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Juvenile hormone regulation of microRNAs is mediated by E75 in the Dengue vector mosquito Aedes aegypti. Proc Natl Acad Sci U S A 2021; 118:2102851118. [PMID: 34266957 DOI: 10.1073/pnas.2102851118] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
MicroRNAs (miRNAs) are small noncoding RNAs that play critical roles in controlling posttranscriptional gene regulation and have a profound effect on mosquito reproduction and metabolism. Juvenile hormone (JH) is critical for achieving reproductive competence in the main vector of human arboviral diseases, Aedes aegypti We report a JH-mediated mechanism governing miRNA expression. Using a transcription factor screen with multiple primary miRNA (pri-miRNA) promoters, we identified that the Ecdysone-induced protein E75 (E75) isoform (E75-RD) induced miRNA gene promoter activity. E75 binding sites were determined in miRNA promoters by means of cell transfection assay. E75-RD was found to be up-regulated by JH, as shown by the JH application and RNA interference (RNAi) of the JH receptor Methoprene-tolerant (Met). Small RNA sequencing from RNAi of Met and E75 displayed an overlapping miRNA cohort, suggesting E75 to be an intermediate component within the JH hierarchical network controlling miRNAs. Further experiments confirmed that E75-RD positively regulates several miRNAs including miR-2940. Reducing miR-2940 resulted in the arrest of follicle development and number of eggs laid. Performing miRNA target predictions and RT-qPCR from antagomir Ant-2940-3p-treated fat body tissues identified the mRNA target Clumsy (AAEL002518) The molecular interaction between this gene target and miR-2940 was confirmed using an in vitro dual luciferase assay in Drosophila S2 cells and in Ae. aegypti Aag2 cell lines. Finally, we performed a phenotypic rescue experiment to demonstrate that miR-2940/Clumsy is responsible for the disruption in egg development. Collectively, these results established the role of JH-mediated E75-RD in regulation of miRNA gene expression during the mosquito reproductive cycle.
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Douchet L, Haramboure M, Baldet T, L'Ambert G, Damiens D, Gouagna LC, Bouyer J, Labbé P, Tran A. Comparing sterile male releases and other methods for integrated control of the tiger mosquito in temperate and tropical climates. Sci Rep 2021; 11:7354. [PMID: 33795801 PMCID: PMC8016901 DOI: 10.1038/s41598-021-86798-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Accepted: 03/19/2021] [Indexed: 11/09/2022] Open
Abstract
The expansion of mosquito species worldwide is creating a powerful network for the spread of arboviruses. In addition to the destruction of breeding sites (prevention) and mass trapping, methods based on the sterile insect technique (SIT), the autodissemination of pyriproxyfen (ADT), and a fusion of elements from both of these known as boosted SIT (BSIT), are being developed to meet the urgent need for effective vector control. However, the comparative potential of these methods has yet to be explored in different environments. This is needed to propose and integrate informed guidelines into sustainable mosquito management plans. We extended a weather-dependent model of Aedes albopictus population dynamics to assess the effectiveness of these different vector control methods, alone or in combination, in a tropical (Reunion island, southwest Indian Ocean) and a temperate (Montpellier area, southern France) climate. Our results confirm the potential efficiency of SIT in temperate climates when performed early in the year (mid-March for northern hemisphere). In such a climate, the timing of the vector control action was the key factor in its success. In tropical climates, the potential of the combination of methods becomes more relevant. BSIT and the combination of ADT with SIT were twice as effective compared to the use of SIT alone.
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Affiliation(s)
- Léa Douchet
- CIRAD, UMR ASTRE, 97491, Sainte-Clotilde, Reunion, France
- ASTRE, CIRAD, INRAE, Univ Montpellier, Montpellier, France
| | - Marion Haramboure
- CIRAD, UMR ASTRE, 97491, Sainte-Clotilde, Reunion, France.
- ASTRE, CIRAD, INRAE, Univ Montpellier, Montpellier, France.
- ISEM, CNRS, IRD, EPHE, Université de Montpellier, Montpellier, France.
- TETIS, AgroParisTech, CIRAD, CNRS, INRAE, Univ Montpellier, Montpellier, France.
| | - Thierry Baldet
- CIRAD, UMR ASTRE, 97491, Sainte-Clotilde, Reunion, France
- ASTRE, CIRAD, INRAE, Univ Montpellier, Montpellier, France
| | - Gregory L'Ambert
- Department of Research and Development, EID Méditerranée, Montpellier, France
| | - David Damiens
- IRD, CNRS-UM-IRD, UMR MIVEGEC, Montpellier, Reunion, France
- IRD/GIP CYROI, Sainte-Clotilde, Reunion, France
| | - Louis Clément Gouagna
- IRD, CNRS-UM-IRD, UMR MIVEGEC, Montpellier, Reunion, France
- IRD/GIP CYROI, Sainte-Clotilde, Reunion, France
| | - Jeremy Bouyer
- ASTRE, CIRAD, INRAE, Univ Montpellier, Montpellier, France
- CIRAD, UMR ASTRE, 34398, Montpellier, France
- Insect Pest Control Laboratory, Joint FAO/IAEA Programme of Nuclear Techniques in Food and Agriculture, 1400, Vienna, Austria
- CIRAD, UMR ASTRE, 97410, Saint-Pierre, Reunion, France
| | - Pierrick Labbé
- ISEM, CNRS, IRD, EPHE, Université de Montpellier, Montpellier, France
| | - Annelise Tran
- CIRAD, UMR ASTRE, 97491, Sainte-Clotilde, Reunion, France
- ASTRE, CIRAD, INRAE, Univ Montpellier, Montpellier, France
- TETIS, AgroParisTech, CIRAD, CNRS, INRAE, Univ Montpellier, Montpellier, France
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Gopalan RB, Babu BV, Sugunan AP, Murali A, Ma MS, Balasubramanian R, Philip S. Community engagement to control dengue and other vector-borne diseases in Alappuzha municipality, Kerala, India. Pathog Glob Health 2021; 115:258-266. [PMID: 33734036 DOI: 10.1080/20477724.2021.1890886] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
Introduction Vector-borne diseases (VBDs) are a serious threat in many Indian states, including Kerala. Community-based decentralized planning and engagement are effective strategies that can make positive behavioral changes to control VBDs. Methods This community-based implementation research was conducted during November 2016 - October 2018 in Alappuzha municipality in Kerala, India. It was conducted in two phases. In the first phase, formative research was conducted to know the community's profile and perceptions and thus to plan and develop an appropriate intervention. Baseline data on some entomological indicators were also collected. These data were used to assess the impact of the intervention by comparing with the post-intervention data. In the second phase, an intervention through the community's engagement was implemented in selected wards. The activities included the formation of community committees and the vector control and source reduction activities with the community engagement and inter-sectoral coordination. Results The intervention resulted in a positive change among the community to engage in vector control activities. These efforts along with inter-sectoral coordination resulted in successfully implementing vector source reduction activities. In both wards, pre- and post-intervention entomological data (house index: 16.7 vs 6.0 and 64.2 vs. 8.6; container index: 24.8 vs. 12.1 and 37.7 vs. 18.1; and Breteau index: 21.3 vs. 7.3 and 47.7 vs. 8.6) revealed a considerable vector source reduction. Conclusion The findings of this study suggest considering and including community engagement in public health policy as the main thrust to control VBDs.
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Affiliation(s)
| | - Bontha Veerraju Babu
- Division of Socio-Behavioural & Health Systems Research, Indian Council of Medical Research, New Delhi, India
| | | | - Anju Murali
- ICMR-National Institute of Virology, Kerala Unit, Alappuzha, India
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Oliva CF, Benedict MQ, Collins CM, Baldet T, Bellini R, Bossin H, Bouyer J, Corbel V, Facchinelli L, Fouque F, Geier M, Michaelakis A, Roiz D, Simard F, Tur C, Gouagna LC. Sterile Insect Technique (SIT) against Aedes Species Mosquitoes: A Roadmap and Good Practice Framework for Designing, Implementing and Evaluating Pilot Field Trials. INSECTS 2021; 12:191. [PMID: 33668374 PMCID: PMC7996155 DOI: 10.3390/insects12030191] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 02/16/2021] [Accepted: 02/20/2021] [Indexed: 12/20/2022]
Abstract
Aedes albopictus and Aedes aegypti are invasive mosquito species that impose a substantial risk to human health. To control the abundance and spread of these arboviral pathogen vectors, the sterile insect technique (SIT) is emerging as a powerful complement to most commonly-used approaches, in part, because this technique is ecologically benign, specific, and non-persistent in the environment if releases are stopped. Because SIT and other similar vector control strategies are becoming of increasing interest to many countries, we offer here a pragmatic and accessible 'roadmap' for the pre-pilot and pilot phases to guide any interested party. This will support stakeholders, non-specialist scientists, implementers, and decision-makers. Applying these concepts will ensure, given adequate resources, a sound basis for local field trialing and for developing experience with the technique in readiness for potential operational deployment. This synthesis is based on the available literature, in addition to the experience and current knowledge of the expert contributing authors in this field. We describe a typical path to successful pilot testing, with the four concurrent development streams of Laboratory, Field, Stakeholder Relations, and the Business and Compliance Case. We provide a graphic framework with criteria that must be met in order to proceed.
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Affiliation(s)
- Clélia F. Oliva
- Centre Technique Interprofessionnel des Fruits et Légumes (CTIFL), Centre Opérationnel de Balandran, 751 Chemin de Balandran, 30127 Bellegarde, France;
- Collectif TIS (Technique de l’Insecte Stérile), 751 Chemin de Balandran, 30127 Bellegarde, France
| | | | - C Matilda Collins
- Centre for Environmental Policy, Imperial College London, London SW7 1NE, UK;
| | - Thierry Baldet
- ASTRE (Animal, Santé, Territoires, Risques, Ecosystèmes), Cirad, Univ Montpellier, 34398 Montpellier, France; (T.B.); (J.B.)
| | - Romeo Bellini
- Centro Agricoltura Ambiente “Giorgio Nicoli”, S.r.l. Via Sant’Agata, 835, 40014 Crevalcore, Italy;
| | - Hervé Bossin
- Institut Louis Malardé, Papeete, 98713 Tahiti, French Polynesia;
| | - Jérémy Bouyer
- ASTRE (Animal, Santé, Territoires, Risques, Ecosystèmes), Cirad, Univ Montpellier, 34398 Montpellier, France; (T.B.); (J.B.)
- Insect Pest Control Laboratory, Joint FAO/IAEA Programme of Nuclear Techniques in Food and Agriculture, IAEA Vienna, Wagramer Strasse 5, 1400 Vienna, Austria
| | - Vincent Corbel
- UMR MIVEGEC (Maladies Infectieuses et Vecteurs: Écologie, Génétique, Évolution et Contrôle), IRD-CNRS-Univ. Montpellier, 34394 Montpellier, France; (V.C.); (D.R.); (F.S.)
| | - Luca Facchinelli
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK;
| | - Florence Fouque
- TDR (Special Programme for Research and Training in Tropical Diseases), WHO, 20 Avenue Appia, 1121 Geneva, Switzerland;
| | - Martin Geier
- Biogents AG, Weissenburgstr. 22, 93055 Regensburg, Germany;
| | - Antonios Michaelakis
- Benaki Phytopathological Institute. 8, S. Delta str., Kifissia, 14561 Athens, Greece;
| | - David Roiz
- UMR MIVEGEC (Maladies Infectieuses et Vecteurs: Écologie, Génétique, Évolution et Contrôle), IRD-CNRS-Univ. Montpellier, 34394 Montpellier, France; (V.C.); (D.R.); (F.S.)
| | - Frédéric Simard
- UMR MIVEGEC (Maladies Infectieuses et Vecteurs: Écologie, Génétique, Évolution et Contrôle), IRD-CNRS-Univ. Montpellier, 34394 Montpellier, France; (V.C.); (D.R.); (F.S.)
| | - Carlos Tur
- Grupo Tragsa–KM. 4,5 Bajo, A28476208-EMPRE, Moncada, 46113 Valencia, Spain;
| | - Louis-Clément Gouagna
- UMR MIVEGEC (Maladies Infectieuses et Vecteurs: Écologie, Génétique, Évolution et Contrôle), IRD-CNRS-Univ. Montpellier, 34394 Montpellier, France; (V.C.); (D.R.); (F.S.)
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Knerer G, Currie CSM, Brailsford SC. The economic impact and cost-effectiveness of combined vector-control and dengue vaccination strategies in Thailand: results from a dynamic transmission model. PLoS Negl Trop Dis 2020; 14:e0008805. [PMID: 33095791 PMCID: PMC7654761 DOI: 10.1371/journal.pntd.0008805] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2018] [Revised: 11/10/2020] [Accepted: 09/17/2020] [Indexed: 01/17/2023] Open
Abstract
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.
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Affiliation(s)
- Gerhart Knerer
- Mathematical Sciences, University of Southampton, Highfield, Southampton, United Kingdom
- * E-mail:
| | - Christine S. M. Currie
- Mathematical Sciences, University of Southampton, Highfield, Southampton, United Kingdom
| | - Sally C. Brailsford
- Southampton Business School, University of Southampton, Highfield, Southampton, United Kingdom
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Análisis de costo-efectividad del uso del programa VECTOS en el control rutinario de enfermedades transmitidas por Aedes aegypti en dos municipios de Santander, Colombia. BIOMÉDICA 2020; 40:270-282. [PMID: 32673456 PMCID: PMC7505512 DOI: 10.7705/biomedica.4658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Indexed: 12/04/2022]
Abstract
Introducción. Las enfermedades transmitidas por Aedes aegypti son un problema de salud pública. VECTOS es un programa novedoso de integración de estrategias de control de vectores. Objetivo. Evaluar el costo-efectividad del uso del VECTOS en los programas de control rutinario de enfermedades transmitidas por el vector Aedes aegypti en el municipio de San Juan de Girón (Santander). Materiales y métodos. Se evaluó el costo-efectividad del programa empleando un modelo de análisis de decisiones desde la perspectiva de las autoridades locales de salud. Se estudió la integración de las estrategias de control de vectores mediante el programa VECTOS utilizado en el municipio de San Juan de Girón durante el 2016, con el control rutinario llevado a cabo sin VECTOS en el municipio de Floridablanca. Se calculó la razón incremental del costo-efectividad (RICE), usando como medida de efectividad los años de vida ajustados por discapacidad (AVAD). Resultados. El uso del programa VECTOS fue rentable a una tasa de ahorro de USD$ 660,4 por cada AVAD evitado en comparación con el control de rutina en Floridablanca. El modelo probabilístico indicó que el sistema fue costo-efectivo en el 70 % de las 10.000 iteraciones para un umbral entre 1 y 3 PIB per cápita. Conclusiones. El programa VECTOS fue muy costo-efectivo en el municipio de San Juan de Girón. Su uso puede adoptarse en otros municipios del país donde las enfermedades transmitidas por A. aegypti son endémicas.
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Bardach AE, García-Perdomo HA, Alcaraz A, Tapia López E, Gándara RAR, Ruvinsky S, Ciapponi A. Interventions for the control of Aedes aegypti in Latin America and the Caribbean: systematic review and meta-analysis. Trop Med Int Health 2019; 24:530-552. [PMID: 30771267 DOI: 10.1111/tmi.13217] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To determine the effectiveness and degree of implementation of interventions for the control of Aedes aegypti in Latin America and the Caribbean (LAC) as reported in scientific literature. METHODS We searched MEDLINE, EMBASE, CENTRAL, SOCINDEX, and LILACS, for experimental and observational studies, economic assessments and qualitative experiences carried out in LAC from 2000 to 2016. We assessed incidence and morbimortality of Aedes aegypti-related diseases and entomological indices: Breteau (containers), House, and Pupae per Person. We used GRADE methodology for assessing quality of evidence. RESULTS Of 1826 records retrieved, 75 were included and 9 cluster randomised clinical trials could be meta-analysed. We did not identify any intervention supported by a high certainty of evidence. In consistency with qualitative evidence, health education and community engagement probably reduces the entomological indices, as do the use of insecticide-treated materials, indoor residual spraying and the management of containers. There is low certainty of evidence supporting the use of ovitraps or larvitraps, and the integrated epidemiological surveillance strategy to improve indices and reduce the incidence of dengue. The reported degree of implementation of these vector control interventions was variable and most did not extend to whole cities and were not sustained beyond 2 years. CONCLUSIONS We found a general lack of evidence on effectiveness of vector control in the region, despite a few interventions that showed moderate to low certainty of evidence. It is important to engage and educate the community, apart from achieving the implementation of integrated actions between the health and other sectors at national and regional level.
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Affiliation(s)
- Ariel Esteban Bardach
- Instituto de Efectividad Clínica y Sanitaria, Centro de Investigación de Epidemiología y Salud Pública, Buenos Aires, Argentina.,Consejo Nacional de Investigaciones Científicas y Técnicas and Centro Cochrane, Buenos Aires, Argentina
| | | | - Andrea Alcaraz
- Instituto de Efectividad Clínica y Sanitaria, Centro de Investigación de Epidemiología y Salud Pública, Buenos Aires, Argentina
| | - Elena Tapia López
- Instituto de Efectividad Clínica y Sanitaria, Centro de Investigación de Epidemiología y Salud Pública, Buenos Aires, Argentina
| | - Ruth Amanda Ruano Gándara
- Instituto de Efectividad Clínica y Sanitaria, Centro de Investigación de Epidemiología y Salud Pública, Buenos Aires, Argentina
| | - Silvina Ruvinsky
- Hospital de Pediatría "Pedro Garrahan", Ciudad Autónoma de Buenos Aires, Buenos Aires, Argentina
| | - Agustín Ciapponi
- Instituto de Efectividad Clínica y Sanitaria, Centro de Investigación de Epidemiología y Salud Pública, Buenos Aires, Argentina.,Consejo Nacional de Investigaciones Científicas y Técnicas and Centro Cochrane, Buenos Aires, Argentina
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Fitzpatrick C, Haines A, Bangert M, Farlow A, Hemingway J, Velayudhan R. An economic evaluation of vector control in the age of a dengue vaccine. PLoS Negl Trop Dis 2017; 11:e0005785. [PMID: 28806786 PMCID: PMC5573582 DOI: 10.1371/journal.pntd.0005785] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Revised: 08/28/2017] [Accepted: 07/06/2017] [Indexed: 01/16/2023] Open
Abstract
INTRODUCTION Dengue is a rapidly emerging vector-borne Neglected Tropical Disease, with a 30-fold increase in the number of cases reported since 1960. The economic cost of the illness is measured in the billions of dollars annually. Environmental change and unplanned urbanization are conspiring to raise the health and economic cost even further beyond the reach of health systems and households. The health-sector response has depended in large part on control of the Aedes aegypti and Ae. albopictus (mosquito) vectors. The cost-effectiveness of the first-ever dengue vaccine remains to be evaluated in the field. In this paper, we examine how it might affect the cost-effectiveness of sustained vector control. METHODS We employ a dynamic Markov model of the effects of vector control on dengue in both vectors and humans over a 15-year period, in six countries: Brazil, Columbia, Malaysia, Mexico, the Philippines, and Thailand. We evaluate the cost (direct medical costs and control programme costs) and cost-effectiveness of sustained vector control, outbreak response and/or medical case management, in the presence of a (hypothetical) highly targeted and low cost immunization strategy using a (non-hypothetical) medium-efficacy vaccine. RESULTS Sustained vector control using existing technologies would cost little more than outbreak response, given the associated costs of medical case management. If sustained use of existing or upcoming technologies (of similar price) reduce vector populations by 70-90%, the cost per disability-adjusted life year averted is 2013 US$ 679-1331 (best estimates) relative to no intervention. Sustained vector control could be highly cost-effective even with less effective technologies (50-70% reduction in vector populations) and in the presence of a highly targeted and low cost immunization strategy using a medium-efficacy vaccine. DISCUSSION Economic evaluation of the first-ever dengue vaccine is ongoing. However, even under very optimistic assumptions about a highly targeted and low cost immunization strategy, our results suggest that sustained vector control will continue to play an important role in mitigating the impact of environmental change and urbanization on human health. If additional benefits for the control of other Aedes borne diseases, such as Chikungunya, yellow fever and Zika fever are taken into account, the investment case is even stronger. High-burden endemic countries should proceed to map populations to be covered by sustained vector control.
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Affiliation(s)
- Christopher Fitzpatrick
- Department of Control of Neglected Tropical Diseases, World Health Organization, Geneva, Switzerland
- * E-mail:
| | - Alexander Haines
- Department of Control of Neglected Tropical Diseases, World Health Organization, Geneva, Switzerland
- National Guideline Centre, Royal College of Physicians, London, United Kingdom
| | - Mathieu Bangert
- Department of Control of Neglected Tropical Diseases, World Health Organization, Geneva, Switzerland
| | - Andrew Farlow
- Oxford Martin School, University of Oxford, Oxford, United Kingdom
| | - Janet Hemingway
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Raman Velayudhan
- Department of Control of Neglected Tropical Diseases, World Health Organization, Geneva, Switzerland
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Rather IA, Parray HA, Lone JB, Paek WK, Lim J, Bajpai VK, Park YH. Prevention and Control Strategies to Counter Dengue Virus Infection. Front Cell Infect Microbiol 2017; 7:336. [PMID: 28791258 PMCID: PMC5524668 DOI: 10.3389/fcimb.2017.00336] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 07/10/2017] [Indexed: 01/05/2023] Open
Abstract
Dengue is currently the highest and rapidly spreading vector-borne viral disease, which can lead to mortality in its severe form. The globally endemic dengue poses as a public health and economic challenge that has been attempted to suppress though application of various prevention and control techniques. Therefore, broad spectrum techniques, that are efficient, cost-effective, and environmentally sustainable, are proposed and practiced in dengue-endemic regions. The development of vaccines and immunotherapies have introduced a new dimension for effective dengue control and prevention. Thus, the present study focuses on the preventive and control strategies that are currently employed to counter dengue. While traditional control strategies bring temporary sustainability alone, implementation of novel biotechnological interventions, such as sterile insect technique, paratransgenesis, and production of genetically modified vectors, has improved the efficacy of the traditional strategies. Although a large-scale vector control strategy can be limited, innovative vaccine candidates have provided evidence for promising dengue prevention measures. The use of tetravalent dengue vaccine (CYD-TDV) has been the most effective so far in treating dengue infections. Nonetheless, challenges and limitation hinder the progress of developing integrated intervention methods and vaccines; while the improvement in the latest techniques and vaccine formulation continues, one can hope for a future without the threat of dengue virus.
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Affiliation(s)
- Irfan A Rather
- Department of Applied Microbiology and Biotechnology, School of Biotechnology, Yeungnam UniversityGyeongsan, South Korea
| | - Hilal A Parray
- Department of Biotechnology, Daegu UniversityGyungsan, South Korea
| | - Jameel B Lone
- Department of Biotechnology, Daegu UniversityGyungsan, South Korea
| | - Woon K Paek
- National Science Museum, Ministry of Science, ICT and Future PlanningDaejeon, South Korea
| | - Jeongheui Lim
- National Science Museum, Ministry of Science, ICT and Future PlanningDaejeon, South Korea
| | - Vivek K Bajpai
- Department of Applied Microbiology and Biotechnology, School of Biotechnology, Yeungnam UniversityGyeongsan, South Korea
| | - Yong-Ha Park
- Department of Applied Microbiology and Biotechnology, School of Biotechnology, Yeungnam UniversityGyeongsan, South Korea
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Constenla D, Garcia C, Lefcourt N. Assessing the Economics of Dengue: Results from a Systematic Review of the Literature and Expert Survey. PHARMACOECONOMICS 2015; 33:1107-1135. [PMID: 26048354 DOI: 10.1007/s40273-015-0294-7] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
BACKGROUND The economics of dengue is complex and multifaceted. OBJECTIVES We performed a systematic review of the literature to provide a critical overview of the issues related to dengue economics research and to form a background with which to address the question of cost. METHODS Three literature databases were searched [PubMed, Embase and Latin American and Caribbean Health Sciences Literature (LILACS)], covering a period from 1980 to 2013, to identify papers meeting preset inclusion criteria. Studies were reviewed for methodological quality on the basis of a quality checklist developed for this purpose. An expert survey was designed to identify priority areas in dengue economics research and to identify gaps between the methodology and actual practice. Survey responses were combined with the literature review findings to determine stakeholder priorities in dengue economics research. RESULTS The review identified over 700 papers. Forty-two of these papers met the selection criteria. The studies that were reviewed presented results from 32 dengue-endemic countries, underscoring the importance of dengue as a global public health problem. Cost analyses were the most common, with 21 papers, followed by nine cost-effectiveness analyses and seven cost-of-illness studies, indicating a relatively strong mix of methodologies. Dengue annual overall costs (in 2010 values) ranged from US$13.5 million (in Nicaragua) to $56 million (in Malaysia), showing cost variations across countries. Little consistency exists in the way costs were estimated and dengue interventions evaluated, making generalizations around costs difficult. CONCLUSIONS The current evidence suggests that dengue costs are substantial because of the cost of hospital care and lost earnings. Further research in this area will broaden our understanding of the true economic impact of dengue.
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Affiliation(s)
- Dagna Constenla
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, 855 N. Wolfe Street, Suite 600, Baltimore, 21205, USA.
- Dengue Vaccine Initiative (DVI), Baltimore, USA.
| | - Cristina Garcia
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, 855 N. Wolfe Street, Suite 600, Baltimore, 21205, USA
| | - Noah Lefcourt
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, 855 N. Wolfe Street, Suite 600, Baltimore, 21205, USA
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Healy K, Hamilton G, Crepeau T, Healy S, Unlu I, Farajollahi A, Fonseca DM. Integrating the public in mosquito management: active education by community peers can lead to significant reduction in peridomestic container mosquito habitats. PLoS One 2014; 9:e108504. [PMID: 25255027 PMCID: PMC4177891 DOI: 10.1371/journal.pone.0108504] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Accepted: 09/01/2014] [Indexed: 11/19/2022] Open
Abstract
Mosquito species that utilize peridomestic containers for immature development are commonly aggressive human biters, and because they often reach high abundance, create significant nuisance. One of these species, the Asian tiger mosquito Aedes albopictus, is an important vector of emerging infectious diseases, such as dengue, chikungunya, and Zika fevers. Integrated mosquito management (IMM) of Ae. albopictus is particularly difficult because it requires access to private yards in urban and suburban residences. It has become apparent that in the event of a public health concern due to this species, homeowners will have to be active participants in the control process by reducing mosquito habitats in their properties, an activity known as source reduction. However, limited attempts at quantifying the effect of source reduction by homeowners have had mixed results. Of note, many mosquito control programs in the US have some form of education outreach, however the primary approach is often passive focusing on the distribution of education materials as flyers. In 2010, we evaluated the use of active community peer education in a source reduction program, using AmeriCorps volunteers. The volunteers were mobilized over a 4-week period, in two areas with approximately 1,000 residences each in urban Mercer and suburban Monmouth counties in New Jersey, USA. The volunteers were first provided training on peridomestic mosquitoes and on basic approaches to reducing the number of container habitats for mosquito larvae in backyards. Within the two treatment areas the volunteers successfully engaged 758 separate homes. Repeated measures analysis of variance showed a significant reduction in container habitats in the sites where the volunteers actively engaged the community compared to untreated control areas in both counties. Our results suggest that active education using community peer educators can be an effective means of source reduction, and a critical tool in the arsenal against peridomestic mosquitoes.
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Affiliation(s)
- Kristen Healy
- Center for Vector Biology, Department of Entomology, Rutgers University, New Brunswick, New Jersey, United States of America
- * E-mail:
| | - George Hamilton
- Center for Vector Biology, Department of Entomology, Rutgers University, New Brunswick, New Jersey, United States of America
| | - Taryn Crepeau
- Monmouth County Mosquito Extermination Commission, Eatontown, New Jersey, United States of America
| | - Sean Healy
- Monmouth County Mosquito Extermination Commission, Eatontown, New Jersey, United States of America
| | - Isik Unlu
- Mercer County Mosquito Commission, West Trenton, New Jersey, United States of America
| | - Ary Farajollahi
- Mercer County Mosquito Commission, West Trenton, New Jersey, United States of America
| | - Dina M. Fonseca
- Center for Vector Biology, Department of Entomology, Rutgers University, New Brunswick, New Jersey, United States of America
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Schiavo R, Leung MM, Brown M. Communicating risk and promoting disease mitigation measures in epidemics and emerging disease settings. Pathog Glob Health 2014; 108:76-94. [PMID: 24649867 PMCID: PMC4005587 DOI: 10.1179/2047773214y.0000000127] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
OBJECTIVE This review aims to identify and assess evidence on interventions to communicate risk and promote disease mitigation measures in epidemics and emerging disease outbreak settings. The study focuses on data that are relevant to low and middle-income country (LMIC) settings. METHODS We conducted a comprehensive literature search using five major electronic databases (Pubmed Medline, Biomed Central, EMBASE, Science of Citation Index, and Cochrane Library) and other sources to identify relevant studies published from January 2002 to July 2013. The review was guided by the socio-ecological model/perspective of public health and the ideation theory and focused on interventions at the community, healthcare, and multi-sectoral settings, which also reflect key intervention levels of the Ottawa Charter for Health Promotion. Eligible quantitative studies were selected according to specific study criteria and assessed using the Critical Appraisal Skills Program (CASP) framework. Conversely, qualitative studies, reviews, case studies, and editorials were not included. Studies were selected by two independent reviewers. RESULTS Twenty-nine relevant studies from 16 countries were included. Most studies focused on a single intervention or intervention level, rather than multi-sectoral interventions. The majority of the evidence relates to programs aimed at behavioral and social results (or relevant intermediate steps) within a specific population group. Two studies included implications for improvements in health service delivery, two studies examined the intervention's impact on health systems-related outcomes, and three had also implications for environmental health outcomes. Cost- and health equity-related implications for select evidence were also discussed. CONCLUSIONS The paucity of well-designed quantitative evaluations of interventions to communicate health risk and promote disease control measures in LMICs does not allow for any definitive conclusions. Yet, the review identified several promising interventions and areas for future investigation. Among them, community-based and participatory interventions seemed to be central within epidemic and emerging disease settings, particularly in low-resource settings. Yet, evidence on their effectiveness is not conclusive and needs to be explored by future studies. Other promising areas for future investigation include multi-component and multi-sectoral approaches to intervention design. Major research gaps referred to any evaluation of the impact of these kinds of interventions on health policy adoption and/or implementation, and social determinants of health. Research on cost-effectiveness also needs to be strengthened. This review identified several research gaps and questions, and discusses potential future directions for increasing capacity for future and more rigorous assessments.
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Key Words
- Behavior change communication,
- Communication preparedness,
- Cost,
- Development communication,
- Emerging diseases,
- Epidemics,
- Global health,
- Health communication,
- Health equity,
- Health promotion,
- Health service delivery,
- Health systems,
- Low and middle-income countries (LMICs),
- Outbreak control,
- Public health,
- Risk communication,
- Social change communication,
- Vulnerable and underserved populations
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Affiliation(s)
| | - May May Leung
- CUNY School of Public Health, New York, NY, USA
- Hunter College, New York, NY, USA
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13
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Thuilliez J, Bellia C, Dehecq JS, Reilhes O. Household-level expenditure on protective measures against mosquitoes on the island of La Réunion, France. PLoS Negl Trop Dis 2014; 8:e2609. [PMID: 24392170 PMCID: PMC3879241 DOI: 10.1371/journal.pntd.0002609] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Accepted: 11/15/2013] [Indexed: 11/19/2022] Open
Abstract
Background For decades La Réunion has experienced a number of epidemics that have resulted in efforts to control the density of Aedes species on this Island. This study was conducted to assess household-level expenditure on protective measures against mosquito nuisance on the Island of La Réunion in 2012. Methodology/Principal Findings Data was collected during a cross-sectional survey of 1024 households and used to determine the relationship between the use of chemically-based protective measures and subjective and objective indicators of the density of Aedes albopictus. The average household expenditure in July 2012 was USD 9.86 and the total household-level expenditure over a one-year period was extrapolated to USD 28.05million (range: USD 25.58 million to USD 30.76 million). Much of this money was spent on measures thought to be relatively ineffective against Aedes mosquitoes. Expenditure on protective measures was not influenced by the level of knowledge on mosquitoes or by the visual nuisance they generated at home, but rather by the perception of risk related to a future epidemic of chikungunya and socioeconomic factors. Most importantly, household spending on protective measures was found to be influenced by a measure of zone-level mosquito density (the Breteau index), but not by objective indicators of the presence of mosquitoes within or around the house. Conclusions/Significance Household-level expenditure on chemically-based protective measures is high when compared to the investment made by public entities to achieve vector control, and it is differentially influenced by subjective and objective measures of mosquito density. The current situation could be improved, firstly by ensuring that the public is well-informed about mosquitoes and the effectiveness of various protective measures, and secondly by implementing interventions that could either complement current vector-control strategies and improve their effectiveness on a country-level, or that would steer the population toward the appropriate behaviours. The French Ministry of Health has, for decades, dedicated numerous resources to control mosquito density on the Island of La Réunion. These efforts were strengthened following an outbreak of chikungunya, a virus transmitted by Aedes mosquitoes, in 2005–2006. In order to understand how public perception and behaviour is affected by this vector, a study was undertaken in 2012. Public behaviour was assessed using estimates of household expenditure on protective measures against mosquitoes. Information was gathered using a survey administered to 1024 households on the Island. Knowledge about mosquitoes was found to be poor across the sample, while perceptions of a risk from epidemics were high. The threat of a chikungunya epidemic was found to be associated with increased expenditure on protective measures, as was a zone-level measure of mosquito density, the Breateau Index. The most important finding is that overall household expenditure due to mosquitoes over a one-year period is USD 28.05 million, rather high when compared to the public service investment. Future vector-control in La Réunion needs to ensure that public health messages are understood by the population and that interventions are implemented that promote appropriate behaviours and reduce current spending at the household-level on protective measures.
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Affiliation(s)
- Josselin Thuilliez
- CES-CNRS, Université Paris 1, Panthéon-Sorbonne, Centre d'économie de la Sorbonne, Maison des Sciences Economiques, Paris, France
- * E-mail:
| | - Claire Bellia
- Institut de Recherche pour le Développement (IRD), Parc Technologique Universitaire, BP172 - 97492 Sainte Clotilde Cedex, La Réunion, France
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Stahl HC, Butenschoen VM, Tran HT, Gozzer E, Skewes R, Mahendradhata Y, Runge-Ranzinger S, Kroeger A, Farlow A. Cost of dengue outbreaks: literature review and country case studies. BMC Public Health 2013; 13:1048. [PMID: 24195519 PMCID: PMC4228321 DOI: 10.1186/1471-2458-13-1048] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2013] [Accepted: 10/27/2013] [Indexed: 11/28/2022] Open
Abstract
Background Dengue disease surveillance and vector surveillance are presumed to detect dengue outbreaks at an early stage and to save – through early response activities – resources, and reduce the social and economic impact of outbreaks on individuals, health systems and economies. The aim of this study is to unveil evidence on the cost of dengue outbreaks. Methods Economic evidence on dengue outbreaks was gathered by conducting a literature review and collecting information on the costs of recent dengue outbreaks in 4 countries: Peru, Dominican Republic, Vietnam, and Indonesia. The literature review distinguished between costs of dengue illness including cost of dengue outbreaks, cost of interventions and cost-effectiveness of interventions. Results Seventeen publications on cost of dengue showed a large range of costs from 0.2 Million US$ in Venezuela to 135.2 Million US$ in Brazil. However, these figures were not standardized to make them comparable. Furthermore, dengue outbreak costs are calculated differently across the publications, and cost of dengue illness is used interchangeably with cost of dengue outbreaks. Only one paper from Australia analysed the resources saved through active dengue surveillance. Costs of vector control interventions have been reported in 4 studies, indicating that the costs of such interventions are lower than those of actual outbreaks. Nine papers focussed on the cost-effectiveness of dengue vaccines or dengue vector control; they do not provide any direct information on cost of dengue outbreaks, but their modelling methodologies could guide future research on cost-effectiveness of national surveillance systems. The country case studies – conducted in very different geographic and health system settings - unveiled rough estimates for 2011 outbreak costs of: 12 million US$ in Vietnam, 6.75 million US$ in Indonesia, 4.5 million US$ in Peru and 2.8 million US$ in Dominican Republic (all in 2012 US$). The proportions of the different cost components (vector control; surveillance; information, education and communication; direct medical and indirect costs), as percentage of total costs, differed across the respective countries. Resources used for dengue disease control and treatment were country specific. Conclusions The evidence so far collected further confirms the methodological challenges in this field: 1) to define technically dengue outbreaks (what do we measure?) and 2) to measure accurately the costs in prospective field studies (how do we measure?). Currently, consensus on the technical definition of an outbreak is sought through the International Research Consortium on Dengue Risk Assessment, Management and Surveillance (IDAMS). Best practice guidelines should be further developed, also to improve the quality and comparability of cost study findings. Modelling the costs of dengue outbreaks and validating these models through field studies should guide further research.
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Affiliation(s)
- Hans-Christian Stahl
- Global Health Task Force, Freiburg University Medical Center, Freiburg im Breisgau, Germany.
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Pérez D, Lefèvre P, Castro M, Toledo ME, Zamora G, Bonet M, Van der Stuyft P. Diffusion of community empowerment strategies for Aedes aegypti control in Cuba: a muddling through experience. Soc Sci Med 2013; 84:44-52. [PMID: 23517703 DOI: 10.1016/j.socscimed.2013.02.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2012] [Revised: 12/16/2012] [Accepted: 02/05/2013] [Indexed: 10/27/2022]
Abstract
Effective participatory strategies in dengue control have been developed and assessed as small-scale efforts. The challenge is to scale-up and institutionalize these strategies within dengue control programs. We describe and critically analyze the diffusion process of an effective empowerment strategy within the Cuban Aedes aegypti control program, focusing on decision-making at the national level, to identify ways forward to institutionalize such strategies in Cuba and elsewhere. From 2005 to 2009, we carried out a process-oriented case study. We used participant observation, in-depth interviews with key informants involved in the diffusion process and document analysis. In a first phase, the data analysis was inductive. In a second phase, to enhance robustness of the analysis, emerging categories were contrasted with Rogers' five-stage conceptual model of the innovation-decision process, which was eventually used as the analytical framework. The diffusion of the empowerment strategy was a continuous and dynamic process. Adoption was a result of the perceived potential match between the innovative empowerment strategy and the performance gap of the Ae. aegypti control program. During implementation, the strategy was partially modified by top level Ae. aegypti control program decision-makers to accommodate program characteristics. However, structure, practices and organizational culture of the control program did not change significantly. Thus rejection occurred. It was mainly due to insufficient dissemination of know-how and underlying principles of the strategy by innovation developers, but also to resistance to change. The innovation-diffusion process has produced mitigated results to date, and the control program is still struggling to find ways to move forward. Improving the innovation strategy by providing the necessary knowledge about the innovation and addressing control program organizational changes is crucial for successful diffusion of empowerment strategies. Issues highlighted in this particular experience might be relevant in the innovation-diffusion process of other complex innovations within health systems.
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Affiliation(s)
- Dennis Pérez
- Epidemiology Division, Tropical Medicine Institute Pedro Kouri, Autopista Novia del Mediodía, Km. 6 ½, La Lisa. P.O. Box 601, Marianao 13, Havana City, Cuba.
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Castro M, Sánchez L, Pérez D, Carbonell N, Lefèvre P, Vanlerberghe V, Van der Stuyft P. A community empowerment strategy embedded in a routine dengue vector control programme: a cluster randomised controlled trial. Trans R Soc Trop Med Hyg 2012; 106:315-21. [DOI: 10.1016/j.trstmh.2012.01.013] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2011] [Revised: 01/30/2012] [Accepted: 01/30/2012] [Indexed: 11/25/2022] Open
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Manda H, Arce LM, Foggie T, Shah P, Grieco JP, Achee NL. Effects of irritant chemicals on Aedes aegypti resting behavior: is there a simple shift to untreated "safe sites"? PLoS Negl Trop Dis 2011; 5:e1243. [PMID: 21814587 PMCID: PMC3144182 DOI: 10.1371/journal.pntd.0001243] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2011] [Accepted: 06/03/2011] [Indexed: 11/18/2022] Open
Abstract
Background Previous studies have identified the behavioral responses of Aedes aegypti to irritant and repellent chemicals that can be exploited to reduce man-vector contact. Maximum efficacy of interventions based on irritant chemical actions will, however, require full knowledge of variables that influence vector resting behavior and how untreated “safe sites” contribute to overall impact. Methods Using a laboratory box assay, resting patterns of two population strains of female Ae. aegypti (THAI and PERU) were evaluated against two material types (cotton and polyester) at various dark:light surface area coverage (SAC) ratio and contrast configuration (horizontal and vertical) under chemical-free and treated conditions. Chemicals evaluated were alphacypermethrin and DDT at varying concentrations. Results Under chemical-free conditions, dark material had significantly higher resting counts compared to light material at all SAC, and significantly increased when material was in horizontal configuration. Cotton elicited stronger response than polyester. Within the treatment assays, significantly higher resting counts were observed on chemical-treated dark material compared to untreated light fabric. However, compared to matched controls, significantly less resting observations were made on chemical-treated dark material overall. Most importantly, resting observations on untreated light material (or “safe sites”) in the treatment assay did not significantly increase for many of the tests, even at 25% SAC. Knockdown rates were ≤5% for all assays. Significantly more observations of flying mosquitoes were made in test assays under chemical-treatment conditions as compared to controls. Conclusions/Significance When preferred Ae. aegypti resting sites are treated with chemicals, even at reduced treatment coverage area, mosquitoes do not simply move to safe sites (untreated areas) following contact with the treated material. Instead, they become agitated, using increased flight as a proxy indicator. It is this contact irritant response that may elicit escape behavior from a treated space and is a focus of exploitation for reducing man-vector contact inside homes. Aedes aegypti, the primary vector mosquito of dengue virus, typically lives near or inside human dwellings, and feeds preferentially on humans. The control of this mosquito vector remains the most important dengue prevention method. The use of chemicals at levels toxic to mosquitoes is currently the only confirmed effective adult vector control strategy with interventions usually applied following epidemic onset. However, research indicates that sub-lethal chemical approaches to prevent human-vector contact at the house level exist: contact irritancy and spatial repellency. The optimum efficacy of an intervention based on contact irritant actions of chemicals will, however, require full knowledge of variables that will influence vector resting behavior and thereby chemical uptake from treated sources. Here we characterize the resting patterns of female Ae. aegypti on two material types at various dark:light surface area coverage ratios and contrast configurations under chemical-free and treated conditions using a laboratory behavioral assay. Change in resting behavior between baseline and treatment conditions was quantified to determine potential negative effects of untreated surfaces (“safe sites”) when irritant responses are elicited. We show that treatment of preferred resting sites with known irritant compounds do not stimulate mosquitoes to move to safe sites after making contact with treated surfaces.
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Affiliation(s)
- Hortance Manda
- Department of Preventive Medicine and Biometrics, Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America.
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Lee BY, Connor DL, Kitchen SB, Bacon KM, Shah M, Brown ST, Bailey RR, Laosiritaworn Y, Burke DS, Cummings DAT. Economic value of dengue vaccine in Thailand. Am J Trop Med Hyg 2011; 84:764-72. [PMID: 21540387 PMCID: PMC3083745 DOI: 10.4269/ajtmh.2011.10-0624] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
With several candidate dengue vaccines under development, this is an important time to help stakeholders (e.g., policy makers, scientists, clinicians, and manufacturers) better understand the potential economic value (cost-effectiveness) of a dengue vaccine, especially while vaccine characteristics and strategies might be readily altered. We developed a decision analytic Markov simulation model to evaluate the potential health and economic value of administering a dengue vaccine to an individual (≤ 1 year of age) in Thailand from the societal perspective. Sensitivity analyses evaluated the effects of ranging various vaccine (e.g., cost, efficacy, side effect), epidemiological (dengue risk), and disease (treatment-seeking behavior) characteristics. A ≥ 50% efficacious vaccine was highly cost-effective [< 1× per capita gross domestic product (GDP) ($4,289)] up to a total vaccination cost of $60 and cost-effective [< 3× per capita GDP ($12,868)] up to a total vaccination cost of $200. When the total vaccine series was $1.50, many scenarios were cost saving.
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Affiliation(s)
- Bruce Y Lee
- University of Pittsburgh School of Medicine, 200 Meyran Avenue, Pittsburgh, PA 15213, USA.
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Toledo ME, Rodriguez A, Valdés L, Carrión R, Cabrera G, Banderas D, Ceballos E, Domeqc M, Peña C, Baly A, Vanlerberghe V, Van der Stuyft P. Evidence on impact of community-based environmental management on dengue transmission in Santiago de Cuba. Trop Med Int Health 2011; 16:744-7. [PMID: 21418448 DOI: 10.1111/j.1365-3156.2011.02762.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
During the dengue outbreak that struck Santiago de Cuba in 2006-2007, we conducted an observational study in the Mariana Grajales district, the former setting of a community trial for Aedes aegypti control. In the trial, community working groups (CWG) had been created in 29 randomly selected intervention house blocks, and routine vector control activities alone were conducted in the remaining 30 control blocks. The CWG elaborated and implemented with the population plans and activities to reduce Aedes infestation. They were still functional in 2006 and continued organizing community-based environmental management activities. The attack rate of dengue fever during the outbreak was 8.5 per 1000 inhabitants in the former intervention blocks and 38.1 per 1000 inhabitants in the control blocks, which corresponds to a relative risk of 4.5 (95% CI 3.1-6.5). There was a significantly higher proportion of unaffected intervention blocks, and affected blocks had on average substantially less cases than affected control blocks. This study indicates that community-based environmental management inserted in the routine A. aegypti control programme can not only sustainably curb vector infestation but also have an impact on dengue transmission.
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Affiliation(s)
- Maria E Toledo
- Instituto de Medicina Tropical Pedro Kourí, Habana, Cuba.
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Beatty ME, Beutels P, Meltzer MI, Shepard DS, Hombach J, Hutubessy R, Dessis D, Coudeville L, Dervaux B, Wichmann O, Margolis HS, Kuritsky JN. Health economics of dengue: a systematic literature review and expert panel's assessment. Am J Trop Med Hyg 2011; 84:473-88. [PMID: 21363989 PMCID: PMC3042827 DOI: 10.4269/ajtmh.2011.10-0521] [Citation(s) in RCA: 119] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Dengue vaccines are currently in development and policymakers need appropriate economic studies to determine their potential financial and public health impact. We searched five databases (PubMed, EMBASE, LILAC, EconLit, and WHOLIS) to identify health economics studies of dengue. Forty-three manuscripts were identified that provided primary data: 32 report economic burden of dengue and nine are comparative economic analyses assessing various interventions. The remaining two were a willingness-to-pay study and a policymaker survey. An expert panel reviewed the existing dengue economic literature and recommended future research to fill information gaps. Although dengue is an important vector-borne disease, the economic literature is relatively sparse and results have often been conflicting because of use of inconsistent assumptions. Health economic research specific to dengue is urgently needed to ensure informed decision making on the various options for controlling and preventing this disease.
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Affiliation(s)
- Mark E Beatty
- Pediatric Dengue Vaccine Initiative, International Vaccine Institute, Kwanak-gu, Seoul, Republic of Korea.
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Ocampo CB, Salazar-Terreros MJ, Mina NJ, McAllister J, Brogdon W. Insecticide resistance status of Aedes aegypti in 10 localities in Colombia. Acta Trop 2011; 118:37-44. [PMID: 21300017 DOI: 10.1016/j.actatropica.2011.01.007] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2010] [Revised: 01/21/2011] [Accepted: 01/29/2011] [Indexed: 11/16/2022]
Abstract
Insecticide resistance is one of the major threats to the effectiveness of vector control programs. In order to establish a baseline susceptibility profile of Aedes aegypti in the southwest of Colombia, 10 localities in four Departments (States) were evaluated. Standardized WHO bioassay, CDC bottle bioassay and microplate biochemical assays of non-specific β-esterase (NSE), mixed function oxidases (MFO) and acetylcholinesterase were used. Cross resistance was evaluated with field collected mosquitoes that underwent selection pressure in the laboratory from DDT, propoxur and lambdacyhalothrin during three alternate generations. Mosquitoes with mortality rates below 80% in bioassays were considered resistant. Insecticide resistance varied geographically. Insecticide resistance was observed in 100% of localities in which mosquitoes were exposed to DDT, bendiocarb and temephos using both assays. WHO bioassays showed susceptibility to pyrethroids in all the localities evaluated, however CDC bottle bioassays showed decreases in susceptibility especially with lambdacyhalothrin. All localities showed susceptibility to the organophosphate malathion. Mosquitoes from eight regions with evidence of resistance to any of the insecticide evaluated were also evaluated biochemically. Mosquitoes from five of these regions had increased levels of NSE and two regions had increased levels of MFO. Increase levels of NSE explain partially the low susceptibility to temephos found in all the localities. However, the biochemical mechanisms evaluated do not explain all the resistance observed. Cross resistance was observed between the DDT-selected strain and lambdacyhalothrin, and between the lambdacyhalothrin-selected strain and propoxur and vice versa. The selected strains do not show changes in the biochemical assays evaluated, therefore the observed cross-resistance suggests different biochemical mechanisms. This study shows that Ae. aegypti from Colombia can develop resistance to most of the insecticide classes in the market. Periodic surveillance of insecticide resistance is necessary in order to maintain effective interventions. This study helped to establish the National Network for the surveillance of the insecticide resistance in Colombia.
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Affiliation(s)
- Clara B Ocampo
- Centro Internacional de Entrenamiento e Investigaciones Médicas, Carrera, Cali, Colombia.
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Sanchez L, Perez D, Cruz G, Castro M, Kourí G, Shkedy Z, Vanlerberghe V, Van der Stuyft P. Intersectoral coordination, community empowerment and dengue prevention: six years of controlled interventions in Playa Municipality, Havana, Cuba. Trop Med Int Health 2009; 14:1356-64. [PMID: 19840350 DOI: 10.1111/j.1365-3156.2009.02379.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To document the process, outcome and effectiveness of a community-based intervention for dengue control. METHODS The primary intervention, focused on strengthening intersectoral coordination, was initiated by researchers in January 2000 in a pilot area in Playa municipality, Havana. In August 2002 health authorities extended the intervention to neighbouring areas, one of which was selected for evaluation. In August 2003 a complementary strategy, focused on community empowerment, was initiated in half of the pilot area. In our control area, routine dengue activities continued throughout the study period. Longitudinal process assessment was carried out using document analysis, interviews and group discussions. Random population surveys in 1999, 2002 and 2005 assessed levels of participation and behavioural changes. Entomological surveillance data from 1999 to 2005 were used to determine effectiveness. RESULTS Mean scores for participation in the pilot area were 1.6, 3.4 and 4.4 at baseline, and 2 years after initiating intersectoral coordination and intersectoral coordination plus community empowerment interventions, respectively. While in the control area little behavioural change was observed over time, changes were considerable in the pilot and extension areas, with 80% of households involved in the community empowerment intervention showed adequate behavioural patterns. The pilot and extension areas attained comparable entomological effectiveness with significantly lower Breteau indices (BIs) than the control area. The pilot (sub-) area with the community empowerment intervention reached BIs below 0.1 that continued to be significantly lower than the one in the control area until the end of the study. CONCLUSION The study showed a trend in the levels and quality of participation, behavioural change and effectiveness of Aedes control from the routine activities only over an intervention with intersectoral coordination to one that combined intersectoral coordination and community empowerment approach.
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Affiliation(s)
- L Sanchez
- Institute of Tropical Medicine "Pedro Kouri", Havana City, Cuba.
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Vanlerberghe V, Toledo ME, Rodríguez M, Gomez D, Baly A, Benitez JR, Van der Stuyft P. Community involvement in dengue vector control: cluster randomised trial. BMJ 2009; 338:b1959. [PMID: 19509031 PMCID: PMC2694260 DOI: 10.1136/bmj.b1959] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
OBJECTIVE To assess the effectiveness of an integrated community based environmental management strategy to control Aedes aegypti, the vector of dengue, compared with a routine strategy. DESIGN Cluster randomised trial. SETTING Guantanamo, Cuba. PARTICIPANTS 32 circumscriptions (around 2000 inhabitants each). INTERVENTIONS The circumscriptions were randomly allocated to control clusters (n=16) comprising routine Aedes control programme (entomological surveillance, source reduction, selective adulticiding, and health education) and to intervention clusters (n=16) comprising the routine Aedes control programme combined with a community based environmental management approach. MAIN OUTCOME MEASURES The primary outcome was levels of Aedes infestation: house index (number of houses positive for at least one container with immature stages of Ae aegypti per 100 inspected houses), Breteau index (number of containers positive for immature stages of Ae aegypti per 100 inspected houses), and the pupae per inhabitant statistic (number of Ae aegypti pupae per inhabitant). RESULTS All clusters were subjected to the intended intervention; all completed the study protocol up to February 2006 and all were included in the analysis. At baseline the Aedes infestation levels were comparable between intervention and control clusters: house index 0.25% v 0.20%, pupae per inhabitant 0.44x10(-3) v 0.29x10(-3). At the end of the intervention these indices were significantly lower in the intervention clusters: rate ratio for house indices 0.49 (95% confidence interval 0.27 to 0.88) and rate ratio for pupae per inhabitant 0.27 (0.09 to 0.76). CONCLUSION A community based environmental management embedded in a routine control programme was effective at reducing levels of Aedes infestation. TRIAL REGISTRATION Current Controlled Trials ISRCTN88405796.
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Affiliation(s)
- V Vanlerberghe
- Epidemiology and Disease Control Unit, Public Health Department, Institute of Tropical Medicine, Nationalestraat 155, 2000 Antwerp, Belgium.
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Hutton G. Economic evaluation of environmental health interventions to support decision making. ENVIRONMENTAL HEALTH INSIGHTS 2008; 2:137-55. [PMID: 21572840 PMCID: PMC3091345 DOI: 10.4137/ehi.s1152] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Environmental burden of disease represents one quarter of overall disease burden, hence necessitating greater attention from decision makers both inside and outside the health sector. Economic evaluation techniques such as cost-effectiveness analysis and cost-benefit analysis provide key information to health decision makers on the efficiency of environmental health interventions, assisting them in choosing interventions which give the greatest social return on limited public budgets and private resources. The aim of this article is to review economic evaluation studies in three environmental health areas-water, sanitation, hygiene (WSH), vector control, and air pollution-and to critically examine the policy relevance and scientific quality of the studies for selecting and funding public programmers. A keyword search of Medline from 1990-2008 revealed 32 studies, and gathering of articles from other sources revealed a further 18 studies, giving a total of 50 economic evaluation studies (13 WSH interventions, 16 vector control and 21 air pollution). Overall, the economic evidence base on environmental health interventions remains relatively weak-too few studies per intervention, of variable scientific quality and from diverse locations which limits generalisability of findings. Importantly, there still exists a disconnect between economic research, decision making and programmer implementation. This can be explained by the lack of translation of research findings into accessible documentation for policy makers and limited relevance of research findings, and the often low importance of economic evidence in budgeting decisions. These findings underline the importance of involving policy makers in the defining of research agendas and commissioning of research, and improving the awareness of researchers of the policy environment into which their research feeds.
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Erlanger TE, Keiser J, Utzinger J. Effect of dengue vector control interventions on entomological parameters in developing countries: a systematic review and meta-analysis. MEDICAL AND VETERINARY ENTOMOLOGY 2008; 22:203-221. [PMID: 18816269 DOI: 10.1111/j.1365-2915.2008.00740.x] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The aim of this review was to compare the effects of different dengue vector control interventions (i.e. biological control, chemical control, environmental management and integrated vector management) with respect to the following entomological parameters: Breteau index (BI), container index (CI), and house index (HI). We systematically searched PubMed, ISI Web of Science, Science Direct, the Dengue Bulletin of the World Health Organization and reference lists of retrieved articles on dengue vector control interventions in developing countries. We extracted data on the effectiveness of different dengue vector control interventions (defined as the relative reduction of an entomological measure caused by the intervention compared with the control or pre-intervention phase) and calculated a measure of combined relative effectiveness, with 95% confidence intervals (95% c.i.). We identified 56 publications covering 61 dengue vector control interventions. Integrated vector management was found to be the most effective method to reduce the CI, HI and BI, resulting in random combined relative effectiveness values of 0.12 (95% c.i. 0.02-0.62), 0.17 (95% c.i. 0.02-1.28) and 0.33 (95% c.i. 0.22-0.48), respectively. Environmental management showed a relatively low effectiveness of 0.71 (95% c.i. 0.55-0.90) for the BI, 0.49 (95% c.i. 0.30-0.79) for the CI and 0.43 (95% c.i. 0.31-0.59) for the HI. Biological control (relative effectiveness for the CI: 0.18) usually targeted a small number of people (median population size: 200; range 20-2500), whereas integrated vector management focused on larger populations (median: 12 450; range: 210-9 600 000). In conclusion, dengue vector control is effective in reducing vector populations, particularly when interventions use a community-based, integrated approach, which is tailored to local eco-epidemiological and sociocultural settings and combined with educational programmes to increase knowledge and understanding of best practice. New research should assess the density-dependent effectiveness of each control measure in order to estimate whether reducing vector numbers has an impact on dengue transmission when populations are at a critical threshold.
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Affiliation(s)
- T E Erlanger
- Department of Public Health and Epidemiology, Swiss Tropical Institute, Basel, Switzerland
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