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Tian L, Liang C, Huang X, Liu Z, Su J, Guo C, Zhu G, Sun J. Genomic epidemiology of dengue in Shantou, China, 2019. Front Public Health 2023; 11:1035060. [PMID: 37522010 PMCID: PMC10374217 DOI: 10.3389/fpubh.2023.1035060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Accepted: 06/23/2023] [Indexed: 08/01/2023] Open
Abstract
Objectives Dengue has been endemic in Southeast Asian countries for decades. There are few reports tracing the dynamics of dengue in real time. In this study, we generated hundreds of pathogen genomes to understand the genomic epidemiology of an outbreak in a hyper-endemic area of dengue. Methods We leveraged whole-genome short-read sequencing (PE150) to generate genomes of the dengue virus and investigated the genomic epidemiology of a dengue virus transmission in a mesoscale outbreak in Shantou, China, in 2019. Results The outbreak was sustained from July to December 2019. The total accumulated number of laboratory-confirmed cases was 944. No gender bias or fatalities were recorded. Cambodia and Singapore were the main sources of imported dengue cases (74.07%, n = 20). A total of 284 dengue virus strains were isolated, including 259 DENV-1, 24 DENV-2, and 1 DENV-3 isolates. We generated the entire genome of 252 DENV isolates (229 DENV-1, 22 DENV-2, and 1 DENV-3), which represented 26.7% of the total cases. Combined epidemiological and phylogenetic analyses indicated multiple independent introductions. The internal transmission evaluations and transmission network reconstruction supported the inference of phylodynamic analysis, with high Bayes factor support in BSSVS analysis. Two expansion founders and transmission chains were detected in CCH and LG of Shantou. Conclusions We observed the instant effects of genomic epidemiology in monitoring the dynamics of DENV and highlighted its prospects for real-time tracing of outbreaks of other novel agents in the future.
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Affiliation(s)
- Lina Tian
- Guangdong Provincial Center for Disease Control and Prevention, Guangdong Provincial Institute of Public Health, Guangzhou, China
- Guangdong Provincial Center for Disease Control and Prevention, Guangzhou, China
- School of Mathematics and Computing Science, Guilin University of Electronic Technology, Guilin, China
| | - Chumin Liang
- Guangdong Provincial Center for Disease Control and Prevention, Guangdong Provincial Institute of Public Health, Guangzhou, China
- Guangdong Provincial Center for Disease Control and Prevention, Guangzhou, China
| | - Xiaorong Huang
- Guangdong Provincial Center for Disease Control and Prevention, Guangdong Provincial Institute of Public Health, Guangzhou, China
- Guangdong Provincial Center for Disease Control and Prevention, Guangzhou, China
- School of Public Health, Southern Medical University, Guangzhou, China
| | - Zhe Liu
- Guangdong Provincial Center for Disease Control and Prevention, Guangdong Provincial Institute of Public Health, Guangzhou, China
- Guangdong Provincial Center for Disease Control and Prevention, Guangzhou, China
| | - Juan Su
- Guangdong Provincial Center for Disease Control and Prevention, Guangzhou, China
| | - Chuan Guo
- Center for Disease Control and Prevention of Shantou City, Shantou, Guangdong, China
| | - Guanghu Zhu
- School of Mathematics and Computing Science, Guilin University of Electronic Technology, Guilin, China
| | - Jiufeng Sun
- Guangdong Provincial Center for Disease Control and Prevention, Guangdong Provincial Institute of Public Health, Guangzhou, China
- Guangdong Provincial Center for Disease Control and Prevention, Guangzhou, China
- School of Public Health, Southern Medical University, Guangzhou, China
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Sarkar MMH, Rahman MS, Islam MR, Rahman A, Islam MS, Banu TA, Akter S, Goswami B, Jahan I, Habib MA, Uddin MM, Mia MZ, Miah MI, Shaikh AA, Khan MS. Comparative phylogenetic analysis and transcriptomic profiling of Dengue (DENV-3 genotype I) outbreak in 2021 in Bangladesh. Virol J 2023; 20:127. [PMID: 37337232 PMCID: PMC10278332 DOI: 10.1186/s12985-023-02030-1] [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: 12/28/2022] [Accepted: 04/04/2023] [Indexed: 06/21/2023] Open
Abstract
Background The next-generation sequencing (NGS) technology facilitates in-depth study of host-pathogen metatranscriptome. We, therefore, implicated phylodynamic and transcriptomic approaches through NGS technology to know/understand the dengue virus (DENV) origin and host response with dengue fever. Methods In this study, blood serum RNA was extracted from 21 dengue patients and 3 healthy individuals. Total transcriptomic data were analyzed for phylogenetic, phylodynamic, differential express gene (DEG), and gene ontology (GO) using respective bioinformatics tools. Results The viral genome sequence revealed dengue viral genome size ranges 10647 to 10707 nucleotide. Phylogenetic and phylodynamic analysis showed that the 2021 epidemic isolates were DENV-3 genotype-I and maintained as a new clade in compared to 2019 epidemic. Transcriptome analysis showed a total of 2686 genes were DEG in dengue patients compared to control with a q-value < 0.05. DESeq2 plot counts function of the top 24 genes with the smallest q-values of differential gene expression of RNA-seq data showed that 11 genes were upregulated, whereas 13 genes were downregulated. GO analysis showed a significant upregulation (p = < 0.001) in a process of multicellular organismal, nervous system, sensory perception of chemical stimulus, and G protein-coupled receptor signaling pathways in the dengue patients. However, there were a significant downregulation (p = < 0.001) of intracellular component, cellular anatomical entity, and protein-containing complex in dengue patients. Most importantly, there was a significant increase of a class of immunoregulatory proteins in dengue patients in compared to the controls, with increased GO of immune system process. In addition, upregulation of toll receptor (TLR) signaling pathways were found in dengue patients. These TLR pathways were particularly involved for the activation of innate system coupled with adaptive immune system that probably involved the rapid elimination of dengue virus infected cells. These differentially expressed genes could be further investigated for target based prophylactic interventions for dengue. Conclusion This is a first report describing DENV complete genomic features and differentially expressed genes in patients in Bangladesh. These genes may have diagnostic and therapeutic values for dengue infection. Continual genomic surveillance is required to further investigate the shift in dominant genotypes in relation to viral pathogenesis. Supplementary Information The online version contains supplementary material available at 10.1186/s12985-023-02030-1.
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Affiliation(s)
| | - M Shaminur Rahman
- Department of Microbiology, Jashore University of Science and Technology, Jashore, Bangladesh
| | - M Rafiul Islam
- Department of Microbiology, University of Dhaka, Dhaka, Bangladesh
| | - Arafat Rahman
- Department of Microbiology, Noakhali Science and Technology University, Noakhali, Bangladesh
| | | | - Tanjina Akhtar Banu
- Bangladesh Council of Scientific and Industrial Research (BCSIR), Dhaka, Bangladesh
| | - Shahina Akter
- Bangladesh Council of Scientific and Industrial Research (BCSIR), Dhaka, Bangladesh
| | - Barna Goswami
- Bangladesh Council of Scientific and Industrial Research (BCSIR), Dhaka, Bangladesh
| | - Iffat Jahan
- Bangladesh Council of Scientific and Industrial Research (BCSIR), Dhaka, Bangladesh
| | - Md Ahashan Habib
- Bangladesh Council of Scientific and Industrial Research (BCSIR), Dhaka, Bangladesh
| | - Mohammad Mohi Uddin
- Bangladesh Council of Scientific and Industrial Research (BCSIR), Dhaka, Bangladesh
| | - Md Zakaria Mia
- Department of Microbiology, Jagannath University, Dhaka, Bangladesh
| | - Md Ibrahim Miah
- Department of Microbiology, University of Dhaka, Dhaka, Bangladesh
| | - Aftab Ali Shaikh
- Bangladesh Council of Scientific and Industrial Research (BCSIR), Dhaka, Bangladesh
| | - Md Salim Khan
- Bangladesh Council of Scientific and Industrial Research (BCSIR), Dhaka, Bangladesh.
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Carvalho DO, Costa-da-Silva AL, Petersen V, de Souza MS, Ioshino RS, Marques ICS, Franz AWE, Olson KE, James AA, Capurro ML. Transgene-induced cell death following dengue-2 virus infection in Aedes aegypti. Sci Rep 2023; 13:5958. [PMID: 37045866 PMCID: PMC10097671 DOI: 10.1038/s41598-023-32895-9] [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: 10/10/2022] [Accepted: 04/04/2023] [Indexed: 04/14/2023] Open
Abstract
Dengue viruses (DENVs) are mosquito-borne flaviviruses causing millions of human infections each year and pose a challenge for public health systems worldwide. Aedes aegypti is the principal vector species transmitting DENVs to humans. Controlling Ae. aegypti is difficult due to the abundance of breeding sites and increasing insecticide resistance in the vector populations. Developing new vector control strategies is critical for decreasing the disease burden. One potential approach is genetically replacing Ae. aegypti populations with vector populations highly resistant to DENV transmission. Here, we focus on an alternative strategy for generating dengue 2 virus (DENV-2) resistance in genetically-modified Ae. aegypti in which the mosquitoes express an inactive form of Michelob_x (Mx), an antagonist of the Inhibitor of Apoptosis (IAP), to induce apoptosis in those cells in which actively replicating DENV-2 is present. The inactive form of Mx was flanked by the RRRRSAG cleavage motif, which was recognized by the NS2B/NS3 protease of the infecting DENV-2 thereby releasing and activating Mx which then induced apoptosis. Our transgenic strain exhibited a significantly higher mortality rate than the non-transgenic control when infected with DENV-2. We also transfected a DNA construct containing inactive Mx fused to eGFP into C6/36 mosquito cells and indirectly observed Mx activation on days 3 and 6 post-DENV-2 infections. There were clear signs that the viral NS2B/NS3 protease cleaved the transgene, thereby releasing Mx protein into the cytoplasm, as was confirmed by the detection of eGFP expression in infected cells. The present study represents proof of the concept that virus infection can be used to induce apoptosis in infected mosquito cells.
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Affiliation(s)
- Danilo O Carvalho
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, 05508, Brazil.
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
| | - Andre L Costa-da-Silva
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, 05508, Brazil
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Vivian Petersen
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, 05508, Brazil
| | - Micael Santana de Souza
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, 05508, Brazil
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Rafaella S Ioshino
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, 05508, Brazil
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Isabel C S Marques
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, 05508, Brazil
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Alexander W E Franz
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, MO, 65211, USA
| | - Ken E Olson
- Center for Vector-Borne Infectious Diseases (CVID), Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO, 80523-1685, USA
| | - Anthony A James
- Department of Microbiology & Molecular Genetics, University of California, Irvine, CA, 92697, USA
- Department of Molecular Biology & Biochemistry, University of California, Irvine, CA, 92697, USA
| | - Margareth L Capurro
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, 05508, Brazil.
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
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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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Mulderij-Jansen V, Pundir P, Grillet ME, Lakiang T, Gerstenbluth I, Duits A, Tami A, Bailey A. Effectiveness of Aedes-borne infectious disease control in Latin America and the Caribbean region: A scoping review. PLoS One 2022; 17:e0277038. [PMID: 36322603 PMCID: PMC9629598 DOI: 10.1371/journal.pone.0277038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 10/18/2022] [Indexed: 11/05/2022] Open
Abstract
Background Aedes aegypti and Aedes albopictus are primary vectors of emerging or re-emerging arboviruses that threaten public health worldwide. Many efforts have been made to develop interventions to control these Aedes species populations. Still, countries in the Latin America and the Caribbean (LAC) region struggle to create/design/develop sustainable and effective control strategies. This scoping review synthesises evidence concerning the effectiveness of Ae. aegypti and Ae. albopictus prevention and control interventions performed in LAC (2000–2021). The findings can be used to evaluate, compare and develop more effective control strategies. Methodology The review is based on the methodology by Joanna Briggs Institute for conducting a scoping review. The MEDLINE (via PubMed and Web of Science), Cochrane Library, Scopus, EMBASE and ScienceDirect databases were used to search for articles. Grey literature was searched from governmental and non-governmental organisation websites. Four reviewers independently screened all titles and abstracts and full-text of the articles using the Rayyan web application, based on pre-defined eligibility criteria. Results A total of 122 publications were included in the review. Most studies focused on dengue virus infection and data on Ae. aegypti. Entomological data were mainly used to determine the intervention’s effectiveness. An integrated control intervention was the most commonly employed strategy in both regions. Biological control measures, environmental management, and health education campaigns on community participation achieved more sustainable results than an intervention where only a chemical control measure was used. Challenges to implementing interventions were insufficient financial support, resources, workforce, intersectoral collaboration and legislation. Conclusions Based on the synthesised data, an integrated vector (Aedes) management focused on community participation seems to be the most effective approach to mitigate Aedes-borne infectious diseases. Maintaining the approach’s effect remains challenging as it requires multisectoral and multi-disciplinary team engagement and active community participation. Future research needs to address the barriers to program implementation and maintenance as data on this topic is lacking.
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Affiliation(s)
- Vaitiare Mulderij-Jansen
- Department of Medical Microbiology and Infection Prevention, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
- Faculty of Geosciences, Department of Human Geography and Spatial Planning, International Development Studies, Utrecht University, Utrecht, Netherlands
- Department of Epidemiology, Curaçao Biomedical & Health Research Institute, Willemstad, Curaçao
- * E-mail:
| | - Prachi Pundir
- George Institute for Global Health, New Delhi, India
| | - Maria E. Grillet
- Facultad de Ciencias, Instituto de Zoología y Ecología Tropical, Universidad Central de Venezuela, Caracas, Venezuela
| | | | - Izzy Gerstenbluth
- Department of Epidemiology, Curaçao Biomedical & Health Research Institute, Willemstad, Curaçao
- Epidemiology and Research Unit, Ministry of Health Environment and Nature of Curaçao, Willemstad, Curaçao
| | - Ashley Duits
- Red Cross Blood Bank Foundation, Willemstad, Curaҫao
- Department of Immunology, Curaçao Biomedical & Health Research Institute, Willemstad, Curaçao
- Institute for Medical Education, University Medical Center Groningen, Groningen, The Netherlands
| | - Adriana Tami
- Department of Medical Microbiology and Infection Prevention, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Ajay Bailey
- Faculty of Geosciences, Department of Human Geography and Spatial Planning, International Development Studies, Utrecht University, Utrecht, Netherlands
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Gómez M, Macedo AT, Pedrosa MC, Hohana F, Barros V, Pires B, Barbosa L, Brito M, Garziera L, Argilés-Herrero R, Virginio JF, Carvalho DO. Exploring Conditions for Handling Packing and Shipping Aedes aegypti Males to Support an SIT Field Project in Brazil. INSECTS 2022; 13:871. [PMID: 36292819 PMCID: PMC9604236 DOI: 10.3390/insects13100871] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 09/16/2022] [Accepted: 09/21/2022] [Indexed: 06/16/2023]
Abstract
The sterile insect technique (SIT) application, as an alternative tool for conventional mosquito control methods, has recently gained prominence. Nevertheless, some SIT components require further development, such as protocols under large-scale conditions, focusing on packing and shipping mosquitoes, and considering transporting time. Immobilization of Aedes aegypti males was tested at temperatures 4, 7, 10, and 14 °C, and each temperature was assessed for 60, 90, and 120 min. The recovery after 24 h was also studied. Chilled and control-reared males had comparable survival rates for all conditions, although 4 °C for 120 min impacted male survival. The male escape rate was affected after 60 min of exposure at 4 °C; this difference was not significant, with 24 h of recovery. First, we defined the successful immobilization at 4 °C for 60 min, thus enabling the evaluation of two transportation intervals: 6 and 24 h, with the assessment of different compaction densities of 100 and 150 mosquitoes/cm3 at 10 °C to optimize the shipment. Compaction during simulated mosquito shipments reduced survival rates significantly after 6 and 24 h. In the mating propensity and insemination experiments, the sterile males managed to inseminate 40 to 66% for all treatments in laboratory conditions. The male insemination propensity was affected only by the highest compaction condition concerning the control. The analysis of the densities (100 and 150 males/cm3) showed that a higher density combined with an extended shipment period (24 h) negatively impacted the percentage of inseminated females. The results are very helpful in developing and improving the SIT packing and shipment protocols. Further studies are required to evaluate all combined parameters' synergetic effects that can combine irradiation to assess sexual competitiveness when sterile males are released into the field.
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Affiliation(s)
- Maylen Gómez
- Biofábrica Moscamed Brasil, Quadra D-13, Lote 15, Distrito Industrial do São Francisco, Juazeiro 48909-733, Brazil
- Insect Pest Control Subprogramme, Joint FAO/IAEA Programme of Nuclear Techniques in Food and Agriculture, P.O. Box 100 Vienna, Austria
| | - Aline T. Macedo
- Biofábrica Moscamed Brasil, Quadra D-13, Lote 15, Distrito Industrial do São Francisco, Juazeiro 48909-733, Brazil
| | - Michelle C. Pedrosa
- Biofábrica Moscamed Brasil, Quadra D-13, Lote 15, Distrito Industrial do São Francisco, Juazeiro 48909-733, Brazil
| | - Fernanda Hohana
- Biofábrica Moscamed Brasil, Quadra D-13, Lote 15, Distrito Industrial do São Francisco, Juazeiro 48909-733, Brazil
| | - Verenna Barros
- Biofábrica Moscamed Brasil, Quadra D-13, Lote 15, Distrito Industrial do São Francisco, Juazeiro 48909-733, Brazil
| | - Bianca Pires
- Biofábrica Moscamed Brasil, Quadra D-13, Lote 15, Distrito Industrial do São Francisco, Juazeiro 48909-733, Brazil
| | - Lucas Barbosa
- Biofábrica Moscamed Brasil, Quadra D-13, Lote 15, Distrito Industrial do São Francisco, Juazeiro 48909-733, Brazil
| | - Miriam Brito
- Biofábrica Moscamed Brasil, Quadra D-13, Lote 15, Distrito Industrial do São Francisco, Juazeiro 48909-733, Brazil
| | - Luiza Garziera
- Biofábrica Moscamed Brasil, Quadra D-13, Lote 15, Distrito Industrial do São Francisco, Juazeiro 48909-733, Brazil
| | - Rafael Argilés-Herrero
- Insect Pest Control Subprogramme, Joint FAO/IAEA Programme of Nuclear Techniques in Food and Agriculture, P.O. Box 100 Vienna, Austria
| | - Jair F. Virginio
- Biofábrica Moscamed Brasil, Quadra D-13, Lote 15, Distrito Industrial do São Francisco, Juazeiro 48909-733, Brazil
| | - Danilo O. Carvalho
- Insect Pest Control Subprogramme, Joint FAO/IAEA Programme of Nuclear Techniques in Food and Agriculture, P.O. Box 100 Vienna, Austria
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Taborda A, Chamorro C, Quintero J, Carrasquilla G, Londoño D. Cost-effectiveness of a Dengue Vector Control Intervention in Colombia. Am J Trop Med Hyg 2022; 107:tpmd200669. [PMID: 35436764 PMCID: PMC9294672 DOI: 10.4269/ajtmh.20-0669] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Accepted: 11/01/2021] [Indexed: 12/02/2022] Open
Abstract
Dengue is a public health problem in Colombia and in the municipality of Girardot, an area of high risk for dengue transmission. We present the results of an economic evaluation from the societal perspective and 1-year time horizon comparing the regular control program for dengue prevention versus an intervention that comprised an environmental management strategy by covering the most Aedes aegypti productive breeding sites with insecticide covers, community actions, and educational activities. The effectiveness of the intervention was measured as the reduction in probability of dengue infection obtained from a community trial. Resource use was estimated from clinical records that were validated by clinical experts; unit costs were taken from national tariffs. Patient costs were obtained from a household survey. We found that the intervention generated an additional cost of USD20.9 per household and an incremental effectiveness of 0.00173 (reduction in the probability of reported dengue cases). Overall, both alternatives generate similar effectiveness, but the new intervention was associated with increasing costs. We conclude the new intervention is a potentially cost-effective option in areas where high prevalence of dengue exists.
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Martynova T, Kamanda P, Sim C. Transcriptome profiling reveals sex-specific gene expressions in pupal and adult stages of the mosquito Culex pipiens. INSECT MOLECULAR BIOLOGY 2022; 31:24-32. [PMID: 34460975 PMCID: PMC9190208 DOI: 10.1111/imb.12735] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 08/25/2021] [Accepted: 08/27/2021] [Indexed: 05/03/2023]
Abstract
Understanding the development process of male and female mosquitoes provides important basic information for sterile insect release programmes and is important for improving other vector control strategies. However, little is known about the molecular mechanisms that distinguish male from female-specific developmental processes in this species. We used IlluminaRNA-seq to identify sex-specific genes during pupal and adult stages. One hundred and forty-seven genes were expressed only in pupal males, 56 genes were expressed in adult males and another 82 genes were commonly expressed in both male samples. In addition, 26 genes were expressed only in the pupal females, 163 genes were found in the adult females and only one gene was expressed in both female samples. A further quantitative real-time PCR validation of selected genes from the RNA sequencing (RNA-seq) analysis confirmed upregulation of those genes in a sex-specific manner, including: fibrinogen and fibronectin, a zinc finger protein, phospholipase A(2) and a serine protein for female pupae; venom allergen 3, a perlecan, testis-specific serine/threonine-protein kinase 1, testis-specific serine/threonine-protein kinase 6 and cytochrome c-2 for male pupae; a salivary protein, D7 protein precursor, trypsin 7 precursor, D7 protein and nanos for female adults; and tetraspanin F139, cytosol aminopeptidase, testis-specific serine/threonine-protein kinase 1, a testis-specific serine/threonine-protein kinase 6 and a C-type lectin for male adults. These findings provide insight into the development and physiology of Culex mosquitoes, which will help in the development of more effective control methods for these disease vectors.
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Transcriptome Analysis of an Aedes albopictus Cell Line Single- and Dual-Infected with Lammi Virus and WNV. Int J Mol Sci 2022; 23:ijms23020875. [PMID: 35055061 PMCID: PMC8777793 DOI: 10.3390/ijms23020875] [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: 12/16/2021] [Revised: 01/10/2022] [Accepted: 01/12/2022] [Indexed: 11/27/2022] Open
Abstract
Understanding the flavivirus infection process in mosquito hosts is important and fundamental in the search for novel control strategies that target the mosquitoes’ ability to carry and transmit pathogenic arboviruses. A group of viruses known as insect-specific viruses (ISVs) has been shown to interfere with the infection and replication of a secondary arbovirus infection in mosquitoes and mosquito-derived cell lines. However, the molecular mechanisms behind this interference are unknown. Therefore, in the present study, we infected the Aedes albopictus cell line U4.4 with either the West Nile virus (WNV), the insect-specific Lammi virus (LamV) or an infection scheme whereby cells were pre-infected with LamV 24 h prior to WNV challenge. The qPCR analysis showed that the dual-infected U4.4 cells had a reduced number of WNV RNA copies compared to WNV-only infected cells. The transcriptome profiles of the different infection groups showed a variety of genes with altered expression. WNV-infected cells had an up-regulation of a broad range of immune-related genes, while in LamV-infected cells, many genes related to stress, such as different heat-shock proteins, were up-regulated. The transcriptome profile of the dual-infected cells was a mix of up- and down-regulated genes triggered by both viruses. Furthermore, we observed an up-regulation of signal peptidase complex (SPC) proteins in all infection groups. These SPC proteins have shown importance for flavivirus assembly and secretion and could be potential targets for gene modification in strategies for the interruption of flavivirus transmission by mosquitoes.
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Dias ÍKR, Martins RMG, Sobreira CLDS, Rocha RMGS, Lopes MDSV. Ações educativas de enfrentamento ao Aedes Aegypti: revisão integrativa. CIENCIA & SAUDE COLETIVA 2022; 27:231-242. [DOI: 10.1590/1413-81232022271.33312020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Accepted: 11/06/2020] [Indexed: 11/22/2022] Open
Abstract
Resumo Objetivou sintetizar os estudos, publicados na literatura cientifica, que abordem estratégias de enfrentamento às arboviroses mediante ações educativas. Os dados foram coletados nas bases de dados: LILACS, BDENF e MEDLINE utilizando os descritores “Educação em Saúde” e “Aedes” empregando o operador booleano “AND”. Foram encontrados 242 estudos, dos quais após aplicação dos critérios de inclusão e exclusão, 14 foram incluídos na revisão. Os dados foram analisados utilizando a abordagem qualitativa. Foram identificadas quatro categorias: ações de enfrentamento vetorial mediante capacitação da comunidade; mobilização social em torno do combate às arboviroses; combate vetorial a partir de ações educativas associadas ao uso de controle biológico; ações integradas de enfrentamento às arboviroses. Infere-se que a educação em saúde é um elemento indispensável para o enfrentamento às arboviroses que deverá ser implementada de forma conjunta e articuladas às demais estratégia de combate vetorial.
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Lee CH, Chang K, Chen YM, Tsai JT, Chen YJ, Ho WH. Epidemic prediction of dengue fever based on vector compartment model and Markov chain Monte Carlo method. BMC Bioinformatics 2021; 22:118. [PMID: 34749630 PMCID: PMC8576924 DOI: 10.1186/s12859-021-04059-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Accepted: 03/02/2021] [Indexed: 11/15/2022] Open
Abstract
Background Dengue epidemics is affected by vector-human interactive dynamics. Infectious disease prevention and control emphasize the timing intervention at the right diffusion phase. In such a way, control measures can be cost-effective, and epidemic incidents can be controlled before devastated consequence occurs. However, timing relations between a measurable signal and the onset of the pandemic are complex to be discovered, and the typical lag period regression is difficult to capture in these complex relations. This study investigates the dynamic diffusion pattern of the disease in terms of a probability distribution. We estimate the parameters of an epidemic compartment model with the cross-infection of patients and mosquitoes in various infection cycles. We comprehensively study the incorporated meteorological and mosquito factors that may affect the epidemic of dengue fever to predict dengue fever epidemics. Results We develop a dual-parameter estimation algorithm for a composite model of the partial differential equations for vector-susceptible-infectious-recovered with exogeneity compartment model, Markov chain Montel Carlo method, and boundary element method to evaluate the epidemic periodicity under the effect of environmental factors of dengue fever, given the time series data of 2000–2016 from three cities with a population of 4.7 million. The established computer model of “energy accumulation-delayed diffusion-epidemics” is proven to be effective to predict the future trend of reported and unreported infected incidents. Our artificial intelligent algorithm can inform the authority to cease the larvae at the highest vector infection time. We find that the estimated dengue report rate is about 20%, which is close to the number of official announcements, and the percentage of infected vectors increases exponentially yearly. We suggest that the executive authorities should seriously consider the accumulated effect among infected populations. This established epidemic prediction model of dengue fever can be used to simulate and evaluate the best time to prevent and control dengue fever. Conclusions Given our developed model, government epidemic prevention teams can apply this platform before they physically carry out the prevention work. The optimal suggestions from these models can be promptly accommodated when real-time data have been continuously corrected from clinics and related agents.
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Affiliation(s)
- Chien-Hung Lee
- Department of Public Health, College of Health Sciences, Kaohsiung Medical University, Kaohsiung, Taiwan.,Research Center for Environmental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.,Department of Medical Research, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.,Office of Institutional Research and Planning Section, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Ko Chang
- Department of Internal Medicine, Kaohsiung Municipal Hsiao-Kang Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Yao-Mei Chen
- School of Nursing, Kaohsiung Medical University, Kaohsiung, Taiwan.,Superintendent Office, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
| | - Jinn-Tsong Tsai
- Department of Computer Science, National Pingtung University, Pingtung, Taiwan.,Department of Healthcare Administration and Medical Informatics, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Yenming J Chen
- Management School, National Kaohsiung University of Science and Technology, Kaohsiung, Taiwan.
| | - Wen-Hsien Ho
- Department of Medical Research, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan. .,Department of Healthcare Administration and Medical Informatics, Kaohsiung Medical University, Kaohsiung, Taiwan.
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12
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Kernbach ME, Martin LB, Unnasch TR, Hall RJ, Jiang RHY, Francis CD. Light pollution affects West Nile virus exposure risk across Florida. Proc Biol Sci 2021; 288:20210253. [PMID: 33757351 PMCID: PMC8059973 DOI: 10.1098/rspb.2021.0253] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 03/02/2021] [Indexed: 12/19/2022] Open
Abstract
Emerging infectious diseases (EIDs) present global health threats, and their emergences are often linked to anthropogenic change. Artificial light at night (ALAN) is one form of anthropogenic change that spans beyond urban boundaries and may be relevant to EIDs through its influence on the behaviour and physiology of hosts and/or vectors. Although West Nile virus (WNV) emergence has been described as peri-urban, we hypothesized that exposure risk could also be influenced by ALAN in particular, which is testable by comparing the effects of ALAN on prevalence while controlling for other aspects of urbanization. By modelling WNV exposure among sentinel chickens in Florida, we found strong support for a nonlinear relationship between ALAN and WNV exposure risk in chickens with peak WNV risk occurring at low ALAN levels. Although our goal was not to discern how ALAN affected WNV relative to other factors, effects of ALAN on WNV exposure were stronger than other known drivers of risk (i.e. impervious surface, human population density). Ambient temperature in the month prior to sampling, but no other considered variables, strongly influenced WNV risk. These results indicate that ALAN may contribute to spatio-temporal changes in WNV risk, justifying future investigations of ALAN on other vector-borne parasites.
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Affiliation(s)
- Meredith E. Kernbach
- Center for Global Health and Infectious Disease Research, College of Public Health, University of South Florida, 3720 Spectrum Blvd., Tampa, FL 33612, USA
| | - Lynn B. Martin
- Center for Global Health and Infectious Disease Research, College of Public Health, University of South Florida, 3720 Spectrum Blvd., Tampa, FL 33612, USA
| | - Thomas R. Unnasch
- Center for Global Health and Infectious Disease Research, College of Public Health, University of South Florida, 3720 Spectrum Blvd., Tampa, FL 33612, USA
| | - Richard J. Hall
- Odum School of Ecology and Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, 501 D.W. Brooks Dr., Athens, GA 30602, USA
| | - Rays H. Y. Jiang
- Center for Global Health and Infectious Disease Research, College of Public Health, University of South Florida, 3720 Spectrum Blvd., Tampa, FL 33612, USA
| | - Clinton D. Francis
- Department of Biological Sciences, California Polytechnic State University, 1 Grand Ave., San Luis Obispo, CA 93407, USA
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13
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Soh S, Ho SH, Seah A, Ong J, Dickens BS, Tan KW, Koo JR, Cook AR, Tan KB, Sim S, Ng LC, Lim JT. Economic impact of dengue in Singapore from 2010 to 2020 and the cost-effectiveness of Wolbachia interventions. PLOS GLOBAL PUBLIC HEALTH 2021; 1:e0000024. [PMID: 36962069 PMCID: PMC10021432 DOI: 10.1371/journal.pgph.0000024] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Accepted: 09/15/2021] [Indexed: 05/01/2023]
Abstract
The release of Wolbachia-infected mosquitoes is a promising disease intervention strategy that aims to control dengue and other arboviral infections. While early field trials and modelling studies suggest promising epidemiological and entomological outcomes, the overall cost effectiveness of the technology is not well studied in a resource rich setting nor under the suppression approach that aims to suppress the wild-type mosquito population through the release of Wolbachia-infected males. We used economical and epidemiological data from 2010 to 2020 to first ascertain the economic and health costs of dengue in Singapore, a high income nation where dengue is hyper-endemic. The hypothetical cost effectiveness of a national Wolbachia suppression program was then evaluated historically from 2010 to 2020. We estimated that the average economic impact of dengue in Singapore from 2010 to 2020 in constant 2010US$ ranged from $1.014 to $2.265 Billion. Using empirically derived disability weights, we estimated a disease burden of 7,645-21,262 DALYs from 2010-2020. Under an assumed steady-state running cost of a national Wolbachia suppression program in Singapore, we conservatively estimate that Wolbachia would cost an estimated $50,453-$100,907 per DALYs averted and would lead to an estimated $329.40 Million saved in economic costs over 2010 to 2020 under 40% intervention efficacy. Wolbachia releases in Singapore are expected to be highly cost-effective and its rollout must be prioritised to reduce the onward spread of dengue.
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Affiliation(s)
- Stacy Soh
- Environmental Health Institute, National Environment Agency, Singapore, Singapore
| | - Soon Hoe Ho
- Environmental Health Institute, National Environment Agency, Singapore, Singapore
| | - Annabel Seah
- Environmental Health Institute, National Environment Agency, Singapore, Singapore
| | - Janet Ong
- Environmental Health Institute, National Environment Agency, Singapore, Singapore
| | - Borame Sue Dickens
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore, Singapore
| | - Ken Wei Tan
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore, Singapore
| | - Joel Ruihan Koo
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore, Singapore
| | - Alex R. Cook
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore, Singapore
| | | | - Shuzhen Sim
- Environmental Health Institute, National Environment Agency, Singapore, Singapore
| | - Lee Ching Ng
- Environmental Health Institute, National Environment Agency, Singapore, Singapore
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Jue Tao Lim
- Environmental Health Institute, National Environment Agency, Singapore, Singapore
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore, Singapore
- * E-mail:
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14
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Whiteman A, Loaiza JR, Yee DA, Poh KC, Watkins AS, Lucas KJ, Rapp TJ, Kline L, Ahmed A, Chen S, Delmelle E, Oguzie JU. Do socioeconomic factors drive Aedes mosquito vectors and their arboviral diseases? A systematic review of dengue, chikungunya, yellow fever, and Zika Virus. One Health 2020; 11:100188. [PMID: 33392378 PMCID: PMC7772681 DOI: 10.1016/j.onehlt.2020.100188] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 10/06/2020] [Accepted: 10/07/2020] [Indexed: 12/17/2022] Open
Abstract
As the threat of arboviral diseases continues to escalate worldwide, the question of, "What types of human communities are at the greatest risk of infection?" persists as a key gap in the existing knowledge of arboviral diseases transmission dynamics. Here, we comprehensively review the existing literature on the socioeconomic drivers of the most common Aedes mosquito-borne diseases and Aedes mosquito presence/abundance. We reviewed a total of 182 studies on dengue viruses (DENV), chikungunya virus (CHIKV), yellow fever virus (YFVV), Zika virus (ZIKV), and presence of Aedes mosquito vectors. In general, associations between socioeconomic conditions and both Aedes-borne diseases and Aedes mosquitoes are highly variable and often location-specific. Although 50% to 60% of studies found greater presence or prevalence of disease or vectors in areas with lower socioeconomic status, approximately half of the remaining studies found either positive or null associations. We discuss the possible causes of this lack of conclusiveness as well as the implications it holds for future research and prevention efforts.
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Affiliation(s)
- Ari Whiteman
- Smithsonian Tropical Research Institute, Panama City, Panama
| | - Jose R. Loaiza
- Smithsonian Tropical Research Institute, Panama City, Panama
- Instituto de Investigaciones Científicas & Servicios de Alta Tecnología, Edificio 219, Clayton PO 0843–01103, Ciudad del Saber, Panama
- Programa Centroamericano de Maestría en Entomología, Universidad de Panamá, Panama
| | - Donald A. Yee
- School of Biological, Environmental, & Earth Sciences, University of Southern Mississippi, Hattiesburg, MS, United States of America
| | - Karen C. Poh
- Department of Entomology, Pennsylvania State University, University Park, PA, United States of America
| | | | - Keira J. Lucas
- Collier Mosquito Control District, Naples, FL, United States of America
| | - Tyler J. Rapp
- University of North Carolina School of Medicine, Chapel Hill, NC, United States of America
| | - Lillie Kline
- Woodward Academy, Atlanta, GA, United States of America
| | - Ayman Ahmed
- Institute of Endemic Diseases, University of Khartoum, Sudan
- World Reference Center for Emerging Viruses and Arboviruses, The Institute for Human Infections and Immunity, Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, United States of America
| | - Shi Chen
- Public Health Sciences, University of North Carolina at Charlotte, United States of America
| | - Eric Delmelle
- Geography and Earth Sciences, University of North Carolina at Charlotte, United States of America
| | - Judith Uche Oguzie
- College of Natural Sciences Redeemer's University, Ede Osun State, Nigeria
- African Center of Excellence for Genomics of Infectious Diseases Redeemer's University Ede, Osun State, Nigeria
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15
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Knerer G, Currie CSM, Brailsford SC. The economic impact and cost-effectiveness of combined vector-control and dengue vaccination strategies in Thailand: results from a dynamic transmission model. PLoS Negl Trop Dis 2020; 14:e0008805. [PMID: 33095791 PMCID: PMC7654761 DOI: 10.1371/journal.pntd.0008805] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2018] [Revised: 11/10/2020] [Accepted: 09/17/2020] [Indexed: 01/17/2023] Open
Abstract
BACKGROUND AND AIMS Dengue fever is a major public health problem in tropical/subtropical regions. Prior economic analyses have predominantly evaluated either vaccination or vector-control programmes in isolation and do not really consider the incremental benefits and cost-effectiveness of mixed strategies and combination control. We estimated the cost-effectiveness of single and combined approaches in Thailand. METHODS The impacts of different control interventions were analysed using a previously published mathematical model of dengue epidemiology and control incorporating seasonality, age structure, consecutive infection, cross protection, immune enhancement and combined vector-host transmission. An economic model was applied to simulation results to estimate the cost-effectiveness of 4 interventions and their various combinations (6 strategies): i) routine vaccination of 1-year olds; ii) chemical vector control strategies targeting adult and larval stages separately; iii) environmental management/ public health education and awareness [EM/ PHEA]). Payer and societal perspectives were considered. The health burden of dengue fever was assessed using disability-adjusted life-years (DALYs) lost. Costs and effects were assessed for 10 years. Costs were discounted at 3% annually and updated to 2013 United States Dollars. Incremental cost-effectiveness analysis was carried out after strategies were rank-ordered by cost, with results presented in a table of incremental analysis. Sensitivity and scenario analyses were undertaken; and the impact and cost-effectiveness of Wolbachia was evaluated in exploratory scenario analyses. RESULTS From the payer and societal perspectives, 2 combination strategies were considered optimal, as all other control strategies were dominated. Vaccination plus adulticide plus EM/ PHEA was deemed cost-effective according to multiple cost-effectiveness criteria. From the societal perspective, incremental differences vs. adulticide and EM/ PHEA resulted in costs of $157.6 million and DALYs lost of 12,599, giving an expected ICER of $12,508 per DALY averted. Exploratory scenario analyses showed Wolbachia to be highly cost-effective ($343 per DALY averted) vs. other single control measures. CONCLUSIONS Our model shows that individual interventions can be cost-effective, but that important epidemiological reductions and economic impacts are demonstrated when interventions are combined as part of an integrated approach to combating dengue fever. Exploratory scenario analyses demonstrated the potential epidemiological and cost-effective impact of Wolbachia when deployed at scale on a nationwide basis. Our findings were robust in the face of sensitivity analyses.
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Affiliation(s)
- Gerhart Knerer
- Mathematical Sciences, University of Southampton, Highfield, Southampton, United Kingdom
- * E-mail:
| | - Christine S. M. Currie
- Mathematical Sciences, University of Southampton, Highfield, Southampton, United Kingdom
| | - Sally C. Brailsford
- Southampton Business School, University of Southampton, Highfield, Southampton, United Kingdom
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16
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Managing disease outbreaks: The importance of vector mobility and spatially heterogeneous control. PLoS Comput Biol 2020; 16:e1008136. [PMID: 32822342 PMCID: PMC7480881 DOI: 10.1371/journal.pcbi.1008136] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 09/09/2020] [Accepted: 07/09/2020] [Indexed: 12/25/2022] Open
Abstract
Management strategies for control of vector-borne diseases, for example Zika or dengue, include using larvicide and/or adulticide, either through large-scale application by truck or plane or through door-to-door efforts that require obtaining permission to access private property and spray yards. The efficacy of the latter strategy is highly dependent on the compliance of local residents. Here we develop a model for vector-borne disease transmission between mosquitoes and humans in a neighborhood setting, considering a network of houses connected via nearest-neighbor mosquito movement. We incorporate large-scale application of adulticide via aerial spraying through a uniform increase in vector death rates in all sites, and door-to-door application of larval source reduction and adulticide through a decrease in vector emergence rates and an increase in vector death rates in compliant sites only, where control efficacies are directly connected to real-world experimentally measurable control parameters, application frequencies, and control costs. To develop mechanistic insight into the influence of vector motion and compliance clustering on disease controllability, we determine the basic reproduction number R0 for the system, provide analytic results for the extreme cases of no mosquito movement, infinite hopping rates, and utilize degenerate perturbation theory for the case of slow but non-zero hopping rates. We then determine the application frequencies required for each strategy (alone and combined) in order to reduce R0 to unity, along with the associated costs. Cost-optimal strategies are found to depend strongly on mosquito hopping rates, levels of door-to-door compliance, and spatial clustering of compliant houses, and can include aerial spray alone, door-to-door treatment alone, or a combination of both. The optimization scheme developed here provides a flexible tool for disease management planners which translates modeling results into actionable control advice adaptable to system-specific details.
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17
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Brady OJ, Kharisma DD, Wilastonegoro NN, O'Reilly KM, Hendrickx E, Bastos LS, Yakob L, Shepard DS. The cost-effectiveness of controlling dengue in Indonesia using wMel Wolbachia released at scale: a modelling study. BMC Med 2020; 18:186. [PMID: 32641039 PMCID: PMC7346418 DOI: 10.1186/s12916-020-01638-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2020] [Accepted: 05/15/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Release of virus-blocking Wolbachia-infected mosquitoes is an emerging disease control strategy that aims to control dengue and other arboviral infections. Early entomological data and modelling analyses have suggested promising outcomes, and wMel Wolbachia releases are now ongoing or planned in 12 countries. To help inform government, donor, or philanthropist decisions on scale-up beyond single city releases, we assessed this technology's cost-effectiveness under alternative programmatic options. METHODS Using costing data from existing Wolbachia releases, previous dynamic model-based estimates of Wolbachia effectiveness, and a spatially explicit model of release and surveillance requirements, we predicted the costs and effectiveness of the ongoing programme in Yogyakarta City and three new hypothetical programmes in Yogyakarta Special Autonomous Region, Jakarta, and Bali. RESULTS We predicted Wolbachia to be a highly cost-effective intervention when deployed in high-density urban areas with gross cost-effectiveness below $1500 per DALY averted. When offsets from the health system and societal perspective were included, such programmes even became cost saving over 10-year time horizons with favourable benefit-cost ratios of 1.35 to 3.40. Sequencing Wolbachia releases over 10 years could reduce programme costs by approximately 38% compared to simultaneous releases everywhere, but also delays the benefits. Even if unexpected challenges occurred during deployment, such as emergence of resistance in the medium-term or low effective coverage, Wolbachia would remain a cost-saving intervention. CONCLUSIONS Wolbachia releases in high-density urban areas are expected to be highly cost-effective and could potentially be the first cost-saving intervention for dengue. Sites with strong public health infrastructure, fiscal capacity, and community support should be prioritised.
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Affiliation(s)
- Oliver J Brady
- Centre for the Mathematical Modelling of Infectious Diseases, London School of Hygiene & Tropical Medicine, London, UK.
- Department of Infectious Disease Epidemiology, Faculty of Epidemiology and Population Health, London School of Hygiene & Tropical Medicine, London, UK.
| | - Dinar D Kharisma
- Heller School for Social Policy and Management, Brandeis University,, Waltham, MA, USA
| | - Nandyan N Wilastonegoro
- Faculty of Medicine, Public Health and Nursing, Gadjah Mada University, Yogyakarta, Indonesia
| | - Kathleen M O'Reilly
- Centre for the Mathematical Modelling of Infectious Diseases, London School of Hygiene & Tropical Medicine, London, UK
- Department of Disease Control, Faculty of Infectious Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
| | - Emilie Hendrickx
- Centre for the Mathematical Modelling of Infectious Diseases, London School of Hygiene & Tropical Medicine, London, UK
- Department of Infectious Disease Epidemiology, Faculty of Epidemiology and Population Health, London School of Hygiene & Tropical Medicine, London, UK
| | - Leonardo S Bastos
- Centre for the Mathematical Modelling of Infectious Diseases, London School of Hygiene & Tropical Medicine, London, UK
- Department of Infectious Disease Epidemiology, Faculty of Epidemiology and Population Health, London School of Hygiene & Tropical Medicine, London, UK
| | - Laith Yakob
- Centre for the Mathematical Modelling of Infectious Diseases, London School of Hygiene & Tropical Medicine, London, UK
- Department of Disease Control, Faculty of Infectious Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
| | - Donald S Shepard
- Heller School for Social Policy and Management, Brandeis University,, Waltham, MA, USA
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18
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Hirsch J, Faber BW, Crowe JE, Verstrepen B, Cornelissen G. E. coli production process yields stable dengue 1 virus-sized particles (VSPs). Vaccine 2020; 38:3305-3312. [PMID: 32197924 DOI: 10.1016/j.vaccine.2020.03.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 02/26/2020] [Accepted: 03/02/2020] [Indexed: 12/25/2022]
Abstract
Dengue fever is one of the most wide-spread vector-borne diseases in the world. Although dengue-associated mortality is low, morbidity and economic impact are high. Current licensed vaccines are limited and mediate only partial protection, thus a cost-effective vaccine with improved efficacy is strongly needed. In this work, recombinant dengue serotype 1 E protein was produced in E. coli, inclusion bodies were isolated and the E protein solubilized in urea and purified using an immobilized metal chelate affinity column. The protein was refolded by dialysis in order to obtain virus-like particles (VLPs). Particle assembly was confirmed using size-exclusion chromatography, dynamic light scattering (DLS), transmission electron microscopy (TEM), atomic force microscopy and stimulated emission depletion fluorescence (STED) microscopy. Particle diameter was strongly dependent on temperature, pH, buffer salt composition, and addition of L-arginine. Particles were stable in carbonate buffer at pH 9.5 and higher at 4 °C and did not aggregate during short-term temperature increase up to 55 °C. However, on basis of the above analyses, especially the results of DLS, TEM and STED, it was concluded that the particles obtained did not have an optimal virus-like structure and were therefore designated "virus-sized particles" (VSPs) rather than VLPs. Immunization of rabbits with the particles did not induce neutralizing antibodies, despite the recognition of the native virus by rabbit antibodies. As the titers against the immunogen were much higher than against the (heat-inactivated) virus, it is assumed that the conformation of the particles at the time of immunization was not optimal. Studies are currently underway to improve the quality of the E protein virus-sized particles towards true virus-like particles in order to optimize its potential as a dengue vaccine candidate.
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Affiliation(s)
- Janet Hirsch
- Hamburg University of Applied Sciences, Ulmenliet 20, 21033 Hamburg, Germany.
| | - Bart W Faber
- Department of Parasitology, Biomedical Primate Research Centre, Lange Kleiweg 161, 2288 GJ Rijswijk, the Netherlands.
| | - James E Crowe
- Departments of Pediatrics and Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, 2213 Garland Avenue, Nashville, TN 37232-0417, USA.
| | - Babs Verstrepen
- Department of Virology, Biomedical Primate Research Centre, Lange Kleiweg 161, 2288 GJ Rijswijk, the Netherlands.
| | - Gesine Cornelissen
- Hamburg University of Applied Sciences, Ulmenliet 20, 21033 Hamburg, Germany.
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Tschampl CA, Undurraga EA, Ledogar RJ, Coloma J, Legorreta-Soberanis J, Paredes-Solís S, Arosteguí J, Hernández-Álvarez C, Harris E, Andersson N, Shepard DS. Cost-effectiveness of community mobilization (Camino Verde) for dengue prevention in Nicaragua and Mexico: A cluster randomized controlled trial. Int J Infect Dis 2020; 94:59-67. [PMID: 32179138 DOI: 10.1016/j.ijid.2020.03.026] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 03/07/2020] [Accepted: 03/08/2020] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND We assessed the cost-effectiveness of Camino Verde, a community-based mobilization strategy to prevent and control dengue and other mosquito-borne diseases. A cluster-randomized controlled trial in Managua, Nicaragua, and in three coastal regions in Guerrero, Mexico (75 intervention and 75 control clusters), Camino Verde used non-governmental community health workers, called brigadistas, to support community mobilization. This donor-funded trial demonstrated reductions of 29.5% (95% confidence interval, CI: 3.8%-55.3%) on dengue infections and 24.7% (CI: 1.8%-51.2%) on self-reported cases. METHODS We estimated program costs through a micro-costing approach and semi-structured questionnaires. We show results as incremental cost-effectiveness ratios (ICERs) for costs per disability-adjusted life-year (DALYs) averted and conducted probabilistic sensitivity analyses. FINDINGS The Camino Verde trial spent US$16.72 in Mexico and $7.47 in Nicaragua per person annually. We found an average of 910 (CI: 487-1 353) and 500 (CI: 250-760) dengue cases averted annually per million population in Mexico and Nicaragua, respectively, compared to control communities. The ICER in Mexico was US$29 618 (CI: 13 869-66 898) per DALY averted, or 3.0 times per capita GDP. For Nicaragua, the ICER was US$29 196 (CI: 14294-72181) per DALY averted, or 16.9 times per capita GDP. INTERPRETATION Camino Verde, as implemented in the research context, was marginally cost-effective in Mexico, and not cost-effective in Nicaragua, from a healthcare sector perspective. Nicaragua's low per capita GDP and the use of grant-funded management personnel weakened the cost-effectiveness results. Achieving efficiencies by incorporating Camino Verde activities into existing public health programs would make Camino Verde cost-effective.
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Affiliation(s)
- Cynthia A Tschampl
- Schneider Institutes for Health Policy, The Heller School for Social Policy and Management, Brandeis University, Waltham, MA, USA
| | - Eduardo A Undurraga
- Escuela de Gobierno, Pontificia Universidad Católica de Chile, Santiago, RM, Chile
| | | | - Josefina Coloma
- Division of Infectious Diseases and Vaccinology, School of Public Health, University of California, Berkeley, Berkeley, CA, USA
| | - Jose Legorreta-Soberanis
- Centro de Investigación de Enfermedades Tropicales (CIET), Universidad Autónoma de Guerrero, Acapulco, Mexico
| | - Sergio Paredes-Solís
- Centro de Investigación de Enfermedades Tropicales (CIET), Universidad Autónoma de Guerrero, Acapulco, Mexico
| | | | | | - Eva Harris
- Division of Infectious Diseases and Vaccinology, School of Public Health, University of California, Berkeley, Berkeley, CA, USA
| | - Neil Andersson
- Centro de Investigación de Enfermedades Tropicales (CIET), Universidad Autónoma de Guerrero, Acapulco, Mexico; Department of Family Medicine, McGill University, Montreal, Canada
| | - Donald S Shepard
- Schneider Institutes for Health Policy, The Heller School for Social Policy and Management, Brandeis University, Waltham, MA, USA.
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20
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Thompson R, Martin Del Campo J, Constenla D. A review of the economic evidence of Aedes-borne arboviruses and Aedes-borne arboviral disease prevention and control strategies. Expert Rev Vaccines 2020; 19:143-162. [PMID: 32077343 DOI: 10.1080/14760584.2020.1733419] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Introduction: Aedes-borne arboviruses contributes substantially to the disease and cost burden.Areas covered: We performed a systematic review of the economic evidence surrounding aedes-borne arboviruses and strategies to prevent and control these diseases to inform disease control policy decisions and research directions. We searched four databases covering an 18-year period (2000-2018) to identify arboviral disease-related cost of illness studies, cost studies of vector control and prevention strategies, cost-effectiveness analyses and cost-benefit analyses. We identified 74 published studies that revealed substantial global total costs in yellow fever virus and dengue virus ranging from 2.1 to 57.3 billion USD. Cost studies of vector control and surveillance programs are limited, but a few studies found that costs of vector control programs ranged from 5.62 to 73.5 million USD. Cost-effectiveness evidence was limited across Aedes-borne diseases, but generally found targeted dengue vaccination programs cost-effective. This review revealed insufficient economic evidence for vaccine introduction and implementation of surveillance and vector control programs.Expert opinion: Evidence of the economic burden of aedes-borne arboviruses and the economic impact of strategies for arboviral disease prevention and control is critical to inform policy decisions and to secure continued financial support for these preventive and control measures.
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Affiliation(s)
- Ryan Thompson
- Department of International Health, Johns Hopkins Bloomberg School of Public Health (JHBSPH), International Vaccine Access Center (IVAC), Baltimore, MD, USA
| | | | - Dagna Constenla
- Department of International Health, Johns Hopkins Bloomberg School of Public Health (JHBSPH), International Vaccine Access Center (IVAC), Baltimore, MD, USA
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Abstract
Dengue virus (DENV) belongs to the family Flaviviridae, genus Flavivirus. It is a single-stranded positive-sense ribonucleic acid virus with 10,700 bases. The genus Flavivirus includes other arthropod borne viruses such as yellow fever virus, West Nile virus, Zika virus, tick-borne encephalitis virus. It infects ~50–200 million people annually, putting over 3.6 billion people living in tropical regions at risk and causing ~20,000 deaths annually. The expansion of dengue is attributed to factors such as the modern dynamics of climate change, globalization, travel, trade, socioeconomics, settlement, and also viral evolution. There are four antigenically different serotypes of DENV based on the differences in their viral structural and nonstructural proteins. DENV infection causes a spectrum of illness ranging from asymptomatic to dengue fever to severe dengue shock syndrome. Infection with one serotype confers lifelong immunity against that serotype, but heterologus infection leads to severe dengue hemorrhagic fever due to antibody-dependent enhancement. Diagnosis of dengue infections is based mainly on serological detection of either antigen in acute cases or antibodies in both acute and chronic infection. Viral detection and real-time PCR detection though helpful is not feasible in resource poor setup. Treatment of dengue depends on symptomatic management along with fluid resuscitation and may require platelet transfusion. Although vaccine development is in late stages of development, developing a single vaccine against four serotypes often causes serious challenges to researchers; hence, the main stay of prevention is vector control and management.
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Charette M, Berrang-Ford L, Coomes O, Llanos-Cuentas EA, Cárcamo C, Kulkarni M, Harper SL. Dengue Incidence and Sociodemographic Conditions in Pucallpa, Peruvian Amazon: What Role for Modification of the Dengue-Temperature Relationship? Am J Trop Med Hyg 2019; 102:180-190. [PMID: 31701852 DOI: 10.4269/ajtmh.19-0033] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Dengue is a climate-sensitive disease with an increasing global burden. Although the relationship between meteorological conditions and dengue incidence is well established, less is known about the modifying nature of sociodemographic variables on that relationship. We assess the strength and direction of sociodemographic effect modification of the temperature-dengue relationship in the second largest city of the Peruvian Amazon to identify populations that may have heightened vulnerability to dengue under varying climate conditions. We used weekly dengue counts and averaged meteorological variables to evaluate the association between disease incidence, meteorological exposures, and sociodemographic effect modifiers (gender, age, and district) in negative binomial regression models. District was included to consider geographical effect modification. We found that being a young child or elderly, being female, and living in the district of Manantay increased dengue's incidence rate ratio (IRR) as a result of 1°C increase in weekly mean temperature (IRR = 2.99, 95% CI: 1.99-4.50 for women less than 5 years old and IRR = 2.86, 95% CI: = 1.93-4.22 for women older than 65 years, both estimates valid for the rainy season). The effect of temperature on dengue depended on season, with stronger effects during rainy seasons. Sociodemographic variables can provide options for intervention to mitigate health impacts with a changing climate. Our results indicate that patterns of baseline risk between regions and sociodemographic conditions can differ substantially from trends in climate sensitivity. These results challenge the assumption that the distribution of climate change impacts will be patterned similarly to existing social gradients in health.
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Affiliation(s)
- Margot Charette
- Department of Geography, McGill University, Montreal, Canada
| | - Lea Berrang-Ford
- Priestley International Centre for Climate, University of Leeds, Leeds, United Kingdom
| | - Oliver Coomes
- Department of Geography, McGill University, Montreal, Canada
| | | | - César Cárcamo
- School of Public Health and Administration, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Manisha Kulkarni
- School of Epidemiology, Public Health and Preventive Medicine, University of Ottawa, Ottawa, Canada
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Wu H, Wu C, Lu Q, Ding Z, Xue M, Lin J. Evaluating the effects of control interventions and estimating the inapparent infections for dengue outbreak in Hangzhou, China. PLoS One 2019; 14:e0220391. [PMID: 31393899 PMCID: PMC6687121 DOI: 10.1371/journal.pone.0220391] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Accepted: 07/15/2019] [Indexed: 11/19/2022] Open
Abstract
Background The number of dengue fever (DF) cases and the number of dengue outbreaks have increased in recent years in Zhejiang Province, China. An unexpected dengue outbreak was reported in Hangzhou in 2017 and caused more than one thousand dengue cases. This study was undertaken to evaluate the effectiveness of the actual control measures, estimate the proportion of inapparent infections during this outbreak and simulate epidemic development based on different levels of control measures taking inapparent infections into consideration. Methods The epidemic data of dengue cases in Hangzhou, Zhejiang Province, in 2017 and the number of the people exposed to the outbreaks were obtained from the China Information Network System of Disease Prevention and Control. The epidemic without intervention measures was used to estimate the unknown parameters. A susceptible-exposed-infectious/inapparent-recovered (SEIAR) model was used to estimate the effectiveness of the control interventions. The inapparent infections were also evaluated at the same time. Results In total, 1137 indigenous dengue cases were reported in Hangzhou in 2017. The number of indigenous dengue cases was estimated by the SEIAR model. This number was predicted to reach 6090 by the end of November 2, 2017, if no control measures were implemented. The total number of reported cases was reduced by 81.33% in contrast to the estimated incidence without intervention. The number of average daily inapparent cases was 10.18 times higher than the number of symptomatic cases. The earlier and more rigorously the vector control interventions were implemented, the more effective they were. The results showed that implementing vector control continuously for more than twenty days was more effective than every few days of implementation. Case isolation is not sufficient enough for epidemic control and only reduced the incidence by 38.10% in contrast to the estimated incidence without intervention, even if case isolation began seven days after the onset of the first case. Conclusions The practical control interventions in the outbreaks that occurred in Hangzhou City were highly effective. The proportion of inapparent infections was large, and it played an important role in transmitting the disease during this epidemic. Early, continuous and high efficacy vector control interventions are necessary to limit the development of a dengue epidemic. Timely diagnosis and case reporting are important in the intervention at an early stage of the epidemic.
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Affiliation(s)
- Haocheng Wu
- Zhejiang Province Center for Disease Control and Prevention, Hangzhou, Zhejiang Province, China
- Key Laboratory for Vaccine, Prevention and Control of Infectious Disease of Zhejiang Province, Hangzhou, Zhejiang Province, China
| | - Chen Wu
- Zhejiang Province Center for Disease Control and Prevention, Hangzhou, Zhejiang Province, China
| | - Qinbao Lu
- Zhejiang Province Center for Disease Control and Prevention, Hangzhou, Zhejiang Province, China
| | - Zheyuan Ding
- Zhejiang Province Center for Disease Control and Prevention, Hangzhou, Zhejiang Province, China
| | - Ming Xue
- Hangzhou Centre for Disease Control and Prevention, Hangzhou, Zhejiang, Province, China
| | - Junfen Lin
- Zhejiang Province Center for Disease Control and Prevention, Hangzhou, Zhejiang Province, China
- Key Laboratory for Vaccine, Prevention and Control of Infectious Disease of Zhejiang Province, Hangzhou, Zhejiang Province, China
- * E-mail:
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McCormack CP, Ghani AC, Ferguson NM. Fine-scale modelling finds that breeding site fragmentation can reduce mosquito population persistence. Commun Biol 2019; 2:273. [PMID: 31372512 PMCID: PMC6658551 DOI: 10.1038/s42003-019-0525-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Accepted: 06/27/2019] [Indexed: 02/03/2023] Open
Abstract
Fine-scale geographic variation in the transmission intensity of mosquito-borne diseases is primarily caused by variation in the density of female adult mosquitoes. Therefore, an understanding of fine-scale mosquito population dynamics is critical to understanding spatial heterogeneity in disease transmission and persistence at those scales. However, mathematical models of dengue and malaria transmission, which consider the dynamics of mosquito larvae, generally do not account for the fragmented structure of larval breeding sites. Here, we develop a stochastic metapopulation model of mosquito population dynamics and explore the impact of accounting for breeding site fragmentation when modelling fine-scale mosquito population dynamics. We find that, when mosquito population densities are low, fragmentation can lead to a reduction in population size, with population persistence dependent on mosquito dispersal and features of the underlying landscape. We conclude that using non-spatial models to represent fine-scale mosquito population dynamics may substantially underestimate the stochastic volatility of those populations.
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Affiliation(s)
- Clare P. McCormack
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, W2 1PG UK
| | - Azra C. Ghani
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, W2 1PG UK
| | - Neil M. Ferguson
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, W2 1PG UK
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Senapati A, Sardar T, Ganguly KS, Ganguly KS, Chattopadhyay AK, Chattopadhyay J. Impact of adult mosquito control on dengue prevalence in a multi-patch setting: A case study in Kolkata (2014-2015). J Theor Biol 2019; 478:139-152. [PMID: 31229456 DOI: 10.1016/j.jtbi.2019.06.021] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 06/17/2019] [Accepted: 06/19/2019] [Indexed: 11/17/2022]
Abstract
Dengue is one of the deadliest mosquito-borne disease prevalent mainly in tropical and sub-tropical regions. Controlling the spread of this disease becomes a major concern to the public health authority. World Health Organization (WHO) adopted several mosquito control strategies to reduce the disease prevalence. In this work, a general multi-patch non-autonomous dengue model is formulated to capture the temporal and spatial transmission mechanism of the disease and the effectiveness of different adult mosquito control strategies in reducing dengue prevalence is evaluated. During the period (2014-2015) the dengue situation of Kolkata which is one of the most dengue affected city in India is considered in our study. Depending on geographical location, Kolkata is divided into five regions and our model is fitted to the monthly dengue cases of these five regions during the above-mentioned period. By considering control specific characteristics (e.g. efficacy, environment persistence) of the mosquito control strategies, we study the efficiency of three adult mosquito controls and their combined effect in reducing dengue prevalence. From our study, it is observed that control with higher environment persistence performs better in comparison to the controls having low environment persistence. It is also observed that, connectedness between the regions play a key role in the effectiveness of the control strategies.
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Affiliation(s)
- Abhishek Senapati
- Agricultural and Ecological Research Unit, Indian Statistical Institute, 203, B. T. Road, Kolkata 700108, India.
| | - Tridip Sardar
- Department of Mathematics, Dinabandhu Andrews College, Kolkata, West Bengal 700084, India
| | | | | | | | - Joydev Chattopadhyay
- Agricultural and Ecological Research Unit, Indian Statistical Institute, 203, B. T. Road, Kolkata 700108, India
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Jain R, Sontisirikit S, Iamsirithaworn S, Prendinger H. Prediction of dengue outbreaks based on disease surveillance, meteorological and socio-economic data. BMC Infect Dis 2019; 19:272. [PMID: 30898092 PMCID: PMC6427843 DOI: 10.1186/s12879-019-3874-x] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Accepted: 03/04/2019] [Indexed: 02/08/2023] Open
Abstract
Background The goal of this research is to create a system that can use the available relevant information about the factors responsible for the spread of dengue and; use it to predict the occurrence of dengue within a geographical region, so that public health experts can prepare for, manage and control the epidemic. Our study presents new geospatial insights into our understanding and management of health, disease and health-care systems. Methods We present a machine learning-based methodology capable of providing forecast estimates of dengue prediction in each of the fifty districts of Thailand by leveraging data from multiple data sources. Using a set of prediction variables, we show an increase in prediction accuracy of the model with an optimal combination of predictors which include: meteorological data, clinical data, lag variables of disease surveillance, socioeconomic data and the data encoding spatial dependence on dengue transmission. We use Generalized Additive Models (GAMs) to fit the relationships between the predictors (with a lag of one month) and the clinical data of Dengue hemorrhagic fever (DHF) using the data from 2008 to 2012. Using the data from 2013 to 2015 and a comparative set of prediction models, we evaluate the predictive ability of the fitted models according to RMSE and SRMSE as well as using adjusted R-squared value, deviance explained and change in AIC. Results The model allows for combining different predictors to make forecasts with a lead time of one month and also describe the statistical significance of the variables used to characterize the forecast. The discriminating ability of the final model was evaluated against Bangkok specific constant threshold and WHO moving threshold of the epidemic in terms of specificity, sensitivity, positive predictive value (PPV), and negative predictive value (NPV). Conclusions The out-of-sample validation showed poorer results than the in-sample validation, however it demonstrated ability in detecting outbreaks up-to one month ahead. We also determine that for the predicting dengue outbreaks within a district, the influence of dengue incidences and socioeconomic data from the surrounding districts is statistically significant. This validates the influence of movement patterns of people and spatial heterogeneity of human activities on the spread of the epidemic.
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Affiliation(s)
| | - Sra Sontisirikit
- Asian Institute of Technology, School of Engineering and Technology, Bangkok, Thailand
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27
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Bardach AE, García-Perdomo HA, Alcaraz A, Tapia López E, Gándara RAR, Ruvinsky S, Ciapponi A. Interventions for the control of Aedes aegypti in Latin America and the Caribbean: systematic review and meta-analysis. Trop Med Int Health 2019; 24:530-552. [PMID: 30771267 DOI: 10.1111/tmi.13217] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To determine the effectiveness and degree of implementation of interventions for the control of Aedes aegypti in Latin America and the Caribbean (LAC) as reported in scientific literature. METHODS We searched MEDLINE, EMBASE, CENTRAL, SOCINDEX, and LILACS, for experimental and observational studies, economic assessments and qualitative experiences carried out in LAC from 2000 to 2016. We assessed incidence and morbimortality of Aedes aegypti-related diseases and entomological indices: Breteau (containers), House, and Pupae per Person. We used GRADE methodology for assessing quality of evidence. RESULTS Of 1826 records retrieved, 75 were included and 9 cluster randomised clinical trials could be meta-analysed. We did not identify any intervention supported by a high certainty of evidence. In consistency with qualitative evidence, health education and community engagement probably reduces the entomological indices, as do the use of insecticide-treated materials, indoor residual spraying and the management of containers. There is low certainty of evidence supporting the use of ovitraps or larvitraps, and the integrated epidemiological surveillance strategy to improve indices and reduce the incidence of dengue. The reported degree of implementation of these vector control interventions was variable and most did not extend to whole cities and were not sustained beyond 2 years. CONCLUSIONS We found a general lack of evidence on effectiveness of vector control in the region, despite a few interventions that showed moderate to low certainty of evidence. It is important to engage and educate the community, apart from achieving the implementation of integrated actions between the health and other sectors at national and regional level.
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Affiliation(s)
- Ariel Esteban Bardach
- Instituto de Efectividad Clínica y Sanitaria, Centro de Investigación de Epidemiología y Salud Pública, Buenos Aires, Argentina.,Consejo Nacional de Investigaciones Científicas y Técnicas and Centro Cochrane, Buenos Aires, Argentina
| | | | - Andrea Alcaraz
- Instituto de Efectividad Clínica y Sanitaria, Centro de Investigación de Epidemiología y Salud Pública, Buenos Aires, Argentina
| | - Elena Tapia López
- Instituto de Efectividad Clínica y Sanitaria, Centro de Investigación de Epidemiología y Salud Pública, Buenos Aires, Argentina
| | - Ruth Amanda Ruano Gándara
- Instituto de Efectividad Clínica y Sanitaria, Centro de Investigación de Epidemiología y Salud Pública, Buenos Aires, Argentina
| | - Silvina Ruvinsky
- Hospital de Pediatría "Pedro Garrahan", Ciudad Autónoma de Buenos Aires, Buenos Aires, Argentina
| | - Agustín Ciapponi
- Instituto de Efectividad Clínica y Sanitaria, Centro de Investigación de Epidemiología y Salud Pública, Buenos Aires, Argentina.,Consejo Nacional de Investigaciones Científicas y Técnicas and Centro Cochrane, Buenos Aires, Argentina
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Öhlund P, Lundén H, Blomström AL. Insect-specific virus evolution and potential effects on vector competence. Virus Genes 2019; 55:127-137. [PMID: 30632016 PMCID: PMC6458977 DOI: 10.1007/s11262-018-01629-9] [Citation(s) in RCA: 85] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 12/21/2018] [Indexed: 01/08/2023]
Abstract
The advancement in high-throughput sequencing technology and bioinformatics tools has spurred a new age of viral discovery. Arthropods is the largest group of animals and has shown to be a major reservoir of different viruses, including a group known as insect-specific viruses (ISVs). The majority of known ISVs have been isolated from mosquitoes and shown to belong to viral families associated with animal arbovirus pathogens, such as Flaviviridae, Togaviridae and Phenuiviridae. These insect-specific viruses have a strict tropism and are unable to replicate in vertebrate cells, these properties are interesting for many reasons. One is that these viruses could potentially be utilised as biocontrol agents using a similar strategy as for Wolbachia. Mosquitoes infected with the viral agent could have inferior vectorial capacity of arboviruses resulting in a decrease of circulating arboviruses of public health importance. Moreover, insect-specific viruses are thought to be ancestral to arboviruses and could be used to study the evolution of the switch from single-host to dual-host. In this review, we discuss new discoveries and hypothesis in the field of arboviruses and insect-specific viruses.
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Affiliation(s)
- Pontus Öhlund
- Section of Virology, Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, Box 7028, 750 07, Uppsala, Sweden
| | - Hanna Lundén
- Section of Virology, Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, Box 7028, 750 07, Uppsala, Sweden
| | - Anne-Lie Blomström
- Section of Virology, Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, Box 7028, 750 07, Uppsala, Sweden.
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Metz SW, Thomas A, Brackbill A, Xianwen Y, Stone M, Horvath K, Miley MJ, Luft C, DeSimone JM, Tian S, de Silva AM. Nanoparticle delivery of a tetravalent E protein subunit vaccine induces balanced, type-specific neutralizing antibodies to each dengue virus serotype. PLoS Negl Trop Dis 2018; 12:e0006793. [PMID: 30248097 PMCID: PMC6171938 DOI: 10.1371/journal.pntd.0006793] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Revised: 10/04/2018] [Accepted: 08/27/2018] [Indexed: 11/18/2022] Open
Abstract
Dengue virus (DENV) is the causative agent of dengue fever and dengue hemorrhagic shock syndrome. Dengue vaccine development is challenging because of the need to induce protection against four antigenically distinct DENV serotypes. Recent studies indicate that tetravalent DENV vaccines must induce balanced, serotype-specific neutralizing antibodies to achieve durable protective immunity against all 4 serotypes. With the leading live attenuated tetravalent DENV vaccines, it has been difficult to achieve balanced and type-specific responses to each serotype, most likely because of unbalanced replication of vaccine viral strains. Here we evaluate a tetravalent DENV protein subunit vaccine, based on recombinant envelope protein (rE) adsorbed to the surface of poly (lactic-co-glycolic acid) (PLGA) nanoparticles for immunogenicity in mice. In monovalent and tetravalent formulations, we show that particulate rE induced higher neutralizing antibody titers compared to the soluble rE antigen alone. Importantly, we show the trend that tetravalent rE adsorbed to nanoparticles stimulated a more balanced serotype specific antibody response to each DENV serotype compared to soluble antigens. Our results demonstrate that tetravalent DENV subunit vaccines displayed on nanoparticles have the potential to overcome unbalanced immunity observed for leading live-attenuated vaccine candidates.
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Affiliation(s)
- Stefan W. Metz
- Department of Microbiology and Immunology, University of North Carolina, Chapel Hill, Chapel Hill, NC, United States of America
| | - Ashlie Thomas
- Department of Microbiology and Immunology, University of North Carolina, Chapel Hill, Chapel Hill, NC, United States of America
| | - Alex Brackbill
- Department of Pharmacology, University of North Carolina, Chapel Hill, Chapel Hill, NC, United States of America
| | - Yi Xianwen
- Lineberger Comprehensive Center, University of North Carolina, Chapel Hill, Chapel Hill, NC, United States of America
| | - Michele Stone
- Liquidia Technologies, Research Triangle Park, Durham, NC, United States of America
| | - Katie Horvath
- Liquidia Technologies, Research Triangle Park, Durham, NC, United States of America
| | - Michael J. Miley
- Department of Pharmacology, University of North Carolina, Chapel Hill, Chapel Hill, NC, United States of America
| | - Chris Luft
- Liquidia Technologies, Research Triangle Park, Durham, NC, United States of America
| | - Joseph M. DeSimone
- Liquidia Technologies, Research Triangle Park, Durham, NC, United States of America
- Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, Chapel Hill, NC, United States of America
- Department of Chemistry, University of North Carolina, Chapel Hill, Chapel Hill, NC, United States of America
| | - Shaomin Tian
- Department of Microbiology and Immunology, University of North Carolina, Chapel Hill, Chapel Hill, NC, United States of America
- * E-mail: (ST); (AMdS)
| | - Aravinda M. de Silva
- Department of Microbiology and Immunology, University of North Carolina, Chapel Hill, Chapel Hill, NC, United States of America
- * E-mail: (ST); (AMdS)
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Cheng YH, Lin YJ, Chen SC, You SH, Chen WY, Hsieh NH, Yang YF, Liao CM. Assessing health burden risk and control effect on dengue fever infection in the southern region of Taiwan. Infect Drug Resist 2018; 11:1423-1435. [PMID: 30233221 PMCID: PMC6132233 DOI: 10.2147/idr.s169820] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND The high prevalence of dengue in Taiwan and the consecutive large dengue outbreaks in the period 2014-2015 suggest that current control interventions are suboptimal. Understanding the effect of control effort is crucial to inform future control strategies. OBJECTIVES We developed a framework to measure season-based health burden risk from 2001 to 2014. We reconstructed various intervention coverage to assess the attributable effect of dengue infection control efforts. MATERIALS AND METHODS A dengue-mosquito-human transmission dynamic was used to quantify the vector-host interactions and to estimate the disease epidemics. We used disability-adjusted life years (DALYs) to assess health burden risk. A temperature-basic reproduction number (R0)-DALYs relationship was constructed to examine the potential impacts of temperature on health burden. Finally, a health burden risk model linked a control measure model to evaluate the effect of dengue control interventions. RESULTS We showed that R0 and DALYs peaked at 25°C with estimates of 2.37 and 1387, respectively. Results indicated that most dengue cases occurred in fall with estimated DALYs of 323 (267-379, 95% CI) at 50% risk probability. We found that repellent spray had by far the largest control effect with an effectiveness of ~71% in all seasons. Pesticide spray and container clean-up have both made important contributions to reducing prevalence/incidence. Repellent, pesticide spray, container clean-up together with Wolbachia infection suppress dengue outbreak by ~90%. CONCLUSION Our presented modeling framework provides a useful tool to measure dengue health burden risk and to quantify the effect of dengue control on dengue infection prevalence and disease incidence in the southern region of Taiwan.
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Affiliation(s)
- Yi-Hsien Cheng
- Institute of Computational Comparative Medicine (ICCM), Department of Anatomy and Physiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS, USA
| | - Yi-Jun Lin
- Institute of Food Safety and Health Risk Assessment, National Yang-Ming University, Taipei, Taiwan, Republic of China
| | - Szu-Chieh Chen
- Department of Public Health, Chung Shan Medical University, Taichung, Taiwan, Republic of China,
- Department of Family and Community Medicine, Chung Shan Medical University Hospital, Taichung, Taiwan, Republic of China,
| | - Shu-Han You
- Institute of Food Safety and Risk Management, National Taiwan Ocean University, Keelung, Taiwan, Republic of China
| | - Wei-Yu Chen
- Department of Biomedical Science and Environmental Biology, Kaohsiung Medical University, Kaohsiung, Taiwan, Republic of China
- Research Center for Environmental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan, Republic of China
| | - Nan-Hung Hsieh
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, USA
| | - Ying-Fei Yang
- Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei, Taiwan, Republic of China,
| | - Chung-Min Liao
- Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei, Taiwan, Republic of China,
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Sense of community and willingness to support malaria intervention programme in urban poor Accra, Ghana. Malar J 2018; 17:289. [PMID: 30097021 PMCID: PMC6086070 DOI: 10.1186/s12936-018-2424-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 07/21/2018] [Indexed: 11/10/2022] Open
Abstract
Background The extensive research on community members’ willingness to support malaria interventions ignores the role of psychosocial determinants. This study assesses the impact of individuals’ sense of community (perceptions of community cohesion, altruism, seeking help from neighbours and migrant status) on their willingness to participate in a mosquito control programme using data on 768 individuals from the 2013 RIPS Urban Health and Poverty Survey in poor coastal communities in Accra, Ghana. A contingent valuation experiment was employed to elicit individuals’ willingness to support the programme by contributing nothing, labour time/money only or both. Results Findings show that different dimensions of sense of community related differently with willingness to support the programme. Perceived community cohesion was associated with lower odds while help-seeking from neighbours and being a migrant were associated with higher odds of supporting the programme. Altruism was the only dimension not linked to willingness to participate. Conclusions Different dimensions of sense of community are associated with community members’ willingness to provide labour, time or both to support the malaria eradication programme. The findings of this study have implications for targeting social relational aspects, in addition to geographical aspects, of communities with malaria-resilient policy and intervention. They also warrant further research on psychosocial factors that predict willingness to support health programmes in urban poor settings.
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Elsinga J, Schmidt M, Lizarazo EF, Vincenti-Gonzalez MF, Velasco-Salas ZI, Arias L, Burgerhof JGM, Tami A. Knowledge, Attitudes, and Preventive Practices Regarding Dengue in Maracay, Venezuela. Am J Trop Med Hyg 2018; 99:195-203. [PMID: 29848406 PMCID: PMC6085811 DOI: 10.4269/ajtmh.17-0528] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Accepted: 04/02/2018] [Indexed: 01/28/2023] Open
Abstract
Dengue, a viral mosquito-borne disease currently affects more than 2.5 billion people living in endemic areas worldwide. In vector control, social mobilization and community behavioral changes are of crucial importance. Here, we identified the factors influencing community dengue preventive practices in a high-transmission urban area in Venezuela. Between September 2013 and February 2014, a cross-sectional study at the household level was carried out in Maracay city, Venezuela. A precoded questionnaire was used to obtain information on people's knowledge, attitudes, and use of preventive practices in relation to dengue. Concomitantly, entomological data was collected from households. In 80% of the 105 included households, 1-5 preventive practices (e.g., repellents, insecticides) against mosquito bites were used. However, 57% of the examined houses had potential Aedes breeding sites indoors and/or outdoors, most of which positive for Aedes spp. larvae/pupae. Preventive practices were associated with a previous dengue infection (P = 0.030) and a better knowledge on dengue symptoms and transmission route (P = 0.020). In turn, knowledge was associated with feeling at risk (P < 0.001), a previous dengue infection (P = 0.010), and reported exposure to information sources of dengue (P = 0.011). Even though the knowledge level of the community over transmission ways was high, and most of the individuals took measures to avoid mosquito bites, potential mosquito breeding sites were present in almost two-thirds of the examined properties. Health promotion activities in Venezuela should aim at raising awareness at the community level on the importance of combining mosquito bite prevention with removal of breeding sites in and around the households.
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Affiliation(s)
- Jelte Elsinga
- University of Groningen, University Medical Center Groningen, Department of Medical Microbiology, Groningen, The Netherlands
| | - Masja Schmidt
- University of Groningen, University Medical Center Groningen, Department of Medical Microbiology, Groningen, The Netherlands
| | - Erley F. Lizarazo
- University of Groningen, University Medical Center Groningen, Department of Medical Microbiology, Groningen, The Netherlands
- Instituto de Investigaciones Biomédicas, Universidad de Carabobo, Maracay, Venezuela
| | - Maria F. Vincenti-Gonzalez
- University of Groningen, University Medical Center Groningen, Department of Medical Microbiology, Groningen, The Netherlands
- Instituto de Investigaciones Biomédicas, Universidad de Carabobo, Maracay, Venezuela
| | - Zoraida I. Velasco-Salas
- University of Groningen, University Medical Center Groningen, Department of Medical Microbiology, Groningen, The Netherlands
- Departamento de Biología, Facultad Experimental de Ciencia y Tecnología, Universidad de Carabobo, Valencia, Venezuela
| | - Luzlexis Arias
- Instituto de Investigaciones Biomédicas, Universidad de Carabobo, Maracay, Venezuela
| | - Johannes G. M. Burgerhof
- Department of Epidemiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Adriana Tami
- University of Groningen, University Medical Center Groningen, Department of Medical Microbiology, Groningen, The Netherlands
- Departamento de Parasitología, Facultad de Ciencias de la Salud, Universidad de Carabobo, Valencia, Venezuela
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The containment of potential outbreaks triggered by imported Chikungunya cases in Italy: a cost utility epidemiological assessment of vector control measures. Sci Rep 2018; 8:9034. [PMID: 29899520 PMCID: PMC5998040 DOI: 10.1038/s41598-018-27443-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 05/30/2018] [Indexed: 12/14/2022] Open
Abstract
The arrival of infected travelers from endemic regions can trigger sustained autochthonous transmission of mosquito-borne pathogens in Europe. In 2007 a Chikungunya outbreak was observed in central Italy, mostly affecting two villages characterised by a high density of Aedes albopictus. The outbreak was mitigated through intervention strategies reducing the mosquito abundance. Ten years later, in 2017, sustained Chikungunya transmission was documented in both central and southern Italy. The proposed analysis identifies suitable reactive measures for the containment and mitigation of future epidemics by combining epidemiological modeling with a health economic approach, considering different arrival times of imported infections and possible delays in the notification of cases. Obtained estimates suggest that, if the first notification will occur in the middle of the mosquito breeding season, the combination of larvicides, adulticides and breeding sites removal represents the optimal strategy. In particular, we found that interventions implemented in 2007 were cost-effective, with about 3200 prevented cases, 1450 DALYs averted and €13.5 M saved. Moreover, larvicides are proven to be more cost beneficial in early summer and warmer seasons, while adulticides should be preferred in autumn and colder seasons. Our results provide useful indications supporting urgent decision-making of public health authorities in response to emerging mosquito-borne epidemics.
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Durham DP, Fitzpatrick MC, Ndeffo-Mbah ML, Parpia AS, Michael NL, Galvani AP. Evaluating Vaccination Strategies for Zika Virus in the Americas. Ann Intern Med 2018; 168:621-630. [PMID: 29610863 PMCID: PMC5955609 DOI: 10.7326/m17-0641] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Background Mosquito-borne and sexually transmitted Zika virus has become widespread across Central and South America and the Caribbean. Many Zika vaccine candidates are under active development. Objective To quantify the effect of Zika vaccine prioritization of females aged 9 to 49 years, followed by males aged 9 to 49 years, on incidence of prenatal Zika infections. Design A compartmental model of Zika transmission between mosquitoes and humans was developed and calibrated to empirical estimates of country-specific mosquito density. Mosquitoes were stratified into susceptible, exposed, and infected groups; humans were stratified into susceptible, exposed, infected, recovered, and vaccinated groups. Age-specific fertility rates, Zika sexual transmission, and country-specific demographics were incorporated. Setting 34 countries and territories in the Americas with documented Zika outbreaks. Target Population Males and females aged 9 to 49 years. Intervention Age- and sex-targeted immunization using a Zika vaccine with 75% efficacy. Measurements Annual prenatal Zika infections. Results For a base-case vaccine efficacy of 75% and vaccination coverage of 90%, immunizing females aged 9 to 49 years (the World Health Organization target population) would reduce the incidence of prenatal infections by at least 94%, depending on the country-specific Zika attack rate. In regions where an outbreak is not expected for at least 10 years, vaccination of women aged 15 to 29 years is more efficient than that of women aged 30 years or older. Limitation Population-level modeling may not capture all local and neighborhood-level heterogeneity in mosquito abundance or Zika incidence. Conclusion A Zika vaccine of moderate to high efficacy may virtually eliminate prenatal infections through a combination of direct protection and transmission reduction. Efficiency of age-specific targeting of Zika vaccination depends on the timing of future outbreaks. Primary Funding Source National Institutes of Health.
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Affiliation(s)
- DP Durham
- Center for Infectious Disease Modeling and Analysis, Yale School of Public Health, 135 College St, New Haven, CT 06510
| | - MC Fitzpatrick
- Center for Infectious Disease Modeling and Analysis, Yale School of Public Health, 135 College St, New Haven, CT 06510
- Center for Vaccine Development, University of Maryland School of Medicine, 685 W Baltimore St, Baltimore, MD 21201
| | - ML Ndeffo-Mbah
- Center for Infectious Disease Modeling and Analysis, Yale School of Public Health, 135 College St, New Haven, CT 06510
| | - AS Parpia
- Center for Infectious Disease Modeling and Analysis, Yale School of Public Health, 135 College St, New Haven, CT 06510
| | - NL Michael
- U.S. Military HIV Research Program (MHRP), Walter Reed Army Institute of Research, 6720A Rockledge Drive, Bethesda, MD 20817
| | - AP Galvani
- Center for Infectious Disease Modeling and Analysis, Yale School of Public Health, 135 College St, New Haven, CT 06510
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Borlase A, Webster JP, Rudge JW. Opportunities and challenges for modelling epidemiological and evolutionary dynamics in a multihost, multiparasite system: Zoonotic hybrid schistosomiasis in West Africa. Evol Appl 2018; 11:501-515. [PMID: 29636802 PMCID: PMC5891036 DOI: 10.1111/eva.12529] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2017] [Accepted: 08/01/2017] [Indexed: 01/01/2023] Open
Abstract
Multihost multiparasite systems are evolutionarily and ecologically dynamic, which presents substantial trans-disciplinary challenges for elucidating their epidemiology and designing appropriate control. Evidence for hybridizations and introgressions between parasite species is gathering, in part in line with improvements in molecular diagnostics and genome sequencing. One major system where this is becoming apparent is within the Genus Schistosoma, where schistosomiasis represents a disease of considerable medical and veterinary importance, the greatest burden of which occurs in sub-Saharan Africa. Interspecific hybridizations and introgressions bring an increased level of complexity over and above that already inherent within multihost, multiparasite systems, also representing an additional source of genetic variation that can drive evolution. This has the potential for profound implications for the control of parasitic diseases, including, but not exclusive to, widening host range, increased transmission potential and altered responses to drug therapy. Here, we present the challenging case example of haematobium group Schistosoma spp. hybrids in West Africa, a system involving multiple interacting parasites and multiple definitive hosts, in a region where zoonotic reservoirs of schistosomiasis were not previously considered to be of importance. We consider how existing mathematical model frameworks for schistosome transmission could be expanded and adapted to zoonotic hybrid systems, exploring how such model frameworks can utilize molecular and epidemiological data, as well as the complexities and challenges this presents. We also highlight the opportunities and value such mathematical models could bring to this and a range of similar multihost, multi and cross-hybridizing parasites systems in our changing world.
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Affiliation(s)
- Anna Borlase
- Department of Pathobiology and Population SciencesCentre for Emerging, Endemic and Exotic DiseasesRoyal Veterinary CollegeUniversity of LondonLondonUK
- Department of Infectious Disease EpidemiologyLondon Centre for Neglected Tropical Disease ResearchSchool of Public HealthImperial College LondonLondonUK
| | - Joanne P. Webster
- Department of Pathobiology and Population SciencesCentre for Emerging, Endemic and Exotic DiseasesRoyal Veterinary CollegeUniversity of LondonLondonUK
- Department of Infectious Disease EpidemiologyLondon Centre for Neglected Tropical Disease ResearchSchool of Public HealthImperial College LondonLondonUK
| | - James W. Rudge
- Department of Infectious Disease EpidemiologyLondon Centre for Neglected Tropical Disease ResearchSchool of Public HealthImperial College LondonLondonUK
- Communicable Diseases Policy Research GroupLondon School of Hygiene and Tropical MedicineLondonUK
- Faculty of Public HealthMahidol UniversityBangkokThailand
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Luh DL, Liu CC, Luo YR, Chen SC. Economic cost and burden of dengue during epidemics and non-epidemic years in Taiwan. J Infect Public Health 2018; 11:215-223. [DOI: 10.1016/j.jiph.2017.07.021] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Revised: 05/29/2017] [Accepted: 07/09/2017] [Indexed: 10/19/2022] Open
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Abstract
PURPOSE OF REVIEW Dengue, the most common arbovirus, is an increasingly significant cause of morbidity worldwide. After decades of research, an approved tetravalent dengue vaccine is finally available. Models constructed using recently available vaccine efficacy data allow for a data-driven discussion of the potential impact of dengue vaccine deployment on global control. RECENT FINDINGS Phase 3 efficacy trials demonstrated that the approved dengue vaccine, chimeric yellow fever-dengue-tetravalent dengue vaccine, has an efficacy of 60% against dengue illness of any severity. However, among dengue unexposed recipients, vaccination offers limited efficacy and may increase dengue severity. The WHO consequently recommends dengue vaccination for populations in which 70% of intended recipients are dengue seropositive. Models predict that routine childhood dengue vaccine may reduce dengue burden, but over time, population-level impact may be limited. Additional vaccine candidates in late-stage development may not suffer from the same limitations as chimeric yellow fever-dengue-tetravalent dengue vaccine. SUMMARY The efficacy and safety profile of the recently approved dengue vaccine is favorable only in previously dengue exposed recipients, which limits its potential for global control. Future work must evaluate the approved vaccine's long-term durability, efficacy of other late phase vaccine candidates, and potential for vector control efforts to work synergistically with vaccine deployment.
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Huang YW, Lee CT, Wang TC, Kao YC, Yang CH, Lin YM, Huang KS. The Development of Peptide-based Antimicrobial Agents against Dengue Virus. Curr Protein Pept Sci 2018; 19:998-1010. [PMID: 29852867 PMCID: PMC6446661 DOI: 10.2174/1389203719666180531122724] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Revised: 04/20/2018] [Accepted: 05/25/2018] [Indexed: 11/22/2022]
Abstract
Dengue fever has become an imminent threat to international public health because of global warming and climate change. The World Health Organization proclaimed that more than 50% of the world's population is at risk of dengue virus (DENV) infection. Therefore, developing a clinically approved vaccine and effective therapeutic remedy for treating dengue fever is imperative. Peptide drug development has become a novel pharmaceutical research field. This article reviews various peptidesbased antimicrobial agents targeting three pathways involved in the DENV lifecycle. Specifically, they are peptide vaccines from immunomodulation, peptide drugs that inhibit virus entry, and peptide drugs that interfere with viral replication. Many antiviral peptide studies against DENV have been conducted in animal model trials, and progression to clinical trials for these promising peptide drugs is anticipated.
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Affiliation(s)
| | | | | | | | | | | | - Keng-Shiang Huang
- Address correspondence to this author at the School of Chinese Medicine for Post-Baccalaureate, I-Shou University, Kaohsiung, Taiwan;, Tel: +886-988-399-979; E-mail:
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An Envelope-Modified Tetravalent Dengue Virus-Like-Particle Vaccine Has Implications for Flavivirus Vaccine Design. J Virol 2017; 91:JVI.01181-17. [PMID: 28956764 DOI: 10.1128/jvi.01181-17] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Accepted: 09/09/2017] [Indexed: 12/30/2022] Open
Abstract
Dengue viruses (DENV) infect 50 to 100 million people each year. The spread of DENV-associated infections is one of the most serious public health problems worldwide, as there is no widely available vaccine or specific therapeutic for DENV infections. To address this, we developed a novel tetravalent dengue vaccine by utilizing virus-like particles (VLPs). We created recombinant DENV1 to -4 (DENV1-4) VLPs by coexpressing precursor membrane (prM) and envelope (E) proteins, with an F108A mutation in the fusion loop structure of E to increase the production of VLPs in mammalian cells. Immunization with DENV1-4 VLPs as individual, monovalent vaccines elicited strong neutralization activity against each DENV serotype in mice. For use as a tetravalent vaccine, DENV1-4 VLPs elicited high levels of neutralization activity against all four serotypes simultaneously. The neutralization antibody responses induced by the VLPs were significantly higher than those with DNA or recombinant E protein immunization. Moreover, antibody-dependent enhancement (ADE) was not observed against any serotype at a 1:10 serum dilution. We also demonstrated that the Zika virus (ZIKV) VLP production level was enhanced by introducing the same F108A mutation into the ZIKV envelope protein. Taken together, these results suggest that our strategy for DENV VLP production is applicable to other flavivirus VLP vaccine development, due to the similarity in viral structures, and they describe the promising development of an effective tetravalent vaccine against the prevalent flavivirus.IMPORTANCE Dengue virus poses one of the most serious public health problems worldwide, and the incidence of diseases caused by the virus has increased dramatically. Despite decades of effort, there is no effective treatment against dengue. A safe and potent vaccine against dengue is still needed. We developed a novel tetravalent dengue vaccine by using virus-like particles (VLPs), which are noninfectious because they lack the viral genome. Previous attempts of other groups to use dengue VLPs resulted in generally poor yields. We found that a critical amino acid mutation in the envelope protein enhances the production of VLPs. Our tetravalent vaccine elicited potent neutralizing antibody responses against all four DENV serotypes. Our findings can also be applied to vaccine development against other flaviviruses, such as Zika virus or West Nile virus.
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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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Abstract
The first approved dengue vaccine, CYD-TDV, a chimeric, live-attenuated, tetravalent dengue virus vaccine, was recently licensed in 13 countries, including Brazil. In light of recent vaccine approval, we modeled the cost-effectiveness of potential vaccination policies mathematically based on data from recent vaccine efficacy trials that indicated that vaccine efficacy was lower in seronegative individuals than in seropositive individuals. In our analysis, we investigated several vaccination programs, including routine vaccination, with various vaccine coverage levels and those with and without large catch-up campaigns. As it is unclear whether the vaccine protects against infection or just against disease, our model incorporated both direct and indirect effects of vaccination. We found that in the presence of vaccine-induced indirect protection, the cost-effectiveness of dengue vaccination decreased with increasing vaccine coverage levels because the marginal returns of herd immunity decreases with vaccine coverage. All routine dengue vaccination programs that we considered were cost-effective, reducing dengue incidence significantly. Specifically, a routine dengue vaccination of 9-year-olds would be cost-effective when the cost of vaccination per individual is less than $262. Furthermore, the combination of routine vaccination and large catch-up campaigns resulted in a greater reduction of dengue burden (by up to 93%) than routine vaccination alone, making it a cost-effective intervention as long as the cost per course of vaccination is $255 or less. Our results show that dengue vaccination would be cost-effective in Brazil even with a relatively low vaccine efficacy in seronegative individuals.
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Affiliation(s)
- Eunha Shim
- Department of Mathematics, Soongsil University, Seoul, Republic of Korea
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Tian H, Sun Z, Faria NR, Yang J, Cazelles B, Huang S, Xu B, Yang Q, Pybus OG, Xu B. Increasing airline travel may facilitate co-circulation of multiple dengue virus serotypes in Asia. PLoS Negl Trop Dis 2017; 11:e0005694. [PMID: 28771468 PMCID: PMC5542384 DOI: 10.1371/journal.pntd.0005694] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Accepted: 06/08/2017] [Indexed: 12/26/2022] Open
Abstract
The incidence of dengue has grown dramatically in recent decades worldwide, especially in Southeast Asia and the Americas with substantial transmission in 2014-2015. Yet the mechanisms underlying the spatio-temporal circulation of dengue virus (DENV) serotypes at large geographical scales remain elusive. Here we investigate the co-circulation in Asia of DENV serotypes 1-3 from 1956 to 2015, using a statistical framework that jointly estimates migration history and quantifies potential predictors of viral spatial diffusion, including socio-economic, air transportation and maritime mobility data. We find that the spread of DENV-1, -2 and -3 lineages in Asia is significantly associated with air traffic. Our analyses suggest the network centrality of air traffic hubs such as Thailand and India contribute to seeding dengue epidemics, whilst China, Cambodia, Indonesia, and Singapore may establish viral diffusion links with multiple countries in Asia. Phylogeographic reconstructions help to explain how growing air transportation networks could influence the dynamics of DENV circulation.
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Affiliation(s)
- Huaiyu Tian
- State Key Laboratory of Remote Sensing Science, College of Global Change and Earth System Science, Beijing Normal University, Beijing, China
| | - Zhe Sun
- Ministry of Education Key Laboratory for Earth System Modeling, Department of Earth System Science, School of Environment, Tsinghua University, Beijing, China
| | | | - Jing Yang
- State Key Laboratory of Remote Sensing Science, College of Global Change and Earth System Science, Beijing Normal University, Beijing, China
| | - Bernard Cazelles
- Ecologie & Evolution, UMR 7625, UPMC-ENS, Paris, France
- UMMISCO UMI 209 IRD - UPMC, Bondy, France
| | - Shanqian Huang
- State Key Laboratory of Remote Sensing Science, College of Global Change and Earth System Science, Beijing Normal University, Beijing, China
- Department of Zoology, University of Oxford, Oxford, United Kingdom
| | - Bo Xu
- Ministry of Education Key Laboratory for Earth System Modeling, Department of Earth System Science, School of Environment, Tsinghua University, Beijing, China
| | - Qiqi Yang
- State Key Laboratory of Remote Sensing Science, College of Global Change and Earth System Science, Beijing Normal University, Beijing, China
| | - Oliver G. Pybus
- Department of Zoology, University of Oxford, Oxford, United Kingdom
- * E-mail: (OP); (BiX)
| | - Bing Xu
- State Key Laboratory of Remote Sensing Science, College of Global Change and Earth System Science, Beijing Normal University, Beijing, China
- Ministry of Education Key Laboratory for Earth System Modeling, Department of Earth System Science, School of Environment, Tsinghua University, Beijing, China
- * E-mail: (OP); (BiX)
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Liu T, Zhu G, He J, Song T, Zhang M, Lin H, Xiao J, Zeng W, Li X, Li Z, Xie R, Zhong H, Wu X, Hu W, Zhang Y, Ma W. Early rigorous control interventions can largely reduce dengue outbreak magnitude: experience from Chaozhou, China. BMC Public Health 2017; 18:90. [PMID: 28768542 PMCID: PMC5541667 DOI: 10.1186/s12889-017-4616-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2016] [Accepted: 07/20/2017] [Indexed: 01/03/2023] Open
Abstract
Background Dengue fever is a severe public heath challenge in south China. A dengue outbreak was reported in Chaozhou city, China in 2015. Intensified interventions were implemented by the government to control the epidemic. However, it is still unknown the degree to which intensified control measures reduced the size of the epidemics, and when should such measures be initiated to reduce the risk of large dengue outbreaks developing? Methods We selected Xiangqiao district as study setting because the majority of the indigenous cases (90.6%) in Chaozhou city were from this district. The numbers of daily indigenous dengue cases in 2015 were collected through the national infectious diseases and vectors surveillance system, and daily Breteau Index (BI) data were reported by local public health department. We used a compartmental dynamic SEIR (Susceptible, Exposed, Infected and Removed) model to assess the effectiveness of control interventions, and evaluate the control effect of intervention timing on dengue epidemic. Results A total of 1250 indigenous dengue cases was reported from Xiangqiao district. The results of SEIR modeling using BI as an indicator of actual control interventions showed a total of 1255 dengue cases, which is close to the reported number (n = 1250). The size and duration of the outbreak were highly sensitive to the intensity and timing of interventions. The more rigorous and earlier the control interventions implemented, the more effective it yielded. Even if the interventions were initiated several weeks after the onset of the dengue outbreak, the interventions were shown to greatly impact the prevalence and duration of dengue outbreak. Conclusions This study suggests that early implementation of rigorous dengue interventions can effectively reduce the epidemic size and shorten the epidemic duration.
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Affiliation(s)
- Tao Liu
- Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, No. 160, Qunxian Road, Panyu District, Guangzhou, 511430, China
| | - Guanghu Zhu
- Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, No. 160, Qunxian Road, Panyu District, Guangzhou, 511430, China
| | - Jianfeng He
- Guangdong Provincial Center for Disease Control and Prevention, No. 160, Qunxian Road, Panyu District, Guangzhou, 511430, China
| | - Tie Song
- Guangdong Provincial Center for Disease Control and Prevention, No. 160, Qunxian Road, Panyu District, Guangzhou, 511430, China
| | - Meng Zhang
- Guangdong Provincial Center for Disease Control and Prevention, No. 160, Qunxian Road, Panyu District, Guangzhou, 511430, China
| | - Hualiang Lin
- Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, No. 160, Qunxian Road, Panyu District, Guangzhou, 511430, China
| | - Jianpeng Xiao
- Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, No. 160, Qunxian Road, Panyu District, Guangzhou, 511430, China
| | - Weilin Zeng
- Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, No. 160, Qunxian Road, Panyu District, Guangzhou, 511430, China
| | - Xing Li
- Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, No. 160, Qunxian Road, Panyu District, Guangzhou, 511430, China
| | - Zhihao Li
- Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, No. 160, Qunxian Road, Panyu District, Guangzhou, 511430, China
| | - Runsheng Xie
- Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, No. 160, Qunxian Road, Panyu District, Guangzhou, 511430, China
| | - Haojie Zhong
- Guangdong Provincial Center for Disease Control and Prevention, No. 160, Qunxian Road, Panyu District, Guangzhou, 511430, China
| | - Xiaocheng Wu
- Guangdong Provincial Center for Disease Control and Prevention, No. 160, Qunxian Road, Panyu District, Guangzhou, 511430, China.,Faculty of Medical Statistics and Epidemiology, School of Public Health, Sun Yat-sen University, Guangzhou, 510080, China
| | - Wenbiao Hu
- School of Public Health and Social Work & Institute of Health and Biomedical Innovation, Queensland University of Technology, QLD, Brisbane, Australia
| | - Yonghui Zhang
- Guangdong Provincial Center for Disease Control and Prevention, No. 160, Qunxian Road, Panyu District, Guangzhou, 511430, China.
| | - Wenjun Ma
- Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, No. 160, Qunxian Road, Panyu District, Guangzhou, 511430, China.
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Shim E. Cost-effectiveness of dengue vaccination in Yucatán, Mexico using a dynamic dengue transmission model. PLoS One 2017; 12:e0175020. [PMID: 28380060 PMCID: PMC5381893 DOI: 10.1371/journal.pone.0175020] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Accepted: 03/20/2017] [Indexed: 11/29/2022] Open
Abstract
Background The incidence of dengue fever (DF) is steadily increasing in Mexico, burdening health systems with consequent morbidities and mortalities. On December 9th, 2015, Mexico became the first country for which the dengue vaccine was approved for use. In anticipation of a vaccine rollout, analysis of the cost-effectiveness of the dengue vaccination program that quantifies the dynamics of disease transmission is essential. Methods We developed a dynamic transmission model of dengue in Yucatán, Mexico and its proposed vaccination program to incorporate herd immunity into our analysis of cost-effectiveness analysis. Our model also incorporates important characteristics of dengue epidemiology, such as clinical cross-immunity and susceptibility enhancement upon secondary infection. Using our model, we evaluated the cost-effectiveness and economic impact of an imperfect dengue vaccine in Yucatán, Mexico. Conclusions Our study indicates that a dengue vaccination program would prevent 90% of cases of symptomatic DF incidence as well as 90% of dengue hemorrhagic fever (DHF) incidence and dengue-related deaths annually. We conclude that a dengue vaccine program in Yucatán, Mexico would be very cost-effective as long as the vaccination cost per individual is less than $140 and $214 from health care and societal perspectives, respectively. Furthermore, at an exemplary vaccination cost of $250 USD per individual on average, dengue vaccination is likely to be cost-effective 43% and 88% of the time from health care and societal perspectives, respectively.
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Affiliation(s)
- Eunha Shim
- Department of Mathematics, Soongsil University, Seoul, Republic of Korea
- * E-mail:
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Undurraga EA, Edillo FE, Erasmo JNV, Alera MTP, Yoon IK, Largo FM, Shepard DS. Disease Burden of Dengue in the Philippines: Adjusting for Underreporting by Comparing Active and Passive Dengue Surveillance in Punta Princesa, Cebu City. Am J Trop Med Hyg 2017; 96:887-898. [PMID: 28093542 PMCID: PMC5392638 DOI: 10.4269/ajtmh.16-0488] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 11/29/2016] [Indexed: 02/05/2023] Open
Abstract
AbstractDengue virus (DENV) is a serious threat to public health. Having reliable estimates of the burden of dengue is important to inform policy and research, but surveillance systems are not designed to capture all symptomatic DENV infections. We derived the rate of reporting of dengue by comparing active surveillance of symptomatic DENV infections in a prospective community-based seroepidemiological cohort study (N = 1008) of acute febrile illness in Punta Princesa, Cebu City, Philippines, with passive surveillance data from the Cebu City Health Department. Febrile episodes detected in a weekly follow-up of participants were tested for serotype-specific DENV by hemi-nested reverse transcription-polymerase chain reaction (nested RT-PCR) and acute/convalescent blood samples tested by dengue IgM/IgG enzyme immunoassay. We estimated the burden of dengue in the Philippines in disability-adjusted life years (DALYs), and conducted a probabilistic sensitivity analysis using Monte-Carlo simulations to address uncertainty. The results showed a 21% cumulative reporting rate of symptomatic DENV infections, equivalent to an expansion factor of 4.7 (95% certainty level [CL]: 2.2-15.1). Based on surveillance data in the Philippines for 2010-2014, we estimated 794,255 annual dengue episodes (95% CL: 463,000-2,076,000) and a disease burden of 535 (95% CL: 380-994) DALYs per million population using age weights and time discounting and 997 (95% CL: 681-1,871) DALYs per million population without age and time adjustments. Dengue imposes a substantial burden in the Philippines; almost 10 times higher than estimated for rabies, about twice the burden of intestinal fluke infections, and about 10% of the burden of tuberculosis. Our estimates should inform policy makers and raise awareness among the public.
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Affiliation(s)
- Eduardo A. Undurraga
- Schneider Institutes for Health Policy, Heller School, Brandeis University, Waltham, MA
| | - Frances E. Edillo
- Department of Biology, University of San Carlos, Cebu City, Philippines
| | | | | | - In-Kyu Yoon
- Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
- Dengue Vaccine Initiative, International Vaccine Institute, Seoul, Republic of Korea
| | - Francisco M. Largo
- Department of Economics, University of San Carlos, Cebu City, Philippines
| | - Donald S. Shepard
- Schneider Institutes for Health Policy, Heller School, Brandeis University, Waltham, MA
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Srinivasan K, Tapia B, Rodriguez A, Wood R, Salinas JJ. Species abundance and temporal variation of arbovirus vectors in Brownsville, Texas. Rev Panam Salud Publica 2017. [PMID: 28444003 PMCID: PMC6612715 DOI: 10.26633/rpsp.2017.28] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The recent outbreaks of the dengue fever and West Nile viruses and the looming threats of the Zika and chikungunya viruses highlight the importance of establishing effective, proactive arboviral surveillance in communities at high risk of transmission, such as those on the Texas–Mexico border. Currently, there are no approved human vaccines available for these mosquito-borne diseases, so entomological control and case management are the only known methods for decreasing disease incidence. The principal vectors, which include Culex quinquefasciatus, Aedes aegypti, and Ae. Albopictus, all have an established presence in South Texas. The public health response to most arbovirus outbreaks in the region has been reactionary rather than proactive. However, after the 2005 dengue outbreak and subsequent fatality, the City of Brownsville Public Health Department began collecting data on mosquito vector abundance and incidence. The objective of this study was to describe the various species of mosquitoes found in vector surveillance in Brownsville, Texas, during 2009–2013; quantify their prevalence; and identify any associations with temporal or weather-related variations. The results confirm a significant mosquito population in Brownsville in late winter months, indicating a high risk of arbovirus transmission in South Texas year-round, and not just until November, previously considered the end date of arbovirus season by state health services. The data from Brownsville’s surveillance program can help characterize local vector ecology and facilitate more proactive mitigation of future arboviral threats in South Texas.
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Affiliation(s)
- Krithika Srinivasan
- University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
| | - Beatriz Tapia
- University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
| | - Arturo Rodriguez
- City of Brownsville Department of Public Health, Brownsville, Texas, United States of America
| | - Robert Wood
- University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
| | - Jennifer J Salinas
- Texas Tech University Health Sciences Center at El Paso, El Paso, Texas, United States of America
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Cromwell EA, Stoddard ST, Barker CM, Van Rie A, Messer WB, Meshnick SR, Morrison AC, Scott TW. The relationship between entomological indicators of Aedes aegypti abundance and dengue virus infection. PLoS Negl Trop Dis 2017; 11:e0005429. [PMID: 28333938 PMCID: PMC5363802 DOI: 10.1371/journal.pntd.0005429] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Accepted: 02/21/2017] [Indexed: 11/21/2022] Open
Abstract
Routine entomological monitoring data are used to quantify the abundance of Ae. aegypti. The public health utility of these indicators is based on the assumption that greater mosquito abundance increases the risk of human DENV transmission, and therefore reducing exposure to the vector decreases incidence of infection. Entomological survey data from two longitudinal cohort studies in Iquitos, Peru, linked with 8,153 paired serological samples taken approximately six months apart were analyzed. Indicators of Ae. aegypti density were calculated from cross-sectional and longitudinal entomological data collected over a 12-month period for larval, pupal and adult Ae. aegypti. Log binomial models were used to estimate risk ratios (RR) to measure the association between Ae. aegypti abundance and the six-month risk of DENV seroconversion. RRs estimated using cross-sectional entomological data were compared to RRs estimated using longitudinal data. Higher cross-sectional Ae. aegypti densities were not associated with an increased risk of DENV seroconversion. Use of longitudinal entomological data resulted in RRs ranging from 1.01 (95% CI: 1.01, 1.02) to 1.30 (95% CI: 1.17, 1.46) for adult stage density estimates and RRs ranging from 1.21 (95% CI: 1.07, 1.37) to 1.75 (95% CI: 1.23, 2.5) for categorical immature indices. Ae. aegypti densities calculated from longitudinal entomological data were associated with DENV seroconversion, whereas those measured cross-sectionally were not. Ae. aegypti indicators calculated from cross-sectional surveillance, as is common practice, have limited public health utility in detecting areas or populations at high risk of DENV infection.
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Affiliation(s)
- Elizabeth A. Cromwell
- Department of Epidemiology, University of North Carolina, Gillings School of Global Public Health, Chapel Hill, North Carolina, United States of America
| | - Steven T. Stoddard
- Graduate School of Public Health, San Diego State University, San Diego, California, United States of America
| | - Christopher M. Barker
- Department of Entomology and Nematology, University of California, Davis, Davis, California, United States of America
| | - Annelies Van Rie
- Department of Epidemiology, University of North Carolina, Gillings School of Global Public Health, Chapel Hill, North Carolina, United States of America
| | - William B. Messer
- Division of Infectious Diseases, Oregon Health and Science University, Portland, Oregon, United States of America
| | - Steven R. Meshnick
- Department of Epidemiology, University of North Carolina, Gillings School of Global Public Health, Chapel Hill, North Carolina, United States of America
| | - Amy C. Morrison
- 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
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Qualls WA, Naranjo DP, Subía MA, Ramon G, Cevallos V, Grijalva I, Gómez E, Arheart KL, Fuller DO, Beier JC. Movement of Aedes aegypti following a sugar meal and its implication in the development of control strategies in Durán, Ecuador. JOURNAL OF VECTOR ECOLOGY : JOURNAL OF THE SOCIETY FOR VECTOR ECOLOGY 2016; 41:224-231. [PMID: 27860016 DOI: 10.1111/jvec.12217] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Accepted: 06/20/2016] [Indexed: 05/15/2023]
Abstract
We evaluated how the presence of sugar sources impacted the distribution of Aedes aegypti in different habitats in Durán, Ecuador. Land cover and normalized difference vegetation index maps were used to guide a random point sampling routine to select study grids (30 m × 30 m) in low vegetation (LV) and high vegetation (HV). Five individual plants, at one home in the LV and HV grid, were treated with a different colored, non-attractive, 60% sucrose solution to determine mosquito feeding and movement. Sugar alone is not attractive to mosquitoes, so spraying vegetation with a dyed sugar solution can be used for visual determination of sugar feeding. Outdoor collections using BG sentinel traps and indoor collections using aspirators were conducted at the treatment home and with collection points at 20, 40, and 60 m surrounding the treatment home for three consecutive days. A total of 3,245 mosquitoes in two genera, Aedes and Culex, was collected. The proportion of stained Ae. aegypti females was 56.8% (510/898) and 0% for males. For Culex, 63.9% (248/388) females and 36.1% (140/388) males were collected stained. Aedes aegypti and Culex spp. were found up to 60 m stained in both LV and HV grids. Significantly more stained females Ae. aegypti were found inside homes compared to females and males of Culex spp. in both habitats. This study identifies that outdoor sugar feeding is a common behavior of Ae. aegypti and can be targeted as a control strategy in urban habitats in Latin America.
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Affiliation(s)
- Whitney A Qualls
- University of Miami Miller School of Medicine, Department of Public Health Sciences, Miami, FL, U.S.A. 33136
- PROMETEO, Secretaría de Educación Superior, Ciencia, Tecnología e Innovación, Quito, Ecuador
| | - Diana P Naranjo
- University of Miami Miller School of Medicine, Department of Public Health Sciences, Miami, FL, U.S.A. 33136
| | | | - Giovanni Ramon
- Instituto Nacional de Investigación en Salud Pública, Quito, Ecuador
| | - Varsovia Cevallos
- Instituto Nacional de Investigación en Salud Pública, Quito, Ecuador
| | - Isabel Grijalva
- Universidad Católica de Santiago de Guayaquil, Facultad de Ciencias Médicas, Guayas, Ecuador
| | - Eduardo Gómez
- Universidad Católica de Santiago de Guayaquil, Facultad de Ciencias Médicas, Guayas, Ecuador
- Ministerio de Salud Pública del Ecuador
| | - Kristopher L Arheart
- University of Miami Miller School of Medicine, Department of Public Health Sciences, Miami, FL, U.S.A. 33136
| | - Douglas O Fuller
- Department of Geography, University of Miami, Coral Gables, FL 33136, U.S.A
| | - John C Beier
- University of Miami Miller School of Medicine, Department of Public Health Sciences, Miami, FL, U.S.A. 33136
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Tang B, Xiao Y, Tang S, Wu J. Modelling weekly vector control against Dengue in the Guangdong Province of China. J Theor Biol 2016; 410:65-76. [PMID: 27650706 DOI: 10.1016/j.jtbi.2016.09.012] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Revised: 09/13/2016] [Accepted: 09/15/2016] [Indexed: 11/19/2022]
Abstract
We develop a mathematical model to closely mimic the integrated program of impulsive vector control (every Friday afternoon since the initiation of the program) and continuous patient treatment and isolation implemented in the Guangdong Province of China during its 2014 dengue outbreak. We fitted the data of accumulated infections and used the parameterized model to carry out a retrospective analysis to estimate the basic reproduction number 1.7425 (95% CI 1.4443-2.0408), the control reproduction number 0.1709, and the mosquito-killing ratios 0.1978, 0.2987, 0.6158 and 0.5571 on October 3, 10, 17 and 24, respectively. This suggests that integrated intervention is highly effective in controlling the dengue outbreak. We also simulated outbreak outcomes under different variations of the implemented interventions. We showed that skipping one Friday for vector control would not result in raising the control reproduction number to the threshold value 1 but would lead to significant increase in the accumulated infections at the end of the outbreak. The findings indicate that quick and persistent impulsive implementation of vector control result in an effective reduction in the control reproduction number and hence lead to significant decline of new infections.
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Affiliation(s)
- Biao Tang
- School of Mathematics and Statistics, Xi'an Jiaotong University, Xi'an 710049, PR China; Centre for Disease Modelling, York Institute for Health Research, York University, Toronto, ON, Canada M3J 1P3
| | - Yanni Xiao
- School of Mathematics and Statistics, Xi'an Jiaotong University, Xi'an 710049, PR China.
| | - Sanyi Tang
- College of Mathematics and Information Science, Shaanxi Normal University, Xi'an 710062, PR China
| | - Jianhong Wu
- Centre for Disease Modelling, York Institute for Health Research, York University, Toronto, ON, Canada M3J 1P3
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Dengue fever virus in Pakistan: effects of seasonal pattern and temperature change on distribution of vector and virus. Rev Med Virol 2016; 27. [DOI: 10.1002/rmv.1899] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Revised: 07/18/2016] [Accepted: 07/19/2016] [Indexed: 02/01/2023]
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