scholarly journals A Comparative Analysis of the Relative Efficacy of Vector-Control Strategies Against Dengue Fever

2014 ◽  
Vol 76 (3) ◽  
pp. 697-717 ◽  
Author(s):  
Marcos Amaku ◽  
Francisco Antonio Bezerra Coutinho ◽  
Silvia Martorano Raimundo ◽  
Luis Fernandez Lopez ◽  
Marcelo Nascimento Burattini ◽  
...  
Keyword(s):  
Comparative Analysis ◽  
Vector Control ◽  
Dengue Fever ◽  
Control Strategies ◽  
Relative Efficacy

scholarly journals The economic impact and cost-effectiveness of combined vector-control and dengue vaccination strategies in Thailand: results from a dynamic transmission model

2020 ◽  
Vol 14 (10) ◽  
pp. e0008805
Author(s):  
Gerhart Knerer ◽  
Christine S. M. Currie ◽  
Sally C. Brailsford
Keyword(s):  
Public Health ◽  
Cost Effectiveness ◽  
Vector Control ◽  
Dengue Fever ◽  
Control Strategies ◽  
Cost Effective ◽  
Scenario Analyses ◽  
Life Years ◽  
The Cost ◽  
The Impact

Background and aims Dengue fever is a major public health problem in tropical/subtropical regions. Prior economic analyses have predominantly evaluated either vaccination or vector-control programmes in isolation and do not really consider the incremental benefits and cost-effectiveness of mixed strategies and combination control. We estimated the cost-effectiveness of single and combined approaches in Thailand. Methods The impacts of different control interventions were analysed using a previously published mathematical model of dengue epidemiology and control incorporating seasonality, age structure, consecutive infection, cross protection, immune enhancement and combined vector-host transmission. An economic model was applied to simulation results to estimate the cost-effectiveness of 4 interventions and their various combinations (6 strategies): i) routine vaccination of 1-year olds; ii) chemical vector control strategies targeting adult and larval stages separately; iii) environmental management/ public health education and awareness [EM/ PHEA]). Payer and societal perspectives were considered. The health burden of dengue fever was assessed using disability-adjusted life-years (DALYs) lost. Costs and effects were assessed for 10 years. Costs were discounted at 3% annually and updated to 2013 United States Dollars. Incremental cost-effectiveness analysis was carried out after strategies were rank-ordered by cost, with results presented in a table of incremental analysis. Sensitivity and scenario analyses were undertaken; and the impact and cost-effectiveness of Wolbachia was evaluated in exploratory scenario analyses. Results From the payer and societal perspectives, 2 combination strategies were considered optimal, as all other control strategies were dominated. Vaccination plus adulticide plus EM/ PHEA was deemed cost-effective according to multiple cost-effectiveness criteria. From the societal perspective, incremental differences vs. adulticide and EM/ PHEA resulted in costs of $157.6 million and DALYs lost of 12,599, giving an expected ICER of $12,508 per DALY averted. Exploratory scenario analyses showed Wolbachia to be highly cost-effective ($343 per DALY averted) vs. other single control measures. Conclusions Our model shows that individual interventions can be cost-effective, but that important epidemiological reductions and economic impacts are demonstrated when interventions are combined as part of an integrated approach to combating dengue fever. Exploratory scenario analyses demonstrated the potential epidemiological and cost-effective impact of Wolbachia when deployed at scale on a nationwide basis. Our findings were robust in the face of sensitivity analyses.

scholarly journals Reducing dengue fever cases at the lowest budget: a constrained optimization approach applied to Thailand

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Gerhart Knerer ◽  
Christine S. M. Currie ◽  
Sally C. Brailsford
Keyword(s):  
Public Health ◽  
Constrained Optimization ◽  
Vector Control ◽  
Dengue Fever ◽  
Time Horizon ◽  
Control Strategies ◽  
Budget Constraints ◽  
Scenario Analyses ◽  
Fixed Budget ◽  
Dengue Control

Abstract Background With the challenges that dengue fever (DF) presents to healthcare systems and societies, public health officials must determine where best to allocate scarce resources and restricted budgets. Constrained optimization (CO) helps to address some of the acknowledged limitations of conventional health economic analyses and has typically been used to identify the optimal allocation of resources across interventions subject to a variety of constraints. Methods A dynamic transmission model was developed to predict the number of dengue cases in Thailand at steady state. A CO was then applied to identify the optimal combination of interventions (release of Wolbachia-infected mosquitoes and paediatric vaccination) within the constraints of a fixed budget, set no higher than cost estimates of the current vector control programme, to minimize the number of dengue cases and disability-adjusted life years (DALYs) lost. Epidemiological, cost, and effectiveness data were informed by national data and the research literature. The time horizon was 10 years. Scenario analyses examined different disease management and intervention costs, budget constraints, vaccine efficacy, and optimization time horizon. Results Under base-case budget constraints, the optimal coverage of the two interventions to minimize dengue incidence was predicted to be nearly equal (Wolbachia 50%; paediatric vaccination 49%) with corresponding coverages under lower bound (Wolbachia 54%; paediatric vaccination 10%) and upper bound (Wolbachia 67%; paediatric vaccination 100%) budget ceilings. Scenario analyses indicated that the most impactful situations related to the costs of Wolbachia and paediatric vaccination with decreases/ increases in costs of interventions demonstrating a direct correlation with coverage (increases/ decreases) of the respective control strategies under examination. Conclusions Determining the best investment strategy for dengue control requires the identification of the optimal mix of interventions to implement in order to maximize public health outcomes, often under fixed budget constraints. A CO model was developed with the objective of minimizing dengue cases (and DALYs lost) over a 10-year time horizon, within the constraints of the estimated budgets for vector control in the absence of vaccination and Wolbachia. The model provides a tool for developing estimates of optimal coverage of combined dengue control strategies that minimize dengue burden at the lowest budget.

PENGARUH PELATIHAN PENGENDALIAN VEKTOR DEMAM BERDARAH TERHADAP MAYA INDEX PADA SISWA SEKOLAH DASAR DI MAJALENGKA

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Wawan Kurniawan
Keyword(s):  
Vector Control ◽  
Dengue Fever ◽  
Dengue Hemorrhagic Fever ◽  
Intervention Group ◽  
Hemorrhagic Fever ◽  
Control Group ◽  
Control Group Design ◽  
Group Design ◽  
Quasi Experimental ◽  
Dengue Vector Control

ABSTRAK  Latar belakang: Demam Berdarah Dengue (DBD) disebabkan oleh virus Dengue dapat menyebabkan kematian. Pencegahan DBD yang dianggap paling tepat adalah Pemberantasan Sarang Nyamuk (PSN). Penelitian ini bertujuan untuk mengetahui pengaruh pelatihan pengendalian vektor Demam Berdarah pada siswa sekolah dasar terhadap Maya Index di Majalengka. Metode: Penelitian ini menggunakan desain quasi experiment (pretest-posttest control group design). Sebanyak 4 sekolah terpilih sebagai kelompok intervensi dan 4 sekolah lainnya sebagai kontrol. Subyek penelitian adalah siswa kelas IV-VI yang terdiri dari 171 siswa pada kelompok intervensi dan 163 pada kelompok kontrol. Instrumen yang digunakan adalah formulir pemantauan jentik berkala. Hasil: Jumlah rumah dengan kategori Maya Index tinggi berkurang dari 27,5% menjadi 9,4%. Terjadi penurunan angka BRI kategori tinggi pada kelompok intervensi dari 20,5% menjadi 1,8%. Pada kelompok kontrol tidak terjadi penurunan angka BRI kategori tinggi (22,1%), sebaliknya terjadi penurunan kategori rendah dari 34,4% menjadi 3,7%. Tidak terjadi penurunan angka HRI pada kelompok intervensi maupun kontrol. Kesimpulan: Pelatihan pengendalian vektor Demam Berdarah dapat menurunkan nilai BRI dan Maya Index, tetapi tidak berpengaruh terhadap nilai HRI. Tidak adanya perubahan nilai HRI menunjukkan bahwa kebersihan dan sanitasi lingkungan merupakan faktor yang berpengaruh terhadap probabilitas kejadian demam berdarah. Kata Kunci : Demam Berdarah, Maya Index, pelatihan, pengendalian vektor   ABSTRACT Background: Dengue Hemorrhagic Fever (DHF) caused by Dengue virus could cause death. The most appropriate prevention of Dengue is eradication of mosquito nests (PSN). This study aims to determine the effect of Dengue vector control training on elementary students towards Maya Index in Majalengka. Method: This study used quasi-experimental design (pretest-posttest control group design). A total of 4 schools were selected as intervention groups and 4 other schools as controls. The subjects were students in grades IV-VI consisting of 171 students in the intervention group and 163 in the control group. The instrument used was periodic larva monitoring form. Results: The number of houses with a high Maya Index category in the intervention group decreased from 27.5% to 9.4%. There was a decrease in the high BRI category in the intervention group from 20.5% to 1.8%. In the control group, there was no decrease in the high BRI category (22.1%), on the contrary, there was a decrease in the low category from 34.4% to 3.7%. There was no decrease in HRI rates both of intervention or control groups. Conclusion: Dengue Fever vector control training could decrease the value of BRI and Maya Index, but does not affect the value of HRI. The absence of changes in HRI  indicate that environmental hygiene and sanitation are factors that influence the probability of dengue fever occurrence. Keywords: Dengue Hemorrhagic Fever, Maya Index, training, vector control

scholarly journals High insecticide resistance mediated by different mechanisms in Culex quinquefasciatus populations from the city of Yaoundé, Cameroon

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Abdou Talipouo ◽  
Konstantinos Mavridis ◽  
Elysée Nchoutpouen ◽  
Borel Djiappi-Tchamen ◽  
Emmanouil Alexandros Fotakis ◽  
...  
Keyword(s):  
Insecticide Resistance ◽  
Vector Control ◽  
High Resistance ◽  
Culex Quinquefasciatus ◽  
Control Strategies ◽  
Cuticular Hydrocarbon ◽  
Control Measures ◽  
High Frequencies ◽  
The City ◽  
Integrated Vector Control

AbstractCulex mosquitoes particularly Culex quinquefasciatus are important arboviral and filariasis vectors, however despite this important epidemiological role, there is still a paucity of data on their bionomics. The present study was undertaken to assess the insecticide resistance status of Cx. quinquefasciatus populations from four districts of Yaoundé (Cameroon). All Culex quinquefasciatus populations except one displayed high resistance to bendiocarb and malathion with mortalities ranging from 0 to 89% while high resistance intensity against both permethrin and deltamethrin was recorded. Molecular analyses revealed high frequencies of the ACE-1 G119S mutation (ranging from 0 to 33%) and kdr L1014F allele (ranging from 55 to 74%) in all Cx. quinquefasciatus populations. Significant overexpression was detected for cytochrome P450s genes CYP6AA7 and CYP6Z10, as well as for Esterase A and Esterase B genes. The total cuticular hydrocarbon content, a proxy of cuticular resistance, was significantly increased (compared to the S-lab strain) in one population. The study confirms strong insecticide resistance mediated by different mechanisms in Cx. quinquefasciatus populations from the city of Yaoundé. The expansion of insecticide resistance in Culex populations could affect the effectiveness of current vector control measures and stress the need for the implementation of integrated vector control strategies in urban settings.

scholarly journals Predicting Aedes aegypti infestation using landscape and thermal features

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Camila Lorenz ◽  
Marcia C. Castro ◽  
Patricia M. P. Trindade ◽  
Maurício L. Nogueira ◽  
Mariana de Oliveira Lage ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Aedes Aegypti ◽  
Vector Control ◽  
Land Surface ◽  
Urban Areas ◽  
Negative Binomial ◽  
Control Strategies ◽  
Winter Season ◽  
Landsat 8 ◽  
Thermal Features

AbstractIdentifying Aedes aegypti breeding hotspots in urban areas is crucial for the design of effective vector control strategies. Remote sensing techniques offer valuable tools for mapping habitat suitability. In this study, we evaluated the association between urban landscape, thermal features, and mosquito infestations. Entomological surveys were conducted between 2016 and 2019 in Vila Toninho, a neighborhood of São José do Rio Preto, São Paulo, Brazil, in which the numbers of adult female Ae. aegypti were recorded monthly and grouped by season for three years. We used data from 2016 to 2018 to build the model and data from summer of 2019 to validate it. WorldView-3 satellite images were used to extract land cover classes, and land surface temperature data were obtained using the Landsat-8 Thermal Infrared Sensor (TIRS). A multilevel negative binomial model was fitted to the data, which showed that the winter season has the greatest influence on decreases in mosquito abundance. Green areas and pavements were negatively associated, and a higher cover of asbestos roofs and exposed soil was positively associated with the presence of adult females. These features are related to socio-economic factors but also provide favorable breeding conditions for mosquitos. The application of remote sensing technologies has significant potential for optimizing vector control strategies, future mosquito suppression, and outbreak prediction.

scholarly journals Optimal Control of a Dengue-Dengvaxia Model: Comparison Between Vaccination and Vector Control

2021 ◽  
Vol 9 (1) ◽  
pp. 198-212
Author(s):  
Cheryl Q. Mentuda
Keyword(s):  
Optimal Control ◽  
Vector Control ◽  
Basic Reproduction Number ◽  
Human Population ◽  
Model Comparison ◽  
Reproduction Number ◽  
Control Strategies ◽  
Minimum Principle ◽  
Transmitted Disease ◽  
The Basic Reproduction Number

Abstract Dengue is the most common mosquito-borne viral infection transmitted disease. It is due to the four types of viruses (DENV-1, DENV-2, DENV-3, DENV-4), which transmit through the bite of infected Aedes aegypti and Aedes albopictus female mosquitoes during the daytime. The first globally commercialized vaccine is Dengvaxia, also known as the CYD-TDV vaccine, manufactured by Sanofi Pasteur. This paper presents a Ross-type epidemic model to describe the vaccine interaction between humans and mosquitoes using an entomological mosquito growth population and constant human population. After establishing the basic reproduction number ℛ0, we present three control strategies: vaccination, vector control, and the combination of vaccination and vector control. We use Pontryagin’s minimum principle to characterize optimal control and apply numerical simulations to determine which strategies best suit each compartment. Results show that vector control requires shorter time applications in minimizing mosquito populations. Whereas vaccinating the primary susceptible human population requires a shorter time compared to the secondary susceptible human.

scholarly journals Public health response and lessons learned from the 2014 chikungunya epidemic in Grenada

2017 ◽  
Vol 41 ◽  
pp. 1 ◽  
Author(s):  
Martin S Forde ◽  
Francis Martin ◽  
George Mitchell ◽  
Satesh Bidaisee
Keyword(s):  
Health Care ◽  
Vector Control ◽  
Control Strategies ◽  
Lessons Learned ◽  
Epidemiological Surveillance ◽  
Mosquito Vector ◽  
Public Health Response ◽  
Island State ◽  
Health Response ◽  
Multiple Challenges

In June 2014, the first cases of chikungunya virus (CHIKV) were diagnosed on the island of Carriacou, part of the tri-island state of Grenada. In the three months that followed, CHIKV spread rapidly, with conservative estimates of the population infected of at least 60%. Multiple challenges were encountered in the battle to manage the spread and impact of this high–attack rate virus, including 1) limited indigenous laboratory diagnostic capabilities; 2) an under-resourced health care system; 3) a skeptical general public, hesitant to accept facts about the origin and mode of transmission of the new virus; and 4) resistance to the vector control strategies used. Lessons learned from the outbreak included the need for 1) a robust and reliable epidemiological surveillance system; 2) effective strategies for communicating with the general population; 3) exploration of other methods of mosquito vector control; and 4) a careful review of all health care policies and protocols to ensure that effective, organized responses are triggered when an infectious outbreak occurs.

Environmental Vector Control Practices among Households of Patients with Dengue Fever during the Epidemic of 2018 in Kerala, India

2021 ◽  
Vol 8 (02) ◽  
pp. 48-52
Author(s):  
Chintha Sujatha ◽  
Reshma Rajan Sudha ◽  
Sreejith Lalitha Krishnankutty ◽  
Prajitha Kannamkottapilly Chandrasekharan
Keyword(s):  
Vector Control ◽  
Dengue Fever ◽  
Protective Factor ◽  
Significant Risk ◽  
Public Health Problem ◽  
Community Level ◽  
Control Measures ◽  
Major Public Health Problem ◽  
Cross Sectional ◽  
Breeding Habitats

BACKGROUND Dengue fever is a major public health problem in Kerala. Vector control measures practiced at household level is the most cost-effective way of controlling dengue. This study aims to assess environmental measures of vector control practised among households of suspected or confirmed dengue patients in Thiruvananthapuram district of Kerala. METHODS A cross sectional study was done among households of patients diagnosed with dengue fever and reported in Integrated Disease Surveillance Programme (IDSP) in Thiruvananthapuram district from June to December 2018. Investigators interviewed the household members and made direct observations to collect data on vector control practices using a structured questionnaire. RESULTS A total of 108 houses were surveyed. Potential breeding habitats were found in 58 (53.7 %) houses. Aedes larva was found in containers from four (3.7 %) houses. Dry day observance was not regular with only 5 (4.6 %) houses practicing it weekly. Waste management practiced was proper in 47 (43.5 %) houses. Community level pre monsoon preparedness for epidemics was done in the vicinity of 53 (49.1 %) houses and it was found to be a protective factor against presence of breeding habitats in and around houses (p = 0.013). Low education (p = 0.012) and low occupational status (p = 0.017) were found to be significant risk factors. CONCLUSIONS Even during an epidemic, with occurrence of infections in the family, only half of the households are practising adequate vector control methods. Community level interventions and targeted information education campaign will help improve practice of environmental methods of vector control in dengue. KEYWORDS Dengue, Vector Control, Aedes Control, Environmental Methods, Community Interventions

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