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Laranjeira C, Pereira M, Oliveira R, Barbosa G, Fernandes C, Bermudi P, Resende E, Fernandes E, Nogueira K, Andrade V, Quintanilha J, Santos J, Chiaravalloti-Neto F. Automatic mapping of high-risk urban areas for Aedes aegypti infestation based on building facade image analysis. PLoS Negl Trop Dis 2024; 18:e0011811. [PMID: 38829905 DOI: 10.1371/journal.pntd.0011811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Accepted: 05/17/2024] [Indexed: 06/05/2024] Open
Abstract
BACKGROUND Dengue, Zika, and chikungunya, whose viruses are transmitted mainly by Aedes aegypti, significantly impact human health worldwide. Despite the recent development of promising vaccines against the dengue virus, controlling these arbovirus diseases still depends on mosquito surveillance and control. Nonetheless, several studies have shown that these measures are not sufficiently effective or ineffective. Identifying higher-risk areas in a municipality and directing control efforts towards them could improve it. One tool for this is the premise condition index (PCI); however, its measure requires visiting all buildings. We propose a novel approach capable of predicting the PCI based on facade street-level images, which we call PCINet. METHODOLOGY Our study was conducted in Campinas, a one million-inhabitant city in São Paulo, Brazil. We surveyed 200 blocks, visited their buildings, and measured the three traditional PCI components (building and backyard conditions and shading), the facade conditions (taking pictures of them), and other characteristics. We trained a deep neural network with the pictures taken, creating a computational model that can predict buildings' conditions based on the view of their facades. We evaluated PCINet in a scenario emulating a real large-scale situation, where the model could be deployed to automatically monitor four regions of Campinas to identify risk areas. PRINCIPAL FINDINGS PCINet produced reasonable results in differentiating the facade condition into three levels, and it is a scalable strategy to triage large areas. The entire process can be automated through data collection from facade data sources and inferences through PCINet. The facade conditions correlated highly with the building and backyard conditions and reasonably well with shading and backyard conditions. The use of street-level images and PCINet could help to optimize Ae. aegypti surveillance and control, reducing the number of in-person visits necessary to identify buildings, blocks, and neighborhoods at higher risk from mosquito and arbovirus diseases.
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Affiliation(s)
- Camila Laranjeira
- Department of Computer Science, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Matheus Pereira
- Department of Computer Science, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Raul Oliveira
- Department of Epidemiology, School of Public Health of University of São Paulo, São Paulo, Brazil
| | - Gerson Barbosa
- Pasteur Institute, Secretary of Health of the State of São Paulo, São Paulo, Brazil
| | - Camila Fernandes
- Department of Epidemiology, School of Public Health of University of São Paulo, São Paulo, Brazil
| | - Patricia Bermudi
- Department of Epidemiology, School of Public Health of University of São Paulo, São Paulo, Brazil
| | - Ester Resende
- Department of Computer Science, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Eduardo Fernandes
- Department of Computer Science, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Keiller Nogueira
- Computer Science and Mathematics, University of Stirling, Stirling, United Kingdom
| | - Valmir Andrade
- Epidemiologic Surveillance Center, Secretary of Health of the State of São Paulo, São Paulo, Brazil
| | - José Quintanilha
- Institute of Energy and Environment, University of São Paulo, São Paulo, Brazil
| | - Jefersson Santos
- Department of Computer Science, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
- Department of Computer Science, University of Sheffield, Sheffield, United Kingdom
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Cavany S, Huber JH, Wieler A, Tran QM, Alkuzweny M, Elliott M, España G, Moore SM, Perkins TA. Does ignoring transmission dynamics lead to underestimation of the impact of interventions against mosquito-borne disease? BMJ Glob Health 2023; 8:e012169. [PMID: 37652566 PMCID: PMC10476117 DOI: 10.1136/bmjgh-2023-012169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 07/17/2023] [Indexed: 09/02/2023] Open
Abstract
New vector-control technologies to fight mosquito-borne diseases are urgently needed, the adoption of which depends on efficacy estimates from large-scale cluster-randomised trials (CRTs). The release of Wolbachia-infected mosquitoes is one promising strategy to curb dengue virus (DENV) transmission, and a recent CRT reported impressive reductions in dengue incidence following the release of these mosquitoes. Such trials can be affected by multiple sources of bias, however. We used mathematical models of DENV transmission during a CRT of Wolbachia-infected mosquitoes to explore three such biases: human movement, mosquito movement and coupled transmission dynamics between trial arms. We show that failure to account for each of these biases would lead to underestimated efficacy, and that the majority of this underestimation is due to a heretofore unrecognised bias caused by transmission coupling. Taken together, our findings suggest that Wolbachia-infected mosquitoes could be even more promising than the recent CRT suggested. By emphasising the importance of accounting for transmission coupling between arms, which requires a mathematical model, we highlight the key role that models can play in interpreting and extrapolating the results from trials of vector control interventions.
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Affiliation(s)
- Sean Cavany
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, USA
| | - John H Huber
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, USA
| | - Annaliese Wieler
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, USA
| | - Quan Minh Tran
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, USA
| | - Manar Alkuzweny
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, USA
| | - Margaret Elliott
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, USA
| | - Guido España
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, USA
| | - Sean M Moore
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, USA
| | - T Alex Perkins
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, USA
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Modahl CM, Chowdhury A, Low DHW, Manuel MC, Missé D, Kini RM, Mendenhall IH, Pompon J. Midgut transcriptomic responses to dengue and chikungunya viruses in the vectors Aedes albopictus and Aedes malayensis. Sci Rep 2023; 13:11271. [PMID: 37438463 DOI: 10.1038/s41598-023-38354-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Accepted: 07/06/2023] [Indexed: 07/14/2023] Open
Abstract
Dengue (DENV) and chikungunya (CHIKV) viruses are among the most preponderant arboviruses. Although primarily transmitted through the bite of Aedes aegypti mosquitoes, Aedes albopictus and Aedes malayensis are competent vectors and have an impact on arbovirus epidemiology. Here, to fill the gap in our understanding of the molecular interactions between secondary vectors and arboviruses, we used transcriptomics to profile the whole-genome responses of A. albopictus to CHIKV and of A. malayensis to CHIKV and DENV at 1 and 4 days post-infection (dpi) in midguts. In A. albopictus, 1793 and 339 genes were significantly regulated by CHIKV at 1 and 4 dpi, respectively. In A. malayensis, 943 and 222 genes upon CHIKV infection, and 74 and 69 genes upon DENV infection were significantly regulated at 1 and 4 dpi, respectively. We reported 81 genes that were consistently differentially regulated in all the CHIKV-infected conditions, identifying a CHIKV-induced signature. We identified expressed immune genes in both mosquito species, using a de novo assembled midgut transcriptome for A. malayensis, and described the immune architectures. We found the JNK pathway activated in all conditions, generalizing its antiviral function to Aedines. Our comprehensive study provides insight into arbovirus transmission by multiple Aedes vectors.
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Affiliation(s)
- Cassandra M Modahl
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore
- Liverpool School of Tropical Medicine, Liverpool, U.K
| | - Avisha Chowdhury
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore
- Toronto Centre for Liver Disease, Toronto General Hospital, University Health Network, University of Toronto, Toronto, Canada
| | - Dolyce H W Low
- Programme in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore, Singapore
| | - Menchie C Manuel
- Programme in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore, Singapore
| | - Dorothée Missé
- MIVEGEC, Univ. Montpellier, IRD, CNRS, Montpellier, France
| | - R Manjunatha Kini
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Ian H Mendenhall
- Programme in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore, Singapore
| | - Julien Pompon
- Programme in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore, Singapore.
- MIVEGEC, Univ. Montpellier, IRD, CNRS, Montpellier, France.
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Carrillo MA, Cardenas R, Yañez J, Petzold M, Kroeger A. Risk of dengue, Zika, and chikungunya transmission in the metropolitan area of Cucuta, Colombia: cross-sectional analysis, baseline for a cluster-randomised controlled trial of a novel vector tool for water containers. BMC Public Health 2023; 23:1000. [PMID: 37254133 DOI: 10.1186/s12889-023-15893-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2023] [Accepted: 05/15/2023] [Indexed: 06/01/2023] Open
Abstract
BACKGROUND Arbovirus diseases such as dengue, Zika, and chikungunya are a public health threat in tropical and subtropical areas. In the absence of a vaccine or specific treatment, vector management (in this case the control of the primary vector Aedes aegypti) is the best practice to prevent the three diseases. A good understanding of vector behaviour, ecology, human mobility and water use can help design effective vector control programmes. This study collected baseline information on these factors for identifying the arbovirus transmission risk and assessed the requirements for a large intervention trial in Colombia. METHODS Baseline surveys were conducted in 5,997 households, randomly selected from 24 clusters (neighbourhoods with on average 2000 houses and 250 households inspected) in the metropolitan area of Cucuta, Colombia. The study established population characteristics including water management and mobility as well as larval-pupal indices which were estimated and compared in all clusters. Additionally, the study estimated disease incidence from two sources: self-reported dengue cases in the household survey and cases notified by the national surveillance system. RESULTS In all 24 study clusters similar social and demographic characteristics were found but the entomological indicators and estimated disease incidence rates varied. The entomological indicators showed a high vector infestation: House Index = 25.1%, Container Index = 12.3% and Breteau Index = 29.6. Pupae per person Index (PPI) as an indicator of the transmission risk showed a large range from 0.22 to 2.04 indicating a high transmission risk in most clusters. The concrete ground tanks for laundry -mostly outdoors and uncovered- were the containers with the highest production of Ae. aegypti as 86.3% of all 17,613 pupae were identified in these containers. Also, the annual incidence of dengue was high: 841.6 self-reported cases per 100,000 inhabitants and the dengue incidence notified by the National surveillance system was 1,013.4 cases per 100,000 in 2019. Only 2.2% of the households used container water for drinking. 40.3% of the study population travelled during the day (when Aedes mosquitoes bite) outside their clusters. CONCLUSIONS The production of Ae. aegypti mosquitoes occurred almost exclusively in concrete ground tanks for laundry (lavadero), the primary intervention target. The baseline study provides necessary evidence for the design and implementation of a cluster randomized intervention trial in Colombia.
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Affiliation(s)
- Maria Angelica Carrillo
- Centre for Medicine and Society, Master Programme Global Urban Health, Albert-Ludwigs University Freiburg, Freiburg in Breisgau, Germany.
| | - Rocio Cardenas
- Centre for Medicine and Society, Master Programme Global Urban Health, Albert-Ludwigs University Freiburg, Freiburg in Breisgau, Germany
| | - Johanna Yañez
- Vector Control Programme, Instituto Departamental de Salud Norte de Santander, Cucuta, Colombia
| | - Max Petzold
- Institute of Public Health, Gothenburg University, Göteborg, Sweden
| | - Axel Kroeger
- Centre for Medicine and Society, Master Programme Global Urban Health, Albert-Ludwigs University Freiburg, Freiburg in Breisgau, Germany
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Baldoquín Rodríguez W, Mirabal M, Van der Stuyft P, Gómez Padrón T, Fonseca V, Castillo RM, Monteagudo Díaz S, Baetens JM, De Baets B, Toledo Romaní ME, Vanlerberghe V. The Potential of Surveillance Data for Dengue Risk Mapping: An Evaluation of Different Approaches in Cuba. Trop Med Infect Dis 2023; 8:tropicalmed8040230. [PMID: 37104355 PMCID: PMC10143650 DOI: 10.3390/tropicalmed8040230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 04/03/2023] [Accepted: 04/11/2023] [Indexed: 04/28/2023] Open
Abstract
To better guide dengue prevention and control efforts, the use of routinely collected data to develop risk maps is proposed. For this purpose, dengue experts identified indicators representative of entomological, epidemiological and demographic risks, hereafter called components, by using surveillance data aggregated at the level of Consejos Populares (CPs) in two municipalities of Cuba (Santiago de Cuba and Cienfuegos) in the period of 2010-2015. Two vulnerability models (one with equally weighted components and one with data-derived weights using Principal Component Analysis), and three incidence-based risk models were built to construct risk maps. The correlation between the two vulnerability models was high (tau > 0.89). The single-component and multicomponent incidence-based models were also highly correlated (tau ≥ 0.9). However, the agreement between the vulnerability- and the incidence-based risk maps was below 0.6 in the setting with a prolonged history of dengue transmission. This may suggest that an incidence-based approach does not fully reflect the complexity of vulnerability for future transmission. The small difference between single- and multicomponent incidence maps indicates that in a setting with a narrow availability of data, simpler models can be used. Nevertheless, the generalized linear mixed multicomponent model provides information of covariate-adjusted and spatially smoothed relative risks of disease transmission, which can be important for the prospective evaluation of an intervention strategy. In conclusion, caution is needed when interpreting risk maps, as the results vary depending on the importance given to the components involved in disease transmission. The multicomponent vulnerability mapping needs to be prospectively validated based on an intervention trial targeting high-risk areas.
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Affiliation(s)
| | - Mayelin Mirabal
- Unidad de Información y Biblioteca, Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico
| | | | - Tania Gómez Padrón
- Centro Provincial de Higiene Epidemiología y Microbiología, Dirección Provincial de Salud, Santiago de Cuba 90100, Cuba
| | - Viviana Fonseca
- Centro Provincial de Higiene Epidemiología y Microbiología, Dirección Provincial de Salud, Santiago de Cuba 90100, Cuba
| | - Rosa María Castillo
- Unidad Provincial de Vigilancia y Lucha Antivectorial, Dirección Provincial de Salud, Santiago de Cuba 90100, Cuba
| | - Sonia Monteagudo Díaz
- Centro Provincial de Higiene Epidemiología y Microbiología, Dirección Provincial de Salud, Cienfuegos 55100, Cuba
| | - Jan M Baetens
- KERMIT, Department of Data Analysis and Mathematical Modelling, Ghent University, Coupure Links 653, 9000 Ghent, Belgium
| | - Bernard De Baets
- KERMIT, Department of Data Analysis and Mathematical Modelling, Ghent University, Coupure Links 653, 9000 Ghent, Belgium
| | | | - Veerle Vanlerberghe
- Public Health Department, Institute of Tropical Medicine, Nationalestraat 155, 2000 Antwerp, Belgium
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Abstract
Flaviviruses are vector-borne pathogens capable of causing devastating human diseases. The re-emergence of Zika in 2016 notoriously led to a widescale epidemic in the Americas. New daunting evidence suggests that a single mutation in Zika virus genome may increase transmission and pathogenesis, further highlighting the need to be prepared for flavivirus outbreaks. Dengue, in particular infects about 400 million people each year, leading to reoccurring local outbreaks. Public health efforts to mitigate flavivirus transmission is largely dependent on vector control strategies, as only a limited number of flavivirus vaccines have been developed thus far. There are currently no commercially available antivirals for flaviviruses, leaving supportive care as the primary treatment option. In this review, we will briefly paint a broad picture of the flavivirus landscape in terms of therapeutics, with particular focus on viral targets, promising novel compounds entering the drug discovery pipeline, as well as model systems for evaluating drug efficacy.
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Ogunlade ST, Meehan MT, Adekunle AI, McBryde ES. A Systematic Review of Mathematical Models of Dengue Transmission and Vector Control: 2010-2020. Viruses 2023; 15:254. [PMID: 36680294 PMCID: PMC9862433 DOI: 10.3390/v15010254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Revised: 01/12/2023] [Accepted: 01/13/2023] [Indexed: 01/19/2023] Open
Abstract
Vector control methods are considered effective in averting dengue transmission. However, several factors may modify their impact. Of these controls, chemical methods, in the long run, may increase mosquitoes' resistance to chemicides, thereby decreasing control efficacy. The biological methods, which may be self-sustaining and very effective, could be hampered by seasonality or heatwaves (resulting in, e.g., loss of Wolbachia infection). The environmental methods that could be more effective than the chemical methods are under-investigated. In this study, a systematic review is conducted to explore the present understanding of the effectiveness of vector control approaches via dengue transmission models.
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Affiliation(s)
- Samson T. Ogunlade
- Australian Institute of Tropical Health and Medicine, James Cook University, Townsville 4811, Australia
- College of Medicine and Dentistry, James Cook University, Townsville 4811, Australia
| | - Michael T. Meehan
- Australian Institute of Tropical Health and Medicine, James Cook University, Townsville 4811, Australia
| | - Adeshina I. Adekunle
- Australian Institute of Tropical Health and Medicine, James Cook University, Townsville 4811, Australia
- Defence Science and Technology Group, Department of Defence, Melbourne 3207, Australia
| | - Emma S. McBryde
- Australian Institute of Tropical Health and Medicine, James Cook University, Townsville 4811, Australia
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Dufault SM, Tanamas SK, Indriani C, Utarini A, Ahmad RA, Jewell NP, Simmons CP, Anders KL. Disruption of spatiotemporal clustering in dengue cases by wMel Wolbachia in Yogyakarta, Indonesia. Sci Rep 2022; 12:9890. [PMID: 35701454 PMCID: PMC9198086 DOI: 10.1038/s41598-022-13749-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 05/27/2022] [Indexed: 10/25/2022] Open
Abstract
Dengue exhibits focal clustering in households and neighborhoods, driven by local mosquito population dynamics, human population immunity, and fine scale human and mosquito movement. We tested the hypothesis that spatiotemporal clustering of homotypic dengue cases is disrupted by introduction of the arbovirus-blocking bacterium Wolbachia (wMel-strain) into the Aedes aegypti mosquito population. We analysed 318 serotyped and geolocated dengue cases (and 5921 test-negative controls) from a randomized controlled trial in Yogyakarta, Indonesia of wMel deployments. We find evidence of spatial clustering up to 300 m among the 265 dengue cases (3083 controls) in the untreated trial arm. Participant pairs enrolled within 30 days and 50 m had a 4.7-fold increase (compared to 95% CI on permutation-based null distribution: 0.1, 1.2) in the odds of being homotypic (i.e. potentially transmission-related) as compared to pairs occurring at any distance. In contrast, we find no evidence of spatiotemporal clustering among the 53 dengue cases (2838 controls) resident in the wMel-treated arm. Introgression of wMel Wolbachia into Aedes aegypti mosquito populations interrupts focal dengue virus transmission leading to reduced case incidence; the true intervention effect may be greater than the 77% efficacy measured in the primary analysis of the Yogyakarta trial.
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Affiliation(s)
- Suzanne M. Dufault
- grid.47840.3f0000 0001 2181 7878Division of Biostatistics, School of Public Health, University of California, Berkeley, Berkeley, USA
| | - Stephanie K. Tanamas
- grid.1002.30000 0004 1936 7857World Mosquito Program, Institute of Vector-borne Disease, Monash University, Clayton, 3800 Australia
| | - Citra Indriani
- grid.8570.a0000 0001 2152 4506World Mosquito Program Yogyakarta, Centre for Tropical Medicine, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, 55281 Indonesia
| | - Adi Utarini
- grid.8570.a0000 0001 2152 4506World Mosquito Program Yogyakarta, Centre for Tropical Medicine, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, 55281 Indonesia
| | - Riris Andono Ahmad
- grid.8570.a0000 0001 2152 4506World Mosquito Program Yogyakarta, Centre for Tropical Medicine, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, 55281 Indonesia
| | - Nicholas P. Jewell
- grid.47840.3f0000 0001 2181 7878Division of Biostatistics, School of Public Health, University of California, Berkeley, Berkeley, USA ,grid.8991.90000 0004 0425 469XLondon School of Hygiene and Tropical Medicine, Bloomsbury, London, WC1E 7HT UK
| | - Cameron P. Simmons
- grid.1002.30000 0004 1936 7857World Mosquito Program, Institute of Vector-borne Disease, Monash University, Clayton, 3800 Australia
| | - Katherine L. Anders
- grid.1002.30000 0004 1936 7857World Mosquito Program, Institute of Vector-borne Disease, Monash University, Clayton, 3800 Australia
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Juarez JG, Carbajal E, Dickinson KL, Garcia-Luna S, Vuong N, Mutebi JP, Hemme RR, Badillo-Vargas I, Hamer GL. The unreachable doorbells of South Texas: community engagement in colonias on the US-Mexico border for mosquito control. BMC Public Health 2022; 22:1176. [PMID: 35698216 PMCID: PMC9190097 DOI: 10.1186/s12889-022-13426-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 05/11/2022] [Indexed: 11/17/2022] Open
Abstract
Mosquitoes and the diseases they transmit continue to place millions of people at risk of infection around the world. Novel methods of vector control are being developed to provide public health officials with the necessary tools to prevent disease transmission and reduce local mosquito populations. However, these methods will require public acceptance for a sustainable approach and evaluations at local settings. We present our efforts in community engagement carried out in colonias of the Lower Rio Grande Valley in south Texas for mosquito surveillance, control, and ecological projects. Along the US-Mexico border the term colonia refers to impoverished communities that are usually inhabited by families of Hispanic heritage. The different engagements were carried out from September 2016 to February 2019; during this time, we had three distinct phases for community engagement. In Phase 1 we show the initial approach to the colonias in which we assessed security and willingness to participate; in Phase 2 we carried out the first recruitment procedure involving community meetings and house-to-house recruitment; and in Phase 3 we conducted a modified recruitment procedure based on community members' input. Our findings show that incorporating community members in the development of communication materials and following their suggestions for engagement allowed us to generate culturally sensitive recruitment materials and to better understand the social relationships and power dynamics within these communities. We were able to effectively reach a larger portion of the community and decrease the dropout rate of participants. Progress gained with building trust in the communities allowed us to convey participant risks and benefits of collaborating with our research projects. Community engagement should be viewed as a key component of any local vector control program as well as for any scientific research project related to vector control. Even in the face of budgetary constraints, small efforts in community engagement go a long way.
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Affiliation(s)
- Jose G Juarez
- Department of Entomology, Texas A&M University, College Station, TX, USA
| | - Ester Carbajal
- Department of Entomology, Texas A&M University, College Station, TX, USA
| | | | - Selene Garcia-Luna
- Department of Entomology, Texas A&M University, College Station, TX, USA
| | - Nga Vuong
- Division of Vector Borne Diseases, Centers for Disease Control and Prevention, Fort Collins, CO, USA
| | - John-Paul Mutebi
- Division of Vector Borne Diseases, Centers for Disease Control and Prevention, Fort Collins, CO, USA
| | - Ryan R Hemme
- Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, Dengue Branch, San Juan, PR, USA
| | | | - Gabriel L Hamer
- Department of Entomology, Texas A&M University, College Station, TX, USA.
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10
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Collins MH, Potter GE, Hitchings MDT, Butler E, Wiles M, Kennedy JK, Pinto SB, Teixeira ABM, Casanovas-Massana A, Rouphael NG, Deye GA, Simmons CP, Moreira LA, Nogueira ML, Cummings DAT, Ko AI, Teixeira MM, Edupuganti S. EVITA Dengue: a cluster-randomized controlled trial to EValuate the efficacy of Wolbachia-InfecTed Aedes aegypti mosquitoes in reducing the incidence of Arboviral infection in Brazil. Trials 2022; 23:185. [PMID: 35236394 PMCID: PMC8889395 DOI: 10.1186/s13063-022-05997-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2021] [Accepted: 01/03/2022] [Indexed: 11/12/2022] Open
Abstract
Background Arboviruses transmitted by Aedes aegypti including dengue, Zika, and chikungunya are a major global health problem, with over 2.5 billion at risk for dengue alone. There are no licensed antivirals for these infections, and safe and effective vaccines are not yet widely available. Thus, prevention of arbovirus transmission by vector modification is a novel approach being pursued by multiple researchers. However, the field needs high-quality evidence derived from randomized, controlled trials upon which to base the implementation and maintenance of vector control programs. Here, we report the EVITA Dengue trial design (DMID 17-0111), which assesses the efficacy in decreasing arbovirus transmission of an innovative approach developed by the World Mosquito Program for vector modification of Aedes mosquitoes by Wolbachia pipientis. Methods DMID 17-0111 is a cluster-randomized trial in Belo Horizonte, Brazil, with clusters defined by primary school catchment areas. Clusters (n = 58) will be randomized 1:1 to intervention (release of Wolbachia-infected Aedes aegypti mosquitoes) vs. control (no release). Standard vector control activities (i.e., insecticides and education campaigns for reduction of mosquito breeding sites) will continue as per current practice in the municipality. Participants (n = 3480, 60 per cluster) are children aged 6–11 years enrolled in the cluster-defining school and living within the cluster boundaries who will undergo annual serologic surveillance for arboviral infection. The primary objective is to compare sero-incidence of arboviral infection between arms. Discussion DMID 17-0111 aims to determine the efficacy of Wolbachia-infected mosquito releases in reducing human infections by arboviruses transmitted by Aedes aegypti and will complement the mounting evidence for this method from large-scale field releases and ongoing trials. The trial also represents a critical step towards robustness and rigor for how vector control methods are assessed, including the simultaneous measurement and correlation of entomologic and epidemiologic outcomes. Data from this trial will inform further the development of novel vector control methods. Trial registration ClinicalTrials.govNCT04514107. Registered on 17 August 2020 Primary sponsor: National Institute of Health, National Institute of Allergy and Infectious Diseases Supplementary Information The online version contains supplementary material available at 10.1186/s13063-022-05997-4.
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Affiliation(s)
- Matthew H Collins
- Department of Medicine, Division of Infectious Diseases, The Hope Clinic of the Emory Vaccine Center, Emory University, Atlanta, GA, USA
| | - Gail E Potter
- Biostatistics Research Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA.,The Emmes Company, LLC, Rockville, USA
| | - Matt D T Hitchings
- Emerging Pathogens Institute and Department of Biology, University of Florida, Gainesville, FL, USA
| | - Ellie Butler
- Department of Medicine, Division of Infectious Diseases, The Hope Clinic of the Emory Vaccine Center, Emory University, Atlanta, GA, USA
| | - Michelle Wiles
- Department of Medicine, Division of Infectious Diseases, The Hope Clinic of the Emory Vaccine Center, Emory University, Atlanta, GA, USA
| | | | - Sofia B Pinto
- World Mosquito Program, Monash University, Melbourne, 3800, Australia
| | - Adla B M Teixeira
- School of Education, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Minas Gerais, Brazil
| | - Arnau Casanovas-Massana
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, USA
| | - Nadine G Rouphael
- Department of Medicine, Division of Infectious Diseases, The Hope Clinic of the Emory Vaccine Center, Emory University, Atlanta, GA, USA
| | - Gregory A Deye
- Division of Microbiology and Infectious Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, MD, USA
| | - Cameron P Simmons
- World Mosquito Program, Monash University, Melbourne, 3800, Australia
| | - Luciano A Moreira
- Instituto René Rachou, Fiocruz, Belo Horizonte, Minas Gerais, Brazil
| | - Mauricio L Nogueira
- Medical School of São Jose do Rio Preto FAMERP, São Jose do Rio Preto, São Paulo, Brazil
| | - Derek A T Cummings
- Emerging Pathogens Institute and Department of Biology, University of Florida, Gainesville, FL, USA.
| | - Albert I Ko
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, USA. .,Instituto Gonçalo Moniz, Fundação Oswaldo Cruz (Fiocruz), Salvador, Bahia, Brazil.
| | - Mauro M Teixeira
- Department of Biochemistry and Immunology, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
| | - Srilatha Edupuganti
- Department of Medicine, Division of Infectious Diseases, The Hope Clinic of the Emory Vaccine Center, Emory University, Atlanta, GA, USA.
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11
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Potter GE, Carnegie NB, Sugimoto JD, Diallo A, Victor JC, Neuzil KM, Halloran ME. Using social contact data to improve the overall effect estimate of a cluster-randomized influenza vaccination program in Senegal. J R Stat Soc Ser C Appl Stat 2022; 71:70-90. [PMID: 35721226 PMCID: PMC9202735 DOI: 10.1111/rssc.12522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
This study estimates the overall effect of two influenza vaccination programs consecutively administered in a cluster-randomized trial in western Senegal over the course of two influenza seasons from 2009-2011. We apply cutting-edge methodology combining social contact data with infection data to reduce bias in estimation arising from contamination between clusters. Our time-varying estimates reveal a reduction in seasonal influenza from the intervention and a nonsignificant increase in H1N1 pandemic influenza. We estimate an additive change in overall cumulative incidence (which was 6.13% in the control arm) of -0.68 percentage points during Year 1 of the study (95% CI: -2.53, 1.18). When H1N1 pandemic infections were excluded from analysis, the estimated change was -1.45 percentage points and was significant (95% CI, -2.81, -0.08). Because cross-cluster contamination was low (0-3% of contacts for most villages), an estimator assuming no contamination was only slightly attenuated (-0.65 percentage points). These findings are encouraging for studies carefully designed to minimize spillover. Further work is needed to estimate contamination - and its effect on estimation - in a variety of settings.
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Affiliation(s)
- Gail E. Potter
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, and the Emmes Company, Rockville Maryland, USA
| | | | - Jonathan D. Sugimoto
- University of Washington and Epidemiologic Research and Information Center, Veterans Affairs Puget Sound Health Care System and Fred Hutchinson Cancer Research Center, Seattle Washington, USA
| | - Aldiouma Diallo
- Institut de Recherche pour le Développement, Niakhar Senegal
| | | | | | - M. Elizabeth Halloran
- University of Washington Department of Biostatistics and Fred Hutchinson Cancer Research Center, Seattle Washington, USA
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12
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Brady OJ, Kucharski AJ, Funk S, Jafari Y, Loock MV, Herrera-Taracena G, Menten J, Edmunds WJ, Sim S, Ng LC, Hué S, Hibberd ML. Case-area targeted interventions (CATI) for reactive dengue control: Modelling effectiveness of vector control and prophylactic drugs in Singapore. PLoS Negl Trop Dis 2021; 15:e0009562. [PMID: 34379641 PMCID: PMC8357181 DOI: 10.1371/journal.pntd.0009562] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 06/14/2021] [Indexed: 11/21/2022] Open
Abstract
BACKGROUND Targeting interventions to areas that have recently experienced cases of disease is one strategy to contain outbreaks of infectious disease. Such case-area targeted interventions (CATI) have become an increasingly popular approach for dengue control but there is little evidence to suggest how precisely targeted or how recent cases need to be, to mount an effective response. The growing interest in the development of prophylactic and therapeutic drugs for dengue has also given new relevance for CATI strategies to interrupt transmission or deliver early treatment. METHODS/PRINCIPAL FINDINGS Here we develop a patch-based mathematical model of spatial dengue spread and fit it to spatiotemporal datasets from Singapore. Simulations from this model suggest CATI strategies could be effective, particularly if used in lower density areas. To maximise effectiveness, increasing the size of the radius around an index case should be prioritised even if it results in delays in the intervention being applied. This is partially because large intervention radii ensure individuals receive multiple and regular rounds of drug dosing or vector control, and thus boost overall coverage. Given equivalent efficacy, CATIs using prophylactic drugs are predicted to be more effective than adult mosquito-killing vector control methods and may even offer the possibility of interrupting individual chains of transmission if rapidly deployed. CATI strategies quickly lose their effectiveness if baseline transmission increases or case detection rates fall. CONCLUSIONS/SIGNIFICANCE These results suggest CATI strategies can play an important role in dengue control but are likely to be most relevant for low transmission areas where high coverage of other non-reactive interventions already exists. Controlled field trials are needed to assess the field efficacy and practical constraints of large operational CATI strategies.
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Affiliation(s)
- Oliver J. Brady
- Centre for Mathematical Modelling of Infectious Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
- Department of Infectious Disease Epidemiology, Faculty of Epidemiology and Public Health, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Adam J. Kucharski
- Centre for Mathematical Modelling of Infectious Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
- Department of Infectious Disease Epidemiology, Faculty of Epidemiology and Public Health, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Sebastian Funk
- Centre for Mathematical Modelling of Infectious Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
- Department of Infectious Disease Epidemiology, Faculty of Epidemiology and Public Health, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Yalda Jafari
- Centre for Mathematical Modelling of Infectious Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
- Department of Infectious Disease Epidemiology, Faculty of Epidemiology and Public Health, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Marnix Van Loock
- Janssen Global Public Health, Janssen Pharmaceutica NV, Beerse, Belgium
| | - Guillermo Herrera-Taracena
- Janssen Global Public Health, Janssen Research & Development, LLC, Horsham, Pennsylvania, United States of America
| | - Joris Menten
- Quantitative Sciences, Janssen Pharmaceutica NV, Beerse, Belgium
| | - W. John Edmunds
- Centre for Mathematical Modelling of Infectious Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
- Department of Infectious Disease Epidemiology, Faculty of Epidemiology and Public Health, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Shuzhen Sim
- Environmental Health Institute, National Environment Agency, Singapore, Singapore
| | - Lee-Ching Ng
- Environmental Health Institute, National Environment Agency, Singapore, Singapore
| | - Stéphane Hué
- Centre for Mathematical Modelling of Infectious Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
- Department of Infectious Disease Epidemiology, Faculty of Epidemiology and Public Health, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Martin L. Hibberd
- Department of Infection Biology, Faculty of Infectious Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
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13
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Moquin SA, Simon O, Karuna R, Lakshminarayana SB, Yokokawa F, Wang F, Saravanan C, Zhang J, Day CW, Chan K, Wang QY, Lu S, Dong H, Wan KF, Lim SP, Liu W, Seh CC, Chen YL, Xu H, Barkan DT, Kounde CS, Sim WLS, Wang G, Yeo HQ, Zou B, Chan WL, Ding M, Song JG, Li M, Osborne C, Blasco F, Sarko C, Beer D, Bonamy GMC, Sasseville VG, Shi PY, Diagana TT, Yeung BKS, Gu F. NITD-688, a pan-serotype inhibitor of the dengue virus NS4B protein, shows favorable pharmacokinetics and efficacy in preclinical animal models. Sci Transl Med 2021; 13:13/579/eabb2181. [PMID: 33536278 DOI: 10.1126/scitranslmed.abb2181] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Accepted: 01/13/2021] [Indexed: 12/12/2022]
Abstract
Dengue virus (DENV) is a mosquito-borne flavivirus that poses a threat to public health, yet no antiviral drug is available. We performed a high-throughput phenotypic screen using the Novartis compound library and identified candidate chemical inhibitors of DENV. This chemical series was optimized to improve properties such as anti-DENV potency and solubility. The lead compound, NITD-688, showed strong potency against all four serotypes of DENV and demonstrated excellent oral efficacy in infected AG129 mice. There was a 1.44-log reduction in viremia when mice were treated orally at 30 milligrams per kilogram twice daily for 3 days starting at the time of infection. NITD-688 treatment also resulted in a 1.16-log reduction in viremia when mice were treated 48 hours after infection. Selection of resistance mutations and binding studies with recombinant proteins indicated that the nonstructural protein 4B is the target of NITD-688. Pharmacokinetic studies in rats and dogs showed a long elimination half-life and good oral bioavailability. Extensive in vitro safety profiling along with exploratory rat and dog toxicology studies showed that NITD-688 was well tolerated after 7-day repeat dosing, demonstrating that NITD-688 may be a promising preclinical candidate for the treatment of dengue.
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Affiliation(s)
- Stephanie A Moquin
- Novartis Institutes for Biomedical Research, Emeryville, CA 94608, USA.,Novartis Institute for Tropical Diseases, Emeryville, CA 94608, USA
| | - Oliver Simon
- Novartis (Singapore) Pte Ltd, Singapore 117432, Singapore
| | - Ratna Karuna
- Novartis Institute for Tropical Diseases, Singapore 138670, Singapore
| | | | - Fumiaki Yokokawa
- Novartis Institute for Tropical Diseases, Emeryville, CA 94608, USA
| | - Feng Wang
- Novartis Institutes for Biomedical Research, Emeryville, CA 94608, USA
| | - Chandra Saravanan
- Novartis Institutes for Biomedical Research, Translational Medicine: Preclinical Safety, Cambridge, MA 02139, USA
| | - Jin Zhang
- Novartis Institutes for Biomedical Research, Translational Medicine: Pharmacokinetics, East Hanover, NJ 07936, USA
| | - Craig W Day
- Institute for Antiviral Research, Utah State University, Logan, UT 84322, USA
| | - Katherine Chan
- Novartis Institute for Tropical Diseases, Emeryville, CA 94608, USA
| | - Qing-Yin Wang
- Novartis Institute for Tropical Diseases, Singapore 138670, Singapore
| | - Siyan Lu
- Novartis Institute for Tropical Diseases, Singapore 138670, Singapore
| | - Hongping Dong
- Novartis Institute for Tropical Diseases, Singapore 138670, Singapore
| | - Kah Fei Wan
- Novartis Institute for Tropical Diseases, Singapore 138670, Singapore
| | - Siew Pheng Lim
- Novartis Institute for Tropical Diseases, Singapore 138670, Singapore
| | - Wei Liu
- Novartis Institute for Tropical Diseases, Singapore 138670, Singapore
| | - Cheah Chen Seh
- Novartis Institute for Tropical Diseases, Singapore 138670, Singapore
| | - Yen-Liang Chen
- Novartis Institute for Tropical Diseases, Emeryville, CA 94608, USA
| | - Haoying Xu
- Novartis Institute for Tropical Diseases, Singapore 138670, Singapore
| | - David T Barkan
- Novartis Institutes for Biomedical Research, Emeryville, CA 94608, USA
| | - Cyrille S Kounde
- Novartis Institute for Tropical Diseases, Singapore 138670, Singapore
| | | | - Gang Wang
- Novartis Institute for Tropical Diseases, Singapore 138670, Singapore
| | - Hui-Quan Yeo
- Novartis Institute for Tropical Diseases, Singapore 138670, Singapore
| | - Bin Zou
- Novartis Institute for Tropical Diseases, Singapore 138670, Singapore
| | - Wai Ling Chan
- Novartis Institute for Tropical Diseases, Singapore 138670, Singapore
| | - Mei Ding
- Novartis Institute for Tropical Diseases, Singapore 138670, Singapore
| | - Jae-Geun Song
- Novartis Institutes for Biomedical Research, Emeryville, CA 94608, USA
| | - Min Li
- Novartis Institutes for Biomedical Research, Emeryville, CA 94608, USA
| | - Colin Osborne
- Novartis Institute for Tropical Diseases, Emeryville, CA 94608, USA
| | - Francesca Blasco
- Novartis Institute for Tropical Diseases, Singapore 138670, Singapore
| | | | - David Beer
- Novartis Institute for Tropical Diseases, Singapore 138670, Singapore
| | | | - Vito G Sasseville
- Novartis Institutes for Biomedical Research, Translational Medicine: Preclinical Safety, Cambridge, MA 02139, USA
| | - Pei-Yong Shi
- Novartis Institute for Tropical Diseases, Singapore 138670, Singapore
| | | | - Bryan K S Yeung
- Novartis Institute for Tropical Diseases, Singapore 138670, Singapore.
| | - Feng Gu
- Novartis Institute for Tropical Diseases, Emeryville, CA 94608, USA.
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14
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Kirstein OD, Ayora-Talavera G, Koyoc-Cardeña E, Chan Espinoza D, Che-Mendoza A, Cohuo-Rodriguez A, Granja-Pérez P, Puerta-Guardo H, Pavia-Ruz N, Dunbar MW, Manrique-Saide P, Vazquez-Prokopec GM. Natural arbovirus infection rate and detectability of indoor female Aedes aegypti from Mérida, Yucatán, Mexico. PLoS Negl Trop Dis 2021; 15:e0008972. [PMID: 33395435 PMCID: PMC7781390 DOI: 10.1371/journal.pntd.0008972] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 11/10/2020] [Indexed: 12/03/2022] Open
Abstract
Arbovirus infection in Aedes aegypti has historically been quantified from a sample of the adult population by pooling collected mosquitoes to increase detectability. However, there is a significant knowledge gap about the magnitude of natural arbovirus infection within areas of active transmission, as well as the sensitivity of detection of such an approach. We used indoor Ae. aegypti sequential sampling with Prokopack aspirators to collect all mosquitoes inside 200 houses with suspected active ABV transmission from the city of Mérida, Mexico, and tested all collected specimens by RT-PCR to quantify: a) the absolute arbovirus infection rate in individually tested Ae. aegypti females; b) the sensitivity of using Prokopack aspirators in detecting ABV-infected mosquitoes; and c) the sensitivity of entomological inoculation rate (EIR) and vectorial capacity (VC), two measures ABV transmission potential, to different estimates of indoor Ae. aegypti abundance. The total number of Ae. aegypti (total catch, the sum of all Ae. aegypti across all collection intervals) as well as the number on the first 10-min of collection (sample, equivalent to a routine adult aspiration session) were calculated. We individually tested by RT-PCR 2,161 Aedes aegypti females and found that 7.7% of them were positive to any ABV. Most infections were CHIKV (77.7%), followed by DENV (11.4%) and ZIKV (9.0%). The distribution of infected Aedes aegypti was overdispersed; 33% houses contributed 81% of the infected mosquitoes. A significant association between ABV infection and Ae. aegypti total catch indoors was found (binomial GLMM, Odds Ratio > 1). A 10-min indoor Prokopack collection led to a low sensitivity of detecting ABV infection (16.3% for detecting infected mosquitoes and 23.4% for detecting infected houses). When averaged across all infested houses, mean EIR ranged between 0.04 and 0.06 infective bites per person per day, and mean VC was 0.6 infectious vectors generated from a population feeding on a single infected host per house/day. Both measures were significantly and positively associated with Ae. aegypti total catch indoors. Our findings provide evidence that the accurate estimation and quantification of arbovirus infection rate and transmission risk is a function of the sampling effort, the local abundance of Aedes aegypti and the intensity of arbovirus circulation. Aedes-borne diseases comprise a serious public health burden in many parts of the world, usually affecting low income areas. The ability to detect virus circulation within a population may be key in responding to the threat of outbreaks, providing a cost-effective approach for triggering vector control. Unfortunately, gaps in the knowledge of natural Aedes-borne virus (ABV) infection in Aedes aegypti have led to uncertainties in the consideration of arbovirus surveillance in mosquitoes. Here, we show that the natural infection rate in a mosquito population may not be a function of where Aedes aegypti are, but rather where key human-mosquito contacts occur. Sampling 200 houses with suspected ABV active transmission led us to quantify high virus infection rates in all Aedes aegypti present in the house and use such information to estimate the sensitivity of indoor aspiration with Prokopack devices and two measures of ABV transmission potential. Our findings provide evidence that the accurate quantification of arbovirus infection rate and transmission risk is a function of the sampling effort, the local abundance of Aedes aegypti and the intensity of arbovirus circulation. Results from this study are relevant to understand the value of virus testing of vector populations, and for the design of entomological endpoints relevant for epidemiological trials quantifying the impact of vector control on ABVs.
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Affiliation(s)
- Oscar David Kirstein
- Department of Environmental Sciences, Emory University, Atlanta, Georgia, United States of America
| | - Guadalupe Ayora-Talavera
- Laboratorio de Virología. Centro de Investigaciones Regionales “Dr. Hideyo Noguchi”, Universidad Autónoma de Yucatán, Mérida, Yucatán, México
| | - Edgar Koyoc-Cardeña
- Unidad Colaborativa de Bioensayos Entomológicos, Campus de Ciencias Biológicas y Agropecuarias, Universidad Autónoma de Yucatán, Mérida, Yucatán, México
| | - Daniel Chan Espinoza
- Unidad Colaborativa de Bioensayos Entomológicos, Campus de Ciencias Biológicas y Agropecuarias, Universidad Autónoma de Yucatán, Mérida, Yucatán, México
| | - Azael Che-Mendoza
- Unidad Colaborativa de Bioensayos Entomológicos, Campus de Ciencias Biológicas y Agropecuarias, Universidad Autónoma de Yucatán, Mérida, Yucatán, México
| | - Azael Cohuo-Rodriguez
- Unidad Colaborativa de Bioensayos Entomológicos, Campus de Ciencias Biológicas y Agropecuarias, Universidad Autónoma de Yucatán, Mérida, Yucatán, México
| | - Pilar Granja-Pérez
- Laboratorio Estatal de Salud Pública, Servicios de Salud de Yucatán, Mérida, Yucatán, México
| | - Henry Puerta-Guardo
- Unidad Colaborativa de Bioensayos Entomológicos, Campus de Ciencias Biológicas y Agropecuarias, Universidad Autónoma de Yucatán, Mérida, Yucatán, México
| | - Norma Pavia-Ruz
- Laboratorio de Hematología. Centro de Investigaciones Regionales “Dr. Hideyo Noguchi”, Universidad Autónoma de Yucatán, Mérida, Yucatán, México
| | - Mike W. Dunbar
- Department of Environmental Sciences, Emory University, Atlanta, Georgia, United States of America
| | - Pablo Manrique-Saide
- Unidad Colaborativa de Bioensayos Entomológicos, Campus de Ciencias Biológicas y Agropecuarias, Universidad Autónoma de Yucatán, Mérida, Yucatán, México
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15
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Freitas DA, Souza-Santos R, Carvalho LMA, Barros WB, Neves LM, Brasil P, Wakimoto MD. Congenital Zika syndrome: A systematic review. PLoS One 2020; 15:e0242367. [PMID: 33320867 PMCID: PMC7737899 DOI: 10.1371/journal.pone.0242367] [Citation(s) in RCA: 68] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Accepted: 10/31/2020] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND The signs and symptoms of Zika virus infection are usually mild and self-limited. However, the disease has been linked to neurological complications such as Guillain-Barré syndrome and peripheral nerve involvement, and also to abortion and fetal deaths due to vertical transmission, resulting in various congenital malformations in newborns, including microcephaly. This review aimed to describe the o signs and symptoms that characterize the congenital Zika syndrome. METHODS AND FINDINGS A systematic review was performed with a protocol and described according to the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. The search strategy yielded 2,048 studies. After the exclusion of duplicates and application of inclusion criteria, 46 studies were included. The main signs and symptoms associated with the congenital Zika syndrome were microcephaly, parenchymal or cerebellar calcifications, ventriculomegaly, central nervous system hypoplasia or atrophy, arthrogryposis, ocular findings in the posterior and anterior segments, abnormal visual function and low birthweight for gestational age. CONCLUSIONS Zika virus infection during pregnancy can cause a series of changes in the growth and development of children, while impacting the healthcare system due to the severity of cases. Our findings outline the disease profile in newborns and infants and may contribute to the development and updating of more specific clinical protocols.
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Affiliation(s)
- Danielle A. Freitas
- National School of Public Health, Oswaldo Cruz Foundation, Rio de Janeiro, RJ, Brazil
| | - Reinaldo Souza-Santos
- National School of Public Health, Oswaldo Cruz Foundation, Rio de Janeiro, RJ, Brazil
| | - Liege M. A. Carvalho
- Evandro Chagas National Institute of Infectious Diseases, Oswaldo Cruz Foundation, Rio de Janeiro, RJ, Brazil
| | - Wagner B. Barros
- Evandro Chagas National Institute of Infectious Diseases, Oswaldo Cruz Foundation, Rio de Janeiro, RJ, Brazil
| | - Luiza M. Neves
- Fernandes Figueira Institute, Oswaldo Cruz Foundation, Rio de Janeiro, RJ, Brazil
| | - Patrícia Brasil
- Evandro Chagas National Institute of Infectious Diseases, Oswaldo Cruz Foundation, Rio de Janeiro, RJ, Brazil
| | - Mayumi D. Wakimoto
- Evandro Chagas National Institute of Infectious Diseases, Oswaldo Cruz Foundation, Rio de Janeiro, RJ, Brazil
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16
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Manrique-Saide P, Dean NE, Halloran ME, Longini IM, Collins MH, Waller LA, Gomez-Dantes H, Lenhart A, Hladish TJ, Che-Mendoza A, Kirstein OD, Romer Y, Correa-Morales F, Palacio-Vargas J, Mendez-Vales R, Pérez PG, Pavia-Ruz N, Ayora-Talavera G, Vazquez-Prokopec GM. The TIRS trial: protocol for a cluster randomized controlled trial assessing the efficacy of preventive targeted indoor residual spraying to reduce Aedes-borne viral illnesses in Merida, Mexico. Trials 2020; 21:839. [PMID: 33032661 PMCID: PMC7542575 DOI: 10.1186/s13063-020-04780-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Accepted: 09/29/2020] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Current urban vector control strategies have failed to contain dengue epidemics and to prevent the global expansion of Aedes-borne viruses (ABVs: dengue, chikungunya, Zika). Part of the challenge in sustaining effective ABV control emerges from the paucity of evidence regarding the epidemiological impact of any Aedes control method. A strategy for which there is limited epidemiological evidence is targeted indoor residual spraying (TIRS). TIRS is a modification of classic malaria indoor residual spraying that accounts for Aedes aegypti resting behavior by applying residual insecticides on exposed lower sections of walls (< 1.5 m), under furniture, and on dark surfaces. METHODS/DESIGN We are pursuing a two-arm, parallel, unblinded, cluster randomized controlled trial to quantify the overall efficacy of TIRS in reducing the burden of laboratory-confirmed ABV clinical disease (primary endpoint). The trial will be conducted in the city of Merida, Yucatan State, Mexico (population ~ 1million), where we will prospectively follow 4600 children aged 2-15 years at enrollment, distributed in 50 clusters of 5 × 5 city blocks each. Clusters will be randomly allocated (n = 25 per arm) using covariate-constrained randomization. A "fried egg" design will be followed, in which all blocks of the 5 × 5 cluster receive the intervention, but all sampling to evaluate the epidemiological and entomological endpoints will occur in the "yolk," the center 3 × 3 city blocks of each cluster. TIRS will be implemented as a preventive application (~ 1-2 months prior to the beginning of the ABV season). Active monitoring for symptomatic ABV illness will occur through weekly household visits and enhanced surveillance. Annual sero-surveys will be performed after each transmission season and entomological evaluations of Ae. aegypti indoor abundance and ABV infection rates monthly during the period of active surveillance. Epidemiological and entomological evaluation will continue for up to three transmission seasons. DISCUSSION The findings from this study will provide robust epidemiological evidence of the efficacy of TIRS in reducing ABV illness and infection. If efficacious, TIRS could drive a paradigm shift in Aedes control by considering Ae. aegypti behavior to guide residual insecticide applications and changing deployment to preemptive control (rather than in response to symptomatic cases), two major enhancements to existing practice. TRIAL REGISTRATION ClinicalTrials.gov NCT04343521 . Registered on 13 April 2020. The protocol also complies with the WHO International Clinical Trials Registry Platform (ICTRP) (Additional file 1). PRIMARY SPONSOR National Institutes of Health, National Institute of Allergy and Infectious Diseases (NIH/NIAID).
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Affiliation(s)
- Pablo Manrique-Saide
- Unidad Colaborativa de Bioensayos Entomológicos, Campus de Ciencias Biológicas y Agropecuarias, Universidad Autónoma de Yucatán, Merida, Mexico
| | - Natalie E Dean
- Department of Biostatistics, University of Florida, Gainesville, FL, 32611, USA
| | - M Elizabeth Halloran
- Center for Inference and Dynamics of Infectious Diseases, Seattle, WA, 98109, USA
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA, 98109, USA
- Department of Biostatistics, University of Washington, Seattle, WA, 98109, USA
| | - Ira M Longini
- Department of Biostatistics, University of Florida, Gainesville, FL, 32611, USA
- Emerging Pathogens Institute, University of Florida, Gainesville, FL, 32611, USA
| | - Matthew H Collins
- Hope Clinic of the Emory Vaccine Center, Division of Infectious Diseases, Department of Medicine, School of Medicine, Emory University, Decatur, GA, 30030, USA
| | - Lance A Waller
- Department of Biostatistics and Bioinformatics, Rollins School of Public Health, Emory University, Atlanta, GA, 30322, USA
| | - Hector Gomez-Dantes
- Health Systems Research Center, National Institute of Public Health, Cuernavaca, Mexico
| | - Audrey Lenhart
- Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Thomas J Hladish
- Emerging Pathogens Institute, University of Florida, Gainesville, FL, 32611, USA
- Department of Biology, University of Florida, Gainesville, FL, 32611, USA
| | - Azael Che-Mendoza
- Unidad Colaborativa de Bioensayos Entomológicos, Campus de Ciencias Biológicas y Agropecuarias, Universidad Autónoma de Yucatán, Merida, Mexico
| | - Oscar D Kirstein
- Department of Environmental Sciences, Math and Science Center, Emory University, 400 Dowman Drive, 5th floor, Suite E530, Atlanta, GA, 30322, USA
| | - Yamila Romer
- Department of Environmental Sciences, Math and Science Center, Emory University, 400 Dowman Drive, 5th floor, Suite E530, Atlanta, GA, 30322, USA
| | - Fabian Correa-Morales
- Centro Nacional de Programas Preventivos y Control de Enfermedades (CENAPRECE) Secretaría de Salud Mexico, Mexico City, Mexico
| | | | | | | | - Norma Pavia-Ruz
- Centro de Investigaciones Regionales Hideyo Noguchi, Universidad Autonoma de Yucatan, Merida, Mexico
| | - Guadalupe Ayora-Talavera
- Centro de Investigaciones Regionales Hideyo Noguchi, Universidad Autonoma de Yucatan, Merida, Mexico
| | - Gonzalo M Vazquez-Prokopec
- Department of Environmental Sciences, Math and Science Center, Emory University, 400 Dowman Drive, 5th floor, Suite E530, Atlanta, GA, 30322, USA.
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17
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Lenhart A, Morrison AC, Paz-Soldan VA, Forshey BM, Cordova-Lopez JJ, Astete H, Elder JP, Sihuincha M, Gotlieb EE, Halsey ES, Kochel TJ, Scott TW, Alexander N, McCall PJ. The impact of insecticide treated curtains on dengue virus transmission: A cluster randomized trial in Iquitos, Peru. PLoS Negl Trop Dis 2020; 14:e0008097. [PMID: 32275653 PMCID: PMC7176142 DOI: 10.1371/journal.pntd.0008097] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 04/22/2020] [Accepted: 01/28/2020] [Indexed: 11/18/2022] Open
Abstract
Dengue is one of the most important vector-borne diseases, resulting in an estimated hundreds of millions of infections annually throughout the tropics. Control of dengue is heavily dependent upon control of its primary mosquito vector, Aedes aegypti. Innovative interventions that are effective at targeting the adult stage of the mosquito are needed to increase the options for effective control. The use of insecticide-treated curtains (ITCs) has previously been shown to significantly reduce the abundance of Ae. aegypti in and around homes, but the impact of ITCs on dengue virus (DENV) transmission has not been rigorously quantified. A parallel arm cluster-randomized controlled trial was conducted in Iquitos, Peru to quantify the impact of ITCs on DENV seroconversion as measured through plaque-reduction neutralization tests. Seroconversion data showed that individuals living in the clusters that received ITCs were at greater risk to seroconverting to DENV, with an average seroconversion rate of 50.6 per 100 person-years (PY) (CI: 29.9–71.9), while those in the control arm had an average seroconversion rate of 37.4 per 100 PY (CI: 15.2–51.7). ITCs lost their insecticidal efficacy within 6 months of deployment, necessitating re-treatment with insecticide. Entomological indicators did not show statistically significant differences between ITC and non-ITC clusters. It’s unclear how the lack of protective efficacy reported here is attributable to simple failure of the intervention to protect against Ae. aegypti bites, or the presence of a faulty intervention during much of the follow-up period. The higher risk of dengue seroconversion that was detected in the ITC clusters may have arisen due to a false sense of security that inadvertently led to less routine protective behaviors on the part of households that received the ITCs. Our study provides important lessons learned for conducting cluster randomized trials for vector control interventions against Aedes-transmitted virus infections. Dengue is one of the most important mosquito-borne diseases affecting humans, resulting in an estimated hundreds of millions of infections annually throughout the tropics. To control dengue, most public health programs use a variety of methods to kill the primary mosquito vector, Aedes aegypti. Water holding containers that harbor larvae (and other immature stages) are treated or eliminated. During emergencies, large insecticide spray campaigns are deployed to kill infected adult mosquitoes. Innovative interventions that are effective at targeting adult mosquitoes in sustainable ways are needed to increase the options for control of dengue and other Aedes borne virus diseases. The use of insecticide-treated curtains (ITCs) has previously been shown to significantly reduce Ae. aegypti numbers in and around homes, but the impact of ITCs on dengue virus (DENV) transmission has not previously been quantified. Using a rigorous study design in which 10 clusters (~90 houses per cluster) were provided multiple ITCs to place in their homes was compared to 10 clusters of homes without ITCs. Assignment of which clusters received ITCs was randomized. Blood samples were obtained at 9-month intervals from residents living in all the clusters, so that people with serological evidence of a DENV infection could be identified by comparing paired samples. Seroconversion data showed that individuals living in the clusters that received ITCs were at greater risk to DENV seroconverting, with an average seroconversion rate of 50.6 per 100 person-years (PY) (CI: 29.9–71.9). Conversely, those in the control arm had an average seroconversion rate of 37.4 per 100 PY (CI: 15.2–51.7). ITCs lost their insecticidal efficacy within 6 months of deployment, necessitating re-treatment with insecticide. Ae. aegypti populations did not show statistically significant differences between ITC and non-ITC clusters. The reason for higher transmission in the ITC treated clusters could be attributable to failure of the curtains (loss of efficacy) and/or that the curtains were not sufficiently effective at protecting against mosquito bites. The higher risk of DENV seroconversion in ITC clusters may be due to a false sense of security that inadvertently led to less routine protective behaviors on the part of households that received the ITC.
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Affiliation(s)
- Audrey Lenhart
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Amy C. Morrison
- Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, California, United States of America
- Department of Virology, U.S. Naval Medical Research Unit-6, Lima and Iquitos, Peru
- * E-mail:
| | - Valerie A. Paz-Soldan
- Department of Global Community Health and Behavioral Sciences, Tulane School of Public Health and Tropical Medicine, New Orleans, Louisiana, United States of America
- Facultad de Salud Pública y Administración, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Brett M. Forshey
- Department of Virology, U.S. Naval Medical Research Unit-6, Lima and Iquitos, Peru
| | - Jhonny J. Cordova-Lopez
- Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, California, United States of America
| | - Helvio Astete
- Department of Virology, U.S. Naval Medical Research Unit-6, Lima and Iquitos, Peru
| | - John P. Elder
- San Diego State University, San Diego, California, United States of America
| | - Moises Sihuincha
- Director, Department of Internal Medicine, Hospital de Apoyo Iquitos, Peru
| | - Esther E. Gotlieb
- Department of Global Community Health and Behavioral Sciences, Tulane School of Public Health and Tropical Medicine, New Orleans, Louisiana, United States of America
| | - Eric S. Halsey
- Department of Virology, U.S. Naval Medical Research Unit-6, Lima and Iquitos, Peru
| | - Tadeusz J. Kochel
- Department of Virology, U.S. Naval Medical Research Unit-6, Lima and Iquitos, Peru
| | - Thomas W. Scott
- Department of Entomology and Nematology, University of California, Davis, California, United States of America
| | - Neal Alexander
- MRC Tropical Epidemiology Group, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Philip J. McCall
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
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18
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Cavany SM, España G, Lloyd AL, Waller LA, Kitron U, Astete H, Elson WH, Vazquez-Prokopec GM, Scott TW, Morrison AC, Reiner Jr. RC, Perkins TA. Optimizing the deployment of ultra-low volume and targeted indoor residual spraying for dengue outbreak response. PLoS Comput Biol 2020; 16:e1007743. [PMID: 32310958 PMCID: PMC7200023 DOI: 10.1371/journal.pcbi.1007743] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 05/05/2020] [Accepted: 02/24/2020] [Indexed: 02/03/2023] Open
Abstract
Recent years have seen rising incidence of dengue and large outbreaks of Zika and chikungunya, which are all caused by viruses transmitted by Aedes aegypti mosquitoes. In most settings, the primary intervention against Aedes-transmitted viruses is vector control, such as indoor, ultra-low volume (ULV) spraying. Targeted indoor residual spraying (TIRS) has the potential to more effectively impact Aedes-borne diseases, but its implementation requires careful planning and evaluation. The optimal time to deploy these interventions and their relative epidemiological effects are, however, not well understood. We used an agent-based model of dengue virus transmission calibrated to data from Iquitos, Peru to assess the epidemiological effects of these interventions under differing strategies for deploying them. Specifically, we compared strategies where spray application was initiated when incidence rose above a threshold based on incidence in recent years to strategies where spraying occurred at the same time(s) each year. In the absence of spraying, the model predicted 361,000 infections [inter-quartile range (IQR): 347,000-383,000] in the period 2000-2010. The ULV strategy with the fewest median infections was spraying twice yearly, in March and October, which led to a median of 172,000 infections [IQR: 158,000-183,000], a 52% reduction from baseline. Compared to spraying once yearly in September, the best threshold-based strategy utilizing ULV had fewer median infections (254,000 vs. 261,000), but required more spraying (351 vs. 274 days). For TIRS, the best strategy was threshold-based, which led to the fewest infections of all strategies tested (9,900; [IQR: 8,720-11,400], a 94% reduction), and required fewer days spraying than the equivalent ULV strategy (280). Although spraying twice each year is likely to avert the most infections, our results indicate that a threshold-based strategy can become an alternative to better balance the translation of spraying effort into impact, particularly if used with a residual insecticide.
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Affiliation(s)
- Sean M. Cavany
- Department of Biological Sciences & Eck Institute of Global Health, University of Notre Dame, Notre Dame, Indiana, United States of America
| | - Guido España
- Department of Biological Sciences & Eck Institute of Global Health, University of Notre Dame, Notre Dame, Indiana, United States of America
| | - Alun L. Lloyd
- Department of Mathematics & Biomathematics Graduate Program, North Carolina State University, Raleigh, North Carolina, United States of America
| | - Lance A. Waller
- Department of Biostatistics and Bioinformatics, Rollins School of Public Health, Emory University, Atlanta, Georgia, United States of America
| | - Uriel Kitron
- Department of Environmental Sciences, Emory University, Atlanta, Georgia, United States of America
| | | | - William H. Elson
- Department of Entomology and Nematology, University of California, Davis, Davis, California, United States of America
| | | | - Thomas W. Scott
- Department of Entomology and Nematology, University of California, Davis, Davis, California, United States of America
| | - Amy C. Morrison
- Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, Davis, California, United States of America
| | - Robert C. Reiner Jr.
- Institute of Health Metrics and Evaluation, University of Washington, Seattle, Washington, United States of America
| | - T. Alex Perkins
- Department of Biological Sciences & Eck Institute of Global Health, University of Notre Dame, Notre Dame, Indiana, United States of America
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19
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Hladish TJ, Pearson CAB, Toh KB, Rojas DP, Manrique-Saide P, Vazquez-Prokopec GM, Halloran ME, Longini IM. Designing effective control of dengue with combined interventions. Proc Natl Acad Sci U S A 2020; 117:3319-3325. [PMID: 31974303 PMCID: PMC7022216 DOI: 10.1073/pnas.1903496117] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Viruses transmitted by Aedes mosquitoes, such as dengue, Zika, and chikungunya, have expanding ranges and seem unabated by current vector control programs. Effective control of these pathogens likely requires integrated approaches. We evaluated dengue management options in an endemic setting that combine novel vector control and vaccination using an agent-based model for Yucatán, Mexico, fit to 37 y of data. Our intervention models are informed by targeted indoor residual spraying (TIRS) experiments; trial outcomes and World Health Organization (WHO) testing guidance for the only licensed dengue vaccine, CYD-TDV; and preliminary results for in-development vaccines. We evaluated several implementation options, including varying coverage levels; staggered introductions; and a one-time, large-scale vaccination campaign. We found that CYD-TDV and TIRS interfere: while the combination outperforms either alone, performance is lower than estimated from their separate benefits. The conventional model hypothesized for in-development vaccines, however, performs synergistically with TIRS, amplifying effectiveness well beyond their independent impacts. If the preliminary performance by either of the in-development vaccines is upheld, a one-time, large-scale campaign followed by routine vaccination alongside aggressive new vector control could enable short-term elimination, with nearly all cases avoided for a decade despite continuous dengue reintroductions. If elimination is impracticable due to resource limitations, less ambitious implementations of this combination still produce amplified, longer-lasting effectiveness over single-approach interventions.
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Affiliation(s)
- Thomas J Hladish
- Department of Biology, University of Florida, Gainesville, FL 32611;
- Emerging Pathogens Institute, University of Florida, Gainesville, FL 32611
| | - Carl A B Pearson
- Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London WC1E 7HT, United Kingdom
- Centre for Mathematical Modelling of Infectious Diseases, London School of Hygiene & Tropical Medicine, London WC1E 7HT, United Kingdom
- South African Centre for Epidemiological Modelling and Analysis, Stellenbosch University, Stellenbosch, South Africa 7600
| | - Kok Ben Toh
- School of Natural Resources and Environment, University of Florida, Gainesville, FL 32611
| | - Diana Patricia Rojas
- Department of Biostatistics, University of Florida, Gainesville, FL 32611
- Division of Public Health and Tropical Medicine, James Cook University, Townsville QLD 4814, Australia
| | - Pablo Manrique-Saide
- Collaborative Unit for Entomological Bioassays, Universidad Autónoma de Yucatán, Mérida, Mexico 9700
| | | | - M Elizabeth Halloran
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109
- Center for Inference and Dynamics of Infectious Diseases, Seattle, WA 98109
- Department of Biostatistics, University of Washington, Seattle, WA 98195
| | - Ira M Longini
- Emerging Pathogens Institute, University of Florida, Gainesville, FL 32611
- Department of Biostatistics, University of Florida, Gainesville, FL 32611
- Center for Inference and Dynamics of Infectious Diseases, Seattle, WA 98109
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20
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Abstract
Dengue circulates endemically in many tropical and subtropical regions. In 2012, the World Health Organization (WHO) set out goals to reduce dengue mortality and morbidity by 50% and 25%, respectively, between 2010 and 2020. These goals will not be met. This is, in part, due to existing interventions being insufficiently effective to prevent spread. Further, complex and variable patterns of disease presentation coupled with imperfect surveillance systems mean that even tracking changes in burden is rarely possible. As part of the Sustainable Development Goals, WHO will propose new dengue-specific goals for 2030. The 2030 goals provide an opportunity for focused action on tackling dengue burden but should be carefully developed to be ambitious but also technically feasible. Here we discuss the potential for clearly defined case fatality rates and the rollout of new and effective intervention technologies to form the foundation of these future goals. Further, we highlight how the complexity of dengue epidemiology limits the feasibility of goals that instead target dengue outbreaks.
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21
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Wilke ABB, Chase C, Vasquez C, Carvajal A, Medina J, Petrie WD, Beier JC. Urbanization creates diverse aquatic habitats for immature mosquitoes in urban areas. Sci Rep 2019; 9:15335. [PMID: 31653914 PMCID: PMC6814835 DOI: 10.1038/s41598-019-51787-5] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Accepted: 10/07/2019] [Indexed: 12/22/2022] Open
Abstract
Global increases in temperatures and urbanization are impacting the epidemiology of mosquito-borne diseases. Urbanization processes create suitable habitats for vector mosquitoes in which there are a reduced number of predators, and human hosts are widely available. We hypothesize that mosquito vector species, especially Aedes aegypti, are locally concentrated primarily in those specific habitats at the neighborhood levels that provide suitable conditions and environmental resources needed for mosquito survival. Determining how mosquito vector species composition and abundance depend on environmental resources across habitats addresses where different types of vector control need to be applied. Therefore, our goal was to analyze and identify the most productive aquatic habitats for mosquitoes in Miami-Dade County, Florida. Immature mosquito surveys were conducted throughout Miami-Dade County from April 2018 to June 2019, totaling 2,488 inspections. Mosquitoes were collected in 76 different types of aquatic habitats scattered throughout 141 neighborhoods located in the urbanized areas of Miami-Dade County. A total of 44,599 immature mosquitoes were collected and Ae. aegypti was the most common and abundant species, comprising 43% of all specimens collected. Aedes aegypti was primarily found in buckets, bromeliads, and flower pots, concentrated in specific neighborhoods. Our results showed that aquatic habitats created by anthropogenic land-use modifications (e.g., ornamental bromeliads, buckets, etc.) were positively correlated with the abundance of Ae. aegypti. This study serves to identify how vector mosquitoes utilize the resources available in urban environments and to determine the exact role of these specific urban features in supporting populations of vector mosquito species. Ultimately, the identification of modifiable urban features will allow the development of targeted mosquito control strategies optimized to preventatively control vector mosquitoes in urban areas.
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Affiliation(s)
- André B B Wilke
- Department of Public Health Sciences, Miller School of Medicine, University of Miami, Miami, FL, USA.
| | - Catherine Chase
- Department of Public Health Sciences, Miller School of Medicine, University of Miami, Miami, FL, USA
| | - Chalmers Vasquez
- Miami-Dade County Mosquito Control Division, Miami, FL, United States of America
| | - Augusto Carvajal
- Miami-Dade County Mosquito Control Division, Miami, FL, United States of America
| | - Johana Medina
- Miami-Dade County Mosquito Control Division, Miami, FL, United States of America
| | - William D Petrie
- Miami-Dade County Mosquito Control Division, Miami, FL, United States of America
| | - John C Beier
- Department of Public Health Sciences, Miller School of Medicine, University of Miami, Miami, FL, USA
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22
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Indriani C, Ahmad RA, Wiratama BS, Arguni E, Supriyati E, Sasmono RT, Kisworini FY, Ryan PA, O'Neill SL, Simmons CP, Utarini A, Anders KL. Baseline Characterization of Dengue Epidemiology in Yogyakarta City, Indonesia, before a Randomized Controlled Trial of Wolbachia for Arboviral Disease Control. Am J Trop Med Hyg 2019; 99:1299-1307. [PMID: 30226138 PMCID: PMC6221224 DOI: 10.4269/ajtmh.18-0315] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Dengue is endemic in Indonesia. Here, we describe the epidemiology of dengue in the city of Yogyakarta, Central Java, as a prelude to implementation of a cluster-randomized trial of Wolbachia for the biocontrol of arboviral transmission. Surveillance records from 2006 to 2016 demonstrate seasonal oscillations of dengue incidence with varying magnitude. Two lines of evidence demonstrate a high force of infection; the hospitalized case burden of patients diagnosed with dengue hemorrhagic fever or dengue shock syndrome over the last decade consisted predominantly of children/adolescents, and a serosurvey of 314 healthy children aged 1–10 years found 68% possessed dengue virus–neutralizing antibodies. Finally, a mobility survey indicated children aged 1–10 years, and particularly 1–5 year-olds, spent most of their daytime hours at home. These findings inform the design of clinical trials to measure the impact of novel vector control methods such as Wolbachia introgression into Aedes aegypti mosquitoes, by providing baseline data on disease incidence and identifying subpopulations for recruitment into prospective studies of dengue virus infection and disease. The mobility survey findings indicate that in cluster trials of interventions applied at the community level, young children can reasonably be expected to spend most of their exposure time, in epidemiological terms, within the treatment arm to which they were randomized.
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Affiliation(s)
- Citra Indriani
- Department of Epidemiology, Biostatistics and Population Health, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, Indonesia.,Centre of Tropical Medicine, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, Indonesia
| | - Riris A Ahmad
- Department of Epidemiology, Biostatistics and Population Health, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, Indonesia.,Centre of Tropical Medicine, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, Indonesia
| | - Bayu S Wiratama
- Department of Epidemiology, Biostatistics and Population Health, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, Indonesia.,Centre of Tropical Medicine, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, Indonesia
| | - Eggi Arguni
- Department of Pediatrics, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, Indonesia.,Centre of Tropical Medicine, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, Indonesia
| | - Endah Supriyati
- Centre of Tropical Medicine, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, Indonesia
| | | | | | - Peter A Ryan
- Institute of Vector Borne Disease, Monash University, Melbourne, Australia
| | - Scott L O'Neill
- Institute of Vector Borne Disease, Monash University, Melbourne, Australia
| | - Cameron P Simmons
- Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam.,Institute of Vector Borne Disease, Monash University, Melbourne, Australia
| | - Adi Utarini
- Department of Health Policy and Management, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, Indonesia.,Centre of Tropical Medicine, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, Indonesia
| | - Katherine L Anders
- Institute of Vector Borne Disease, Monash University, Melbourne, Australia
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23
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Liew JWK, Selvarajoo S, Tan W, Ahmad Zaki R, Vythilingam I. Gravid oviposition sticky trap and dengue non-structural 1 antigen test for early surveillance of dengue in multi-storey dwellings: study protocol of a cluster randomized controlled trial. Infect Dis Poverty 2019; 8:71. [PMID: 31477185 PMCID: PMC6720065 DOI: 10.1186/s40249-019-0584-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Accepted: 08/01/2019] [Indexed: 02/08/2023] Open
Abstract
Background Dengue is a global disease, transmitted by the Aedes vectors. In 2018, there were 80 615 dengue cases with 147 deaths in Malaysia. Currently, the nationwide surveillance programs are dependent on Aedes larval surveys and notifications of lab-confirmed human infections. The existing, reactive programs appear to lack sensitivity and proactivity. More efficient dengue vector surveillance/control methods are needed. Methods A parallel, cluster, randomized controlled, interventional trial is being conducted for 18 months in Damansara Damai, Selangor, Malaysia, to determine the efficacy of using gravid oviposition sticky (GOS) trap and dengue non-structural 1 (NS1) antigen test for early surveillance of dengue among Aedes mosquitoes to reduce dengue outbreaks. Eight residential apartments were randomly assigned into intervention and control arms. GOS traps are set at the apartments to collect Aedes weekly, following which dengue NS1 antigen is detected in these mosquitoes. When a dengue-positive mosquito is detected, the community will be advised to execute vector search-and-destroy and protective measures. The primary outcome concerns the the percentage change in the (i) number of dengue cases and (ii) durations of dengue outbreaks. Whereas other outcome measures include the change in density threshold of Aedes and changes in dengue-related knowledge, attitude and practice among cluster inhabitants. Discussion This is a proactive and early dengue surveillance in the mosquito vector that does not rely on notification of dengue cases. Surveillance using the GOS traps should be able to efficiently provide sufficient coverage for multistorey dwellings where population per unit area is likely to be higher. Furthermore, trapping dengue-infected mosquitoes using the GOS trap, helps to halt the dengue transmission carried by the mosquito. It is envisaged that the results of this randomized controlled trial will provide a new proactive, cheap and targeted surveillance tool for the prevention and control of dengue outbreaks. Trial registration This is a parallel-cluster, randomized controlled, interventional trial, registered at ClinicalTrials.gov (ID: NCT03799237), on 8th January 2019 (retrospectively registered). Electronic supplementary material The online version of this article (10.1186/s40249-019-0584-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jonathan Wee Kent Liew
- Department of Parasitology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Sivaneswari Selvarajoo
- Department of Parasitology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Wing Tan
- Department of Parasitology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Rafdzah Ahmad Zaki
- Centre for Epidemiology and Evidence Based Practice, Department of Social and Preventive Medicine, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Indra Vythilingam
- Department of Parasitology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia.
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24
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Nguyen-Tien T, Lundkvist Å, Lindahl J. Urban transmission of mosquito-borne flaviviruses - a review of the risk for humans in Vietnam. Infect Ecol Epidemiol 2019; 9:1660129. [PMID: 31528273 PMCID: PMC6735309 DOI: 10.1080/20008686.2019.1660129] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 08/20/2019] [Indexed: 01/18/2023] Open
Abstract
Vietnam is a tropical country where mosquito-borne diseases are common. This review explores the transmission of mosquito-borne flaviviruses in urban areas of Vietnam. It concludes that urban transmission has mainly been studied for Dengue virus, and so far, much less for Japanese encephalitis virus. Dengue is the most common flavivirus in Vietnam. Due to fast urbanization and favorable climatic conditions, the viral transmission concentrates mainly to large cities with high population density including Ha Noi, Nha Trang and Ho Chi Minh. Human cases of Japanese encephalitis have been controlled by an expanded immunization program. However, this virus is still circulating throughout the country, also in cities due to the pig rearing practices in urban and peri-urban areas. Zika virus is an additional major concern because it has long circulated in the Northern area and is now increasingly diagnosed in urban areas of the Central, Central Highlands and Southern regions using the same mosquito vectors as Dengue virus. There was alarge outbreak of Zika disease from 2016 to early 2017, with most infections observed in Ho Chi Minh city, the largest town in Vietnam. Other flaviviruses circulate in Vietnam but have not been investigated in terms of urban transmission.
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Affiliation(s)
- Thang Nguyen-Tien
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
- International Livestock Research Institute, Hanoi, Vietnam
| | - Åke Lundkvist
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Johanna Lindahl
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
- International Livestock Research Institute, Hanoi, Vietnam
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden
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25
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Sharp TM, Lorenzi O, Torres-Velásquez B, Acevedo V, Pérez-Padilla J, Rivera A, Muñoz-Jordán J, Margolis HS, Waterman SH, Biggerstaff BJ, Paz-Bailey G, Barrera R. Autocidal gravid ovitraps protect humans from chikungunya virus infection by reducing Aedes aegypti mosquito populations. PLoS Negl Trop Dis 2019; 13:e0007538. [PMID: 31344040 PMCID: PMC6657827 DOI: 10.1371/journal.pntd.0007538] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Accepted: 06/10/2019] [Indexed: 12/12/2022] Open
Abstract
Background Public health responses to outbreaks of dengue, chikungunya, and Zika virus have been stymied by the inability to control the primary vector, Aedes aegypti mosquitos. Consequently, the need for novel approaches to Aedes vector control is urgent. Placement of three autocidal gravid ovitraps (AGO traps) in ~85% of homes in a community was previously shown to sustainably reduce the density of female Ae. aegypti by >80%. Following the introduction of chikungunya virus (CHIKV) to Puerto Rico, we conducted a seroprevalence survey to estimate the prevalence of CHIKV infection in communities with and without AGO traps and evaluate their effect on reducing CHIKV transmission. Methods and findings Multivariate models that calculated adjusted prevalence ratios (aPR) showed that among 175 and 152 residents of communities with and without AGO traps, respectively, an estimated 26.1% and 43.8% had been infected with CHIKV (aPR = 0.50, 95% CI: 0.37–0.91). After stratification by time spent in their community, protection from CHIKV infection was strongest among residents who reported spending many or all weekly daytime hours in their community:10.3% seropositive in communities with AGO traps vs. 48.7% in communities without (PR = 0.21, 95% CI: 0.11–0.41). The age-adjusted rate of fever with arthralgia attributable to CHIKV infection was 58% (95% CI: 46–66%). The monthly number of CHIKV-infected mosquitos and symptomatic residents were diminished in communities with AGO traps compared to those without. Conclusions These findings indicate that AGO traps are an effective tool that protects humans from infection with a virus transmitted by Ae. aegypti mosquitos. Future studies should evaluate their protective effectiveness in large, urban communities. Aedes species mosquitos transmit pathogens of public health importance, including dengue, Zika, and chikungunya viruses. No tools exist to control these mosquitos that sustainably and effectively prevent human infections. Autocidal gravid ovitraps (AGO traps) have been shown to sustainably reduce Aedes populations by >80%. After chikungunya virus was introduced into Puerto Rico, we conducted serosurveys in communities with and without AGO traps. We observed a two-fold lower prevalence of chikungunya virus infection among residents of communities with AGO traps compared to communities without. Among infected residents of communities with traps, a significant proportion likely had been infected while outside their community. These findings indicate that AGO traps are an effective tool that protects humans from infection with pathogens transmitted by Aedes mosquitos.
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Affiliation(s)
- Tyler M. Sharp
- Centers for Disease Control and Prevention, Dengue Branch, San Juan, Puerto Rico, United States of America
- United States Public Health Service, Silver Springs, Maryland, United States of America
- * E-mail:
| | - Olga Lorenzi
- Centers for Disease Control and Prevention, Dengue Branch, San Juan, Puerto Rico, United States of America
| | - Brenda Torres-Velásquez
- Centers for Disease Control and Prevention, Dengue Branch, San Juan, Puerto Rico, United States of America
| | - Veronica Acevedo
- Centers for Disease Control and Prevention, Dengue Branch, San Juan, Puerto Rico, United States of America
| | - Janice Pérez-Padilla
- Centers for Disease Control and Prevention, Dengue Branch, San Juan, Puerto Rico, United States of America
| | - Aidsa Rivera
- Centers for Disease Control and Prevention, Dengue Branch, San Juan, Puerto Rico, United States of America
| | - Jorge Muñoz-Jordán
- Centers for Disease Control and Prevention, Dengue Branch, San Juan, Puerto Rico, United States of America
| | - Harold S. Margolis
- Centers for Disease Control and Prevention, Dengue Branch, San Juan, Puerto Rico, United States of America
| | - Stephen H. Waterman
- Centers for Disease Control and Prevention, Dengue Branch, San Juan, Puerto Rico, United States of America
- United States Public Health Service, Silver Springs, Maryland, United States of America
| | - Brad J. Biggerstaff
- Centers for Disease Control and Prevention, Division of Vector-Borne Diseases, Fort Collins, Colorado, United States of America
| | - Gabriela Paz-Bailey
- Centers for Disease Control and Prevention, Dengue Branch, San Juan, Puerto Rico, United States of America
| | - Roberto Barrera
- Centers for Disease Control and Prevention, Dengue Branch, San Juan, Puerto Rico, United States of America
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Stone CM, Schwab SR, Fonseca DM, Fefferman NH. Contrasting the value of targeted versus area-wide mosquito control scenarios to limit arbovirus transmission with human mobility patterns based on different tropical urban population centers. PLoS Negl Trop Dis 2019; 13:e0007479. [PMID: 31269020 PMCID: PMC6608929 DOI: 10.1371/journal.pntd.0007479] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Accepted: 05/20/2019] [Indexed: 11/18/2022] Open
Abstract
Vector control is still our primary intervention for both prevention and mitigation of epidemics of many vector-borne diseases. Efficiently targeting control measures is important since control can involve substantial economic costs. Targeting is not always straightforward, as transmission of vector-borne diseases is affected by various types of host movement. Here we assess how taking daily commuting patterns into consideration can help improve vector control efforts. We examine three tropical urban centers (San Juan, Recife, and Jakarta) that have recently been exposed to Zika and/or dengue infections and consider whether the distribution of human populations and resulting commuting flows affects the optimal scale at which control interventions should be implemented. We developed a stochastic, spatial model and investigated four control scenarios. The scenarios differed in the spatial extent of their implementation and were: 1) a response at the level of an individual neighborhood; 2) a response targeted at a neighborhood in which infected humans were detected and the one with which it was most strongly connected by human movement; 3) a limited area-wide response where all neighborhoods within a certain radius of the focal area were included; and 4) a collective response where all participating neighborhoods implemented control. The relative effectiveness of the scenarios varied only slightly between different settings, with the number of infections averted over time increasing with the scale of implementation. This difference depended on the efficacy of control at the neighborhood level. At low levels of efficacy, the scenarios mirrored each other in infections averted. At high levels of efficacy, impact increased with the scale of the intervention. As a result, the choice between scenarios will not only be a function of the amount of effort decision-makers are willing to invest, but largely epend on the overall effectiveness of vector control approaches. Control and prevention of Aedes-transmitted viruses, such as dengue, chikungunya, or Zika relies heavily on vector control approaches. Given the effort and cost involved in implementation of vector control, targeting of control measures is highly desirable. However, it is unclear to what extent the effectiveness of highly focal and reactive control measures depends on the commuting and movement patterns of humans. To investigate this question, we developed a model and four control scenarios that ranged from highly focal to area-wide larval control. The distribution of humans and their commuting patterns were modelled after three major tropical urban centers, San Juan, Recife, and Jakarta. We show that as implementation is applied across a wider area, a greater number of infections is averted. Critically, this only occurs if the efficacy of control at the neighborhood level is sufficiently high. A consistent outcome across the three settings was that the focal strategy was most likely to provide the best outcome at lower levels of effort, and when the efficacy of control was low. These outcomes suggest that optimal control strategies will likely have to be tailored to individual settings by decision makers and would benefit from localized cost-effectiveness modelling studies.
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Affiliation(s)
- Chris M. Stone
- Illinois Natural History Survey, University of Illinois at Urbana-Champaign, Champaign, IL, United Sates of America
- Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, TN, United Sates of America
- * E-mail:
| | - Samantha R. Schwab
- Department of Ecology, Evolution, and Natural Resources, Rutgers University, New Brunswick, NJ, United Sates of America
| | - Dina M. Fonseca
- Department of Ecology, Evolution, and Natural Resources, Rutgers University, New Brunswick, NJ, United Sates of America
- Center for Vector Biology, Rutgers University, New Brunswick, NJ, United Sates of America
| | - Nina H. Fefferman
- Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, TN, United Sates of America
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Reiner RC, Stoddard ST, Vazquez-Prokopec GM, Astete H, Perkins TA, Sihuincha M, Stancil JD, Smith DL, Kochel TJ, Halsey ES, Kitron U, Morrison AC, Scott TW. Estimating the impact of city-wide Aedes aegypti population control: An observational study in Iquitos, Peru. PLoS Negl Trop Dis 2019; 13:e0007255. [PMID: 31145744 PMCID: PMC6542505 DOI: 10.1371/journal.pntd.0007255] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 02/21/2019] [Indexed: 12/18/2022] Open
Abstract
During the last 50 years, the geographic range of the mosquito Aedes aegypti has increased dramatically, in parallel with a sharp increase in the disease burden from the viruses it transmits, including Zika, chikungunya, and dengue. There is a growing consensus that vector control is essential to prevent Aedes-borne diseases, even as effective vaccines become available. What remains unclear is how effective vector control is across broad operational scales because the data and the analytical tools necessary to isolate the effect of vector-oriented interventions have not been available. We developed a statistical framework to model Ae. aegypti abundance over space and time and applied it to explore the impact of citywide vector control conducted by the Ministry of Health (MoH) in Iquitos, Peru, over a 12-year period. Citywide interventions involved multiple rounds of intradomicile insecticide space spray over large portions of urban Iquitos (up to 40% of all residences) in response to dengue outbreaks. Our model captured significant levels of spatial, temporal, and spatio-temporal variation in Ae. aegypti abundance within and between years and across the city. We estimated the shape of the relationship between the coverage of neighborhood-level vector control and reductions in female Ae. aegypti abundance; i.e., the dose-response curve. The dose-response curve, with its associated uncertainties, can be used to gauge the necessary spraying effort required to achieve a desired effect and is a critical tool currently absent from vector control programs. We found that with complete neighborhood coverage MoH intra-domicile space spray would decrease Ae. aegypti abundance on average by 67% in the treated neighborhood. Our framework can be directly translated to other interventions in other locations with geolocated mosquito abundance data. Results from our analysis can be used to inform future vector-control applications in Ae. aegypti endemic areas globally. Despite the growing threat of arboviruses, there is a dearth of ‘best practices’ for the primary vector control tools used in the field. In the absence of cluster randomized control trials, evidence on the utility (or lack thereof) of vector control interventions must be gleaned from ongoing control programs. Motivated by 12 years of household-level Ae. aegypti abundance surveys and neighborhood-level space-spray campaign data from Iquitos, Peru, we developed a new framework to model mosquito abundance. In spite of significant spatial and temporal heterogeneity, we identified a statistically significant and practically important impact of the local Ministry of Health space-spray campaign, specifically, a reduction of mosquito abundance of 67% when coverage was optimal. Our framework can be directly applied to other locations with geolocated mosquito abundance data and our findings can be used to both optimize resources within Iquitos as well as inform future vector-control interventions in Ae. aegypti endemic areas globally.
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Affiliation(s)
- Robert C. Reiner
- Institute for Health Metrics and Evaluation, Department of Global Health, Schools of Medicine and Public Health, University of Washington, WA, United States of America
- Fogarty International Center, National Institutes of Health, Bethesda, MD, United States of America
- * E-mail:
| | - Steven T. Stoddard
- Fogarty International Center, National Institutes of Health, Bethesda, MD, United States of America
- School of Public Health, San Diego State University, San Diego, CA, United States of America
| | - Gonzalo M. Vazquez-Prokopec
- Fogarty International Center, National Institutes of Health, Bethesda, MD, United States of America
- Department of Environmental Sciences, Emory University, Atlanta, GA, United States of America
| | | | - T. Alex Perkins
- Fogarty International Center, National Institutes of Health, Bethesda, MD, United States of America
- Department of Biological Sciences and Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, United States of America
| | | | | | - David L. Smith
- Institute for Health Metrics and Evaluation, Department of Global Health, Schools of Medicine and Public Health, University of Washington, WA, United States of America
- Fogarty International Center, National Institutes of Health, Bethesda, MD, United States of America
| | | | | | - Uriel Kitron
- Fogarty International Center, National Institutes of Health, Bethesda, MD, United States of America
- Department of Environmental Sciences, Emory University, Atlanta, GA, United States of America
| | - Amy C. Morrison
- U.S. Naval Medical Research Unit N0.6, Lima, Peru
- Department of Entomology, University of California, Davis, CA, United States of America
| | - Thomas W. Scott
- Fogarty International Center, National Institutes of Health, Bethesda, MD, United States of America
- Department of Entomology, University of California, Davis, CA, United States of America
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Koyoc-Cardeña E, Medina-Barreiro A, Cohuo-Rodríguez A, Pavía-Ruz N, Lenhart A, Ayora-Talavera G, Dunbar M, Manrique-Saide P, Vazquez-Prokopec G. Estimating absolute indoor density of Aedes aegypti using removal sampling. Parasit Vectors 2019; 12:250. [PMID: 31113454 PMCID: PMC6528352 DOI: 10.1186/s13071-019-3503-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 05/14/2019] [Indexed: 01/16/2023] Open
Abstract
BACKGROUND Quantification of adult Aedes aegypti abundance indoors has relied on estimates of relative density (e.g. number of adults per unit of sampling or time), most commonly using traps or timed collections using aspirators. The lack of estimates of the sensitivity of collections and lack of a numerical association between relative and the absolute density of adult Ae. aegypti represent a significant gap in vector surveillance. Here, we describe the use of sequential removal sampling to estimate absolute numbers of indoor resting Ae. aegypti and to calculate calibration coefficients for timed Prokopack aspirator collections in the city of Merida, Yucatan State, Mexico. The study was performed in 200 houses that were selected based on recent occurrence of Aedes-borne viral illness in residents. Removal sampling occurred in 10-minute sampling rounds performed sequentially until no Ae. aegypti adult was collected for 3 hours or over 2 consecutive 10-minute periods. RESULTS A total of 3439 Ae. aegypti were collected. The sensitivity of detection of positive houses in the first sampling round was 82.5% for any adult Ae. aegypti, 78.5% for females, 75.5% for males and 73.3% for blood-fed females. The total number of Ae. aegypti per house was on average ~5 times higher than numbers collected for the first sampling round. There was a positive linear relationship between the relative density of Ae. aegypti collected during the first 10-min round and the absolute density for all adult metrics. Coefficients from the linear regression were used to calibrate numbers from 10-min collections into estimates of absolute indoor Ae. aegypti density for all adults, females and males. CONCLUSIONS Exhaustive removal sampling represents a promising method for quantification of absolute indoor Ae. aegypti density, leading to improved entomological estimates of mosquito distribution, a key measure in the assessments of the risk pathogen transmission, disease modeling and the evaluation of vector control interventions.
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Affiliation(s)
- Edgar Koyoc-Cardeña
- Unidad Colaborativa de Bioensayos Entomológicos, Campus de Ciencias. Biológicas y Agropecuarias, Universidad Autónoma de Yucatán, Mérida, Yucatán, Mexico
| | - Anuar Medina-Barreiro
- Unidad Colaborativa de Bioensayos Entomológicos, Campus de Ciencias. Biológicas y Agropecuarias, Universidad Autónoma de Yucatán, Mérida, Yucatán, Mexico
| | - Azael Cohuo-Rodríguez
- Unidad Colaborativa de Bioensayos Entomológicos, Campus de Ciencias. Biológicas y Agropecuarias, Universidad Autónoma de Yucatán, Mérida, Yucatán, Mexico
| | - Norma Pavía-Ruz
- Centro de Investigaciones Regionales "Dr. Hideyo Noguchi", Universidad Autónoma de Yucatán, Mérida, Yucatán, Mexico
| | - Audrey Lenhart
- Entomology Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Guadalupe Ayora-Talavera
- Centro de Investigaciones Regionales "Dr. Hideyo Noguchi", Universidad Autónoma de Yucatán, Mérida, Yucatán, Mexico
| | - Mike Dunbar
- Department of Environmental Sciences, Emory University, Atlanta, GA, USA
| | - Pablo Manrique-Saide
- Unidad Colaborativa de Bioensayos Entomológicos, Campus de Ciencias. Biológicas y Agropecuarias, Universidad Autónoma de Yucatán, Mérida, Yucatán, Mexico
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Dunbar MW, Correa-Morales F, Dzul-Manzanilla F, Medina-Barreiro A, Bibiano-Marín W, Morales-Ríos E, Vadillo-Sánchez J, López-Monroy B, Ritchie SA, Lenhart A, Manrique-Saide P, Vazquez-Prokopec GM. Efficacy of novel indoor residual spraying methods targeting pyrethroid-resistant Aedes aegypti within experimental houses. PLoS Negl Trop Dis 2019; 13:e0007203. [PMID: 30817759 PMCID: PMC6394901 DOI: 10.1371/journal.pntd.0007203] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Accepted: 01/30/2019] [Indexed: 12/17/2022] Open
Abstract
Challenges in maintaining high effectiveness of classic vector control in urban areas has renewed the interest in indoor residual spraying (IRS) as a promising approach for Aedes-borne disease prevention. While IRS has many benefits, application time and intrusive indoor applications make its scalability in urban areas difficult. Modifying IRS to account for Ae. aegypti resting behavior, named targeted IRS (TIRS, spraying walls below 1.5 m and under furniture) can reduce application time; however, an untested assumption is that modifications to IRS will not negatively impact entomological efficacy. We conducted a comparative experimental study evaluating the residual efficacy of classically-applied IRS (as developed for malaria control) compared to two TIRS application methods using a carbamate insecticide against a pyrethroid-resistant, field-derived Ae. aegypti strain. We performed our study within a novel experimental house setting (n = 9 houses) located in Merida (Mexico), with similar layouts and standardized contents. Classic IRS application (insecticide applied to full walls and under furniture) was compared to: a) TIRS: insecticide applied to walls below 1.5 m and under furniture, and b) Resting Site TIRS (RS-TIRS): insecticide applied only under furniture. Mosquito mortality was measured eight times post-application (out to six months post-application) by releasing 100 Ae. aegypti females /house and collecting live and dead individuals after 24 hrs exposure. Compared to Classic IRS, TIRS and RS-TIRS took less time to apply (31% and 82% reduction, respectively) and used less insecticide (38% and 85% reduction, respectively). Mortality of pyrethroid-resistant Ae. aegypti did not significantly differ among the three IRS application methods up to two months post application, and did not significantly differ between Classic IRS and TIRS up to four months post application. These data illustrate that optimizing IRS to more efficiently target Ae. aegypti can both reduce application time and insecticide volume with no apparent reduction in entomological efficacy. Vector control is the primary strategy for managing Aedes aegypti and reducing transmission of Aedes-borne diseases; however, the indoor resting behavior of Ae. aegypti and the evolution of insecticide resistance reduces the effectiveness of many vector control tactics. Indoor residual spraying (IRS) is effective against Ae. aegypti, but lengthy application time makes IRS difficult to scale within urban environments. We compared the application and entomological efficacy of Classic IRS against two novel Aedes-targeting IRS application methods (Targeted IRS [TIRS]- insecticide applied to walls below 1.5 m and under furniture and Resting Site TIRS [RS-TIRS]- insecticide applied only under furniture) within experimental houses using a carbamate insecticide. Both TIRS and RS-TIRS took less time to apply and used less insecticide compared to Classic IRS. Mortality of pyrethroid-resistant Ae. aegypti did not differ among treatments out to two months post-application, and there was no difference in mortality between Classic IRS and TIRS out to four months post-application. These data provide evidence that IRS application methods can be improved to take less time and insecticide yet not lose entomological efficacy, making TIRS more scalable within urban environments. However, larger field studies with epidemiologic endpoints are needed to further assess the efficacy of these modified TIRS techniques.
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Affiliation(s)
- Mike W. Dunbar
- Department of Environmental Sciences, Emory University, Atlanta, Georgia, United States of America
- * E-mail:
| | - Fabian Correa-Morales
- Centro Nacional de Programas Preventivos y Control de Enfermedades (CENAPRECE) Secretaría de Salud México, Ciudad de México, México
| | - Felipe Dzul-Manzanilla
- Centro Nacional de Programas Preventivos y Control de Enfermedades (CENAPRECE) Secretaría de Salud México, Ciudad de México, México
| | - Anuar Medina-Barreiro
- Unidad Colaborativa para Bioensayos Entomológicos, Universidad Autónoma de Yucatán, México, México
| | - Wilbert Bibiano-Marín
- Unidad Colaborativa para Bioensayos Entomológicos, Universidad Autónoma de Yucatán, México, México
| | - Evaristo Morales-Ríos
- Unidad Colaborativa para Bioensayos Entomológicos, Universidad Autónoma de Yucatán, México, México
| | - José Vadillo-Sánchez
- Centro Nacional de Programas Preventivos y Control de Enfermedades (CENAPRECE) Secretaría de Salud México, Ciudad de México, México
| | - Beatriz López-Monroy
- Universidad Autónoma de Nuevo León, Facultad de Ciencias Biológicas, Nuevo León, México
| | - Scott A. Ritchie
- College of Public Health, Medical & Vet Sciences, James Cook University, Cairns, Australia
| | - Audrey Lenhart
- Entomology Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Pablo Manrique-Saide
- Unidad Colaborativa para Bioensayos Entomológicos, Universidad Autónoma de Yucatán, México, México
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Abstract
Mortality from severe dengue is low, but the economic and resource burden on health services remains substantial in endemic settings. Unfortunately, progress towards development of effective therapeutics has been slow, despite notable advances in the understanding of disease pathogenesis and considerable investment in antiviral drug discovery. For decades antibody-dependent enhancement has been the prevalent model to explain dengue pathogenesis, but it was only recently demonstrated in vivo and in clinical studies. At present, the current mainstay of management for most symptomatic dengue patients remains careful observation and prompt but judicious use of intravenous hydration therapy for those with substantial vascular leakage. Various new promising technologies for diagnosis of dengue are currently in the pipeline. New sample-in, answer-out nucleic acid amplification technologies for point-of-care use are being developed to improve performance over current technologies, with the potential to test for multiple pathogens using a single specimen. The search for biomarkers that reliably predict development of severe dengue among symptomatic individuals is also a major focus of current research efforts. The first dengue vaccine was licensed in 2015 but its performance depends on serostatus. There is an urgent need to identify correlates of both vaccine protection and disease enhancement. A crucial assessment of vector control tools should guide a research agenda for determining the most effective interventions, and how to best combine state-of-the-art vector control with vaccination.
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Affiliation(s)
- Annelies Wilder-Smith
- London School of Hygiene & Tropical Medicine, London, UK; Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore; Heidelberg Institute of Global Health, University of Heidelberg, Heidelberg, Germany.
| | - Eng-Eong Ooi
- Duke-National University of Singapore Medical School, Singapore; Saw Swee Hock School of Public Health, National University of Singapore, Singapore
| | - Olaf Horstick
- Heidelberg Institute of Global Health, University of Heidelberg, Heidelberg, Germany
| | - Bridget Wills
- Oxford University Clinical Research Unit, Wellcome Trust Asia Programme, Ho Chi Minh City, Vietnam; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
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España G, Hogea C, Guignard A, ten Bosch QA, Morrison AC, Smith DL, Scott TW, Schmidt A, Perkins TA. Biased efficacy estimates in phase-III dengue vaccine trials due to heterogeneous exposure and differential detectability of primary infections across trial arms. PLoS One 2019; 14:e0210041. [PMID: 30682037 PMCID: PMC6347271 DOI: 10.1371/journal.pone.0210041] [Citation(s) in RCA: 443] [Impact Index Per Article: 88.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 12/14/2018] [Indexed: 01/20/2023] Open
Abstract
Vaccine efficacy (VE) estimates are crucial for assessing the suitability of dengue vaccine candidates for public health implementation, but efficacy trials are subject to a known bias to estimate VE toward the null if heterogeneous exposure is not accounted for in the analysis of trial data. In light of many well-characterized sources of heterogeneity in dengue virus (DENV) transmission, our goal was to estimate the potential magnitude of this bias in VE estimates for a hypothetical dengue vaccine. To ensure that we realistically modeled heterogeneous exposure, we simulated city-wide DENV transmission and vaccine trial protocols using an agent-based model calibrated with entomological and epidemiological data from long-term field studies in Iquitos, Peru. By simulating a vaccine with a true VE of 0.8 in 1,000 replicate trials each designed to attain 90% power, we found that conventional methods underestimated VE by as much as 21% due to heterogeneous exposure. Accounting for the number of exposures in the vaccine and placebo arms eliminated this bias completely, and the more realistic option of including a frailty term to model exposure as a random effect reduced this bias partially. We also discovered a distinct bias in VE estimates away from the null due to lower detectability of primary DENV infections among seronegative individuals in the vaccinated group. This difference in detectability resulted from our assumption that primary infections in vaccinees who are seronegative at baseline resemble secondary infections, which experience a shorter window of detectable viremia due to a quicker immune response. This resulted in an artefactual finding that VE estimates for the seronegative group were approximately 1% greater than for the seropositive group. Simulation models of vaccine trials that account for these factors can be used to anticipate the extent of bias in field trials and to aid in their interpretation.
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Affiliation(s)
- Guido España
- Department of Biological Sciences and Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, United States of America
| | - Cosmina Hogea
- GlaxoSmithKline, Rockville, MD, United States of America
| | | | - Quirine A. ten Bosch
- Department of Biological Sciences and Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, United States of America
| | - Amy C. Morrison
- United States Naval Medical Research Unit No. 6, Lima, Peru
- Department of Entomology and Nematology, University of California, Davis, CA, United States of America
| | - David L. Smith
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, United States of America
| | - Thomas W. Scott
- Department of Entomology and Nematology, University of California, Davis, CA, United States of America
| | | | - T. Alex Perkins
- Department of Biological Sciences and Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, United States of America
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Global Vector Control Guidelines - The Need For Co-Creation. Trends Parasitol 2019; 35:267-270. [PMID: 30658891 DOI: 10.1016/j.pt.2018.12.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 12/22/2018] [Accepted: 12/22/2018] [Indexed: 11/20/2022]
Abstract
In response to the global expansion and re-emergence of vector-borne diseases, WHO launched the Global Vector Control Response program in 2017. The aim is to strengthen vector control through increased capacity, innovation, improved surveillance, better coordination, and integrated action. Will this new approach overcome the failings of previous initiatives?
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Wilder-Smith A, Chawla T, Ooi EE. Dengue: An Expanding Neglected Tropical Disease. NEGLECTED TROPICAL DISEASES - EAST ASIA 2019. [DOI: 10.1007/978-3-030-12008-5_4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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MacCormack-Gelles B, Lima Neto AS, Sousa GS, Nascimento OJ, Machado MMT, Wilson ME, Castro MC. Epidemiological characteristics and determinants of dengue transmission during epidemic and non-epidemic years in Fortaleza, Brazil: 2011-2015. PLoS Negl Trop Dis 2018; 12:e0006990. [PMID: 30507968 PMCID: PMC6292645 DOI: 10.1371/journal.pntd.0006990] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Revised: 12/13/2018] [Accepted: 11/12/2018] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND After being eliminated during the 1950s, dengue reemerged in Brazil in the 1980s. Since then, incidence of the disease has increased, as serotypes move within and between cities. The co-circulation of multiple serotypes contributes to cycles of epidemic and interepidemic years, and a seasonal pattern of transmission is observed annually. Little is known regarding possible differences in the epidemiology of dengue under epidemic and interepidemic scenarios. This study addresses this gap and aims to assess the epidemiological characteristics and determinants of epidemic and interepidemic dengue transmission, utilizing data from the 5th largest city in Brazil (Fortaleza), at fine spatial and temporal scales. METHODS/PRINCIPAL FINDINGS Longitudinal models of monthly rates of confirmed dengue cases were used to estimate the differential contribution of contextual factors to dengue transmission in Fortaleza between 2011 and 2015. Models were stratified by annual climatological schedules and periods of interepidemic and epidemic transmission, controlling for social, economic, structural, entomological, and environmental factors. Results revealed distinct seasonal patterns between interepidemic and epidemic years, with persistent transmission after June in interepidemic years. Dengue was strongly associated with violence across strata, and with poverty and irregular garbage collection during periods of low transmission, but not with other indicators of public service provision or structural deprivation. Scrapyards and sites associated with tire storage were linked to incidence differentially between seasons, with the strongest associations during transitional precipitation periods. Hierarchical clustering analysis suggests that the dengue burden concentrates in the southern periphery of the city, particularly during periods of minimal transmission. CONCLUSIONS/SIGNIFICANCE Our findings have direct programmatic implications. Vector control operations must be sustained after June even in non-epidemic years. More specifically, scrapyards and sites associated with tires (strongly associated with incidence during periods of minimal transmission), require sustained entomological surveillance, particularly during interepidemic intervals and in the urban periphery. Intersectoral collaborations that address urban violence are critical for facilitating the regular activities of vector control agents.
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Affiliation(s)
- Benjamin MacCormack-Gelles
- Department of Global Health and Population, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States of America
| | - Antonio S. Lima Neto
- Fortaleza Municipal Health Secretariat (SMS-Fortaleza), Fortaleza, Ceará, Brazil
- University of Fortaleza (UNIFOR), Fortaleza, Ceará, Brazil
| | - Geziel S. Sousa
- Fortaleza Municipal Health Secretariat (SMS-Fortaleza), Fortaleza, Ceará, Brazil
| | - Osmar J. Nascimento
- Fortaleza Municipal Health Secretariat (SMS-Fortaleza), Fortaleza, Ceará, Brazil
| | | | - Mary E. Wilson
- Department of Global Health and Population, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States of America
- School of Medicine, University of California, San Francisco, California, United States of America
| | - Marcia C. Castro
- Department of Global Health and Population, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States of America
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Horstick O, Boyce R, Runge-Ranzinger S. Building the evidence base for dengue vector control: searching for certainty in an uncertain world. Pathog Glob Health 2018; 112:395-403. [PMID: 30521408 PMCID: PMC6327620 DOI: 10.1080/20477724.2018.1547541] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
This review discusses biological and chemical methods for dengue vector control, using recently emerging summary evidence, meta-analyses and systematic reviews to conclude on practical public health recommendations for Aedes control, which is increasingly relevant in an era of widespread Chikungunya, yellow feer and Zika outbreaks. The analysis follows an a priori framework of systematic reviews by the authors on vector control methods, distinguishing vector control methods into biological, chemical and environmental methods. Findings of each published systematic review by the authors, following each individual vector control method, are summarised and compared in the discussion against the findings of existing meta-analyses covering all vector control methods. Analysing nine systematic reviews and comparing to two existing meta-analyses provided low-to-moderate evidence that the control of Aedes mosquitoes can be achieved using 1) chemical methods, particularly indoor residual spraying and insecticide treated materials, and 2) biological methods, where appropriate. The level of efficacy and community effectiveness of the methods in most studies analysed is low, as was the overall assessment of study quality. Furthermore, the results show that too optimise results, larvae and adults should be targeted simultaneously. The quality of service delivery is probably one of the most important features of this analysis - and including high coverage. The analysis also highlights the urgent need for standards to guide the design and reporting of vector control studies, ensuring the validity and comparability of results. These studies should aim to include measurements of human transmission data - where and when possible.
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Affiliation(s)
- Olaf Horstick
- Heidelberg Institute of Global Health, University of Heidelberg, Germany
| | - Ross Boyce
- Division of Infectious Diseases, University of North Carolina, Chapel Hill, NC, USA
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Anderson KB, Endy TP, Thomas SJ. The dynamic role of dengue cross-reactive immunity: changing the approach to defining vaccine safety and efficacy. THE LANCET. INFECTIOUS DISEASES 2018; 18:e333-e338. [DOI: 10.1016/s1473-3099(18)30126-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Revised: 12/12/2017] [Accepted: 01/25/2018] [Indexed: 12/11/2022]
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Degroote S, Zinszer K, Ridde V. Interventions for vector-borne diseases focused on housing and hygiene in urban areas: a scoping review. Infect Dis Poverty 2018; 7:96. [PMID: 30173670 PMCID: PMC6120073 DOI: 10.1186/s40249-018-0477-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Accepted: 08/06/2018] [Indexed: 11/21/2022] Open
Abstract
BACKGROUND Over half the world's human populations are currently at risk from vector-borne diseases (VBDs), and the heaviest burden is borne by the world's poorest people, communities, and countries. The aim of this study was to conduct a review on VBD interventions relevant to housing and hygiene (including sanitation and waste management) in urban areas. MAIN BODY We conducted a scoping review, which involved systematically searching peer-reviewed and grey literature published between 2000 and 2016 using five scientific databases and one database for grey literature. Different data extraction tools were used for data coding and extraction. We assessed the quality of each study using the Mixed Methods Appraisal Tool and extracted descriptive characteristics and data about implementation process and transferability from all studies using the Template for Intervention Description and Replication and ASTAIRE (a tool for analyzing the transferability of health promotion interventions) tools. We reviewed 44 studies. Overall, the studies were judged to be of high risk for bias. Our results suggest multifaceted interventions, particularly community-based interventions, have the potential to achieve wider and more sustained effects than do standard vertical single-component programs. The evaluations of multifaceted interventions tend to include integrated evaluations, using not only entomological indicators but also acceptability and sustainability indicators. CONCLUSIONS This review highlighted the important need for higher quality research in VBDs and improved and standardized reporting of interventions. Significant research gaps were found regarding qualitative research and implementation research, and results highlighted the need for more interventions focus on sanitation and hygiene practices.
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Affiliation(s)
- Stéphanie Degroote
- University of Montreal Public Health Research Institute, Montreal, Canada.
| | - Kate Zinszer
- University of Montreal Public Health Research Institute, Montreal, Canada
| | - Valéry Ridde
- University of Montreal Public Health Research Institute, Montreal, Canada
- French Institute For Research on sustainable Development (IRD), IRD Paris Descartes University (CEPED), Paris Sorbonne Cities University, Erl Inserm Sagesud, Paris, France
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Challenges and opportunities in controlling mosquito-borne infections. Nature 2018; 559:490-497. [PMID: 30046071 DOI: 10.1038/s41586-018-0318-5] [Citation(s) in RCA: 80] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Accepted: 05/24/2018] [Indexed: 11/08/2022]
Abstract
Mosquito-borne diseases remain a major cause of morbidity and mortality across the tropical regions. Despite much progress in the control of malaria, malaria-associated morbidity remains high, whereas arboviruses-most notably dengue-are responsible for a rising burden of disease, even in middle-income countries that have almost completely eliminated malaria. Here I discuss how new interventions offer the promise of considerable future reductions in disease burden. However, I emphasize that intervention programmes need to be underpinned by rigorous trials and quantitative epidemiological analyses. Such analyses suggest that the long-term goal of elimination is more feasible for dengue than for malaria, even if malaria elimination would offer greater overall health benefit to the public.
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Hladish TJ, Pearson CAB, Patricia Rojas D, Gomez-Dantes H, Halloran ME, Vazquez-Prokopec GM, Longini IM. Forecasting the effectiveness of indoor residual spraying for reducing dengue burden. PLoS Negl Trop Dis 2018; 12:e0006570. [PMID: 29939983 PMCID: PMC6042783 DOI: 10.1371/journal.pntd.0006570] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 07/12/2018] [Accepted: 05/30/2018] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Historically, mosquito control programs successfully helped contain malaria and yellow fever, but recent efforts have been unable to halt the spread of dengue, chikungunya, or Zika, all transmitted by Aedes mosquitoes. Using a dengue transmission model and results from indoor residual spraying (IRS) field experiments, we investigated how IRS-like campaign scenarios could effectively control dengue in an endemic setting. METHODS AND FINDINGS In our model, we found that high levels of household coverage (75% treated once per year), applied proactively before the typical dengue season could reduce symptomatic infections by 89.7% (median of 1000 simulations; interquartile range [IQR]:[83.0%, 94.8%]) in year one and 78.2% (IQR: [71.2%, 88.0%]) cumulatively over the first five years of an annual program. Lower coverage had correspondingly lower effectiveness, as did reactive campaigns. Though less effective than preventative campaigns, reactive and even post-epidemic interventions retain some effectiveness; these campaigns disrupt inter-seasonal transmission, highlighting an off-season control opportunity. Regardless, none of the campaign scenarios maintain their initial effectiveness beyond two seasons, instead stabilizing at much lower levels of benefit: in year 20, median effectiveness was only 27.3% (IQR: [-21.3%, 56.6%]). Furthermore, simply ceasing an initially successful program exposes a population with lowered herd immunity to the same historical threat, and we observed outbreaks more than four-fold larger than pre-intervention outbreaks. These results do not take into account evolving insecticide resistance, thus long-term effectiveness may be lower if new, efficacious insecticides are not developed. CONCLUSIONS Using a detailed agent-based dengue transmission model for Yucatán State, Mexico, we predict that high coverage indoor residual spraying (IRS) interventions can largely eliminate transmission for a few years, when applied a few months before the typical seasonal epidemic peak. However, vector control succeeds by preventing infections, which precludes natural immunization. Thus, as a population benefits from mosquito control, it gradually loses naturally acquired herd immunity, and the control effectiveness declines; this occurs across all of our modeled scenarios, and is consistent with other empirical work. Long term control that maintains early effectiveness would require some combination of increasing investment, complementary interventions such as vaccination, and control programs across a broad region to diminish risk of importation.
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Affiliation(s)
- Thomas J. Hladish
- Department of Biology, University of Florida, Gainesville, FL, USA
- Emerging Pathogens Institute, University of Florida, Gainesville, FL, USA
| | | | - Diana Patricia Rojas
- Emerging Pathogens Institute, University of Florida, Gainesville, FL, USA
- Department of Epidemiology, University of Florida, Gainesville, FL, USA
| | - Hector Gomez-Dantes
- Health Systems Research Center, National Institute of Public Health, Cuernavaca, Mexico
| | - M. Elizabeth Halloran
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
- Center for Inference and Dynamics of Infectious Diseases, Seattle, WA, USA
- Department of Biostatistics, University of Washington, Seattle, WA, USA
| | | | - Ira M. Longini
- Emerging Pathogens Institute, University of Florida, Gainesville, FL, USA
- Center for Inference and Dynamics of Infectious Diseases, Seattle, WA, USA
- Department of Biostatistics, University of Florida, Gainesville, FL, USA
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Mai VQ, Mai TTX, Tam NLM, Nghia LT, Komada K, Murakami H. Prevalence and Risk Factors of Dengue Infection in Khanh Hoa Province, Viet Nam: A Stratified Cluster Sampling Survey. J Epidemiol 2018; 28:488-497. [PMID: 29780057 PMCID: PMC6242784 DOI: 10.2188/jea.je20170090] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Background Dengue is a clinically important arthropod-borne viral disease with increasing global incidence. Here we aimed to estimate the prevalence of dengue infections in Khanh Hoa Province, central Viet Nam, and to identify risk factors for infection. Methods We performed a stratified cluster sampling survey including residents of 3–60 years of age in Nha Trang City, Ninh Hoa District and Dien Khanh District, Khanh Hoa Province, in October 2011. Immunoglobulin G (IgG) and immunoglobulin M (IgM) against dengue were analyzed using a rapid test kit. Participants completed a questionnaire exploring clinical dengue incidence, socio-economic status, and individual behavior. A household checklist was used to examine environment, mosquito larvae presence, and exposure to public health interventions. Results IgG positivity was 20.5% (urban, 16.3%; rural, 23.0%), IgM positivity was 6.7% (urban, 6.4%; rural, 6.9%), and incidence of clinically compatible dengue during the prior 3 months was 2.8 per 1,000 persons (urban, 1.7; rural, 3.4). For IgG positivity, the adjusted odds ratio (AOR) was 2.68 (95% confidence interval [CI], 1.24–5.81) for mosquito larvae presence in water pooled in old tires and was 3.09 (95% CI, 1.75–5.46) for proximity to a densely inhabited area. For IgM positivity, the AOR was 3.06 (95% CI, 1.50–6.23) for proximity to a densely inhabited area. Conclusions Our results indicated rural penetration of dengue infections. Control measures should target densely inhabited areas, and may include clean-up of discarded tires and water-collecting waste.
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Affiliation(s)
| | | | - Ngo Le Minh Tam
- Department of Laboratory Biosafety and Quality Assessment, Nha Trang Pasteur Institute
| | - Le Trung Nghia
- Department of Vector Control and Border Quarantine, Nha Trang Pasteur Institute
| | - Kenichi Komada
- Bureau of International Health Cooperation, National Center for Global Health and Medicine
| | - Hitoshi Murakami
- Bureau of International Health Cooperation, National Center for Global Health and Medicine
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Gleason-Rodríguez G, Castillo-Méndez M, Maya K, Ramos-Castañeda J, Valverde-Garduño V. Dengue virus infection induces chromatin remodeling at locus AAEL006536 in the midgut of Aedes aegypti. SALUD PUBLICA DE MEXICO 2018; 60:41-47. [PMID: 29689655 DOI: 10.21149/8471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2016] [Accepted: 08/14/2017] [Indexed: 11/06/2022] Open
Abstract
OBJECTIVE To identify and characterize Aedes aegypti's AAEL006536 gene proximal upstream cis-regulatory sequences activated by dengue virus infection. MATERIALS AND METHODS A. aegypti Rockefeller strain mosquitoes were blood fed or infected with dengue virus 2. Open chromatinprofiling was then carried out in pools of midguts from each group of mosquitoes. RESULTS The proximal upstream region does not contain open chromatin sites in the midguts of blood-fed mosquitoes as detected by FAIRE-qPCR. In contrast, two cis-regulatory sites were identified in the same upstream region of dengue virus-infected mosquito midguts. The distal sequence contains STAT-, REL- and C/EBP-type transcription factor binding sites. CONCLUSIONS The activation of two proximal cis-regulatory sequences, induced by dengue virus infection, is mediated by chromatin remodeling mechanisms. Binding sites suggest a dengue virus infectioninduced participation of immunity transcription factors in the up-regulation of this gene. This suggests the participation of the AAEL006536 gene in the mosquito's antiviral innate immune response.
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Affiliation(s)
- Graciela Gleason-Rodríguez
- Departamento de Infección e Inmunidad, Centro de Investigación sobre Enfermedades Infecciosas, Instituto Nacional de Salud Pública. México.,Escuela de Salud Pública de México, Instituto Nacional de Salud Pública. México
| | - Manuel Castillo-Méndez
- Departamento de Infección e Inmunidad, Centro de Investigación sobre Enfermedades Infecciosas, Instituto Nacional de Salud Pública. México.,Escuela de Salud Pública de México, Instituto Nacional de Salud Pública. México
| | - Krystal Maya
- Departamento de Infección e Inmunidad, Centro de Investigación sobre Enfermedades Infecciosas, Instituto Nacional de Salud Pública. México
| | - José Ramos-Castañeda
- Departamento de Infección e Inmunidad, Centro de Investigación sobre Enfermedades Infecciosas, Instituto Nacional de Salud Pública. México
| | - Verónica Valverde-Garduño
- Departamento de Infección e Inmunidad, Centro de Investigación sobre Enfermedades Infecciosas, Instituto Nacional de Salud Pública. México.,Escuela de Salud Pública de México, Instituto Nacional de Salud Pública. México
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Gunning CE, Okamoto KW, Astete H, Vasquez GM, Erhardt E, Del Aguila C, Pinedo R, Cardenas R, Pacheco C, Chalco E, Rodriguez-Ferruci H, Scott TW, Lloyd AL, Gould F, Morrison AC. Efficacy of Aedes aegypti control by indoor Ultra Low Volume (ULV) insecticide spraying in Iquitos, Peru. PLoS Negl Trop Dis 2018; 12:e0006378. [PMID: 29624581 PMCID: PMC5906025 DOI: 10.1371/journal.pntd.0006378] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2018] [Revised: 04/18/2018] [Accepted: 03/08/2018] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Aedes aegypti is a primary vector of dengue, chikungunya, Zika, and urban yellow fever viruses. Indoor, ultra low volume (ULV) space spraying with pyrethroid insecticides is the main approach used for Ae. aegypti emergency control in many countries. Given the widespread use of this method, the lack of large-scale experiments or detailed evaluations of municipal spray programs is problematic. METHODOLOGY/PRINCIPAL FINDINGS Two experimental evaluations of non-residual, indoor ULV pyrethroid spraying were conducted in Iquitos, Peru. In each, a central sprayed sector was surrounded by an unsprayed buffer sector. In 2013, spray and buffer sectors included 398 and 765 houses, respectively. Spraying reduced the mean number of adults captured per house by ~83 percent relative to the pre-spray baseline survey. In the 2014 experiment, sprayed and buffer sectors included 1,117 and 1,049 houses, respectively. Here, the sprayed sector's number of adults per house was reduced ~64 percent relative to baseline. Parity surveys in the sprayed sector during the 2014 spray period indicated an increase in the proportion of very young females. We also evaluated impacts of a 2014 citywide spray program by the local Ministry of Health, which reduced adult populations by ~60 percent. In all cases, adult densities returned to near-baseline levels within one month. CONCLUSIONS/SIGNIFICANCE Our results demonstrate that densities of adult Ae. aegypti can be reduced by experimental and municipal spraying programs. The finding that adult densities return to approximately pre-spray densities in less than a month is similar to results from previous, smaller scale experiments. Our results demonstrate that ULV spraying is best viewed as having a short-term entomological effect. The epidemiological impact of ULV spraying will need evaluation in future trials that measure capacity of insecticide spraying to reduce human infection or disease.
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Affiliation(s)
- Christian E. Gunning
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC United States of America
| | - Kenichi W. Okamoto
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC United States of America
| | - Helvio Astete
- Naval Medical Research Unit No. 6, 3230 Lima Pl., Washington DC, Lima and Iquitos, Peru
| | - Gissella M. Vasquez
- Naval Medical Research Unit No. 6, 3230 Lima Pl., Washington DC, Lima and Iquitos, Peru
| | - Erik Erhardt
- Department of Mathematics and Statistics, University of New Mexico, Albuquerque, NM, United States of America
| | - Clara Del Aguila
- Department of Environmental Sanitation, Peruvian Ministry of Health, Iquitos, Peru
| | - Raul Pinedo
- Department of Environmental Sanitation, Peruvian Ministry of Health, Iquitos, Peru
| | - Roldan Cardenas
- Department of Environmental Sanitation, Peruvian Ministry of Health, Iquitos, Peru
| | - Carlos Pacheco
- Department of Environmental Sanitation, Peruvian Ministry of Health, Iquitos, Peru
| | - Enrique Chalco
- Department of Environmental Sanitation, Peruvian Ministry of Health, Iquitos, Peru
| | | | - Thomas W. Scott
- Department of Entomology and Nematology, University of California, Davis, CA, United States of America
| | - Alun L. Lloyd
- Biomathematics Graduate Program and Department of Mathematics, North Carolina State University, Raleigh, NC, United States of America
| | - Fred Gould
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC United States of America
| | - Amy C. Morrison
- Naval Medical Research Unit No. 6, 3230 Lima Pl., Washington DC, Lima and Iquitos, Peru
- Department of Entomology and Nematology, University of California, Davis, CA, United States of America
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Spatio-temporal coherence of dengue, chikungunya and Zika outbreaks in Merida, Mexico. PLoS Negl Trop Dis 2018; 12:e0006298. [PMID: 29543910 PMCID: PMC5870998 DOI: 10.1371/journal.pntd.0006298] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Revised: 03/27/2018] [Accepted: 02/04/2018] [Indexed: 12/12/2022] Open
Abstract
Response to Zika virus (ZIKV) invasion in Brazil lagged a year from its estimated February 2014 introduction, and was triggered by the occurrence of severe congenital malformations. Dengue (DENV) and chikungunya (CHIKV) invasions tend to show similar response lags. We analyzed geo-coded symptomatic case reports from the city of Merida, Mexico, with the goal of assessing the utility of historical DENV data to infer CHIKV and ZIKV introduction and propagation. About 42% of the 40,028 DENV cases reported during 2008–2015 clustered in 27% of the city, and these clustering areas were where the first CHIKV and ZIKV cases were reported in 2015 and 2016, respectively. Furthermore, the three viruses had significant agreement in their spatio-temporal distribution (Kendall W>0.63; p<0.01). Longitudinal DENV data generated patterns indicative of the resulting introduction and transmission patterns of CHIKV and ZIKV, leading to important insights for the surveillance and targeted control to emerging Aedes-borne viruses. Over the past decades, Aedes-borne viruses (dengue, chikungunya, Zika) have become a major source of morbidity within urban areas. Worldwide, public health response to these viruses is reactive to the occurrence of symptomatic cases (a small proportion of all infections). Here we used geocoded passive surveillance data to determine if areas of historically persistent dengue transmission fuel the introduction and propagation of other Aedes-borne viruses. This article provides quantitative evidence of the strong spatio-temporal overlap that occurs between dengue, chikungunya and Zika, all transmitted by Aedes aegypti mosquitoes in the city. Additionally, it emphasizes the value of analyzing long-term geo-coded passive surveillance information to help identify areas for prioritizing surveillance and control. Findings from this article open a window for considering historical DENV data to make predictions of likely sources of invasion for other emerging Aedes-borne viruses, as well as to the consideration of spatially-targeted approaches for delivery of vector control and surveillance. Arbovirus control in complex urban environments can greatly benefit from exploiting existing spatial information for better delivery of interventions.
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Che-Mendoza A, Medina-Barreiro A, Koyoc-Cardeña E, Uc-Puc V, Contreras-Perera Y, Herrera-Bojórquez J, Dzul-Manzanilla F, Correa-Morales F, Ranson H, Lenhart A, McCall PJ, Kroeger A, Vazquez-Prokopec G, Manrique-Saide P. House screening with insecticide-treated netting provides sustained reductions in domestic populations of Aedes aegypti in Merida, Mexico. PLoS Negl Trop Dis 2018; 12:e0006283. [PMID: 29543805 PMCID: PMC5870999 DOI: 10.1371/journal.pntd.0006283] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Revised: 03/27/2018] [Accepted: 01/30/2018] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND There is a need for effective methods to control Aedes aegypti and prevent the transmission of dengue, chikungunya, yellow fever and Zika viruses. Insecticide treated screening (ITS) is a promising approach, particularly as it targets adult mosquitoes to reduce human-mosquito contact. METHODOLOGY/PRINCIPAL FINDINGS A cluster-randomised controlled trial evaluated the entomological efficacy of ITS based intervention, which consisted of the installation of pyrethroid-impregnated long-lasting insecticide-treated netting material fixed as framed screens on external doors and windows. A total of 10 treatment and 10 control clusters (100 houses/cluster) were distributed throughout the city of Merida, Mexico. Cross-sectional entomological surveys quantified indoor adult mosquito infestation at baseline (pre-intervention) and throughout four post-intervention (PI) surveys spaced at 6-month intervals corresponding to dry/rainy seasons over two years (2012-2014). A total of 844 households from intervention clusters (86% coverage) were protected with ITS at the start of the trial. Significant reductions in the indoor presence and abundance of Ae. aegypti adults (OR = 0.48 and IRR = 0.45, P<0.05 respectively) and the indoor presence and abundance of Ae. aegypti female mosquitoes (OR = 0.47 and IRR = 0.44, P<0.05 respectively) were detected in intervention clusters compared to controls. This high level of protective effect was sustained for up to 24 months PI. Insecticidal activity of the ITS material declined with time, with ~70% mortality being demonstrated in susceptible mosquito cohorts up to 24 months after installation. CONCLUSIONS/SIGNIFICANCE The strong and sustained entomological impact observed in this study demonstrates the potential of house screening as a feasible, alternative approach to a sustained long-term impact on household infestations of Ae. aegypti. Larger trials quantifying the effectiveness of ITS on epidemiological endpoints are warranted and therefore recommended.
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Affiliation(s)
- Azael Che-Mendoza
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- Unidad Colaborativa para Bioensayos Entomologicos, Universidad Autonoma de Yucatan, Merida, Yucatan, Mexico
- Centro Nacional de Programas Preventivos y Control de Enfermedades, Secretaria de Salud, Ciudad de Mexico, Mexico
| | - Anuar Medina-Barreiro
- Unidad Colaborativa para Bioensayos Entomologicos, Universidad Autonoma de Yucatan, Merida, Yucatan, Mexico
| | - Edgar Koyoc-Cardeña
- Unidad Colaborativa para Bioensayos Entomologicos, Universidad Autonoma de Yucatan, Merida, Yucatan, Mexico
| | - Valentín Uc-Puc
- Unidad Colaborativa para Bioensayos Entomologicos, Universidad Autonoma de Yucatan, Merida, Yucatan, Mexico
| | - Yamili Contreras-Perera
- Unidad Colaborativa para Bioensayos Entomologicos, Universidad Autonoma de Yucatan, Merida, Yucatan, Mexico
| | - Josué Herrera-Bojórquez
- Unidad Colaborativa para Bioensayos Entomologicos, Universidad Autonoma de Yucatan, Merida, Yucatan, Mexico
| | - Felipe Dzul-Manzanilla
- Centro Nacional de Programas Preventivos y Control de Enfermedades, Secretaria de Salud, Ciudad de Mexico, Mexico
| | - Fabian Correa-Morales
- Centro Nacional de Programas Preventivos y Control de Enfermedades, Secretaria de Salud, Ciudad de Mexico, Mexico
| | - Hilary Ranson
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Audrey Lenhart
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- Centers for Disease Control and Prevention, Entomology Branch, Atlanta, Georgia, United States of America
| | - Philip J. McCall
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Axel Kroeger
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- Special Programme for Research and Training in Tropical Diseases (TDR), World Health Organization, Geneva, Switzerland
| | - Gonzalo Vazquez-Prokopec
- Department of Environmental Sciences, Emory University, Atlanta, Georgia, United States of America
| | - Pablo Manrique-Saide
- Unidad Colaborativa para Bioensayos Entomologicos, Universidad Autonoma de Yucatan, Merida, Yucatan, Mexico
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Rasinhas ADC, da Silva MAN, Caldas GC, Jácome FC, Leonardo R, dos Santos FB, Nunes PCG, Barth OM, Barreto-Vieira DF. First detection of dengue virus in the saliva of immunocompetent murine model. Mem Inst Oswaldo Cruz 2018; 113:e170208. [PMID: 29412340 PMCID: PMC5851051 DOI: 10.1590/0074-02760170208] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 12/04/2017] [Indexed: 12/17/2022] Open
Abstract
The lack of an experimental animal model for the study of dengue pathogenesis is a limiting factor for the development of vaccines and drugs. In previous studies, our group demonstrated the susceptibility of BALB/c mice to infection by dengue virus (DENV) 1 and 2, and the virus was successfully isolated in several organs. In this study, BALB/c mice were experimentally infected intravenously with DENV-4, and samples of their saliva were collected. Viral RNA extracted from the saliva samples was subjected to qRT-PCR, with a detection limit of 0.002 PFU/mL. The presence of DENV-4 viral RNA was detected in the saliva of two mice, presenting viral titers of 109 RNA/mL. The detection of DENV RNA via saliva sampling is not a common practice in dengue diagnosis, due to the lower detection rates in human patients. However, the results observed in this study seem to indicate that, as in humans, detection rates of DENV RNA in mouse saliva are also low, correlating the infection in both cases. This study reports the first DENV detection in the saliva of BALB/c immunocompetent mice experimentally infected with non-neuroadapted DENV-4.
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Affiliation(s)
- Arthur da Costa Rasinhas
- Fundação Oswaldo Cruz-Fiocruz, Instituto Oswaldo Cruz,
Laboratório de Morfologia e Morfogênese Viral, Rio de Janeiro, RJ, Brasil
| | - Marcos Alexandre Nunes da Silva
- Fundação Oswaldo Cruz-Fiocruz, Instituto Oswaldo Cruz,
Laboratório de Morfologia e Morfogênese Viral, Rio de Janeiro, RJ, Brasil
| | - Gabriela Cardoso Caldas
- Fundação Oswaldo Cruz-Fiocruz, Instituto Oswaldo Cruz,
Laboratório de Morfologia e Morfogênese Viral, Rio de Janeiro, RJ, Brasil
| | - Fernanda Cunha Jácome
- Fundação Oswaldo Cruz-Fiocruz, Instituto Oswaldo Cruz,
Laboratório de Morfologia e Morfogênese Viral, Rio de Janeiro, RJ, Brasil
| | - Raphael Leonardo
- Fundação Oswaldo Cruz-Fiocruz, Instituto Oswaldo Cruz,
Laboratório de Morfologia e Morfogênese Viral, Rio de Janeiro, RJ, Brasil
| | - Flávia Barreto dos Santos
- Fundação Oswaldo Cruz-Fiocruz, Instituto Oswaldo Cruz,
Laboratório de Imunologia Viral, Rio de Janeiro, RJ, Brasil
| | | | - Ortrud Monika Barth
- Fundação Oswaldo Cruz-Fiocruz, Instituto Oswaldo Cruz,
Laboratório de Morfologia e Morfogênese Viral, Rio de Janeiro, RJ, Brasil
| | - Debora Ferreira Barreto-Vieira
- Fundação Oswaldo Cruz-Fiocruz, Instituto Oswaldo Cruz,
Laboratório de Morfologia e Morfogênese Viral, Rio de Janeiro, RJ, Brasil
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Quyen DL, Thanh Le N, Van Anh CT, Nguyen NB, Hoang DV, Montgomery JL, Kutcher SC, Hoang Le N, Hien NT, Hue Kien DT, Rabaa M, O’Neill SL, Simmons CP, Anh DD, Anders KL. Epidemiological, Serological, and Virological Features of Dengue in Nha Trang City, Vietnam. Am J Trop Med Hyg 2018; 98:402-409. [PMID: 29313471 PMCID: PMC5929208 DOI: 10.4269/ajtmh.17-0630] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Accepted: 10/31/2017] [Indexed: 11/07/2022] Open
Abstract
Vietnam is endemic for dengue. We conducted a series of retrospective and prospective studies to characterize the epidemiology of dengue and population mobility patterns in Nha Trang city, Vietnam, with a view to rational design of trials of community-level interventions. A 10-year time series of dengue case notifications showed pronounced interannual variability, as well as spatial heterogeneity in ward-level dengue incidence (median annual coefficient of variation k = 0.47). Of 451 children aged 1-10 years enrolled in a cross-sectional serosurvey, almost one-third had evidence of a past dengue virus (DENV) infection, with older children more likely to have a multitypic response indicative of past exposure to ≥ 1 serotype. All four DENV serotypes were detected in hospitalized patients during 8 months of sampling in 2015. Mobility data collected from 1,000 children and young adults via prospective travel diaries showed that, although all ages spent approximately half of their daytime hours (5:00 am-9:00 pm) at home, younger age groups (≤ 14 years) spent a significantly greater proportion of their time within 500 m of home than older respondents. Together these findings inform the rational design of future trials of dengue preventive interventions in this setting by identifying 1) children < 7 years as an optimal target group for a flavivirus-naive serological cohort, 2) children and young adults as the predominant patient population for a study with a clinical end point of symptomatic dengue, and 3) substantial spatial and temporal variations in DENV transmission, with a consequent requirement for a trial to be large enough and of long enough duration to overcome this heterogeneity.
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Affiliation(s)
- Duong Le Quyen
- National Institute of Hygiene and Epidemiology, Hanoi, Vietnam
- Institute for Vector Borne Disease, Monash University, Clayton, Australia
| | - Nguyen Thanh Le
- National Institute of Hygiene and Epidemiology, Hanoi, Vietnam
| | - Cao Thi Van Anh
- National Institute of Hygiene and Epidemiology, Hanoi, Vietnam
| | | | - Dong Van Hoang
- National Institute of Hygiene and Epidemiology, Hanoi, Vietnam
| | | | - Simon C. Kutcher
- Institute for Vector Borne Disease, Monash University, Clayton, Australia
| | - Nguyen Hoang Le
- National Institute of Hygiene and Epidemiology, Hanoi, Vietnam
| | | | - Duong Thi Hue Kien
- Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Maia Rabaa
- Institute for Vector Borne Disease, Monash University, Clayton, Australia
| | - Scott L. O’Neill
- Institute for Vector Borne Disease, Monash University, Clayton, Australia
| | - Cameron P. Simmons
- Institute for Vector Borne Disease, Monash University, Clayton, Australia
- Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
- Department of Microbiology and Immunology, University of Melbourne, Doherty Institute, Melbourne, Australia
| | - Dang Duc Anh
- National Institute of Hygiene and Epidemiology, Hanoi, Vietnam
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Ritchie SA, van den Hurk AF, Smout MJ, Staunton KM, Hoffmann AA. Mission Accomplished? We Need a Guide to the 'Post Release' World of Wolbachia for Aedes-borne Disease Control. Trends Parasitol 2018; 34:217-226. [PMID: 29396201 DOI: 10.1016/j.pt.2017.11.011] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Revised: 11/23/2017] [Accepted: 11/28/2017] [Indexed: 02/05/2023]
Abstract
Historically, sustained control of Aedes aegypti, the vector of dengue, chikungunya, yellow fever, and Zika viruses, has been largely ineffective. Subsequently, two novel 'rear and release' control strategies utilizing mosquitoes infected with Wolbachia are currently being developed and deployed widely. In the incompatible insect technique, male Aedes mosquitoes, infected with Wolbachia, suppress populations through unproductive mating. In the transinfection strategy, both male and female Wolbachia-infected Ae. aegypti mosquitoes rapidly infect the wild population with Wolbachia, blocking virus transmission. It is critical to monitor the long-term stability of Wolbachia in host populations, and also the ability of this bacterium to continually inhibit virus transmission. Ongoing release and monitoring programs must be future-proofed should political support weaken when these vectors are successfully controlled.
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Affiliation(s)
- Scott A Ritchie
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Smithfield, QLD 4878, Australia; Australian Institute of Tropical Health and Medicine, James Cook University, Smithfield, QLD 4878, Australia.
| | - Andrew F van den Hurk
- Public Health Virology, Forensic and Scientific Services, Department of Health, Queensland Government, 39 Kessels Rd, Coopers Plains, QLD 4108, Australia
| | - Michael J Smout
- Australian Institute of Tropical Health and Medicine, James Cook University, Smithfield, QLD 4878, Australia
| | - Kyran M Staunton
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Smithfield, QLD 4878, Australia; Australian Institute of Tropical Health and Medicine, James Cook University, Smithfield, QLD 4878, Australia
| | - Ary A Hoffmann
- School of BioSciences, Bio21 Institute, The University of Melbourne, Melbourne, VIC 3010, Australia
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Toledo ME, Vanlerberghe V, Rosales JP, Mirabal M, Cabrera P, Fonseca V, Gómez Padrón T, Pérez Menzies M, Montada D, Van der Stuyft P. The additional benefit of residual spraying and insecticide-treated curtains for dengue control over current best practice in Cuba: Evaluation of disease incidence in a cluster randomized trial in a low burden setting with intensive routine control. PLoS Negl Trop Dis 2017; 11:e0006031. [PMID: 29117180 PMCID: PMC5695847 DOI: 10.1371/journal.pntd.0006031] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Revised: 11/20/2017] [Accepted: 10/11/2017] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Aedes control interventions are considered the cornerstone of dengue control programmes, but there is scarce evidence on their effect on disease. We set-up a cluster randomized controlled trial in Santiago de Cuba to evaluate the entomological and epidemiological effectiveness of periodical intra- and peri-domiciliary residual insecticide (deltamethrin) treatment (RIT) and long lasting insecticide treated curtains (ITC). METHODOLOGY/PRINCIPAL FINDINGS Sixty three clusters (around 250 households each) were randomly allocated to two intervention (RIT and ITC) and one control arm. Routine Aedes control activities (entomological surveillance, source reduction, selective adulticiding, health education) were applied in the whole study area. The outcome measures were clinical dengue case incidence and immature Aedes infestation. Effectiveness of tools was evaluated using a generalized linear regression model with a negative binomial link function. Despite significant reduction in Aedes indices (Rate Ratio (RR) 0.54 (95%CI 0.32-0.89) in the first month after RIT, the effect faded out over time and dengue incidence was not reduced. Overall, in this setting there was no protective effect of RIT or ITC over routine in the 17months intervention period, with for house index RR of 1.16 (95%CI 0.96-1.40) and 1.25 (95%CI 1.03-1.50) and for dengue incidence RR of 1.43 (95%CI 1.08-1.90) and 0.96 (95%CI 0.72-1.28) respectively. The monthly dengue incidence rate (IR) at cluster level was best explained by epidemic periods (Incidence Rate Ratio (IRR) 5.50 (95%CI 4.14-7.31)), the IR in bordering houseblocks (IRR 1.03 (95%CI 1.02-1.04)) and the IR pre-intervention (IRR 1.02 (95%CI 1.00-1.04)). CONCLUSIONS Adding RIT to an intensive routine Aedes control programme has a transient effect on the already moderate low entomological infestation levels, while ITC did not have any effect. For both interventions, we didn't evidence impact on disease incidence. Further studies are needed to evaluate impact in settings with high Aedes infestation and arbovirus case load.
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Affiliation(s)
- Maria Eugenia Toledo
- Department of Epidemiology, Institute of Tropical Medicine “Pedro Kourí”, La Habana, Cuba
| | - Veerle Vanlerberghe
- Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium
| | - Julio Popa Rosales
- Provincial Center of Surveillance and Vector Control, Santiago de Cuba, Cuba
| | - Mayelin Mirabal
- Finlay Institute - Center for Vaccines Research and Production, Habana, Cuba
| | - Pedro Cabrera
- Provincial Center of Surveillance and Vector Control, Santiago de Cuba, Cuba
| | - Viviana Fonseca
- Provincial Center of Surveillance and Vector Control, Santiago de Cuba, Cuba
| | | | | | - Domingo Montada
- Department of Epidemiology, Institute of Tropical Medicine “Pedro Kourí”, La Habana, Cuba
| | - Patrick Van der Stuyft
- Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium
- University of Ghent, Ghent, Belgium
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de Oliveira S, Villela DAM, Dias FBS, Moreira LA, Maciel de Freitas R. How does competition among wild type mosquitoes influence the performance of Aedes aegypti and dissemination of Wolbachia pipientis? PLoS Negl Trop Dis 2017; 11:e0005947. [PMID: 28991902 PMCID: PMC5648260 DOI: 10.1371/journal.pntd.0005947] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 10/19/2017] [Accepted: 09/08/2017] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Wolbachia has been deployed in several countries to reduce transmission of dengue, Zika and chikungunya viruses. During releases, Wolbachia-infected females are likely to lay their eggs in local available breeding sites, which might already be colonized by local Aedes sp. mosquitoes. Therefore, there is an urgent need to estimate the deleterious effects of intra and interspecific larval competition on mosquito life history traits, especially on the duration of larval development time, larval mortality and adult size. METHODOLOGY/PRINCIPAL FINDINGS Three different mosquito populations were used: Ae. aegypti infected with Wolbachia (wMelBr strain), wild Ae. aegypti and wild Ae. albopictus. A total of 21 treatments explored intra and interspecific larval competition with varying larval densities, species proportions and food levels. Each treatment had eight replicates with two distinct food levels: 0.25 or 0.50 g of Chitosan and fallen avocado leaves. Overall, overcrowding reduced fitness correlates of the three populations. Ae. albopictus larvae presented lower larval mortality, shorter development time to adult and smaller wing sizes than Ae. aegypti. The presence of Wolbachia had a slight positive effect on larval biology, since infected individuals had higher survivorship than uninfected Ae. aegypti larvae. CONCLUSIONS/SIGNIFICANCE In all treatments, Ae. albopictus outperformed both wild Ae. aegypti and the Wolbachia-infected group in larval competition, irrespective of larval density and the amount of food resources. The major force that can slow down Wolbachia invasion is the population density of wild mosquitoes. Given that Ae. aegypti currently dominates in Rio, in comparison with Ae. albopictus frequency, additional attention must be given to the population density of Ae. aegypti during releases to increase the likelihood of Wolbachia invasion.
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Affiliation(s)
- Suellen de Oliveira
- Fundação Oswaldo Cruz, Fiocruz-RJ, Instituto Oswaldo Cruz, Laboratório de Mosquitos Transmissores de Hematozoários, Rio de Janeiro, Brazil
| | | | | | - Luciano Andrade Moreira
- Fundação Oswaldo Cruz, Fiocruz-MG, Instituto René Rachou, Mosquitos vetores: Endossimbiontes e Interação Patógeno-Vetor, Rio de Janeiro, Brazil
| | - Rafael Maciel de Freitas
- Fundação Oswaldo Cruz, Fiocruz-RJ, Instituto Oswaldo Cruz, Laboratório de Mosquitos Transmissores de Hematozoários, Rio de Janeiro, Brazil
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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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