly patients (18 %) compared to non-elderly patients (2.7 %). Multivariate analysis among the elderly subgroup identified altered consciousness and pleural effusion at presentation, along with the development of acute kidney injury, severe hepatitis, and pneumonia during hospitalization, as independent predictors of mortality.

CONCLUSIONS

The current WHO criteria may be insufficient for the timely identification of dengue in the elderly population. Excess mortality in this group underscores the urgent need for updated guidelines. Neurological symptoms, pleural effusion at presentation, and organ impairment during hospitalization are key predictors of mortality in elderly dengue patients.

Spatio-temporal distribution of dengue cases and vectors along with the interrelationship of environmental and climatic factors in the Metropolitan City, Kolkata, India, for 2017-22: calling implications for vector control

We studied the spatio-temporal distribution of dengue at the micro-scale, along with other important factors for disease transmission, like vector prevalence, seasonality, breeding behaviour, entomological indices, and its relation with environmental and climatic factors in Kolkata, one of the most populous metropolitan cities in India, facing dengue upsurge in recent years. We analysed dengue data from 144 wards, city-level meteorological data for 6 years (2017-2022), Land Use Land Cover (LULC) data for 2022, and entomological surveillance data from 7 wards in 2022.Dengue showed high spatial heterogeneity and clustering at the micro-level, with a yearly post-monsoon peak (August-November) accounting for ∼90% of cases and representing a 2-3 month lag between high rainfall, temperature, and relative humidity (RH).Both Ae. aegypti and Ae. albopictus were prevalent, with distinct spatio-temporal distributions and instances of mixed breeding. Ae. aegypti primarily breeds indoors and peri-domestically, showing a strong correlation with rainfall (R² = 0.78, p-value = 0.0003) in indoor habitats and had a perennial presence. In contrast, Ae. albopictus was the more common outdoor breeder, strongly correlating with rainfall (R² = 0.75, p-value = 0.0003) in outdoor habitats.This is the first study from Kolkata, India, highlighting the spatio-temporal distribution of dengue and its links to vector behaviour, climate, and environmental factors. The findings will help identify recent dengue hotspots in Kolkata, which will help in developing targeted vector control strategies.

Climate, inter-serotype competition and arboviral interactions shape dengue dynamics in Thailand

The incidence and global spread of dengue are reaching alarming levels. Thailand represents a critical disease epicenter and demands an understanding of the environmental and evolutionary pressures that sustain DENV transmission. Unlike most affected countries experiencing recurrent outbreaks of the same serotype or replacement of one serotype for another, Thailand is an ecological niche for all four serotypes. Favorable climate and mosquito vector availability maintain a landscape defined by stable, endemic circulation of genotypes, with minimal genetic variation attributed to sporadic, external introductions. This equilibrium is achieved through inter-serotype competition, characterized by reproductive fitness levels that maintain infections (Re>1) and elevated evolutionary rates ( ~ 10-4), which steadily increase the genetic diversity of each serotype. This conclusion is reinforced by the identification of numerous positively selected mutations, skewed in the direction of non-structural proteins conferring replication and transmission advantages versus those present in structural proteins evading neutralizing antibodies. Precipitous drops in DENV cases following outbreaks of Chikungunya suggest that interactions with other arboviruses also impact DENV dynamics through vector competition, replication inhibition or partial cross-protection. Thailand is a major exporter of DENV cases and novel emergent lineages gaining fitness here are likely to spread internationally. Surveillance is therefore paramount to monitor diversification trends and take measures to avoid the establishment of similar sustained, local transmission in other countries.

The overlapping global distribution of dengue, chikungunya, Zika and yellow fever

Arboviruses transmitted mainly by Aedes (Stegomyia) aegypti and Ae. albopictus, including dengue, chikungunya, and Zika viruses, and yellow fever virus in urban settings, pose an escalating global threat. Existing risk maps, often hampered by surveillance biases, may underestimate or misrepresent the true distribution of these diseases and do not incorporate epidemiological similarities despite shared vector species. We address this by generating new global environmental suitability maps for Aedes-borne arboviruses using a multi-disease ecological niche model with a nested surveillance model fit to a dataset of over 21,000 occurrence points. This reveals a convergence in suitability around a common global distribution with recent spread of chikungunya and Zika closely aligning with areas suitable for dengue. We estimate that 5.66 (95% confidence interval 5.64-5.68) billion people live in areas suitable for dengue, chikungunya and Zika and 1.54 (1.53-1.54) billion people for yellow fever. We find large national and subnational differences in surveillance capabilities with higher income more accessible areas more likely to detect, diagnose and report viral diseases, which may have led to overestimation of risk in the United States and Europe. When combined with estimates of uncertainty, these suitability maps can be used by ministries of health to target limited surveillance and intervention resources in new strategies against these emerging threats.

The epidemiology and identification of risk factors associated with severe dengue during the 2023 dengue outbreak in Kaohsiung City, Taiwan

After the previous major dengue fever (DF) outbreaks in 2014 and 2015 in Taiwan, the second-largest DF outbreak re-emerged in 2023. A total of 178 patients with laboratory-confirmed dengue virus (DENV) infection, including 92 DENV-1 and 86 DENV-2 cases, were enrolled in this study conducted during the 2023 dengue outbreak in Kaohsiung City, Taiwan. This study aimed to analyze epidemiological characteristics, clinical severity, and risk factors for severe dengue (SD), as well as the diagnostic implications of the non-structural protein 1 (NS1) antigen rapid test. Patients infected with DENV-2 exhibited significantly older age, higher incidence of secondary infections, diabetes mellitus (DM), hypertension (HT), and longer hospital stays than patients infected with DENV-1. Multivariate analysis revealed that older age (age ≥65), secondary dengue infection, DM, and HT were significant independent predictors of SD. Compared with non-SD cases, SD patients were significantly more likely to be older (age ≥65), to exhibit a higher incidence of secondary infections and a greater prevalence of chronic diseases, including DM and HT. Notably, dengue-confirmed patients with negative NS1 results had a shorter duration since symptom onset (p < 0.001). Our DENV-1 and DENV-2 isolates are related to strains from neighboring Asian countries. Our findings emphasize the important factors of old age, secondary infections, and chronic diseases that contributed to dengue severity. We should meticulously manage these high-risk groups to prevent dengue progression. Screening incoming travelers for DF during the epidemic season will be an important measure to prevent the introduction of DENV into Taiwan.

The Impact of Vitamin D in the Prevention of Influenza, COVID-19, and Dengue: A Review

Since its discovery, vitamin D (VD) has been known for its implications in maintaining bone homeostasis. However, in recent years it has been discovered that the vitamin D receptor is expressed on different cells of the immune system and that these cells can locally produce the active form of this molecule, calcitriol, strongly suggesting that this vitamin might play a key role in both branches of the immune system, innate and adaptive. Recent evidence has demonstrated that VD participates in the different protective phases of the immune system against invading microorganisms, including in the activation and production of antimicrobial peptides, in the inactivation of replication of infectious agents, in the prevention of the exposure of cellular receptors to microbial adhesion, and, more importantly, in the modulation of the inflammatory response. In recent years, the world has witnessed major outbreaks of an ancient infectious disease, dengue fever; the emergence of a pandemic caused by an unknown virus, SARS-CoV-2; and the resurgence of a common respiratory infection, influenza. Despite belonging to different viral families, the etiological agents of these infections present a common trait: their capacity to cause complications not only through their cytopathic effect on target tissues but also through the excessive inflammatory response produced by the human host against an infection. This review outlines the current understanding of the role that vitamin D plays in the prevention of the aforementioned diseases and in the development of their complications through its active participation as a major modulator of the immune response.

Predicting spatio-temporal dynamics of dengue using INLA (integrated nested laplace approximation) in Yogyakarta, Indonesia

INTRODUCTION

Dengue is a mosquito-borne disease caused by the dengue virus, primarily transmitted by Aedes aegypti and Aedes albopictus. Its incidence fluctuates due to spatial and temporal factors, necessitating robust modeling approaches for prediction and risk mapping.

OBJECTIVES

This study aims to develop a spatio-temporal Bayesian model for predicting dengue incidence, integrating climatic, sociodemographic, and environmental factors to improve outbreak forecasting.

METHODS

An ecological study was conducted in the Special Region of Yogyakarta, Indonesia (January 2017-December 2022) using monthly panel data from 78 sub-districts. Secondary data sources included dengue surveillance (Health Office), meteorological data (NASA POWER), sociodemographic data (BPS-Statistics Indonesia), and land use data (Sentinel-2, ESRI). Predictors included rainfall, temperature, humidity, wind speed, atmospheric pressure, population density, and land use patterns. Data analysis was performed using R-INLA, with model performance assessed using Deviance Information Criterion (DIC), Watanabe-Akaike Information Criterion (WAIC), marginal log-likelihood, Mean Absolute Error (MAE), and Root Mean Squared Error (RMSE).

RESULTS

The INLA-based Bayesian model effectively captured spatial and temporal dengue dynamics. Key predictors included rainfall lag 1 and 2 (mean = 0.001), temperature (mean = 0.151, CI: 0.090-0.210), humidity (mean = 0.056, CI: 0.040-0.073), built area (mean = 0.001), and water area (mean = 0.008, CI: 0.005-0.011). Spatial clustering (BYM model, precision = 2163.53) indicated that dengue cases were concentrated in specific areas. The RW2 model (precision = 49.11) confirmed seasonal trends, highlighting climate's role in disease transmission. Model evaluation metrics (DIC = 15017.88, WAIC = 15294.54, log-likelihood = -7845.857) demonstrated good predictive performance. Furthermore, the model's accuracy was assessed using MAE and RMSE values, where MAE = 1.77 indicates an average prediction error of 1-2 cases, while RMSE = 2.97 suggests the presence of occasional larger discrepancies. The RMSE's higher value relative to MAE highlights instances where prediction errors were more significant, as RMSE is more sensitive to large deviations.

CONCLUSIONS

The INLA-based spatio-temporal model is an effective tool for dengue prediction, offering valuable insights for early warning systems and targeted vector control strategies, thereby improving disease prevention and response efforts.

Enhancing Tissue-Specific Antiviral Immunity to Disrupt Arbovirus Transmission by Mosquitoes

Arboviruses, including dengue virus (DENV), Zika virus (ZIKV), and chikungunya virus (CHIKV), pose a significant global health and economic burden, with Aedes aegypti serving as their primary vector. Arbovirus infection in Ae. aegypti progresses sequentially through the midgut (MG), carcass (CA), and salivary glands (SG), with each tissue exhibiting distinct antiviral responses. Here, we investigate tissue-specific antiviral mechanisms, focusing on the small interfering RNA (siRNA) pathway in SGs. Our results reveal that SGs possess weaker antiviral defense and are more susceptible to arboviral infection compared to MGs and CAs. Notably, overexpression of Dicer2 ( Dcr2 ), a key component of the siRNA pathway, in SGs leads to a significant decrease in arboviral replication. Conversely, Dcr2 overexpression in fat bodies, the primary tissue in CAs, only moderately suppresses DENV2 infection and has no notable effect on Mayaro virus (MAYV) infection. Remarkably, the simultaneous overexpression of Dcr2 in both MGs and SGs enhances antiviral activity, effectively blocking the transmission of multiple arboviruses. These findings reveal the tissue-specific dynamics of mosquito antiviral immunity and underscore the potential for targeting SG-specific immunity to disrupt arbovirus transmission, providing a promising approach for controlling mosquito-borne diseases.

Epidemiology of arboviruses in humans and livestock in Ethiopia: a systematic review and meta-analysis

BACKGROUND

Arbovirus infections are a global public health threat, accounting for approximately 73% of the total emerging and re-emerging human infections, where the burden is worsened in sub-Saharan Africa, including Ethiopia. However, the surveillance system has been still challenged, and their burden and magnitude are not well estimated due to underestimates of true arbovirus burdens by passive case detections. To support targeted evidence-based public health decision-making, comprehensive evidence of arbovirus prevalence is crucial. Thus, the aim of this study was to assess the prevalence of arboviruses in humans and livestock in Ethiopia.

METHOD

Articles were extensively searched in bibliographic databases and gray literatures using entry terms or phrases. PRISMA 2020 flow diagram was used and data among studies meeting eligibility criteria extracted in MS Excel sheet and exported into STATA-17 software for analysis. A random-effects model was used to compute the pooled magnitude of arboviruses in humans and livestock. The heterogeneity was quantified using the I2 value. Publication bias was assessed using a funnel plot and Egger's test. Sensitivity analysis, subgroup analysis and meta-regression were performed to explore heterogeneity.

RESULT

Of the 1957 studies identified, 39 human and 6 livestock studies were eligible for meta-analysis. The overall pooled sero-epidemiology of arboviruses in humans using anti-IgG and anti-IgM was 15.43% (95% CI: 12.11-18.76) and 10.04% (95% CI: 6.46-13.62), respectively. The molecular prevalence of arboviruses in humans was 38.42% (95% CI: 21.77-55.08). The pooled prevalence of arboviruses in livestock was 15.77% (95% CI: 0.45, 31.08). Dengue virus, Yellow fever virus, Zika virus, Rift valley fever, West Nile virus, and chikungunya virus in humans and Rift valley fever, West Nile virus, and Schmallenberg virus in livestock were reported.

CONCLUSION

The magnitude of arboviruses in humans and livestock in Ethiopia alarms the need for immediate multi-sectoral interventions such as strengthening laboratory diagnostic capacities, undertaking an integrated regular national surveillance, and implementation of one-health initiatives and a planetary health approach.

Dengue dynamics in Bali: Serotype shifts, genotype replacement and multiple virus lineage circulation in the last 10 years

BACKGROUND

Bali, one of the world's most popular tourist destinations, is hyper-endemic to dengue, an acute febrile illness caused by infection with dengue virus (DENV). Outbreaks of dengue occur annually with worrisome rates of morbidity and mortality. Despite this, comprehensive and continuous virus surveillance is yet to be established. We conducted DENV serotype and genotype surveillance in Bali to monitor viral transmission dynamics.

METHODS

We enrolled febrile patients with dengue clinical symptoms in hospitals in Denpasar, Bali. Clinical evaluations and laboratory assessments were conducted, and blood samples were collected. DENV serotypes were determined using RT-PCR, and genotyping was performed by sequencing the envelope protein gene and the complete genomes. Subsequently, phylogenetic analyses were conducted to analyse the recent data alongside retrospective sequence data.

RESULTS

A total of 62 and 66 dengue patients were recruited during 2018-2020 and 2022, and from these, we obtained DENV serotype data for 49 and 48 individuals, respectively. Among the DENV analysed, the most prevalent serotype in 2018-2020 was DENV-1 (30%) and shifted to DENV-3 (57.6%) in 2022. When compared to data from the last 10 years, serotype shifting was clearly observed. We sequenced the genomes of 60 isolates and observed the presence of multiple virus lineages and the replacement of Genotype IV of DENV-1 with Genotype I. The Cosmopolitan, Genotype I and Genotype II remained the predominant genotypes for DENV-2, DENV-3 and DENV-4, respectively.

CONCLUSION

We reveal that DENV serotype predominance in Bali has been shifting in the past 10 years. While genotype replacement occurred, continuous circulation of local endemic viruses was responsible for the annual outbreak of dengue. These findings indicate the genetic diversity and dynamic nature of DENV circulating in Bali. Routine virus surveillance is important to understand the cyclical patterns of DENV serotypes that is useful to predict the future outbreaks.

Exploration of comprehensive marine natural products database against dengue viral non-structural protein 1 using high-throughput computational studies

Dengue virus (DENV) non-structural protein 1 (NS1) is a versatile quasi-protein essential for the multiplication of the virus. This study applied high-throughput virtual screening (HTVS) and molecular dynamics (MD) simulation to detect the potential marine natural compounds against the NS1 of DENV. The structure of the NS1 protein was retrieved from Protein Data Bank with (PDB ID: 4O6B). Missing residues were added using modeler software. Molecular operating environment (MOE) programme was used to prepare the protein before docking. Virtual screening was performed on PyRx software to identify natural compounds retrieved from Comprehensive Marine Natural Products Database (CMNPD) against the NS1 protein, and best-docked compounds were examined by molecular docking and molecular dynamic (MD) simulation. Out of 31,561 marine compounds, the top 10 compounds showed docking scores lesser than -8.0 kcal/mol. One of the best hit compounds, CMNPD6802, was further analyzed using MD simulation study at 100 nanoseconds and Molecular Mechanics with Generalized Born and Surface Area Solvation (MM/GBSA). Based on its total binding energy, determined using the MM/GBSA approach, CMNPD6802 was ranked first. Its pharmacokinetic properties concerning the target protein NS1 were also evaluated. The results of the MD simulation showed that CMNPD6802 remained in close contact with the protein throughout the activation period, mapped using principal component analysis. These findings suggest that CMNPD6802 could serve as an NS1 inhibitor and may be a potential candidate for treating DENV infections.

Unearthing the inhibitory potential of phytochemicals from Lawsonia inermis L. and some drugs against dengue virus protein NS1: an in silico approach

Dengue has received the status of an epidemic and endemic disease, with countless number of infections every year. Due to the unreliability of vaccines and non-specificity of drugs, it becomes necessary to find plant-based alternatives, with less harmful side effects. Lawsonia inermis L., is the sole source of dye, Mehendi. The rich repertoire of phytochemicals makes it useful, medicinally. The main objectives of the study are to explore the anti-dengue properties of the phytochemicals from Lawsonia inermis, and to shortlist potential candidates in curing the disease. Phytochemicals from the plant, and a set of drugs were screened and docked against NS1 protein, a less explored drug target, needed for maintenance of virus life cycle. Ligand screening and docking analysis concluded gallic acid, and chlorogenic acid to be good candidates, exhibiting high binding affinity and extensive interactions with the protein. From among the shortlisted drugs, only Vibegron showed effective binding affinity with NS1 protein with zero violations to the Lipinski's Rule of 5. Molecular dynamic simulations, executed for a time period of 100 nanoseconds, reveal the performance of a ligand within a solvated system. Chlorogenic and gallic acid, formed more stable and compact complexes with protein, with stable energy parameters and strong binding affinity. This was further validated with snapshots taken every 50 nanoseconds, showing no change in binding site between the ligand and protein, within the stipulated time frame. It was interesting to see that, a phenol (chlorogenic acid), served as a better drug candidate, against the NS1 protein.

Advances in Nanobiosensors for Rapid and Sensitive Detection of Dengue Virus Biomarkers by Using Clinical Laboratory

BACKGROUND

The recent rise in dengue virus (DENV) cases poses a significant threat to human health, with infections ranging from mild to severe and potentially leading to premature death.

OBJECTIVE

To highlight the importance of early detection of DENV and to review advancements in detection technologies, particularly focusing on nanobiosensors.

METHODS

This review examines traditional detection methods for DENV, including molecular, serological, and direct virus culture techniques, while discussing their limitations. It also explores innovative technologies that enhance detection accuracy, speed, and efficiency.

RESULTS

Nonstructural protein 1 (NS1) serves as a key biomarker present in high concentrations during the early stages of DENV infection, underscoring the need for timely detection. Traditional methods, while effective, have limitations that new technologies aim to address. Biosensors, particularly nanobiosensors, have emerged as promising tools for rapid, sensitive, and cost-effective DENV detection.

CONCLUSION

The adoption of advanced detection methods, especially nanobiosensors, is crucial for improving DENV management and reducing human suffering. This review provides a comprehensive overview of nanobiosensors and their applications, presented in an accessible manner for readers.

Non-household environments make a major contribution to dengue transmission: implications for vector control

The incidence of Aedes-borne pathogens has been increasing despite vector control efforts. Control strategies typically target households (HH), where Aedes mosquitoes breed in HH containers and bite indoors. However, our study in Kenyan cities of Kisumu and Ukunda (2019-2022) revealed high Aedes abundance in public spaces, prompting the question: How important are non-household (NH) environments for dengue transmission and control? Using field data and human activity patterns, we developed an agent-based model simulating transmission across HH and five types of NH environments, which was then used to evaluate preventive (before an epidemic) and reactive (after an epidemic commences) vector control scenarios. Our findings estimate over half of infections occurring in NH settings, particularly workplaces, markets and recreational sites. Container removal was more effective in NH than in HH areas, contrasting with the global focus on HH-based management. Greater reductions in dengue cases occurred with early, high-coverage interventions, especially in NH locations. Additionally, local ecological factors, such as uneven water container distribution, influence control outcomes. This study underscores the importance of vector control in both HH and NH environments in endemic settings. It highlights a specific approach to inform evidence-based decision-making to target limited vector control resources for optimal control.

The role of γδ T cells in flavivirus infections: Insights into immune defense and therapeutic opportunities

γδ T cells are a unique subset of unconventional T cells and an important component of the innate immune system. Unlike conventional αβ T cells, γδ T cells can respond rapidly during the early stages of infection, and their antigen recognition is not restricted by MHC molecules. These distinctive features underscore the important role of γδ T cells in viral clearance and infection control. Therefore, γδ T cell-based immunotherapies have been extensively explored for the treatment of a variety of diseases, including viral infections and cancers. Several therapeutic strategies based on γδ T cells have advanced to clinical trials, demonstrating promising safety and efficacy. Currently, there are no effective treatments for flavivirus infections, which are typically characterized by acute onset. Research has shown that γδ T cells can rapidly expand during the early phases of flavivirus infections and effectively suppress viral replication, making them an attractive target for the development of novel therapies for flavivirus infections. This review aims to highlight the immunological roles of γδ T cells in flavivirus infections and to explore the potential of γδ T cell-based therapeutic strategies for the prevention and treatment of these infections.

Why the growth of arboviral diseases necessitates a new generation of global risk maps and future projections

Global risk maps are an important tool for assessing the global threat of mosquito and tick-transmitted arboviral diseases. Public health officials increasingly rely on risk maps to understand the drivers of transmission, forecast spread, identify gaps in surveillance, estimate disease burden, and target and evaluate the impact of interventions. Here, we describe how current approaches to mapping arboviral diseases have become unnecessarily siloed, ignoring the strengths and weaknesses of different data types and methods. This places limits on data and model output comparability, uncertainty estimation and generalisation that limit the answers they can provide to some of the most pressing questions in arbovirus control. We argue for a new generation of risk mapping models that jointly infer risk from multiple data types. We outline how this can be achieved conceptually and show how this new framework creates opportunities to better integrate epidemiological understanding and uncertainty quantification. We advocate for more co-development of risk maps among modellers and end-users to better enable risk maps to inform public health decisions. Prospective validation of risk maps for specific applications can inform further targeted data collection and subsequent model refinement in an iterative manner. If the expanding use of arbovirus risk maps for control is to continue, methods must develop and adapt to changing questions, interventions and data availability.

Pediatric non-congenital central nervous system infections: role of imaging in the emergency department

Neurological emergencies in pediatric patients, including central nervous system infections like meningitis and encephalitis, account for significant morbidity and mortality. Neuroimaging plays an important role in the management of these infections, especially when children present with non-specific symptoms such as fever, seizures, or altered consciousness. While computed tomography scans are typically the initial imaging step, magnetic resonance imaging is preferred for its superior detail and lack of ionizing radiation. Radiologists play a crucial role in guiding clinicians to select the appropriate imaging modality based on clinical presentation, patient age, and available technology. Optimizing techniques for these studies may help to give an overview of imaging protocols and an optimal diagnostic algorithm for these patients. In this article, we delineate the prevalent radiological manifestations associated with the primary etiological agents of central nervous system infections, encompassing bacteria, fungi, viruses, and parasites. Furthermore, we share our clinical experience with particular radiologic findings in select pathologies, underscoring the critical importance of evaluating these non-congenital infections within the context of emergency medical care.

Aedes albopictus responses to transfluthrin-impregnated polyester fabric in a semi-field system at different time periods

Volatile pyrethroid spatial repellents produce airborne chemicals that cause insect repellency and provide personal protection to human users. This study investigated the effect of a passive emanator fabric on the human landing catch (HLC) of Aedes albopictus in a semi-field system (SFS) as well as post-exposure blood-feeding behavior, fecundity, and egg hatchability. A polyester fabric measuring 1029 cm2 impregnated with 2.5 g/m2 transfluthrin (TFT) (6.8 %, w/v) was attached to a black-screened vest to simulate insecticide-treated clothing. Two collectors wearing treated polyester fabric (TFT-P) or untreated fabric conducted HLC from opposite test arenas during morning (06:00-08:00 h) and evening (18:00-20:00 h) trials for 12 days. Recaptured surviving mosquitoes were provided a blood meal for 120 min. The protective efficacy-the percentage reduction of HLC in treatment compared to control-of TFT-P was 60.73 % during the morning trials compared to 31.97 % during the evening trials. Blood feeding was moderately reduced in exposed (37.5 % fed) and unexposed (67.7 % fed) mosquitoes during the morning trials. Similarly, egg hatchability was significantly low in exposed batches (31.2 % hatched) compared to the unexposed (54.5 % hatched) from the morning trials, but not the evening trials. The results highlighted the effect of trial time on TFT-P efficacy, mosquito feeding behavior, and egg hatchability. TFT-P could provide personal protection against Ae. albopictus by preventing bites and offering community protection by reducing feeding propensity. Further open-field tests and evaluations against other mosquito species are needed before public use.

Epidemiological and molecular typing of dengue viruses circulating in Jorhat district, Assam, India

BACKGROUND

Dengue is a significant mosquito-borne infection that causes public health concern, particularly in tropical and subtropical regions. This study aimed to characterize the molecular typing of dengue viruses in Jorhat district, as information on dengue serotypes is scarce in India.

METHODS

A total of 1359 serum samples of clinically suspected dengue cases were tested for non-structural protein 1 (NS1) antigen and Immunoglobulin M (IgM) antibody using enzyme-linked immunosorbent assay (ELISA). Additionally, viral RNA was extracted from positive samples for multiplex reverse transcriptase-polymerase chain reaction (RT-PCR) to determine the dengue serotypes. Seasonal variations, gender, and age-wise incidences were also studied. Statistical analysis was performed to assess demographic and clinical characteristics.

RESULTS

This study depicts a substantial burden of dengue, with 370 (27.22 %) positive samples. IgM and NS1 ELISA tested positive for 42 (11.3 %) and 328 (88.6 %) samples. Dengue virus (DENV) cases predominantly affected males (58.4 %) and the age group of 16-30 years. The major clinical manifestations include fever, headache, and body aches. Serotyping revealed DENV-2 as the predominant serotype, followed by DENV-3 and DENV-1. The co-infection of DENV-2 and DENV-3 was observed in many cases. Seasonal clustering of dengue cases indicates the highest peak in September and October.

CONCLUSIONS

This study provides valuable insights into the epidemiology, diagnosis, and serotyping of dengue viruses in the Jorhat district of Assam, emphasizing the need for continued surveillance and effective vector control measures that should be implemented to mitigate the early detection of dengue in this region.

A Concept Analysis of Health-Seeking Behavior Toward Dengue Fever

Understanding health-seeking behavior toward dengue fever is crucial for early diagnosis and timely treatment to mitigate fatal outcomes. In this paper, a concept analysis based on Walker and Avant's method was performed to define health-seeking behaviors regarding dengue fever. This behavior was defined as a series of actions increasing awareness, promoting preventive measures, facilitating informed health decisions, and ensuring timely access to medical care. This concept analysis clarified how awareness, preventive measures, and access to care influence health-seeking behaviors. Our analysis may help refine health care taxonomies and foster a standardized language for describing health-seeking behaviors in nursing and public health contexts.

[Aedes albopictus (tiger mosquito) and arboviroses: What to expect in the coming years?]

First observed in France in 1999, Aedes albopictus (tiger mosquito) is now established in almost all French departments. As a vector of arboviruses, in particular dengue fever, A. albopictus represents a real threat in Europe, where 304 autochthonous cases of dengue fever were reported in 2024, four times more than the total number of cases reported during the entire 2010-2021 period. Although dengue is asymptomatic in the majority of cases, it can cause severe forms of the disease as hemorrhagic fever (less than 5% of cases). In the context of an unprecedented number of imported cases since the beginning of 2024, notably due to an epidemic in Martinique and Guadeloupe, dengue may be evoked as a diagnosis in patients presenting with a febrile, algic syndrome, which may be accompanied by a skin rash and digestive signs. In this context, entomovirological and epidemiological surveillances are essential to improve our understanding and the control possible future dengue epidemics.