Dengue Epidemics Research Articles

Effects of Daily Weather on Aedes Genus (Culicidae: Diptera) Arthropod Mosquito Vectors Profusion and Dengue Epidemics Transmission: A Systematic Review

Dengue is a vector borne flavivirus usually caused by DENV1 virus, and a quantity of cases reported with DENV2, DENV3, and DENV4 viruses transmitted by Aedes aegypti and Aedes albopictus (Diptera) day biting female vector mosquitoes, belongs to Culicidae family. The symptoms of dengue were first clinically confirmed in Japan during 1943, and later, it was recorded simultaneously in the Asia, Africa, and North America during the 1980. Dengue epidemics situation was reported in the 142 countries across the world Dengue and severe dengue, (Global Strategy for dengue prevention and control, (2012–2020), 2020) and the epidemics had been changed to endemic situation in many of the countries for the past 2 decades, and the people who have been living in the epidemic countries estimated at risk about 450 million. The occurrence of dengue outbreaks and it’s extend have been reported in the tropical and sub-tropical countries across the globe largely in metropolitan, small towns, and semi-urban settlements. The climate variables viz. temperature, relative humidity, saturation deficiency, and rainfall, are fuelled for conducing environment for the vector longevity, survival and also for dengue virus incubations in mosquitoes. Temperature ranges between > 21 and < 34, and relative humidity >70% and <90% has influence on the impact of variations on the vector survival, fecundity, fertility and longevity of female Aedes aegypti and flying capacity is reduced with temperature < 10 0C, and laying egg is reduced with increase of mean temperature >35 0C. Dengue epidemics clusters are directly correlated with abundance of Aedes species mosquitoes which are controlled by the annual average precipitation 300 mm to 1200 mm. The longitudinal dengue epidemics transmissions are mainly associated with monsoon and tend to have seasonal patterns, particularly, during and after the monsoon. Climatic factors are playing important role in the increase or decrease of vector mosquitoes as well as dengue epidemics. Therefore, the present study is addressed on the echelon of daily weather and seasonal change in climate condition and its control on the incidence of dengue outbreaks.

Urgent Need for Real Time Web Mapping GIS Applications to Dengue Surveillance for Epidemic Control and Management in India

Dengue epidemics has been increased both horizontal and vertical structure across the country since 2006, and hence, urgent need for GIS based dengue surveillance for epidemic control and management in the nation. The dengue epidemic cases and the mortality caused by dengue has become essentially public health important in India, and the situation has become worse since 2006. Dengue cases were clinically confirmed with thousands of cases and hundreds of deaths annually. The report of dengue epidemics is becoming daily news nowadays and it was reported from 24 states and Union Territories in India. The spatial and seasonal occurrence of dengue epidemics were reported across the country during the period of April to November annually, however, the vulnerability of epidemics was reported between the periods of mid-July to mid-November of every year. The geo-environmental and climate variables are fuelling to create a conducive environment for profusion of dengue vector mosquitoes Aedes species (Ae. aegypti or Ae. Albopictus). The information relevant to the geographical site specification of dengue vectors breeding habitats, vector abundance, vector density, etc., could be collected using global positioning systems (GPS), and these information are mapped and overlay on the thematic layers of climate variables (Temperature, relative humidity, saturation deficiency and Rainfall) under the geographical information systems (GIS) software platform for spatial analysis (cluster analysis, nearest neighborhood analysis, fussy analysis, probability of maximum and minimum likelihood analysis etc.,) for spatial risk prediction. The Google based internet GIS mapping could be used to embedded web mapping real time situation and updating the information with online data base connectivity (ODBC) within the GIS spatial engine for providing the real time information relevant to the dengue epidemics, and hence, the appropriate precaution measures could be taken to control dengue epidemics in the nation early in advance.

Dengue fever: a decade of burden in Iran.

Since the first reported traveler case of Dengue in Tehran in 2008, the virus has gradually spread across Iran, driven by factors including international travel, climate change, and Aedes mosquito vectors. The disease has manifested in various forms, ranging from mild fever to severe dengue, with notable cases identified in Sistan and Baluchistan Province. Despite the increasing prevalence, Iran faces significant challenges in surveillance, diagnosis, and vector control. This perspective comprehensively analyzes dengue virus epidemiology in Iran, emphasizing the need for enhanced public health strategies, including genomic surveillance, targeted interventions, and health education. The findings highlight the critical importance of addressing these challenges to mitigate the potential for large-scale dengue epidemics and protect public health.

Analysis of the interrelationship between precipitation and confirmed dengue cases in the city of Recife (Brazil) covering climate and public health information.

Large-scale epidemics of arboviruses, such as dengue, have heightened societal awareness regarding the necessity of combating the primary transmission vectors. Equally critical is the identification of environmental conditions and variables that influence vector population dynamics. Aedes aegypti, the primary vector of arboviruses such as dengue and Zika in Brazil, is closely associated with the climatic and geographical conditions of urban environments. This study examines the relationship between precipitation and confirmed dengue cases in Recife (Brazil), employing regression and quantile analyses to evaluate the influence of meteorological conditions on the disease's spread. The findings reveal a direct correlation between monthly averages of precipitation and confirmed cases, although this is apparent only when excluding years of epidemic peaks. The highest number of cases generally aligns with the rainy season, and the lowest with the dry season, with weak, moderate and strong precipitation events being closely linked to increased dengue incidence. However, notable discrepancies were identified: four out of six major outbreaks occurred in drier months, challenging the assumption of a straightforward relationship between rainfall and dengue incidence. These findings underscore the multifaceted nature of dengue dynamics, suggesting that while precipitation plays a significant role, other factors, including serotype circulation and broader climatic phenomena, are equally critical in driving outbreaks. This complexity highlights the need for a more comprehensive understanding of the mechanisms influencing dengue epidemics.

Aedes aegypti feeding behavior during dengue outbreaks in two rural areas of Peru during the Yaku cyclone and El Niño phenomenon of 2023.

Motivation for the study. Dengue epidemics caused by A. aegypti occur during climatic events in tropical countries such as Peru; however, the feeding behavior of the mosquito usually goes unnoticed. Main findings. A. aegypti populations in Marcavelica and Querecotillo showed anthropophilic feeding behavior during cyclone Yaku and in the 2023 El Niño. However, populations with different feeding patterns are not ruled out. Implications. The PCR-RFLP technique of the blood cell cytochrome B gene could be implemented in vector control policies through an entomo-virological surveillance plan. To determine the feeding behavior of Aedes aegypti in dengue outbreaks in two rural areas of Peru during the Yaku cyclone and El Niño phenomenon of 2023. Eight blood samples (8 pools) were obtained from the abdomen of 80 Aedes aegypti specimens captured in the rural districts of Querecotillo and Marcavelica during the Yaku cyclone and El Niño dengue outbreaks. DNA was extracted from the analyzed samples, then a PCR was directed at the CytB gene as a genetic marker and the PCR products were enzymatically digested with the restrictases Hae III and Mwo I. The PCR-RFLP products were visualized by agarose gel electrophoresis at 4%. DNA was obtained from all samples and a 358 bp amplicon was obtained as a PCR product. Likewise, the only RFLP found in Hae III was from Homo sapiens sapiens (233 and 125 bp). RFLP was not found in Hae III of Gallus gallus and RFLP in Mwo I of Canis familiaris and Mus musculus. Aedes aegypti showed conserved anthropophilic feeding behavior in dengue outbreaks in rural areas during the Yaku cyclone and El Niño.

Epidemiological characteristics and transmission dynamics of dengue fever in China

China has experienced successive waves of dengue epidemics over the past decade. Nationwide data on 95,339 dengue cases, 89 surveillance sites for mosquito density and population mobility between 337 cities during 2013-20 were extracted. Weekly dengue time series including time trends and harmonic terms were fitted using seasonal regression models, and the amplitude and peak timing of the annual and semiannual cycles were estimated. A data-driven model-inference approach was used to simulate the epidemic at city-scale and estimate time-evolving epidemiological parameters. We found that the geographical distribution of dengue cases was expanding, and the main imported areas as well as external sources of imported cases changed. Dengue cases were predominantly concentrated in southern China and it exhibited an annual peak of activity, typically peaking in September. The annual amplitude of dengue epidemic varied with latitude (F = 19.62, P = 0.0001), mainly characterizing by large in southern cities and small in northern cities. The effective reproduction number Reff across cities is commonly greater than 1 in several specific months from July to November, further confirming the seasonal fluctuations and spatial heterogeneity of dengue epidemics. The results of this national study help to better informing interventions for future dengue epidemics in China.

Preliminary analysis of socioeconomic variable correlation with geospatial modeling in Costa Rica dengue epidemics

Dengue is a mosquito-transmitted disease that affects more than 5 million people worldwide. It is endemic in more than 100 countries and it has presence in 5 continents. Understanding the dynamics of dengue epidemics is crucial in reducing the massive public health impact this disease has. However, dengue is a complex phenomenon. There are many variables that contribute to the spread of the virus and the interconnection of those variables is not clear. We set out to explore the correlation of socioeconomic variables in dengue epidemics by using a geospatial model. Our study is centered in Costa Rica, a country with a repeated affectation by the virus. We found a possible relationship between number of dengue cases and some socioeconomic variables (dwellings with water pipes, location of work), which open the gates to consider including them in a more sophisticated epidemiological model.

Cryptic transmission and novel introduction of Dengue 1 and 2 genotypes in Colombia.

Dengue fever remains as a public health challenge in Colombia, standing as the most prevalent infectious disease in the country. The cyclic nature of dengue epidemics, occurring approximately every 3years, is intricately linked to meteorological events like El Niño Southern Oscillation (ENSO). Therefore, the Colombian system faces challenges in genomic surveillance. This study aimed to evaluate local dengue virus (DENV) transmission and genetic diversity in four Colombian departments with heterogeneous incidence patterns (department is first-level territorial units in Colombia). For this study, we processed 266 serum samples to identify DENV. Subsequently, we obtained 118 genome sequences by sequencing DENV genomes from serum samples of 134 patients infected with DENV-1 and DENV-2 serotypes. The predominant serotype was DENV-2 (108/143), with the Asian-American (AA) genotype (91/118) being the most prevalent one. Phylogenetic analysis revealed concurrent circulation of two lineages of both DENV-2 AA and DENV-1 V, suggesting ongoing genetic exchange with sequences from Venezuela and Cuba. The continuous migration of Venezuelan citizens into Colombia can contribute to this exchange, emphasizing the need for strengthened prevention measures in border areas. Notably, the time to most recent common ancestor analysis identified cryptic transmission of DENV-2 AA since approximately 2015, leading to the recent epidemic. This challenges the notion that major outbreaks are solely triggered by recent virus introductions, emphasizing the importance of active genomic surveillance. The study also highlighted the contrasting selection pressures on DENV-1 V and DENV-2 AA, with the latter experiencing positive selection, possibly influencing its transmissibility. The presence of a cosmopolitan genotype in Colombia, previously reported in Brazil and Peru, raises concerns about transmission routes, emphasizing the necessity for thorough DENV evolution studies. Despite limitations, the study underscores genomic epidemiology's crucial role in early detection and comprehension of DENV genotypes, recommending the use of advanced sequencing techniques as an early warning system to help prevent and control dengue outbreaks in Colombia and worldwide.

An effective pan-serotype dengue vaccine and enhanced control strategies could help in reducing the severe dengue burden in Bangladesh-A perspective.

Dengue is an important vector-borne disease occurring globally. Dengue virus (DENV) infection can result in a potentially life-threatening disease. To date, no DENV-specific antiviral treatment is available. Moreover, an equally effective pan-serotype dengue virus vaccine is not available. Recently, two DENV vaccines, Dengvaxia and Qdenga, were licensed for limited use. However, none of them have been approved in Bangladesh. DENV is transmitted by Aedes mosquitoes, and global warming caused by climate change favoring Aedes breeding plays an important role in increasing DENV infections in Bangladesh. Dengue is a serious public health concern in Bangladesh. In the year 2023, Bangladesh witnessed its largest dengue outbreak, with the highest number of dengue cases (n = 321,179) and dengue-related deaths (n = 1,705) in a single epidemic year. There is an increased risk of severe dengue in individuals with preexisting DENV-specific immunoglobulin G if the individuals become infected with different DENV serotypes. To date, vector control has remained the mainstay for controlling dengue; therefore, an immediate, strengthened, and effective vector control program is critical and should be regularly performed for controlling dengue outbreaks in Bangladesh. In addition, the use of DENV vaccine in curbing dengue epidemics in Bangladesh requires more consideration and judgment by the respective authority of Bangladesh. This review provides perspectives on the control and prevention of dengue outbreaks. We also discuss the challenges of DENV vaccine use to reduce dengue epidemics infection in Bangladesh.

Effects of Recent Prior Dengue Infection on Risk and Severity of Subsequent SARS-CoV-2 Infection: A Retrospective Cohort Study.

Elucidating whether prior dengue potentially confers cross-protection against COVID-19 is of public health importance in tropical countries at risk of overlapping dengue and COVID-19 epidemics. However, studies to date have yielded conflicting results. We aimed to assess effects of recent prior dengue infection on risk and severity of subsequent SARS-CoV-2 infection among adult Singaporeans. A retrospective cohort study including all adult Singaporeans aged ≥18 years was conducted from 1 July 2021 through 31 October 2022, when a dengue outbreak driven by the DENV3 serotype preceded subsequent waves of SARS-CoV-2 Delta/Omicron transmission in Singapore. SARS-CoV-2 and dengue infection status were classified using national registries. Cox regression models adjusted for demographics, COVID-19 vaccination status, comorbidity, and socioeconomic-status were used to assess risks and severity (hospitalization, severe illness) of SARS-CoV-2 infection occurring after previous recorded dengue infection. A total of 3 366 399 individuals were included, contributing 1 399 696 530 person-days of observation. A total of 13 434 dengue infections and 1 253 520 subsequent SARS-CoV-2 infections were recorded; with an average of 94.7 days (standard deviation = 83.8) between dengue infection and SARS-CoV-2 infection. Preceding dengue infection was associated with a modest increase in risk of subsequent SARS-CoV-2 infection (adjusted hazards ratio [aHR] = 1.13; 95% confidence interval [CI], 1.08-1.17), and significantly elevated risk of subsequent COVID-19 hospitalization (aHR = 3.25; 95% CI, 2.78-3.82) and severe COVID-19 (aHR = 3.39; 95% CI, 2.29-5.03). Increased risk of SARS-CoV-2 infection and adverse COVID-19 outcomes were observed following preceding dengue infection in a national population-based cohort of adult Singaporeans. This observation is of significance in tropical countries with overlapping dengue and COVID-19 outbreaks.

Severe Organ Impairment Was Common in Elderly Individuals with Dengue in Guangdong, China.

Guangdong, China, has experienced several dengue epidemics involving thousands of confirmed cases in recent decades, and elderly individuals suffered severe dengue (SD) most seriously. However, the clinical characteristics and risk factors for SD among elderly patients in Guangdong have not been investigated. Patients older than 65 years were recruited and divided into a dengue fever (DF) group and an SD group according to the 2009 Dengue Guidelines of the WHO. We analyzed the clinical manifestations of the elderly patients with dengue and then assessed the risk factors for SD. Of a total of 1,027 patients, 868 patients were diagnosed as having DF and 159 as having SD. Of the 159 elderly patients with SD, 129 (81%) had comorbidities, with hypertension being the most common. Severe organ impairment (SOI) (115, 54%) was the most common presentation in SD patients, followed by severe plasma leakage (52, 24.4%) and severe hemorrhage (46, 21.6%). The most common symptom of SOI was kidney injury, followed by heart injury and central nervous system injury. Furthermore, multivariate regression revealed that the presence of chronic obstructive pulmonary disease (COPD), a lower red blood cell (RBC) count (≤3.5 × 1012/L; odds ratio [OR], 0.35; 95% CI, 0.17-0.55; P <0.001), lower serum albumin (ALB) (≤35 U/L; OR, 0.18; 95% CI, 0.09-0.32; P <0.001), and hyperpyrexia (body temperature ≥39°C; OR, 1.8; 95% CI, 1.2-2.6, P <0.001) were risk factors for SD. Severe organ impairment was the predominant manifestation in elderly individuals with SD characterized by kidney injury. The potential risk factors of SD such as presence of COPD and hyperpyrexia and lower RBC and ALB levels might help clinicians identify patients with SD early.

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

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

‘Seven Plus One’ a unique approach to assess the knowledge, attitude and practices for dengue prevention and control among frontline workers of a teaching institution in Rishikesh, Uttarakhand

ABSTRACT Background: Dengue which is an arboviral disease transmitted by Aedes aegypti mosquito, drastically affected communities worldwide. It has been showing consistently a rising trend in developing country like India. Study Objectives: To assess the knowledge, attitude and practices (KAPs) related to the prevention and control of dengue fever (DF) among frontline staff members at a medical teaching institution in Rishikesh, Uttarakhand. Materials and Methods: A community-based cross-sectional study was conducted at a medical teaching institution in Rishikesh, Uttarakhand. Out of 830 frontline workers only 208 workers were recruited in a study by the simple random selection method. A semi-structured interview questionnaire was applied to assess the KAPs of participants. Attitude was assessed by four-point Likert scaling. Statistical analysis was done using SPSS version 23 for Windows. Results: A total of 208 participants were interviewed. Majority were male (70.2%) with the age group of 31 to 45 years (71.2%). Majority (50.5%) of participants were educated up to higher secondary and working as a security guard (78.8%). Most (72.6%) of the respondents said the rainy season was the most common outbreak season for dengue. Most (63.6%) of the participants were aware that dengue is transmitted by mosquitoes. The majority (49%) of participants strongly agreed that dengue is a fatal disease. Conclusion: There is an urgent need to prevent and control the epidemics of dengue by adoption of seven plus one model which contributes in reducing the overall burden in healthcare delivery system.

Towards a machine-learning assisted non-invasive classification of dengue severity using wearable PPG data: a prospective clinical study

Dengue epidemics impose considerable strain on healthcare resources. Real-time continuous and non-invasive monitoring of patients admitted to the hospital could lead to improved care and outcomes. We evaluated the performance of a commercially available wearable (SmartCare) utilising photoplethysmography (PPG) to stratify clinical risk for a cohort of hospitalised patients with dengue in Vietnam. We performed a prospective observational study for adult and paediatric patients with a clinical diagnosis of dengue at the Hospital for Tropical Disease, Ho Chi Minh City, Vietnam. Patients underwent PPG monitoring early during admission alongside standard clinical care. PPG waveforms were analysed using machine learning models. Adult patients were classified between 3 severity classes: i) uncomplicated (ward-based), ii) moderate-severe (emergency department-based), and iii) severe (ICU-based). Data from paediatric patients were split into 2 classes: i) severe (during ICU stay) and ii) follow-up (14-21 days after the illness onset). Model performances were evaluated using standard classification metrics and 5-fold stratified cross-validation. We included PPG and clinical data from 132 adults and 15 paediatric patients with a median age of 28 (IQR, 21-35) and 12 (IQR, 9-13) years respectively. 1781h of PPG data were available for analysis. The best performing convolutional neural network models (CNN) achieved a precision of 0.785 and recall of 0.771 in classifying adult patients according to severity class and a precision of 0.891 and recall of 0.891 in classifying between disease and post-disease state in paediatric patients. We demonstrate that the use of a low-cost wearable provided clinically actionable data to differentiate between patients with dengue of varying severity. Continuous monitoring and connectivity to early warning systems could significantly benefit clinical care in dengue, particularly within an endemic setting. Work is currently underway to implement these models for dynamic risk predictions and assist in individualised patient care. EPSRC Centre for Doctoral Training in High-Performance Embedded and Distributed Systems (HiPEDS) (Grant: EP/L016796/1) and the Wellcome Trust (Grants: 215010/Z/18/Z and 215688/Z/19/Z).

Indian Ocean temperature anomalies predict long-term global dengue trends.

Despite identifying El Niño events as a factor in dengue dynamics, predicting the oscillation of global dengue epidemics remains challenging. Here, we investigate climate indicators and worldwide dengue incidence from 1990 to 2019 using climate-driven mechanistic models. We identify a distinct indicator, the Indian Ocean basin-wide (IOBW) index, as representing the regional average of sea surface temperature anomalies in the tropical Indian Ocean. IOBW is closely associated with dengue epidemics for both the Northern and Southern hemispheres. The ability of IOBW to predict dengue incidence likely arises as a result of its effect on local temperature anomalies through teleconnections. These findings indicate that the IOBW index can potentially enhance the lead time for dengue forecasts, leading to better-planned and more impactful outbreak responses.

SERO-PREVALENCE OF DENGUE INFECTION FROM GOVERNMENT HOSPITAL, RAJASTHAN DURING 2022

Background: Viral haemorrhagic fevers are becoming increasingly common in the tropics and subtropics. Dengue fever is currently the most important arthropod‑borne viral disease because of its widespread distribution in more than 100 countries and its potential for extensive outbreaks of life‑threatening disease. Material and Methods: This study was a hospital‑based cross‑sectional study conducted in LaboratoryShrr. R.K.J. Hopsital, Dausa, in Rajasthan, India, between January 2022 to December 2022. The present study included all serum specimens received at laboratory of R.K.J. Hopsital, Dausa, from clinically suspected cases of dengue infection, during this duration. Serum samples were received for serological testing from suspected cases of dengue as advised by consultants from various departments in hospital for laboratory confirmation of suspected cases. Laboratory-confirmed dengue cases were defined as suspected dengue cases with positive dengue serology. Result: The present study analyzed the samples of 1880 of suspected patients during year of 2022. and seropositivity rate of 15% (296/1880) was found out of which 10% (67/648) were seropositive for NS1 antigen and 18% (229/1232) were by IgM ELISA test. The present study revealed trend of cases from August to December 2022 peak of cases was reported in month of September and November. Discussion: The resurgence of dengue has been notable in India and dengue epidemics have been frequently reported in the country both from urban and rural regions. Recent analysis of the past two decades highlighted that, in India, transmission pattern of dengue has changed and widened with shift in peak post-monsoon shifting toward November from October in the recent decade from irregular peak of the previous decade. However, the present pattern in shift of transmission is clear that dengue cannot be considered as a seasonal disease. Conclusions: An alarming rate of increasing emerging and reemerging trends of these arboviral infections are noted in this part of Rajasthan. Hence, the need to focus on proper surveillance, and implementation of prevention and control measure in the country are of utmost priority. Presently, there are no licensed vaccines or antivirals available however, India has initiated several efforts in this direction including traditional medicines. The outcome of this study will help in focusing and improvement of existing surveillance systems and vector control tools, as well as on the development of suitable antiviral agents and formulating candidate vaccine.

Nonlinear impacts of climate change on dengue transmission in mainland China: Underlying mechanisms and future projection

Dengue fever is a climate-sensitive health concern caused by mosquito-borne virus. Both temperature- and precipitation-related factors are important for dengue transmission. Previous studies mainly focused on the effects of individual factors on the spread of dengue. However, given the potential synergistic effects of temperature and precipitation on virus transmission, it is vital to provide a holistic view of their interplay in shaping the transmission patterns. In this study, utilizing a vectorial capacity (VC)-based mathematical model, we investigated the mechanisms by which the daily mean temperature (DMT), diurnal temperature range (DTR) and daily mean precipitation (DMP) jointly influence the dengue spread. We further forecast future dengue patterns in mainland China under different climate scenarios (Shared Socioeconomic Pathways (SSP)) by 2050 and 2080. Results show that these three climate factors trigger complex nonlinear effects on dengue transmission. Interactions between DMT and DTR plays a decisive role in determining the spreading fronts of dengue epidemics, while DMP considerably impacts its transmission intensity. Although future climate changes would facilitate northward expansion of areas at risk of dengue under SSP245 and SSP585, significant contraction would happen under SSP126. These findings illuminate the interacting mechanisms of temperature and precipitation on dengue transmission, call for the comprehensive considerations of DMT, DMP and DTR in formulating effective dengue control policies, and warrant achieving a sustainable future in line with the SSP126 scenario to effectively mitigate dengue transmission risks and ensure a resilient future.

Novel chikungunya and dengue vaccines: travel medicine applications.

Recent epidemics of dengue and chikungunya have highlighted the urgent need for vaccines to reduce the risk of infection in travellers. Given challenges tracking chikungunya outbreaks in real-time and the widespread resurgence of dengue, broader indications for the use of the new chikungunya and dengue vaccines should be considered.

Retrospective Study of Various Factors In Pediatric To Severe Dengue Infection

Introduction: Dengue epidemics are known to have occurred over the last three centuries in tropical, subtropical and temperate areas of the world. Annually a 100 million cases of Dengue fever and half a million cases of dengue hemorrhagic fever (DHF) occur in the world with a case fatality in Asian countries of 0.5%–3.5%. Objective: To assess the various factors in pediatric to severe dengue infection. Methods: A hospital-based Retrospective study was conducted at Department Of Paediatric, Mugda Medical College Hospital, Dhaka, Bangladesh from October to December 2023. Number of patients included in the study was 50. In children with high degree clinical suspicion of Dengue infection NS 1 antigen (who came within first 48 hours of fever) and/or Dengue antibody IgM, IgG (who came after five days of fever) were performed. Positive Dengue cases were taken written informed consent &amp; interviewed on the risk factors of Dengue infection. Data related to patients demography, risk factors, clinical presentation, pattern of Dengue infection and outcome were documented on the pre-structured questionnaire. Results: The study was enrolled 100 patients of suspected dengue fever of whom 50 (50.0%) were serologically confirmed to have dengue infection. 30 (60%) patients were males and 20 (40%) were females. 38 (76%) patients had classic dengue fever while 12 (24%) fulfilled the criteria of dengue hemorrhagic fever. Of those patients with dengue hemorrhagic fever, 6 patients had developed dengue shock syndrome. Among the study 44 (88%) from urban and 6 (12%) rural area patients. All cases and is the most common symptom followed by headache, myalgia, vomiting etc. Hemorrhagic manifestations were seen that included petechiae, ecchymosis, gum bleeding, hematuria, malena, hematemesis and epistaxis. Most common complicationswere hepatic dysfunction, renal failure, multi organ failure, encephalopathy and ARDS. Among 50 suspected dengue cases 38 (76.0%) cases were serologically dengue positive. Among the 38 serologically dengue positive patients 17 (44.7%) were NS1 antigen positive, 13 (34.2%) IgM antibodies and 8(21.0%) both IgM and IgG antibodies positive. The distribution of the serologically dengue positive patients out of 50 clinically suspected cases. Conclusion: Dengue is one amongst the key causes of dedifferentiated fever. It presents as an extremely broad wellness and is hardly recognized as a clinical entity by primary health care physicians. This study highlights the practician the importance of break bone fever to clinicians within the areas of medical specialty, manifestations, complications and outcome of the wellness

Economic optimization of Wolbachia-infected Aedes aegypti release to prevent dengue.

Dengue virus, primarily transmitted by the Aedes aegypti mosquito, is a major public health concern affecting ≈3.83 billion people worldwide. Recent releases of Wolbachia-transinfected Ae. aegypti in several cities worldwide have shown that it can reduce dengue transmission. However, these releases are costly, and, to date, no framework has been proposed for determining economically optimal release strategies that account for both costs associated with disease risk and releases. We present a flexible stochastic dynamic programming framework for determining optimal release schedules for Wolbachia-transinfected mosquitoes that balances the cost of dengue infection with the costs of rearing and releasing transinfected mosquitoes. Using an ordinary differential equation model of Wolbachia and dengue in a hypothetical city loosely describing areas at risk of new dengue epidemics, we determined that an all-or-nothing release strategy that quickly brings Wolbachia to fixation is often the optimal solution. Based on this, we examined the optimal facility size, finding that it was inelastic with respect to the mosquito population size, with a 100% increase in population size resulting in a 50-67% increase in optimal facility size. Furthermore, we found that these results are robust to mosquito life-history parameters and are mostly determined by the mosquito population size and the fitness costs associated with Wolbachia. These results reinforce that Wolbachia-transinfected mosquitoes can reduce the cost of dengue epidemics. Furthermore, they emphasize the importance of determining the size of the target population and fitness costs associated with Wolbachia before releases occur. © 2024 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.