Dengue Control Research Articles

Integrated Vector Control (IVC) Strategies and Services of Barangay Health Stations (BHS) in District 5 of Manila City against Dengue Mosquitoes amid the COVID-19 Pandemic

In the absence of an effective vaccine, integrated vector control (IVC) is the key method for controlling dengue cases. The COVID-19 pandemic lockdown significantly weakened the surveillance, preventive insecticide application, and vector control effectiveness. Therefore, the Department of Health issued a memorandum urging barangays to keep implementing interventions to prevent dengue cases from growing in number. This study aimed to describe the status of the implementation of the IVC component of the National Dengue Prevention and Control Program by the Barangay Health Stations (BHSs) of District 5, Manila City, the Philippines, before the COVID-19 pandemic in 2019 and during the pandemic in 2020. The pandemic affected numerous government programs, so the IVC status before and amid the pandemic is worth describing. The study used a cross-sectional descriptive design with a remote survey being conducted with 144 BHS from 08–23 Feb 2021 using a self-administered questionnaire. Results showed that the BHS conducted larviciding (84.02%), adulticiding either through indoor residual spraying [IRS (86.81%)] or space spraying (77.08%) in 2019. Distributions of insecticide-treated nets [ITN (27.78%)], insecticide-treated curtains [ITC (17.36%)], smoke repellents (54.17%), and skin repellents (50.00%) were also implemented. In 2020 amid the pandemic, 81.94% of BHS implemented larviciding, whereas 83.33% and 77.08% conducted IRS and space spraying, respectively. In addition, ITNs (24.31%), ITCs (17.36%), smoke repellents (52.08%), and skin repellents (44.44%) were also distributed in 2020. Despite the pandemic, most barangays in District 5 continued to implement IVC strategies, which contributed to vector density and possibly prevented an increase in mosquito density that could have led to dengue outbreaks.

Estimating dengue disease and economic burden to inform municipal-level policymakers: Method for a pragmatic city-level observational cohort study.

Recent trials have confirmed the effectiveness of promising dengue control technologies - two vaccines and Wolbachia. These would generally be applied at the municipal level. To help local officials decide which, if any, control strategy to implement, they need affordable, timely, and accurate data on dengue burden. Building on our previous work in Mexico, Indonesia, and Thailand, we developed a streamlined prospective method to estimate dengue burden at the municipal level quickly, accurately, and efficiently. The method entails enrolling and repeatedly interviewing 100 patients with laboratory-confirmed dengue. They will be selected after screening and testing about 1,000 patients with clinical dengue. The method will capture both acute and chronic effects relating to disease, economic burden, and psychological impacts (presenteeism). The total time requirements are 1.5 years, comprised of 0.25 years for planning and approvals, 1 year for data collection (a full dengue cycle), and 0 .25 years for data cleaning and analysis. A collaboration with municipal and academic colleagues in the city of Semarang, Central Java, Indonesia shows how the method could be readily applied in Indonesia's eighth largest city (population 1.8 million). Many surveillance studies gather only information on numbers of cases. This proposed method will provide a comprehensive picture of the dengue burden to the health system, payers, and households at the local level.

Assessing Wolbachia-mediated sterility for dengue control: emulation of a cluster-randomized target trial in Singapore.

Matings between male Aedes aegypti mosquitoes infected with wAlbB strain of Wolbachia and wildtype females yield non-viable eggs. We evaluated the efficacy of releasing wAlbB-infected Ae. aegypti male mosquitoes to suppress dengue. We specified the protocol of a two-arm cluster-randomized test-negative controlled trial (cRCT) and emulated it using a nationally representative test-negative/positive database of individuals reporting for febrile illness to any public hospital, general practitioner or polyclinic. We retrospectively built a cohort of individuals who reside in Wolbachia locations vs a comparator control group who do not reside in Wolbachia locations, using a nationally representative database of all individuals whom report for febrile illness and were tested for dengue at the Environmental Health Institute/hospital laboratories/commercial diagnostic laboratories, through general practitioner clinic, polyclinic or public/private hospital from epidemiological week (EW) 1 2019 to EW26 2022. We emulated a constrained randomization protocol used in cRCTs to balance dengue risk between intervention and control arms in the pre-intervention period. We used the inverse probability weighting approach to further balance the intervention and control groups using a battery of algorithmically selected sociodemographic, environmental and anthropogenic variables. Intention-to-treat analyses were conducted to estimate the risk reduction of dengue given Wolbachia exposure. Intention-to-treat analyses revealed that, compared with controls, Wolbachia releases for 3, 6 and ≥12 months was associated to 47% (95% confidence interval: 25-69%), 44% (33-77%) and 61% (38-78%) protective efficacy against dengue, respectively. When exposed to ≥12 months of Wolbachia releases, protective efficacies ranged from 49% (13-72%) to 77% (60-94%) across years. The proportion of virologically confirmed dengue cases was lower overall in the intervention arm. Protective efficacies were found across all years, age and sex subgroups, with higher durations of Wolbachia exposure associated to greater risk reductions of dengue. Results demonstrated that Wolbachia-mediated sterility can strengthen dengue control in tropical cities, where dengue burden is the greatest.

Public Acceptance Towards BTI (Bacillus Thuringiensis Israelensis) as a Tool for Dengue Control

Public Acceptance Towards BTI (Bacillus Thuringiensis Israelensis) as a Tool for Dengue Control

North–south pathways, emerging variants, and high climate suitability characterize the recent spread of dengue virus serotypes 2 and 3 in the Dominican Republic

BackgroundDengue fever remains a significant public health challenge in tropical and subtropical regions, with its transmission dynamics being influenced by both environmental factors and human mobility. The Dominican Republic, a biodiversity hotspot in the Caribbean, has experienced recurrent dengue outbreaks, yet detailed understanding of the virus's transmission pathways and the impact of climatic factors remains limited. This study aims to elucidate the recent transmission dynamics of the dengue virus (DENV) in the Dominican Republic, utilizing a combination of genomic sequencing and epidemiological data analysis, alongside an examination of historical climate patterns.MethodsWe conducted a comprehensive study involving the genomic sequencing of DENV samples collected from patients across different regions of the Dominican Republic over a two-year period. Phylogenetic analyses were performed to identify the circulation of DENV lineages and to trace transmission pathways. Epidemiological data were integrated to analyze trends in dengue incidence and distribution. Additionally, we integrated historical climate data spanning several decades to assess trends in temperature and their potential impact on DENV transmission potential.ResultsOur results highlight a previously unknown north–south transmission pathway within the country, with the co-circulation of multiple virus lineages. Additionally, we examine the historical climate data, revealing long-term trends towards higher theoretical potential for dengue transmission due to rising temperatures.ConclusionThis multidisciplinary study reveals intricate patterns of dengue virus transmission in the Dominican Republic, characterized by the co-circulation of multiple DENV lineages and a novel transmission pathway. The observed correlation between rising temperatures and increased dengue transmission potential emphasizes the need for integrated climate-informed strategies in dengue control efforts. Our findings offer critical insights for public health authorities in the Dominican Republic and similar settings, guiding resource allocation and the development of preparedness strategies to mitigate the impacts of climate change on dengue transmission.

Anti-Dengue Sanitation Practices: A Health Education Approach for Municipal Sanitary Workers in Puducherry, India.

Introduction Dengue is a mosquito-borne disease of global health concern, especially in tropical areas. Aedes aegypti, its vector, thrives in inadequate sanitation conditions. The role of sanitary workers is pivotal in dengue control and prevention efforts; hence, educating them is essential for enhancing their vector control awareness. Methods This study was conducted among 109 municipal sanitary workers in selected areas of Puducherry, India. Their baseline knowledge, attitudes, and practices (KAP) regarding dengue were assessed through a pretested, semi-structured questionnaire, followed by a targeted health education intervention incorporating novel communication methods such as pocket awareness cards. The impact of the intervention was assessed through an increment in KAP scores, qualitative interviews, and surprise visits to the field during their work hours. Results The mean (± SD) scores in terms of knowledge (4.29 ± 1.77 vs. 7.17 ± 1.02; p < 0.01), attitudes (3.58 ± 1.42 vs. 4.69 ± 0.71; p < 0.01), and practices (1.98 ± 0.84 vs. 4.28 ± 1.12; p < 0.01) significantly increased post-intervention. Qualitative interviews revealed the utility of the intervention, with additional insights on implementation barriers and strategies for the future. Conclusion The study's findings imply that the targeted health education intervention for sanitary workers was effective in improving their knowledge and practices on dengue control. These results demonstrate the potential of future educational initiatives to promote vector control measures among sanitary staff and thereby combat dengue transmission in the community.

KKN Tematik: Membangun Kesadaran Pencegahan dan Pengendalian Penyakit Demam Berdarah Dengue (DBD) di Desa Jeruju Besar

Dengue hemorrhagic fever (DHF) is caused by the bite of the female Aedes aegypti mosquito. Dengue hemorrhagic fever cases that occurred in Kubu Raya have reached 1,061 cases with 4 deaths, as of November 22 2023. The importance of preventing and controlling dengue fever needs to be done to reduce the increasing number of dengue fever cases that occur so that this problem is raised as KKN theme in Jeruju Besar Village. The KKN implementation was carried out in Jeruju Besar Village with a program to prevent and control dengue hemorrhagic fever which included socialization, training in making larvicide and wall magazine, also providing larvicide products, posters and platelet-increasing food. The results of evaluation show that there was an influence of the socialization carried out on increasing knowledge and understanding regarding dengue prevention and control among village residents from an average value of 59.24 to 87.83 and among elementary school students from an average value of 55.09 to 82 .61 which is supported by the Paired Sample T Test. The result of questionnaires also showed a good level of satisfaction from residents, where 82.61% felt that the were useful. Overall, the program implemented went well according to plan and received a very good response so that it was able to increase understanding and knowledge, also increase awareness in preventing and controlling the spread of dengue hemorrhagic fever among the residents of Jeruju Besar Village.

Dengue prevention and control measures in the state of Mato Grosso do Sul in the face os epidemics: a question of environmental education

Dengue is caused by viruses from the Flaviviridae family, from the Flavivirus genus, and has been identified as one of the main vector-borne diseases in the world. According to the epidemiological picture of dengue in Brazil, a wide distribution of Aedes aegypti was observed in all regions with the circulation of three main viral serotypes (DENV1, DENV2 and DENV3) and a great possibility of the introduction of the DENV4 serotype. Its transmission involves vectors of the Aedes genus, with Aedes aegypti being responsible for the urban cycle of the disease. It is an acute disease that can progress to remission of symptoms, or worsening of the case followed by death, a fact that highlights the importance of effective control measures. This work was carried out through retrospective analytical descriptive research with theoretical foundations carried out through a bibliographic review in the Scielo, Scopus, Bireme, Lilacs, MEDLINE and DATASUS databases with the objectives of identifying the number of Dengue cases that occurred in the period 2018 to 2023, the prevention and control measures implemented by the state and the occurrence of possible environmental and human health changes related to the use of these compounds.

Shifting spatial, temporal and demographic patterns of dengue incidence and associated meteorological factors in Jazan Region of Saudi Arabia from 2015-2020.

Dengue poses a considerable public health threat in Saudi Arabia, with escalating outbreaks in Jazan, where seasonal rains create ideal mosquito breeding conditions. Elucidating local epidemiological dynamics is imperative to strengthen evidence-based prevention policies. This study analyzed the spatiotemporal, demographic, and meteorological patterns of dengue in Jazan from 2015-2020. This retrospective cross-sectional study utilized surveillance records for 3427 confirmed dengue cases. Descriptive analyses characterized geographic, seasonal, age, gender, and nationality distributions. Forecasting models project expected epidemics through 2025. Regression analysis identified climate factors associated with monthly case counts. Dengue exhibited shifting seasonal peaks, transitioning into year-round transmission by 2019, indicating endemic establishment. Cases clustered in different high-burden sectors annually, requiring localized vector control. The majority of affected individuals were young male adults, with gender gaps narrowing over time. Saudi nationals had an escalating incidence, but non-citizens showed a higher risk, signaling importation threats. Seasonal outbreaks were associated with temperature, wind speed, and direction. Enhanced surveillance, outbreak forecasting, targeted control activities, and integrated prevention policies grounded in continuous evidence assessment can effectively address endemic dengue transmission in Jazan. This study provides key insights to optimize data-driven decision-making for dengue control in Saudi Arabia.

A review of dengue transmission and dengue therapy among people

Dengue fever is a significant threat to global health, caused by the dengue virus and transmitted mainly by Aedes mosquitoes. It is crucial to understand the transmission dynamics of the virus to develop effective control and prevention strategies. Epidemiological studies have provided valuable insights into outbreaks' spread patterns, risk factors, and nature. These are essential for targeted interventions such as vector control, reducing human-mosquito contact, and community-based preventive measures. At the same time, there is a pressing need to develop effective therapies to alleviate the disease burden and reduce mortality associated with dengue outbreaks. Current therapeutic research focuses on antiviral treatments, supportive care strategies, and vaccine development to combat the diverse clinical manifestations of dengue. To address the multifaceted challenges of dengue, there must be a concerted effort toward developing robust preventive measures, innovative therapies, and enhanced diagnostic tools. A comprehensive understanding of its transmission dynamics coupled with effective therapeutic interventions is pivotal in pursuing dengue control and mitigation, as it poses a formidable global health challenge.

Spatiotemporal analysis of imported and local dengue virus and cases in a metropolis in Southwestern China, 2013–2022

Dengue fever is a viral illness, mainly transmitted by Aedes aegypti and Aedes albopictus. With climate change and urbanisation, more urbanised areas are becoming suitable for the survival and reproduction of dengue vector, consequently are becoming suitable for dengue transmission in China. Chongqing, a metropolis in southwestern China, has recently been hit by imported and local dengue fever, experiencing its first local outbreak in 2019. However, the genetic evolution dynamics of dengue viruses and the spatiotemporal patterns of imported and local dengue cases have not yet been elucidated. Hence, this study implemented phylogenetic analyses using genomic data of dengue viruses in 2019 and 2023 and a spatiotemporal analysis of dengue cases collected from 2013 to 2022. We sequenced a total of 15 nucleotide sequences of E genes. The dengue viruses formed separate clusters and were genetically related to those from Guangdong Province, China, and countries in Southeast Asia, including Laos, Thailand, Myanmar and Cambodia. Chongqing experienced a dengue outbreak in 2019 when 168 imported and 1,243 local cases were reported, mainly in September and October. Few cases were reported in 2013–2018, and only six were imported from 2020 to 2022 due to the COVID-19 lockdowns. Our findings suggest that dengue prevention in Chongqing should focus on domestic and overseas population mobility, especially in the Yubei and Wanzhou districts, where airports and railway stations are located, and the period between August and October when dengue outbreaks occur in endemic regions. Moreover, continuous vector monitoring should be implemented, especially during August–October, which would be useful for controlling the Aedes mosquitoes. This study is significant for defining Chongqing's appropriate dengue prevention and control strategies.

Dengue in Wardha City: Addressing Social and Clinical Challenges

Dengue fever, a major public health concern in tropical and subtropical areas, is a critical issue in Wardha city. The purpose of this study was to analyze Wardha inhabitants’ awareness, knowledge, and habits about dengue illness. The survey, which took place between November 2023 and April 2024, used a structured questionnaire and was delivered to a representative sample of 50 participants from various wards of the city. The questionnaire inquired about respondents’ knowledge of dengue symptoms, mechanisms of transmission, preventative measures, and attitudes toward local dengue control initiatives. Preliminary data show that, while many locals are aware of dengue and its symptoms, there are significant gaps in knowledge about effective preventative techniques, as well as widespread misunderstandings regarding transmission. The poll also preventative measures. Furthermore, the survey found diverse degrees of community engagement in dengue management operations, with many respondents advocating for more thorough and accessible teaching campaigns. These findings show the critical need for targeted educational initiatives and increased community engagement in Wardha city to improve dengue prevention and control. Public health experts and politicians are encouraged to use these findings to create and execute more effective, context-specific dengue control measures.

Exploring community needs in combating aedes mosquitoes and dengue fever: a study with urban community in the recurrent hotspot area

BackgroundAedes mosquitoes are the main vector of dengue infection, a global health threat affecting millions of people annually. Conventional prevention and control methods against dengue outbreaks have only achieved marginal success. Recognizing the complex issue at hand, a multilevel participatory approach is crucial. Thus, alternative strategies that involve community engagement are increasingly being considered and attempted. While community-based vector control programs have been conducted, sustaining behavioral changes among the population remains a challenge. This study aimed to identify the specific community needs in combating Aedes mosquitoes and dengue fever as a basis to guide the development of community-driven initiatives and foster a deeper sense of ownership in the fight against dengue.MethodsBetween 1 August 2022 and 30 November 2022, we conducted a study in Hulu Langat district, Selangor, using a mixed-method design. All participants consented to the study, which comprised 27 participants (FGDs) and 15 participants (IDIs). The IDIs included two participants with a history of dengue fever, one community leader, one faith leader, seven local authorities, and four district health officers. Semi-structured interviews and discussions were performed among stakeholders and community members recruited via purposive and snowball sampling techniques. All interviews were audio-recorded before being analyzed using reflexive thematic analysis.ResultsThese results derived from qualitative data explored the perspectives and needs of communities in combating Aedes mosquitoes and dengue fever. Interviews were conducted with various stakeholders, including community members, leaders, and health officers. The study identified the necessity of decisive actions by authorities to address the impact of the dengue epidemic, the importance of community engagement through partnerships and participatory approaches, the potential benefits of incentives and rewards to enhance community participation, and the need for sustained community engagement and education, especially via the involvement of young people in prevention efforts. These findings provide valuable insights into the design of effective strategies against Aedes mosquitoes and dengue fever.ConclusionsIn short, there is an urgent need for a comprehensive approach involving multiple stakeholders in the fight against Aedes mosquitoes and dengue fever. The approach should incorporate efforts to raise awareness, provide practical resources, and foster community responsibility. The active involvement of teenagers as volunteers can contribute to long-term prevention efforts. Collaboration, resource allocation, and community engagement are crucial for effective dengue control and a healthier environment.

Estimating dengue disease and economic burden to inform municipal-level policymakers: Method for a pragmatic city-level observational cohort study

Background Recent trials have confirmed the effectiveness of promising dengue control technologies – two vaccines, and Wolbachia. These would generally be applied at the municipal level. To help local officials to decide which, if any, control strategy to implement, these officials need affordable, timely, and accurate data on dengue burden. Building on our previous work in Mexico, Indonesia, and Thailand, we developed a streamlined prospective method to estimate dengue burden at the municipal level quickly, accurately, and efficiently. Method The method entails enrolling and repeatedly interviewing 100 patients with laboratory-confirmed dengue. They will be selected after screening and testing about 1,000 patients with clinical dengue. The method will capture both acute and chronic effects relating to disease, economic burden, and psychological impacts (presenteeism). The total time requirements are 1.5 years, comprised of 0.25 years for planning and approvals, 1 year for data collection (a full dengue cycle), and 0 .25 years for data cleaning and analysis. A collaboration with municipal and academic colleagues in the city of Semarang, Central Java, Indonesia shows how the method could be readily applied in Indonesia’s eighth largest city (population 1.8 million). Conclusions Many surveillance studies gather only information on numbers of cases. This proposed method will provide a comprehensive picture of the dengue burden to the health system, payers, and households at the local level.

The empowered family: New narratives to rethink dengue prevention and control in Córdoba, Colombia.

Dengue is a disease that constitutes a public health problem difficult to control due to the multidimensionality of associated factors and the particularities of the territories. This article analyzes the notion of family empowerment related to the prevention and control of dengue in Córdoba, Colombia. From July to October 2023, using a qualitative approach, semi-structured interviews were conducted with 30 family groups located in the municipalities of San Andrés de Sotavento, San Bernardo del Viento, Pueblo Nuevo, and Montería, selected for being indigenous, Afro-descendant, or rural and urban populations in vulnerable conditions. The results show that families, beyond their particular arrangements in terms of structure and dynamics, are aware of their role in the prevention and control of diseases, identifying the capacities required to face dengue. However, they reproduce narratives of conceptual and power dominance that assign a greater commitment on the part of educational and health agents to promote alternatives that contribute to reducing the risks of dengue. The challenges that must be faced for effective family empowerment are discussed, so that prevention practices gain greater strength.

Simulation-based economic evaluation of the Wolbachia method in Brazil: a cost-effective strategy for dengue control

Dengue virus (DENV) is an arbovirus transmitted by Aedes aegypti mosquitoes, which can cause severe conditions such as hemorrhagic fever and dengue shock syndrome. These conditions are associated with adverse social, clinical, and economic consequences in Brazil. Herein, the Wolbachia mosquito replacement method is a promising dengue control strategy. We estimated the economic impact of implementing the Wolbachia mosquito replacement method in seven Brazilian cities. A mathematical microsimulation model tracked nearly 23 million inhabitants over a 20-year period, considering the transitions between five different health states (susceptible, inapparent, outpatient, hospitalised and death). Direct costs included local dengue control programs, Wolbachia implementation and dengue care. Indirect costs related to death and productivity loss, as well as disability-adjusted life-years (DALY) averted were also considered. Without Wolbachia, the model projected 1,762,688 reported dengue cases over 20 years. Implementing the Wolbachia method would avert at least 1,295,566 dengue cases, resulting in lower costs and greater effectiveness in all simulated cities. On average, for every 1000 inhabitants followed for 20 years, the Wolbachia method yielded a cost difference of USD 538,233.68 (BRL 2,691,168.40) and averted 5.56 DALYs. Net monetary benefits (NMB) were positive in all seven cities, ranging from USD 110.72 (BRL 553.59) to USD 1399.19 (BRL 6995.95) per inhabitant. Alternative scenarios have also shown a favourable return on investment with a positive benefit-cost ratio (BCR). Wolbachia is likely a cost-effective strategy in the Brazilian context, consistent with international studies. Sensitivity analysis and alternative scenarios confirmed the robustness of the results. This study was funded by the Wellcome Trust under a grant (224459/Z/21/Z).

‘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.

Cost of controlling the dengue vector Aedes aegypti in the Peruvian amazon.

Motivation for the study. Dengue prevention and control is based on the control of its vector. This study was conducted because of the need to know the costs associated with Aedes aegypti control in a region that carries out planned vector control activities. Main findings. The costs incurred in dengue vector control in the Loreto region in 2017 and 2018 amounted to PEN 4,066,380.25 and PEN 3,807,858.73, respectively. Implications. Knowing the cost of vector control activities will allow us to better plan these activities and have a basis for cost-effectiveness studies with other methods of prevention and control of dengue. To estimate the costs incurred in the control of Aedes aegypti in the Loreto region, during the years 2017 and 2018. We conducted a partial retrospective economic evaluation of the costs of Aedes aegypti control of the Regional Health Directorate Loreto, during the implementation of the Regional Plan for Surveillance and Control of Aedes aegypti. Documentation such as plans, intervention reports and payment slips were reviewed, and interviews were conducted with professional personnel involved in vector control, on the costs of control interventions. We found that the costs incurred in dengue vector control in the Loreto Region in the two years were: PEN 3,807,858 and PEN 4,066,380 during 2017 and 2018, respectively (USD 1,175,264 and USD 1,1210,232 at the 2017 and 2018 exchange rate). However, the effect of control activities is short-lived. The high cost involved in vector control with the methods currently used and the short duration of its effect make it unsustainable. Studies should be conducted in order to find other more efficient methods for dengue control.

Exploring Dengue Dynamics from a Multi-dimensional Surveillance Approach: A Cross-sectional Study from Maharashtra, India

Abstract Introduction: The epidemiology of dengue in India has been intricate. It is pertinent that the multidimensional dengue surveillance approach be formulated with appropriate inferences and implications in developing preventive strategies for dengue control. Materials and Methods: This was a cross-sectional study from Pune city in Western Maharashtra in July 2021, covering an area of 120 acres and population of 3234. A multidimensional dengue field survey was conducted to carry out sector-wise entomological surveillance with simultaneous knowledge and behaviour assessment of the local population. Results: The total number of dengue cases reported were 36 over 2 months. A total of 131/973 containers were found positive, with a total collection of 1140 larvae and 119 pupae. Pupa per person was 0.16. A total of 108 adult female Aedes mosquitoes majorly Aedes albopictus (84%). The xenodiagnoses undertaken were found negative for dengue, chikungunya and Zika virus. The mean knowledge behaviour score assessed was 8.64 ± 2.12 out of 14 with a maximum score of 14 and a minimum score of 02. Conclusion: The current study revealed that there were specific preferred breeding sites such as plastic discarded plates and flowerpots with more cases in particular sector. The knowledge assessment of the local population was good.

Control dengue with Wolbachia: Insights from a two-strain vector-host model with larval competition

Due to deficient treatments and vaccines for dengue viruses, dengue control mainly depends on controlling mosquitoes. Suppressing wild mosquito population size by releasing male-only Wolbachia-carrying mosquitoes into the field has become an eco-friendly alternative for traditional mosquito control methods. By assuming an ideal continuous proportional release strategy, we formulate a two-strain vector-host model incorporating larval competition to describe the affected cross-transmission dynamics of two dengue viruses serotypes. Moreover, antibody-dependent enhancement (ADE) and temporal cross-immunity are considered in this model. Theoretical analysis including the well-posedness, the existence and local stability of dengue-free equilibria in terms of the basic reproduction numbers is conducted. Sensitivity analysis indicates that the basic reproduction numbers are most sensitive to the adult female mortality rate and mosquito bite rate. As expected, intensifying larval competition can prevent the spread of dengue viruses. Unexpectedly, increasing the release ratio can delay the peak time while increase the peak level of both primary and secondary infections. To efficiently eliminate dengue outbreaks, other control methods such as spraying larvicides/adult insecticides and avoiding mosquito bites should be employed simultaneously during the time period gained by releasing Wolbachia-carrying males.