Search Results (105)

Accurate dengue forecasting is essential for sustainable public health planning, especially in tropical regions where the disease remains a persistent threat. This study evaluates the predictive performance of seven modeling approaches—Seasonal Autoregressive Integrated Moving Average (SARIMA), Extreme Gradient Boosting (XGBoost), Recurrent Neural Network (RNN), Long Short-Term Memory (LSTM), Bidirectional LSTM (BiLSTM), Convolutional LSTM (CNN–LSTM), and a Bayesian spatiotemporal model—using monthly dengue incidence data from 2009 to 2023 in Bandung City, Indonesia. Model performance was assessed using MAE, sMAPE, RMSE, and Pearson’s correlation (R). Among all models, the Bayesian spatiotemporal model achieved the best performance, with the lowest MAE (5.543), sMAPE (62.137), and RMSE (7.482), and the highest R (0.723). While SARIMA and XGBoost showed signs of overfitting, the Bayesian model not only delivered more accurate forecasts but also produced spatial risk estimates and identified high-risk hotspots via exceedance probabilities. These features make it particularly valuable for developing early warning systems and guiding targeted public health interventions, supporting the broader goals of sustainable disease management. Full article

Orthoflaviviruses (formerly flaviviruses) are known for their role in numerous diseases affecting both humans and animals. Despite the worldwide distribution of orthoflaviviruses, individual species are only found in endemic or epidemic regions. However, in recent decades, certain orthoflaviviruses have spread beyond their traditional geographic boundaries, even crossing continents. Given the long-distance movements of birds, the knowledge of zoonotic orthoflaviviruses associated with birds is essential because of their possible introduction into new regions, as was the case with West Nile virus and Usutu virus. A thorough literature review was conducted on zoonotic orthoflaviviruses related to birds, including lesser-known (re-)emerging and neglected orthoflaviviruses that are limited to specific regions and/or avian hosts but have the potential to spread to a wider geographical area and pose a higher risk of transmission to humans. Several of these viruses possess significant zoonotic potential and can cause a wide spectrum of diseases in humans, ranging from mild febrile illnesses (Zika virus) to severe neuroinvasive diseases (tick-borne encephalitis, West Nile, Japanese encephalitis virus) and hemorrhagic fevers (yellow fever, dengue virus). Geographic distribution, hosts, vectors, incidence of human infections, and impact on human and animal health of zoonotic flaviviruses related to birds are critically reviewed. The viruses have been categorized based on the role of birds as an orthoflavivirus host and the clinical presentation in human infections. Full article

Dengue fever remains a major global health threat, and mathematical models are crucial for predicting its spread and evaluating control strategies. This study introduces a highly flexible dengue transmission model using a novel piecewise fractional derivative framework, which can capture abrupt changes in epidemic dynamics, such as those caused by public health interventions or seasonal shifts. We conduct a rigorous comparative analysis of four widely used but distinct mechanisms of disease transmission (incidence rates): Harmonic Mean, Holling Type II, Beddington–DeAngelis, and Crowley–Martin. The model’s well-posedness is established, and the basic reproduction number (${\Re }_0$) is derived for each incidence function. Our central finding is that the choice of this mathematical mechanism critically alters predictions. For example, models that account for behavioral changes (Beddington–DeAngelis, Crowley–Martin) identify different key drivers of transmission compared to simpler models. Sensitivity analysis reveals that vector mortality is the most influential control parameter in these more realistic models. These results underscore that accurately representing transmission behavior is essential for reliable epidemic forecasting and for designing effective, targeted intervention strategies. Full article

Dengue, an acute infectious disease caused by the dengue virus, remains a major public health problem in the 21st century. This study investigated the global dengue burden, identified high-risk regions, evaluated the long-term incidence trends, and can inform evidence-based control strategies. Using GBD 2021 data, we analysed the dengue incidence from 1992 to 2021 using age–period–cohort models. We determined the net drift (overall annual percentage change), local drift (annual percentage change for each age group), longitudinal age curves (expected longitudinal age-specific rates), and periods’ (cohorts’) relative risks. In 2021, the global age-standardised incidence rate reached 752.04/100,000 (95% UI: 196.33–1363.35), a 47.26% increase since 1992. High-risk regions included eastern sub-Saharan Africa, Southeast Asia, South Asia, and Latin America and the Caribbean. Southeast Asia experienced the largest rise (65.43%), with a net drift of 2.47% (1992–2021). While individuals aged 5–39 years bore the highest burden, those over 80 faced an elevated risk. Dengue remains a critical public health threat, disproportionately affecting younger populations but increasingly endangering older adults. Targeted interventions in high-risk regions and age groups, coupled with precision public health strategies, are essential to enhance prevention and control efforts. Full article

Climate change is thought to be responsible for the spread of various vector-borne diseases. The current study was conducted to evaluate the impact of different temperature and relative humidity regimes on the developmental stages of the yellow fever mosquito, Aedes aegypti (Diptera: Culicidae). The study also evaluated the impact of larval density on the survival of Ae. aegypti. In addition, the association between vector larval abundance, dengue incidence, and climatic factors were elucidated during 2016–2019 in three populated districts of Punjab, Pakistan, i.e., Lahore, Rawalpindi, and Multan. The results of the study revealed that at 10 °C and 35 °C, egg hatching and adult emergence were significantly reduced, regardless of the relative humidity. In contrast, at 20 °C and 30 °C, the rates of egg and adult survival increased with higher relative humidity. In addition, a density-dependent response was observed regarding larval survival of Ae. aegypti. Moreover, larval incidence was positively correlated with the number of dengue patients, Tmax, RH, and precipitation at Lahore (0.55, 0.23, 0.29, and 0.13), Rawalpindi (0.90, 0.30, 0.21, and 0.14), and Multan (0.05, 0.27, and 0.13) respectively, except in Multan, where a negative correlation (−0.09) with precipitation was observed. The inflow of patients had a positive correlation with the occurrence of a larval population, relative humidity, and precipitation at Lahore, Rawalpindi, and Multan districts, with the scale values of 0.55, 0.25, and 0.16; 0.90, 0.22, and 0.03; and 0.05, 0.06, and 0.03, respectively. In addition, a forecast model, ARIMA, predicted that there was a higher rate of larval occurrence in Rawalpindi, followed by Lahore. This study concluded that the role of precipitation > 200 mm prior to a 1–2-month lag, a 20–30 °C temperature range, and an RH exceeding 60% lead to the occurrence of larvae and dengue case spikes. This study will help to reinforce dengue surveillance and control strategies in Pakistan and to establish early management strategies based on changing climatic factors. Full article

Background: The Amazon region possesses vast natural and anthropogenic ecosystems within a hydroclimatic environment conducive to the proliferation of arboviruses associated with infectious diseases in the human population, notably dengue fever, which poses a recurrent and significant public health challenge. Objective and Methods: We wished to update the dengue mapping for the state of Pará (eastern Amazon) using municipality-level secondary data between 2010 and 2024, including epidemiological information. Furthermore, the seasonal effects of soil and atmospheric meteorological variables (ERA5 reanalysis) on the annual municipal incidence of dengue were statistically analyzed through correlation and cluster-based regression methods. Results: Dengue mapping identified key areas over the central, southwest, and southeast parts of Pará, with eleven municipalities exhibiting extreme dengue counts exceeding 300 cases per 100,000 inhabitants. The epidemiological profile in these cities with worsening transmission showed a higher incidence in adults aged 20–39 years old (39%) and a predominance among women (54%). The majority of dengue cases occur during the rainy season (January to May), accounting for 69% of annual cases, when the climate conditions maximize vector proliferation. The statistical analyses highlighted the significant and spatially heterogeneous influence of regional climate variables on the dengue transmission cycle. Conclusions: This study advances our understanding of climatic drivers of dengue in the Amazon and provides relevant evidence to support region-specific surveillance and control strategies. Full article

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. Full article

The DENV virus circulates freely in endemic regions and causes dengue disease. The vectors are Aedes aegypti and Aedes albopictus. The difficulties inherent in the nature of the DENV virus, its epidemiology, and its increasing incidence in recent years have led to the development of viable alternatives in the search for effective solutions for the treatment of this severe disease. Flavones such as tropoflavin, baicalein, and luteolin have anti-DENV activity. Molecular docking studies were performed between the flavones tropoflavin, baicalein, and luteolin and the DENV E-3 protein. Flavone—DENV E-3 complex interactions were analyzed at the flavonoid binding sites domain I of the B chain and domain II of the A chain reported in the literature. H-bond, π-π stacking, and π-cation interactions between flavones and the DENV E-3 protein at different binding energies were evaluated. Molecular dynamics studies for these interactions were performed to determine the molecular stability of the Flavone—DENV E-3 complexes. I also present here the results of the molecular interactions of the Flavone—DENV E-3―SWCNT complex. Due to recent advances in nanotechnology and their physicochemical properties, the utilization of nanoparticles such as SWCNT has increased in antiviral drug delivery. Full article

Background: Dengue, transmitted by Aedes spp. mosquitoes, poses significant public health challenges in Burkina Faso. This study investigated outbreak thresholds, utilizing historical data since 2018 to explore the climatic impacts on dengue transmission and address knowledge gaps. Methodology: This retrospective ecological study utilized historical and contemporary data from Burkina Faso’s Public Health Ministry (2018–2024) to model dengue outbreak thresholds. A combination of epidemic channel analysis, joinpoint regression, climate–disease relationship analysis, and negative binomial regression was employed to provide comprehensive insights into the factors driving dengue outbreaks. Principal Findings: The incidence of probable dengue cases remained stable, mostly below 5 cases per 100,000 people, except for a sharp surge in week 40 of 2023, peaking at 38 cases per 100,000. This surge was brief, normalizing by week 47, but coincided with a marked increase in mortality, reaching 90 deaths in week 45. Joinpoint regression identified key thresholds, an alert at 2.1 cases per 100,000 by week 41 and an intervention threshold at 19.1 cases by week 44, providing a framework for timely public health responses. Climatic factors significantly influenced dengue transmission, with higher temperatures (RR = 2.764) linked to increased incidence, while higher precipitation (RR = 0.551) was associated with lower case numbers, likely due to disrupted mosquito breeding conditions. Additionally, intermediate precipitation levels showed a complex relationship with higher incidence rates. Conclusions: This study established evidence-based epidemiological thresholds for dengue outbreak detection in Burkina Faso (2018–2024), demonstrating temperature as a primary transmission driver while precipitation showed inverse relationships. Analysis of the 2023 outbreak identified a critical five-week intervention window (weeks 40–45), providing a framework for climate-sensitive early warning systems. These findings advance the understanding of dengue dynamics in West Africa, though future research should integrate geographical and socioeconomic variables to enhance predictive modeling and outbreak preparedness. Full article

Dengue is a growing global public health challenge, with rising incidence and case fatality rates fueled by urbanization and climate change. The substantial mortality, morbidity, and economic burden associated with the disease underscore the need for effective prevention strategies, including vector control, personal protective measures, and vaccination. This narrative review provides a practical guide for clinicians to ensure the appropriate administration of dengue vaccines to at-risk groups, such as individuals in endemic regions and travelers to these areas. Live-attenuated tetravalent dengue vaccines, including Dengvaxia^®, Qdenga^®, and Butantan-DV, have demonstrated efficacy in clinical trials but require careful use due to the risk of antibody-dependent enhancement (ADE). To mitigate this risk, guidelines recommend vaccination primarily for individuals with prior confirmed dengue infection, emphasizing the importance of accessible and affordable point-of-care rapid testing. Co-administration of dengue vaccines with other live-attenuated or inactivated vaccines has been shown to be safe and immunogenic, broadening their potential application. However, live-attenuated vaccines are contraindicated for immunocompromised individuals and pregnant women. Enhancing clinician awareness, expanding diagnostic capabilities, and prioritizing high-risk populations are critical steps to optimize vaccination strategies. Combined with robust prevention programs, these efforts are essential to reducing the global burden of dengue and mitigating its impact. Full article

Background/Objectives: Takeda’s tetravalent dengue vaccine TAK-003 has been approved by the Brazilian regulatory agency ANVISA for dengue disease prevention in individuals aged 4 to 60 years. Dourados, in the state of Mato Grosso do Sul, became the world’s first city to implement a mass vaccination campaign targeting approximately 120,000 individuals. An ongoing collaborative, observational, population-based study using national surveillance and vaccination data was planned to measure the impact of the vaccine on the reduction in dengue incidence. Methods: In this manuscript, the study’s methodology, including its programmatic steps and public health relevance, is described. A collaborative assessment with multidisciplinary researchers in Brazil was conducted to identify key programmatic areas for the successful implementation of the study. These areas included feasibility and site selection assessment, methodology selection, vaccination program implementation, and public health importance. Results/Conclusions: Identification of the public health problem and understanding the disease burden, local healthcare infrastructure, and strategic partnerships were critical for a robust feasibility assessment. One of the feasibility criteria identified was the ability of the Dourados Municipal Health Secretary and the principal investigator to conduct an active vaccination campaign, utilizing extramural activities and diverse communication channels to increase vaccine acceptance and coverage. The selection of analytical methods, such as time series analysis, was dependent on the national and local structures of the databases and data availability. Full article

Background: Dengue has emerged as a significant public health concern in Sao Tome and Principe, with the first documented outbreak occurring between 2022 and 2024. This study examined the epidemiological patterns, environmental determinants, and demographic characteristics of dengue transmission during this period. Methods: We conducted a comprehensive retrospective analysis of laboratory-confirmed dengue cases using national surveillance data, clinical records, and environmental monitoring data. Statistical analyses included demographic profiling, temporal trend assessment, and environmental correlation studies using multiple regression modeling. Results: Among 1264 laboratory-confirmed cases, we observed distinct age-specific vulnerability patterns, with the highest incidence rate in the 70–79 age group (829.6 per 100,000) despite most cases occurring in younger adults. Rainfall emerged as the strongest predictor of dengue transmission (r = 0.96, p < 0.001), explaining 92% of case variance in the regression model. Case distribution showed marked temporal variation, with 91.9% of cases reported in 2022, coinciding with exceptional rainfall (3205 mm). The overall case fatality rate was 0.71% (95% CI: 0.33–1.35), with significant quarterly variations. Geographical analysis revealed concentration in the Água Grande district (68.2% of cases). Conclusions: This first comprehensive analysis of dengue in Sao Tome and Principe demonstrates the crucial role of rainfall in disease transmission and reveals important age-specific vulnerability patterns. These findings provide an evidence base for developing targeted interventions, particularly during high-rainfall periods, and suggest the need for age-stratified clinical protocols in similar island settings. Full article

Background: Brazil has witnessed the co-circulation of dengue virus (DENV), Zika virus (ZIKV), and chikungunya virus (CHIKV), with outbreaks exacerbated by environmental factors, social determinants, and poor sanitation. The recent re-emergence of Oropouche virus (OROV) has added complexity to vector control strategies, emphasizing the need for integrated approaches to curb arboviruses spread. We aimed to analyze temporal trends and spatial distributions with national scope of these emerging arboviruses. Methods: An ecological study using data from the Brazilian Notifiable Diseases Information System the period from 2023 to 2024 was undertaken. Temporal trends were evaluated using Joinpoint regression, while spatial analysis was conducted using Moran’s I, and local indicators of spatial association. Results: Dengue fever cases increased by 322%, while Oropouche fever (OF) increased by 300%. The states of Amazonas and Espírito Santo reported increases in OF cases. Moran’s I test revealed spatial clustering of DENV and CHIKV. Two municipalities in the state of Mato Grosso do Sul showed cocirculation of DENV, CHIKV, and ZIKV. Conclusions: This study identified a surge in arbovirus cases between 2023 and 2024, with peak incidences from January to March and October to December, linked to favorable climatic conditions. Clustering patterns and co-circulation of arboviruses highlight the need for tailored control and prevention strategies and targeted interventions to mitigate their impact. Full article

Dengue infection has been associated with oxidative stress (OS) induction; however, whether such a response predicts the development of complications remains unknown. We conducted a case-control study (1:2 ratio) nested within a cohort of febrile patients with a presumptive or confirmed diagnosis of dengue. Incident cases were patients who developed hypotension or severe bleeding during the follow-up, whereas controls did not. Total antioxidant status (TAS), superoxide dismutase (SOD), and glutathione peroxidase activity (GPx) were quantified in serums obtained ≤96 h from disease onset. The association between each biomarker and complications was evaluated by estimating adjusted odds ratios (ORs) using logistic regression. We evaluated 132 patients (median age: 19.0 years; 58.2% males). TAS and SOD were higher among cases than controls (2.1 versus 1.7 mM and 6.7 versus 6.0 U/mL, respectively), and the opposite was observed for GPx (128.1 versus 133.7 mmol/min/mL); however, none of these contrasts reached statistical significance. In the multivariate analysis, higher levels of TAS and SOD were associated with a higher likelihood of complications up to 3.5 mM (OR = 2.46; 95%CI: 1.10–5.53) and 8.0 U/mL (OR = 1.69; 95%CI: 1.01–2.83), respectively. GPx did not show an association with hypotension or severe bleeding. Our results suggest that the induction of OS during the acute phase of dengue infection might be a prognostic factor of hypotensive and hemorrhagic complications. Full article

Dengue fever, caused by the dengue virus (DENV), poses a significant global health challenge, particularly in tropical and subtropical regions. Recent increases in indigenous DENV cases in Europe are concerning, reflecting rising incidence linked to climate change and the spread of Aedes albopictus mosquitoes. These vectors thrive under environmental conditions like temperature and humidity, which are increasingly influenced by climate change. Additionally, global travel accelerates the cross-border spread of mosquito-borne diseases. DENV manifests clinically in a spectrum from asymptomatic cases to severe conditions like dengue hemorrhagic fever and dengue shock syndrome, influenced by viral serotype and host factors. In 2024, Brazil experienced a fourfold increase in dengue cases compared to 2023, accompanied by higher mortality. Conventional control measures, such as vector control, community engagement, and vaccination, proved insufficient as climate change exacerbated mosquito proliferation, challenging containment efforts. In this regard, our review analyzes prevention measures and therapeutic protocols during the outbreak while addressing DENV transmission dynamics, clinical presentations, and epidemiological shifts. It also evaluates diagnostic strategies combining clinical assessment with serological and molecular testing, providing information to improve diagnostic and preventive measures. The global expansion of dengue-endemic regions, including outbreaks in Europe, highlights the urgent need for enhanced surveillance, proactive interventions, and international collaboration to mitigate the growing threat of Dengue and other arboviruses like West Nile, Zika, Chikungunya, Oropouche, and Yellow Fever viruses. Full article