Dengue Epidemiology Research Articles

Entomo-Virological Aedes aegypti Surveillance Applied for Prediction of Dengue Transmission: A Spatio-Temporal Modeling Study

Currently, DENV transmitted primarily by Aedes aegypti affects approximately one in three people annually. The spatio-temporal heterogeneity of vector infestation and the intensity of arbovirus transmission require surveillance capable of predicting an outbreak. In this work, we used data from 4 years of reported dengue cases and entomological indicators of adult Aedes collected from approximately 3500 traps installed in the city of Foz do Iguaçu, Brazil, to evaluate the spatial and temporal association between vector infestation and the occurrence of dengue cases. Entomological (TPI, ADI and MII) and entomo-virological (EVI) indexes were generated with the goal to provide local health managers with a transmission risk stratification that allows targeting areas for vector control activities. We observed a dynamic pattern in the evaluation; however, it was a low spatio-temporal correlation of Ae. aegypti and incidence of dengue. Independent temporal and spatial effects capture a significant portion of the signal given by human arbovirus cases. The entomo-virological index (EVI) significantly signaled risk in a few areas, whereas entomological indexes were not effective in providing dengue risk alert. Investigating the variation of biotic and abiotic factors between areas with and without correlation should provide more information about the local epidemiology of dengue.

Behavioral and game-theoretic modeling of dengue epidemic: Comment on "Mathematical models for dengue fever epidemiology: A 10-year systematic review" by M. Aguiar et al.

Behavioral and game-theoretic modeling of dengue epidemic: Comment on "Mathematical models for dengue fever epidemiology: A 10-year systematic review" by M. Aguiar et al.

Dengue surge in Pakistan amidst the torrential rains: The threat of a potential outbreak.

With 390 million infections occurring globally and the infection putting half of the world's population at risk, dengue is an illness with potential, life-threatening manifestations such as plasma leakage and fluid retention, severe bleeding, and organ impairment. This disease is already lurking in the various regions of Pakistan, which was recently ravaged by decades' worst flood. With mosquitoes being its eminent transmission source, it is coherent that a country with massive flooding, accumulation of stagnant water, and lack of adequate drainage systems can lead to a dengue outbreak. Pakistan, a low-middle-income country, is still recuperating from the aftershocks of the pandemic, a recent cholera outbreak, and the massive economic destruction they caused, especially in the healthcare sector. Concerningly, the World Health Organizationhas already issued a "second catastrophe" warning for Pakistan in the aftermath of the fatal floods which have caused the destruction of hundreds of health facilities while physicians and medical workers on the ground scramble to combat outbreaks of waterborne and other illnesses. If the spread of dengue isn't contained immediately, it will destroy the healthcare systems across the country and result in massive fatalities. To avoid tragic consequences, the government and concerned authorities must devise plans to launch public health programs aimed at boosting knowledge of the disease, its symptoms, transmission, prevention, and control. In this commentary, we discuss the current spike of dengue virus, epidemiology, transmission patterns, and preventative efforts in the aftermath of Pakistan's disastrous floods.

Epidemiological profile of dengue in Champasak and Savannakhet provinces, Lao People's Democratic Republic, 2003-2020.

Dengue is a public health issue in tropical south-eastern Asia responsible for significant morbidity and mortality. Information on dengue epidemiology is necessary for developing strategies to control infections effectively. In the Lao People’s Democratic Republic (Lao PDR), Champasak and Savannakhet provinces account for around 30% of the national dengue burden. In this study, the dengue epidemiological profile in these two southern provinces of Lao PDR was described by analysing seasonal and spatial dengue notification data from 2003–2020 using the long-term mean (LTM) method. Savannakhet had a higher LTM (132.0 cases/month, 95% confidence interval [Cl]: 92.2–171.7) than Champasak (113.3 cases/month, 95% CI: 86.0–140.5), with peaks in dengue notifications following the rainy season in both provinces. The highest notification rates were observed in July to September; these months were also when the LTM was most frequently exceeded. Previously, dengue notifications were largely confined to the western districts of Savannakhet and the northern districts of Champasak, but more recently, notifications have increased in the eastern districts of Savannakhet and southern districts of Champasak. While the notification rate remained high in children and young adults (5–30 years), especially among students and farmers, a shift in the age structure of dengue cases was observed, with a greater proportion of notifications now occurring in those aged over 30 years. Community-based vector control and prevention programmes are needed to restrict the spread of dengue into new geographical areas in the southern provinces of Lao PDR.

Epidemiology of Dengue in patients with febrile syndrome at Saint Camille Hospital, Ouagadougou, Burkina Faso from 2020 to 2021

Epidemiology of Dengue in patients with febrile syndrome at Saint Camille Hospital, Ouagadougou, Burkina Faso from 2020 to 2021

An assessment of remotely sensed environmental variables on Dengue epidemiology in Central India.

In recent decades, dengue has been expanding rapidly in the tropical cities. Even though environmental factors and landscape features profoundly impact dengue vector abundance and disease epidemiology, significant gaps exist in understanding the role of local environmental heterogeneity on dengue epidemiology in India. In this study, we assessed the role of remotely sensed climatic factors (rainfall, temperature and humidity) and landscape variables (land use pattern, vegetation and built up density) on dengue incidence (2012–2019) in Bhopal city, Central India. Dengue hotspots in the city were assessed through geographical information system based spatial statistics. Dengue incidence increased from 0.59 cases in 2012 to 9.11 cases in 2019 per 10,000 inhabitants, and wards located in Southern Bhopal were found to be dengue hotspots. Distributed lag non-linear model combined with quasi Poisson regression was used to assess the exposure-response association, relative risk (RR), and delayed effects of environmental factors on dengue incidence. The analysis revealed a non-linear relationship between meteorological variables and dengue cases. The model shows that the risk of dengue cases increases with increasing mean temperature, rainfall and absolute humidity. The highest RR of dengue cases (~2.0) was observed for absolute humidity ≥60 g/m3 with a 5–15 week lag. Rapid urbanization assessed by an increase in the built-up area (a 9.1% increase in 2020 compared to 2014) could also be a key factor driving dengue incidence in Bhopal city. The study sheds important insight into the synergistic effects of both the landscape and climatic factors on the transmission dynamics of dengue. Furthermore, the study provides key baseline information on the climatic variables that can be used in the micro-level dengue prediction models in Bhopal and other cities with similar climatic conditions.

Modeling secondary infections with temporary immunity and disease enhancement factor: Mechanisms for complex dynamics in simple epidemiological models

Modeling insights for epidemiological scenarios characterized by chaotic dynamics have been largely unexplored. A rigorous analysis of such systems are essential for a real predictive power and a more accurate disease control decision making. Motivated by dengue fever epidemiology, we study a basic SIR–SIR type model for the host population, capturing differences between primary and secondary infections. This model is the minimalistic version to previously suggested multi-strain models for dengue fever in which deterministic chaos was found in wider parameter regions. Without strain structure of pathogens, we consider temporary immunity after a primary infection and disease enhancement in a subsequent infection to identify to which extent these biological mechanisms can generate complex behavior in simple epidemiological models.Stability analysis of the system is performed using the classical linearization theory, and the qualitative behavior of the model is investigated with a detailed bifurcation analysis. Rich dynamical structures are identified, including the Bogdanov–Takens, cusp and Bautin bifurcations which has never been described in dengue fever epidemiology. Besides the conventional transcritical bifurcation, a backward bifurcation occurs for higher disease enhancement in secondary infections, exhibiting bi-stability when biological temporary immunity period is assumed. The backward bifurcation is formalized using the center manifold theory. While the Hopf and the global homoclinic bifurcation curves were computed numerically, analytical expressions for the transcritical and tangent bifurcations are obtained. The combination of temporary immunity and disease enhancement play a significant role in the complexity of the system dynamics, with chaotic behavior observed after including seasonal forcing.

Dengue virus population genetics in Yogyakarta, Indonesia prior to city-wide Wolbachia deployment.

Dengue has been endemic in Yogyakarta, Indonesia for decades. Here, we report the dengue epidemiology, entomology, and virology in Yogyakarta in 2016-2017, prior to the commencement of the Applying Wolbachia to Eliminate Dengue (AWED) randomized trial. Dengue epidemiological data were compiled and blood samples from dengue-suspected patients were tested for dengue virus (DENV). Ae. aegypti mosquito samples were caught from the field using BG-Sentinel traps and tested for the presence of DENV infection. Sequencing of the DENV E gene was used to determine the phylogeny and genotypes of circulating DENV. Within the last decade, the 2016-2017 dengue incidence was considered very high. Among the 649 plasma samples collected between March 2016-February 2017; and 36,910 mosquito samples collected between December 2016-May 2017, a total of 197 and 38 samples were DENV-positive by qRT-PCR, respectively. All four DENV serotypes were detected, with DENV-3 (n=88; 44.67%) and DENV-1 (n=87; 44.16%) as the predominant serotype, followed by DENV-4 (n=12; 6.09%) and DENV-2 (n=10; 5.08%). The Yogyakarta DENV-1 isolates were classified into Genotype I and IV, while DENV-2, DENV-3, and DENV-4 isolates were classified into the Cosmopolitan genotype, Genotype I, and Genotype II, respectively. Yogyakarta DENV isolates were closely related to Indonesian strains from neighboring Javanese cities, consistent with the endemic circulation of DENV on this highly populous island. Our study provides comprehensive baseline information on the DENV population genetic characteristics in Yogyakarta, which are useful as baseline data for the AWED trial and the future DENV surveillance in the city in the presence of a Wolbachia-infected Ae. aegypti population.

Dengue: A Growing Problem With New Interventions.

Dengue is the disease caused by 1 of 4 distinct, but closely related dengue viruses (DENV-1-4) that are transmitted by Aedes spp. mosquito vectors. It is the most common arboviral disease worldwide, with the greatest burden in tropical and sub-tropical regions. In the absence of effective prevention and control measures, dengue is projected to increase in both disease burden and geographic range. Given its increasing importance as an etiology of fever in the returning traveler or the possibility of local transmission in regions in the United States with competent vectors, as well as the risk for large outbreaks in endemic US territories and associated states, clinicians should understand its clinical presentation and be familiar with appropriate testing, triage, and management of patients with dengue. Control and prevention efforts reached a milestone in June 2021 when the Advisory Committee on Immunization Practices (ACIP) recommended Dengvaxia for routine use in children aged 9 to 16 years living in endemic areas with laboratory confirmation of previous dengue virus infection. Dengvaxia is the first vaccine against dengue to be recommended for use in the United States and one of the first to require laboratory testing of potential recipients to be eligible for vaccination. In this review, we outline dengue pathogenesis, epidemiology, and key clinical features for front-line clinicians evaluating patients presenting with dengue. We also provide a summary of Dengvaxia efficacy, safety, and considerations for use as well as an overview of other potential new tools to control and prevent the growing threat of dengue .

Assessing the role of multiple mechanisms increasing the age of dengue cases in Thailand

The mean age of dengue hemorrhagic fever (DHF) cases increased considerably in Thailand from 8.1 to 24.3 y between 1981 and 2017 (mean annual increase of 0.45 y). Alternative proposed explanations for this trend, such as changes in surveillance practices, reduced mosquito–human contact, and shifts in population demographics, have different implications for global dengue epidemiology. To evaluate the contribution of each of these hypothesized mechanisms to the observed data, we developed 20 nested epidemiological models of dengue virus infection, allowing for variation over time in population demographics, infection hazards, and reporting rates. We also quantified the effect of removing or retaining each source of variation in simulations of the age trajectory. Shifts in the age structure of susceptibility explained 58% of the observed change in age. Adding heterogeneous reporting by age and reductions in per-serotype infection hazard to models with shifts in susceptibility explained an additional 42%. Reductions in infection hazards were mostly driven by changes in the number of infectious individuals at any time (another consequence of shifting age demographics) rather than changes in the transmissibility of individual infections. We conclude that the demographic transition drives the overwhelming majority of the observed change as it changes both the age structure of susceptibility and the number of infectious individuals. With the projected Thai population age structure, our results suggest a continuing increase in age of DHF cases, shifting the burden toward individuals with more comorbidity. These insights into dengue epidemiology may be relevant to many regions of the globe currently undergoing comparable changes in population demographics.

Addressing the COVID-19 pandemic challenges for operational adaptations of a cluster randomized controlled trial on dengue vector control in Malaysia

IntroductionThe COVID-19 pandemic placed an unprecedented overload on healthcare system globally. With all medical resources being dedicated to contain the spread of the disease, the pandemic may have impacted the burden of other infectious diseases such as dengue, particularly in countries endemic for dengue fever. Indeed, the co‐occurrence of COVID‐19 made dengue diagnosis challenging because of some shared clinical manifestations between the two pathogens. Furthermore, the sudden emergence and novelty of this global public health crisis has forced the suspension or slow-down of several research trials due to the lack of sufficient knowledge on how to handle the continuity of research trials during the pandemic. We report on challenges we have faced during the COVID-19 pandemic and measures that were implemented to continue the iDEM project (intervention for Dengue Epidemiology in Malaysia).MethodsThis randomized controlled trial aims to assess the effectiveness of Integrated Vector Management (IVM) on the incidence of dengue in urban Malaysia by combining: targeted outdoor residual spraying (TORS), deployment of auto-dissemination devices (ADDs), and active community engagement (CE). Our operational activities started on February 10, 2020, a few weeks before the implementation of non-pharmaceutical interventions to contain the spread of COVID-19 in Malaysia.ResultsThe three main issues affecting the continuity of the trial were: ensuring the safety of field workers during the interventions; ensuring the planned turnover of TORS application and ADD deployment and services; and maintaining the CE activities as far as possible.ConclusionsEven though the pandemic has created monumental challenges, we ensured the safety of field workers by providing complete personal protective equipment and regular COVID-19 testing. Albeit with delay, we maintained the planned interval time between TORS application and ADDs services by overlapping the intervention cycles instead of having them in a sequential scheme. CE activities continued remotely through several channels (e.g., phone calls and text messages). Sustained efforts of the management team, significant involvement of the Malaysian Ministry of Health and a quick and smart adaptation of the trial organisation according to the pandemic situation were the main factors that allowed the successful continuation of our research.Trial registrationTrial registration number: ISRCTN-81915073. Date of registration: 17/04/2020, 'Retrospectively registered'.

Reduced dengue incidence during the\xa0COVID-19 movement restrictions in Sri Lanka from March 2020 to April 2021

BackgroundDengue is the major mosquito-borne disease in Sri Lanka. After its first detection in January 2020, COVID-19 has become the major health issue in Sri Lanka. The impact of public health measures, notably restrictions on movement of people to curb COVID-19 transmission, on the incidence of dengue during the period March 2020 to April 2021 was investigated.MethodsThe incidence of dengue and COVID-19, rainfall and the public movement restrictions implemented to contain COVID-19 transmission were obtained from Sri Lanka government sources. A Seasonal Autoregressive Integrated Moving Average (SARIMA) model was used to predict the monthly dengue incidence from March 2020 to April 2021 for each of the country’s 25 districts based on five years of pre-pandemic data, and compared with the actual recorded incidence of dengue during this period. Ovitrap collections of Aedes larvae were performed in Jaffna city in the Jaffna district from August 2020 to April 2021 and the findings compared with similar collections made in the pre-pandemic period from March 2019 to December 2019.ResultsThe recorded numbers of dengue cases for every month from March 2020 to April 2021 in the whole country and for all 25 districts over the same period were lower than the numbers of dengue cases predicted from data for the five years (2015–2019) immediately preceding the COVID-19 pandemic. The number of dengue cases recorded nationwide represented a 74% reduction from the predicted number of dengue cases for the March 2020 to April 2021 period. The numbers of Aedes larvae collected from ovitraps per month were reduced by 88.6% with a lower proportion of Ae. aegypti than Ae. albopictus in Jaffna city from August 2020 until April 2021 compared with March 2019 to December 2019.ConclusionPublic health measures that restricted movement of people, closed schools, universities and offices to contain COVID-19 transmission unexpectedly led to a significant reduction in the reported numbers of dengue cases in Sri Lanka. This contrasts with findings reported from Singapore. The differences between the two tropical islands have significant implications for the epidemiology of dengue. Reduced access to blood meals and lower vector densities, particularly of Ae. aegypti, resulting from the restrictions on movement of people, are suggested to have contributed to the lower dengue incidence in Sri Lanka.

Mathematical models for dengue fever epidemiology: A 10-year systematic review.

Mathematical models have a long history in epidemiological research, and as the COVID-19 pandemic progressed, research on mathematical modeling became imperative and very influential to understand the epidemiological dynamics of disease spreading.Mathematical models describing dengue fever epidemiological dynamics are found back from 1970. Dengue fever is a viral mosquito-borne infection caused by four antigenically related but distinct serotypes (DENV-1 to DENV-4). With 2.5 billion people at risk of acquiring the infection, it is a major international public health concern. Although most of the cases are asymptomatic or mild, the disease immunological response is complex, with severe disease linked to the antibody-dependent enhancement (ADE) - a disease augmentation phenomenon where pre-existing antibodies to previous dengue infection do not neutralize but rather enhance the new infection. Here, we present a 10-year systematic review on mathematical models for dengue fever epidemiology. Specifically, we review multi-strain frameworks describing host-to-host and vector-host transmission models and within-host models describing viral replication and the respective immune response.Following a detailed literature search in standard scientific databases, different mathematical models in terms of their scope, analytical approach and structural form, including model validation and parameter estimation using empirical data, are described and analyzed.Aiming to identify a consensus on infectious diseases modeling aspects that can contribute to public health authorities for disease control, we revise the current understanding of epidemiological and immunological factors influencing the transmission dynamics of dengue. This review provide insights on general features to be considered to model aspects of real-world public health problems, such as the current epidemiological scenario we are living in.

Epidemiology of Dengue in Argentina: Antibodies seroprevalence in blood donors and circulating serotypes.

Currently, dengue virus (DENV) infection is a world public health concern. In recent decades, three major outbreaks and a substantial growth of DENV infection prevalence have been observed in Argentina. However, there is a paucity of data on DENV epidemiology in this country. To estimate DENV antibodies seroprevalence and determine the circulating serotypes in a population-based study. Anti-DENV IgG antibodies were determined in 1,530 prospectively collected samples from blood donors throughout the country (April 2020 to April 2021). DENV serotyping was performed in 251 retrospectively analyzed samples (2016-2020). Overall, anti-DENV IgG was detected in 220 (14.4%) blood donors. Seroprevalence was significantly higher in men (17.3%) than in women (11.3%), p <0.001. A higher seroprevalence was observed in the Northeast (24.0%), compared to the Center (12.9%) and Northwest (10.8%) regions, (p <0.001). Prevalence of DENV serotypes was 79.3% (n=199) for DENV-1, 0.8% (n=2) for DENV-2, and 19.9% (n=50) for DENV-4. DENV serotypes were unevenly distributed in samples from different outbreaks and regions. This study provides new insights and updated data on the epidemiology of dengue in Argentina. The registered antibody seroprevalence is among the lowest one among Latin-American countries, raising cost-benefit objections with regards to massive vaccination policies. However, a high proportion of more than one circulating serotype should not be overlooked, as it is a warning of severe dengue possible increase in future Argentine outbreaks, which warrants close monitoring. • This study provides new insights on dengue (DENV) epidemiology in argentina. • Anti-DENV IgG was detected in 220/1530 (14.4%) blood donors in argentina. • Seroprevalence was significantly higher in men (17.3%) than in women (11.3%). • Prevalence of DENV serotypes was 79.3% for DENV-1 and 19.9% for DENV-4.

Joint Multilevel Discrete Competing Risk with Continuous Outcome via Bivariate Copula Model - Application to a Dengue Epidemiology Study, Sri Lanka

Joint Multilevel Discrete Competing Risk with Continuous Outcome via Bivariate Copula Model - Application to a Dengue Epidemiology Study, Sri Lanka

Dengue virus infection modifies mosquito blood-feeding behavior to increase transmission to the host

Mosquito blood-feeding behavior is a key determinant of the epidemiology of dengue viruses (DENV), the most-prevalent mosquito-borne viruses. However, despite its importance, how DENV infection influences mosquito blood-feeding and, consequently, transmission remains unclear. Here, we developed a high-resolution, video-based assay to observe the blood-feeding behavior of Aedes aegypti mosquitoes on mice. We then applied multivariate analysis on the high-throughput, unbiased data generated from the assay to ordinate behavioral parameters into complex behaviors. We showed that DENV infection increases mosquito attraction to the host and hinders its biting efficiency, the latter resulting in the infected mosquitoes biting more to reach similar blood repletion as uninfected mosquitoes. To examine how increased biting influences DENV transmission to the host, we established an invivo transmission model with immuno-competent mice and demonstrated that successive short probes result in multiple transmissions. Finally, to determine how DENV-induced alterations of host-seeking and biting behaviors influence dengue epidemiology, we integrated the behavioral data within a mathematical model. We calculated that the number of infected hosts per infected mosquito, as determined by the reproduction rate, tripled when mosquito behavior was influenced by DENV infection. Taken together, this multidisciplinary study details how DENV infection modulates mosquito blood-feeding behavior to increase vector capacity, proportionally aggravating DENV epidemiology. By elucidating the contribution of mosquito behavioral alterations on DENV transmission to the host, these results will inform epidemiological modeling to tailor improved interventions against dengue.

Co-Circulation of Chikungunya and Multiple DENV Serotypes and Genotypes, Western Indonesia 2015-2016.

Dengue is a mosquito-borne disease of public health concern affecting tropical and subtropical countries, including Indonesia. Although studies on dengue epidemiology have been undertaken in Indonesia, data are lacking in many areas of the country. The aim of this study was to determine dengue virus (DENV) and chikungunya virus (CHIKV) molecular epidemiology in western regions of the Indonesian archipelago. A one-year prospective study was conducted in Aceh and Jambi in 2015 and 2016, respectively, where patients with dengue-like illness were enrolled. Of 205 patients recruited, 29 and 27 were confirmed with dengue in Aceh and Jambi, respectively, and three from Jambi were confirmed with chikungunya. DENV-1 was the predominant serotype identified in Aceh while DENV-2 was predominant in Jambi. All DENV-1 and DENV-2 from both regions were classified as Genotype I and Cosmopolitan genotype, respectively, and all DENV-3 viruses from Jambi were Genotype I. Some viruses, in particular DENV-1, displayed a distinct lineage distribution, where two DENV-1 lineages from Aceh were more closely related to viruses from China instead of Jambi highlighting the role of travel and flight patterns on DENV transmission in the region. DENV-2 from both Aceh and Jambi and DENV-3 from Jambi were all closely related to Indonesian local strains. All three CHIKV belonged to Asian genotype and clustered closely with Indonesian CHIKV strains including those previously circulating in Jambi in 2015, confirming continuous and sustainable transmission of CHIKV in the region. The study results emphasize the importance of continuous epidemiological surveillance of arboviruses in Indonesia and simultaneous testing for CHIKV among dengue-suspected patients.

Climatic factors and the incidence of dengue in Cartagena, Colombian Caribbean Region.

ABSTRACTBackground: The influence of climate on the epidemiology of dengue has scarcely been studied in Cartagena. Methods: The relationship between dengue cases and climatic and macroclimatic factors was explored using an ecological design and bivariate and time-series analyses during lag and non-lag months. Data from 2008-2017 was obtained from the national surveillance system and meteorological stations. Results: Cases correlated only with climatic variables during lag and non-lag months. Decreases in precipitation and humidity and increases in temperature were correlated with an increase in cases. Conclusions: Our findings provide useful information for establishing and strengthening dengue prevention and control strategies.

Spatial- Temporal Spread of Dengue in Delhi: An Empirical Analysis

Background & objectives: The epidemiology of dengue in Delhi is changing over the years and is now making it an endemic disease. It is not only rising but is slowly becoming more severe and spreading much faster than before. Within this perspective, this paper aims to map the distribution and intensity of dengue spread in Delhi on a fine spatial scale for the last decade to build an early warning system for the future. Methods: For this paper, the study followed a methodology that combined dengue data with suitable statistical approaches to find their spatial and temporal spread of dengue over Delhi. For this, primary data on dengue in Delhi was collected from 2009 to 2020 from the South Delhi Municipal Corporation (SDMC). GIS and compiled data were used to map the spatial distribution of Dengue occurrences at the Zonal and ward level. Dengue intensity indices were developed to identify the dengue hotspots and enable localised actions to manage dengue. A time-series analysis enabled understanding of dengue trends in SDMC and carrying out vulnerability assessments to develop a more targeted approach to manage dengue at the local level. Interviews with the select SDMC official using open-ended questions were used to identify the key challenges and issues in the management of dengue in Delhi. Results: Dengue is hyper endemic in the region and shows its presence throughout the year. Dengue is hyper endemic in the city and shows its presence throughout the year, with peaks observed from September to November. The trends in dengue indicate that the city has very rapidly come into the grip of the dengue and the post-monsoon periods observe high incidence rates, with cooler months also experiencing dengue cases. The dengue vector is fast spreading into the areas where it was not present before, which indicates that the dengue vector is adapting to the local environment and soon becomes a perennial feature in the city. We also observe clusters where the dengue is endemic and calls for a targeted measure. Interpretation & conclusion: Dengue in Delhi is perennial now, with peaks observed during the months from September- November. The trend in dengue indicates that the city has very rapidly come into the grip of the dengue, and the post-monsoon periods observe high incidence rates. The dengue vector is fast spreading into the areas where it was not present before. This indicates that dengue is adapting to the local environment and soon will become a perennial feature in the city and calls for a targeted measure.

Dengue Status in a Tertiary Care Rural Hospital

Introduction: Dengue is one the most common arthropod-borne virus-transmitted disease of the tropics. Though many remains asymptomatic, a huge population gets infected with some persons leading to a serious form of the disease. As rapid urbanization allows to thrive the Aedes albopictus mosquito which is mainly involved for the transmission of the disease, seasonal outbreaks are becoming a common fact to deal Acute Febrile Illnesses year after year. Aims/Objectives: To study the epidemiology of dengue through the serological, demographic profile, regional distribution, vectors and circulating serotypes. Materials and Methods: Demographic data and presenting symptoms of fever 10476 cases reported to the clinic were recorded. Suspected patients were tested for dengue, chikungunya, scrub typhus and malaria. Dengue-specific NS1 and IgM ELISAs were performed, followed by RNA extraction, PCR and sequencing to detect circulating DENV serotypes. Results: Of the 10476 fever patients tested from July to September 2021, 2767 cases were Dengue NS1 positive, while 2624 were Dengue IgM positive. Of the 200 samples analyzed, 19.1% had concurrent infection with multiple dengue serotypes DEN 1,2 &amp; 3; 63.8% was DEN 1, and 18.2% was DEN 2. Conclusion: Wardha is endemic to Dengue, and concurrent infections with multiple DENV serotypes have become a frequent finding in this region. The most prevalent febrile illness nowadays is Scrub typhus or Dengue Fever in the rural part of central India, which has predominantly replaced typhoid fever and malaria. They may be asymptomatic or give rise to undifferentiated fever, Dengue Fever (DF), Dengue Haemorrhagic Fever (DHF), or Dengue Shock Syndrome (DSS). Annually, 100 million cases of dengue fever and half a million cases of DHF occur worldwide. It is essential to know the prevalent serotype and disease pattern for better recovery of the patients. Though much research is ongoing for a new vaccine against Dengue, reaching rural India will take time and effort. Early recognition and prompt initiation of appropriate treatment are vital if disease-related morbidity and mortality are to be limited.