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Pérez-Otáñez X, Rodríguez-Hidalgo R, Enríquez S, Celi-Erazo M, Benítez W, Saegerman C, Vaca-Moyano F, Ron-Garrido L, Vanwambeke SO. High-resolution prediction models for Rhipicephalus microplus and Amblyomma cajennense s.l. ticks affecting cattle and their spatial distribution in continental Ecuador using bioclimatic factors. EXPERIMENTAL & APPLIED ACAROLOGY 2024; 92:439-462. [PMID: 38388882 PMCID: PMC11035444 DOI: 10.1007/s10493-023-00883-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Accepted: 12/29/2023] [Indexed: 02/24/2024]
Abstract
In Ecuador, the main tick species affecting cattle are Rhipicephalus microplus and Amblyomma cajennense sensu lato. Understanding their spatial distribution is crucial. To assess their distribution, data from 2895 farms visited between 2012 and 2017 were utilized. Ticks were collected during animal inspections, with each farm's location georeferenced. Bioclimatic variables and vapor pressure deficit data were obtained from Climatologies at High resolution for the Earth´s Land Surface Areas (CHELSA) dataset. They were overlaid to develop predictive maps for each species using Random Forest (RF) models. The cross-validation results for RF prediction models showed high accuracy for both R. microplus and A. cajennense s.l. presence with values of accuracy = 0.97 and 0.98, sensitivity = 0.96 and 0.99, and specificity = 0.96 and 0.93, respectively. A carefully selected subset of bioclimatic variables was used to describe the presence of each tick species. Higher levels of precipitation had positive effect on the presence of R. microplus but a negative effect on A. cajennense s.l. In contrast, isothermality (BIO3) was more important for the presence of A. cajennense s.l. compared to R. microplus. As a result, R. microplus had a broader distribution across the country, while A. cajennense s.l. was mainly found in coastal areas with evident seasonality. The coexistence of both species in some regions could be attributed to transitional zones, whereas high altitudes limited tick presence. This information can aid in developing appropriate tick management plans, particularly considering A. cajennense s.l.'s broad host range species and R. microplus's specificity for cattle. Moreover, the predictive models can identify areas at risk of associated challenging hemoparasite, requiring special attention and mitigation measures.
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Affiliation(s)
- Ximena Pérez-Otáñez
- Instituto de Investigación en Zoonosis-CIZ, Universidad Central del Ecuador, Quito, Ecuador.
- Center for Earth and Climate Research, Earth & Life Institute, Université Catholique de Louvain-UCLouvain, Louvain-La-Neuve, Belgium.
| | - Richar Rodríguez-Hidalgo
- Instituto de Investigación en Zoonosis-CIZ, Universidad Central del Ecuador, Quito, Ecuador
- Facultad de Medicina Veterinaria y Zootecnia, Universidad Central del Ecuador, Quito, Ecuador
| | - Sandra Enríquez
- Instituto de Investigación en Zoonosis-CIZ, Universidad Central del Ecuador, Quito, Ecuador
| | - Maritza Celi-Erazo
- Instituto de Investigación en Zoonosis-CIZ, Universidad Central del Ecuador, Quito, Ecuador
| | - Washington Benítez
- Instituto de Investigación en Zoonosis-CIZ, Universidad Central del Ecuador, Quito, Ecuador
| | - Claude Saegerman
- Research Unit of Epidemiology and Risk Analysis Applied to Veterinary Science (UREAR-ULiège), Fundamental and Applied Research for Animals & Health (FARAH) Center, Faculty of Veterinary Medicine, University of Liege, Liège, Belgium
| | - Franklin Vaca-Moyano
- Instituto de Investigación en Zoonosis-CIZ, Universidad Central del Ecuador, Quito, Ecuador
| | - Lenin Ron-Garrido
- Instituto de Investigación en Zoonosis-CIZ, Universidad Central del Ecuador, Quito, Ecuador
- Facultad de Medicina Veterinaria y Zootecnia, Universidad Central del Ecuador, Quito, Ecuador
- Facultad de Ciencias Agrícolas, Universidad Central del Ecuador, Quito, Ecuador
| | - Sophie O Vanwambeke
- Center for Earth and Climate Research, Earth & Life Institute, Université Catholique de Louvain-UCLouvain, Louvain-La-Neuve, Belgium
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Amenu K, McIntyre KM, Moje N, Knight-Jones T, Rushton J, Grace D. Approaches for disease prioritization and decision-making in animal health, 2000-2021: a structured scoping review. Front Vet Sci 2023; 10:1231711. [PMID: 37876628 PMCID: PMC10593474 DOI: 10.3389/fvets.2023.1231711] [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: 05/30/2023] [Accepted: 09/06/2023] [Indexed: 10/26/2023] Open
Abstract
This scoping review identifies and describes the methods used to prioritize diseases for resource allocation across disease control, surveillance, and research and the methods used generally in decision-making on animal health policy. Three electronic databases (Medline/PubMed, Embase, and CAB Abstracts) were searched for articles from 2000 to 2021. Searches identified 6, 395 articles after de-duplication, with an additional 64 articles added manually. A total of 6, 460 articles were imported to online document review management software (sysrev.com) for screening. Based on inclusion and exclusion criteria, 532 articles passed the first screening, and after a second round of screening, 336 articles were recommended for full review. A total of 40 articles were removed after data extraction. Another 11 articles were added, having been obtained from cross-citations of already identified articles, providing a total of 307 articles to be considered in the scoping review. The results show that the main methods used for disease prioritization were based on economic analysis, multi-criteria evaluation, risk assessment, simple ranking, spatial risk mapping, and simulation modeling. Disease prioritization was performed to aid in decision-making related to various categories: (1) disease control, prevention, or eradication strategies, (2) general organizational strategy, (3) identification of high-risk areas or populations, (4) assessment of risk of disease introduction or occurrence, (5) disease surveillance, and (6) research priority setting. Of the articles included in data extraction, 50.5% had a national focus, 12.3% were local, 11.9% were regional, 6.5% were sub-national, and 3.9% were global. In 15.2% of the articles, the geographic focus was not specified. The scoping review revealed the lack of comprehensive, integrated, and mutually compatible approaches to disease prioritization and decision support tools for animal health. We recommend that future studies should focus on creating comprehensive and harmonized frameworks describing methods for disease prioritization and decision-making tools in animal health.
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Affiliation(s)
- Kebede Amenu
- Global Burden of Animal Diseases (GBADs) Programme, University of Liverpool, Liverpool, United Kingdom
- Department of Microbiology, Immunology and Veterinary, Public Health, College of Veterinary Medicine and Agriculture, Addis Ababa University, Bishoftu, Ethiopia
- Animal and Human Health Program, International Livestock Research Institute (ILRI), Addis Ababa, Ethiopia
| | - K. Marie McIntyre
- Global Burden of Animal Diseases (GBADs) Programme, University of Liverpool, Liverpool, United Kingdom
- Department of Livestock and One Health, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
- Modelling, Evidence and Policy Group, School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Nebyou Moje
- Department of Biomedical Sciences, College of Veterinary Medicine and Agriculture, Addis Ababa University, Bishoftu, Ethiopia
| | - Theodore Knight-Jones
- Global Burden of Animal Diseases (GBADs) Programme, University of Liverpool, Liverpool, United Kingdom
- Animal and Human Health Program, International Livestock Research Institute (ILRI), Addis Ababa, Ethiopia
| | - Jonathan Rushton
- Global Burden of Animal Diseases (GBADs) Programme, University of Liverpool, Liverpool, United Kingdom
- Department of Livestock and One Health, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Delia Grace
- Global Burden of Animal Diseases (GBADs) Programme, University of Liverpool, Liverpool, United Kingdom
- Food and Markets Department, Natural Resources Institute, University of Greenwich, London, United Kingdom
- Animal and Human Health Program, International Livestock Research Institute (ILRI), Nairobi, Kenya
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Tick Diversity and Distribution of Hard (Ixodidae) Cattle Ticks in South Africa. MICROBIOLOGY RESEARCH 2023. [DOI: 10.3390/microbiolres14010004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Ticks are amongst the important ectoparasites where livestock are concerned, as they adversely affect the animals through bloodsucking. In tropical and subtropical countries, they transmit pathogens such as babesiosis, theileriosis, ehrlichiosis, and anaplasmosis in cattle, causing a reduction in production rate and significant concomitant economic losses. Ticks affect 80% of the cattle population across the world, with an estimated economic loss of USD 20–30 billion per year. In South Africa, economic losses in the livestock industry caused by ticks and tick-borne diseases are estimated to exceed USD 33 million per year (ZAR 500 million). There are seven major genera of ixodid ticks in Southern Africa (i.e., Amblyomma, Dermacentor, Haemaphysalis, Hyalomma, Ixodes and Rhipicephalus). The environment in which a tick lives is made up of all the various biological and abiotic factors that are either necessary or unnecessary for its life. The areas where various ticks have been found have been documented in many publications. Using these data, maps of possible species’ habitats can be made. Historical records on tick distribution may be incorrect due to identification mistakes or a change in the tick’s name. All the sources used to generate the maps for this review were unpublished and came from a wide range of sources. To identify tick species and the accompanying microbial ecosystems, researchers are increasingly adopting tick identification methods including 16S and 18S rDNA gene sequencing. Indeed, little is known about the genetic alterations that give important traits, including the predilection for tick hosts, transmission, and acaricide resistance. Opportunities for exploring these changes in tick populations and subpopulations are provided by advancements in omics technologies. The literature on the variety of ixodid ticks, their direct and indirect effects, and control methods in South Africa is compiled in this review.
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Kopsco HL, Smith RL, Halsey SJ. A Scoping Review of Species Distribution Modeling Methods for Tick Vectors. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.893016] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BackgroundGlobally, tick-borne disease is a pervasive and worsening problem that impacts human and domestic animal health, livelihoods, and numerous economies. Species distribution models are useful tools to help address these issues, but many different modeling approaches and environmental data sources exist.ObjectiveWe conducted a scoping review that examined all available research employing species distribution models to predict occurrence and map tick species to understand the diversity of model strategies, environmental predictors, tick data sources, frequency of climate projects of tick ranges, and types of model validation methods.DesignFollowing the PRISMA-ScR checklist, we searched scientific databases for eligible articles, their references, and explored related publications through a graphical tool (www.connectedpapers.com). Two independent reviewers performed article selection and characterization using a priori criteria.ResultsWe describe data collected from 107 peer-reviewed articles that met our inclusion criteria. The literature reflects that tick species distributions have been modeled predominantly in North America and Europe and have mostly modeled the habitat suitability for Ixodes ricinus (n = 23; 21.5%). A wide range of bioclimatic databases and other environmental correlates were utilized among models, but the WorldClim database and its bioclimatic variables 1–19 appeared in 60 (56%) papers. The most frequently chosen modeling approach was MaxEnt, which also appeared in 60 (56%) of papers. Despite the importance of ensemble modeling to reduce bias, only 23 papers (21.5%) employed more than one algorithm, and just six (5.6%) used an ensemble approach that incorporated at least five different modeling methods for comparison. Area under the curve/receiver operating characteristic was the most frequently reported model validation method, utilized in nearly all (98.9%) included studies. Only 21% of papers used future climate scenarios to predict tick range expansion or contraction. Regardless of the representative concentration pathway, six of seven genera were expected to both expand and retract depending on location, while Ornithodoros was predicted to only expand beyond its current range.ConclusionSpecies distribution modeling techniques are useful and widely employed tools for predicting tick habitat suitability and range movement. However, the vast array of methods, data sources, and validation strategies within the SDM literature support the need for standardized protocols for species distribution and ecological niche modeling for tick vectors.
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Zannou OM, Da Re D, Ouedraogo AS, Biguezoton AS, Abatih E, Yao KP, Farougou S, Lempereur L, Vanwambeke SO, Saegerman C. Modelling habitat suitability of the invasive tick Rhipicephalus microplus in West Africa. Transbound Emerg Dis 2022; 69:2938-2951. [PMID: 34985810 DOI: 10.1111/tbed.14449] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 12/25/2021] [Accepted: 12/31/2021] [Indexed: 11/30/2022]
Abstract
Ticks have medical and economic importance due to their ability to transmit pathogens to humans and animals. In tropical and sub-tropical countries, tick-borne diseases (TBD) are among the most important diseases affecting livestock and humans. The fast spread of ticks and TBD requires a quick development and application of efficient prevention and/or control programs. Therefore, prior investigations on TBD and related vectors epidemiology, for instance, through accurate epidemiological models, are mandatory. This study aims to develop models to forecast suitable habitat for Rhipicephalus microplus distribution in West Africa. Tick occurrences were assembled from 10 different studies carried out in six West African countries in the past decade. Six statistical models (maximum entropy in a single model and generalised linear model, generalised additive model, random forest, boosted regression tree and support vector machine model in an ensemble model) were applied and compared to predict the habitat suitability of R. microplus distribution in West Africa. Each model was evaluated with the area under the receiver operating characteristic curve (AUC), the true skill statistic (TSS) and the Boyce index (BI). The selected models had good performance according to their AUC (above .8), TSS (above .7) and BI (above .8). Temperature played a key role in MaxEnt model, whereas normalised difference vegetation index (NDVI) was the most important variable in the ensemble model. The model predictions showed coastal countries of West Africa as more suitable for R. microplus. However, some Sahelian areas seems also favourable. We stress the importance of vector surveillance and control in countries that have not yet detected R. microplus but are in the areas predicted to host suitable habitat. Indeed, awareness-raising and training of different stakeholders must be reinforced for better prevention and control of this tick in these different countries according to their status.
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Affiliation(s)
- Olivier M Zannou
- Research Unit in Epidemiology and Risk Analysis applied to veterinary sciences (UREAR-ULiège), Fundamental and Applied Research for Animal and Health (FARAH) Center, Department of Infectious and Parasitic Diseases, Faculty of Veterinary Medicine, University of Liège, Liege, Belgium.,Vector-borne Diseases and Biodiversity Unit (UMaVeB), International Research and Development Center on Livestock in Sub-humid Areas (CIRDES), Bobo-Dioulasso, Burkina Faso
| | - Daniele Da Re
- Georges Lemaître Center for Earth and Climate Research, Earth and Life Institute, UCLouvain, Louvain-la-Neuve, Belgium
| | - Achille S Ouedraogo
- Vector-borne Diseases and Biodiversity Unit (UMaVeB), International Research and Development Center on Livestock in Sub-humid Areas (CIRDES), Bobo-Dioulasso, Burkina Faso.,Laboratory of Parasitology and Parasitic Diseases, Fundamental and Applied Research for Animal and Health (FARAH) Center, Faculty of Veterinary Medicine, University of Liège, Liège, Belgium
| | - Abel S Biguezoton
- Vector-borne Diseases and Biodiversity Unit (UMaVeB), International Research and Development Center on Livestock in Sub-humid Areas (CIRDES), Bobo-Dioulasso, Burkina Faso
| | - Emmanuel Abatih
- Department of Applied Mathematics, Computer Sciences and Statistics, Ghent University, Gent, Belgium
| | | | - Souaïbou Farougou
- Communicable Diseases Research Unit (URMaT), Polytechnic School of Abomey-Calavi, University of Abomey-Calavi, Cotonou, Republic of Benin
| | - Laetitia Lempereur
- Laboratory of Parasitology and Parasitic Diseases, Fundamental and Applied Research for Animal and Health (FARAH) Center, Faculty of Veterinary Medicine, University of Liège, Liège, Belgium
| | - Sophie O Vanwambeke
- Georges Lemaître Center for Earth and Climate Research, Earth and Life Institute, UCLouvain, Louvain-la-Neuve, Belgium
| | - Claude Saegerman
- Research Unit in Epidemiology and Risk Analysis applied to veterinary sciences (UREAR-ULiège), Fundamental and Applied Research for Animal and Health (FARAH) Center, Department of Infectious and Parasitic Diseases, Faculty of Veterinary Medicine, University of Liège, Liege, Belgium
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Models for Studying the Distribution of Ticks and Tick-Borne Diseases in Animals: A Systematic Review and a Meta-Analysis with a Focus on Africa. Pathogens 2021; 10:pathogens10070893. [PMID: 34358043 PMCID: PMC8308717 DOI: 10.3390/pathogens10070893] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Revised: 06/30/2021] [Accepted: 07/12/2021] [Indexed: 11/17/2022] Open
Abstract
Ticks and tick-borne diseases (TTBD) are constraints to the development of livestock and induce potential human health problems. The worldwide distribution of ticks is not homogenous. Some places are ecologically suitable for ticks but they are not introduced in these areas yet. The absence or low density of hosts is a factor affecting the dissemination of the parasite. To understand the process of introduction and spread of TTBD in different areas, and forecast their presence, scientists developed different models (e.g., predictive models and explicative models). This study aimed to identify models developed by researchers to analyze the TTBD distribution and to assess the performance of these various models with a meta-analysis. A literature search was implemented with PRISMA protocol in two online databases (Scopus and PubMed). The selected articles were classified according to country, type of models and the objective of the modeling. Sensitivity, specificity and accuracy available data of these models were used to evaluate their performance using a meta-analysis. One hundred studies were identified in which seven tick genera were modeled, with Ixodes the most frequently modeled. Additionally, 13 genera of tick-borne pathogens were also modeled, with Borrelia the most frequently modeled. Twenty-three different models were identified and the most frequently used are the generalized linear model representing 26.67% and the maximum entropy model representing 24.17%. A focus on TTBD modeling in Africa showed that, respectively, genus Rhipicephalus and Theileria parva were the most modeled. A meta-analysis on the quality of 20 models revealed that maximum entropy, linear discriminant analysis, and the ecological niche factor analysis models had, respectively, the highest sensitivity, specificity, and area under the curve effect size among all the selected models. Modeling TTBD is highly relevant for predicting their distribution and preventing their adverse effect on animal and human health and the economy. Related results of such analyses are useful to build prevention and/or control programs by veterinary and public health authorities.
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Ghehsareh Ardestani E, Heidari Ghahfarrokhi Z. Ensembpecies distribution modeling of Salvia hydrangea under future climate change scenarios in Central Zagros Mountains, Iran. Glob Ecol Conserv 2021. [DOI: 10.1016/j.gecco.2021.e01488] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
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Yang X, Gao Z, Wang L, Xiao L, Dong N, Wu H, Li S. Projecting the potential distribution of ticks in China under climate and land use change. Int J Parasitol 2021; 51:749-759. [PMID: 33798559 DOI: 10.1016/j.ijpara.2021.01.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 01/19/2021] [Accepted: 01/20/2021] [Indexed: 12/18/2022]
Abstract
Ticks are known as vectors of several pathogens causing various human and animal diseases including Lyme borreliosis, tick-borne encephalitis, and Crimean-Congo hemorrhagic fever. While China is known to have more than 100 tick species well distributed over the country, our knowledge on the likely distribution of ticks in the future remains very limited, which hinders the prevention and control of the risk of tick-borne diseases. In this study, we selected four representative tick species which have different regional distribution foci in mainland China. i.e., Dermacentor marginatus, Dermacentor silvarum, Haemaphysalis longicornis and Ixodes granulatus. We used the MaxEnt model to identify the key environmental factors of tick occurrence and map their potential distributions in 2050 under four combined climate and socioeconomic scenarios (i.e., SSP1-RCP2.6, SSP2-RCP4.5, SSP3-RCP7.0 and SSP5-RCP8.5). We found that the extent of the urban fabric, cropland and forest, temperature annual range and precipitation of the driest month were the main determinants of the potential distributions of the four tick species. Under the combined scenarios, with climate warming, the potential distributions of ticks shifted to further north in China. Due to a decrease in the extent of forest, the distribution probability of ticks declined in central and southern China. In contrast with previous findings on an estimated amplification of tick distribution probability under the extreme emission scenario (RCP8.5), our studies projected an overall reduction in the distribution probability under RCP8.5, owing to an expected effect of land use. Our results could provide new data to help identify the emerging risk areas, with amplifying suitability for tick occurrence, for the prevention and control of tick-borne zoonoses in mainland China. Future directions are suggested towards improved quantity and quality of the tick occurrence database, comprehensiveness of factors and integration of different modelling approaches, and capability to model pathogen spillover at the human-tick interface.
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Affiliation(s)
- Xin Yang
- College of Environment Science and Engineering, Huazhong University of Science and Technology, Wuhan 430070, China
| | - Zheng Gao
- College of Environment Science and Engineering, Huazhong University of Science and Technology, Wuhan 430070, China
| | - Luqi Wang
- College of Environment Science and Engineering, Huazhong University of Science and Technology, Wuhan 430070, China
| | - Lingjun Xiao
- College of Environment Science and Engineering, Huazhong University of Science and Technology, Wuhan 430070, China
| | - Na Dong
- School of Engineering, Newcastle University, Newcastle upon Tyne NE1 7RU, UK
| | - Hongjuan Wu
- College of Environment Science and Engineering, Huazhong University of Science and Technology, Wuhan 430070, China
| | - Sen Li
- College of Environment Science and Engineering, Huazhong University of Science and Technology, Wuhan 430070, China; UK Centre for Ecology & Hydrology, Wallingford OX10 8BB, UK; Environmental Change Institute, University of Oxford, Oxford OX1 3QY, UK.
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Yang X, Gao Z, Zhou T, Zhang J, Wang L, Xiao L, Wu H, Li S. Mapping the Potential Distribution of Major Tick Species in China. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:E5145. [PMID: 32708816 PMCID: PMC7399889 DOI: 10.3390/ijerph17145145] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 07/03/2020] [Accepted: 07/10/2020] [Indexed: 12/29/2022]
Abstract
Ticks are known as the vectors of various zoonotic diseases such as Lyme borreliosis and tick-borne encephalitis. Though their occurrences are increasingly reported in some parts of China, our understanding of the pattern and determinants of ticks' potential distribution over the country remain limited. In this study, we took advantage of the recently compiled spatial dataset of distribution and diversity of ticks in China, analyzed the environmental determinants of ten frequently reported tick species and mapped the spatial distribution of these species over the country using the MaxEnt model. We found that presence of urban fabric, cropland, and forest in a place are key determents of tick occurrence, suggesting ticks were likely inhabited close to where people live. Besides, precipitation in the driest month was found to have a relatively high contribution in mapping tick distribution. The model projected that theses ticks could be widely distributed in the Northwest, Central North, Northeast, and South China. Our results added new evidence on the potential distribution of a variety of major tick species in China and pinpointed areas with a high potential risk of tick bites and tick-borne diseases for raising public health awareness and prevention responses.
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Affiliation(s)
- Xin Yang
- College of Environment Science and engineering, Huazhong University of Science and Technology, Wuhan 430070, China; (X.Y.); (Z.G.); (L.W.); (L.X.); (H.W.)
| | - Zheng Gao
- College of Environment Science and engineering, Huazhong University of Science and Technology, Wuhan 430070, China; (X.Y.); (Z.G.); (L.W.); (L.X.); (H.W.)
| | - Tianli Zhou
- School of Automation, Wuhan University of Technology, Wuhan 430070, China; (T.Z.); (J.Z.)
| | - Jian Zhang
- School of Automation, Wuhan University of Technology, Wuhan 430070, China; (T.Z.); (J.Z.)
| | - Luqi Wang
- College of Environment Science and engineering, Huazhong University of Science and Technology, Wuhan 430070, China; (X.Y.); (Z.G.); (L.W.); (L.X.); (H.W.)
| | - Lingjun Xiao
- College of Environment Science and engineering, Huazhong University of Science and Technology, Wuhan 430070, China; (X.Y.); (Z.G.); (L.W.); (L.X.); (H.W.)
| | - Hongjuan Wu
- College of Environment Science and engineering, Huazhong University of Science and Technology, Wuhan 430070, China; (X.Y.); (Z.G.); (L.W.); (L.X.); (H.W.)
| | - Sen Li
- College of Environment Science and engineering, Huazhong University of Science and Technology, Wuhan 430070, China; (X.Y.); (Z.G.); (L.W.); (L.X.); (H.W.)
- UK Centre for Ecology & Hydrology, Wallingford OX10 8BB, UK
- Environmental Change Institute, University of Oxford, Oxford OX1 3QY, UK
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Young DJN, Blush TD, Landram M, Wright JW, Latimer AM, Safford HD. Assisted gene flow in the context of large‐scale forest management in California,
USA. Ecosphere 2020. [DOI: 10.1002/ecs2.3001] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Affiliation(s)
- Derek J. N. Young
- Department of Plant Sciences University of California Davis California 95616 USA
| | - Thomas D. Blush
- Pacific Southwest Region USDA Forest Service Vallejo California 94592 USA
| | - Michael Landram
- Pacific Southwest Region USDA Forest Service Vallejo California 94592 USA
| | - Jessica W. Wright
- Pacific Southwest Research Station USDA Forest Service Davis California 95618 USA
| | - Andrew M. Latimer
- Department of Plant Sciences University of California Davis California 95616 USA
| | - Hugh D. Safford
- Pacific Southwest Region USDA Forest Service Vallejo California 94592 USA
- Department of Environmental Science and Policy University of California Davis California95616USA
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A countrywide molecular survey leads to a seminal identification of the invasive cattle tick Rhipicephalus (Boophilus) microplus in Cameroon, a decade after it was reported in Cote d'Ivoire. Ticks Tick Borne Dis 2019; 10:585-593. [PMID: 30765191 PMCID: PMC6446184 DOI: 10.1016/j.ttbdis.2019.02.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Revised: 12/17/2018] [Accepted: 02/04/2019] [Indexed: 12/02/2022]
Abstract
The cattle tick Rhipicephalus microplus is the most important arthropod vector of livestock diseases globally. Since its introduction in West Africa a decade ago, it has been reported in Ivory Coast, Benin, Togo, Mali, Burkina Faso and Nigeria with potentially far-reaching adverse impacts on the livestock sector in the region. Cameroon is located on a major route for transboundary cattle trade between Central and West Africa and it is therefore at risk from R. microplus invasion. This study investigated the occurrence of R. microplus in Cameroon, the genetic polymorphism of the tick and population structure of isolates from different regions of the country to provide data that underpin the design of future vector control programs. A cross-sectional survey was conducted in which ticks were collected from cattle at 54 sites across the five Agroecological zones (AEZs) within Cameroon. Tick identity (sex and species) was assigned using taxonomic keys. Species identity was confirmed through amplification and sequencing of the mitochondrial COI and 16S rRNA genes. A total of 7091 ticks were collected out of which 1112 (15.6%) were morphologically identified as R. microplus. The presence of R. microplus was confirmed in 4 out of 5 agroecological zones. Only two haplotypes were identified by both COI and 16S rRNA genes, indicating a very low divergence in the genetic structure of the R. microplus population in Cameroon. 16S rRNA sequence analysis revealed a new haplotype specific to Cameroon. Phylogenetic trees revealed that all isolates of R. microplus from Cameroon were grouped into the previously described Africa/Americas clade. Application of a niche modelling algorithm to R. microplus distribution in Cameroon predicted that suitable habitat for the tick extended into southern Nigeria. This study demonstrated for the first time the presence of R. microplus in Cameroon. Genetic diversity tests indicate that the tick has not evolved significantly since the initial introduction to West Africa. We suggest further longitudinal studies to better define the spatial and temporal expansion of the range of the tick and the drivers of this spread.
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Abstract
Babesiosis, caused by piroplasmid protozoans in the genus Babesia, is arguably the most important vector-borne disease of livestock and companion animals and is growing in importance as a zoonosis. Ixodid ticks were identified as vectors more than a hundred years ago, but the particular tick species transmitting some significant pathogens are still unknown. Moreover, it is only recently that the complexity of the pathogen-tick relationship has been revealed as a result of studies enabled by gene expression and RNA interference methodology. In this article, we provide details of demonstrated and incriminated vectors, maps of the current knowledge of vector distribution, a summary of established features of the pathogen life cycle in the vector, and an outline of molecular research on pathogen-tick relationships. The article concludes with a discussion of vector ecology and disease epidemiology in a global-change context and with suggestions for future research.
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Affiliation(s)
- Jeremy S Gray
- UCD School of Biology and Environmental Science, University College Dublin, Belfield, Dublin 4, Ireland;
| | | | - Annetta Zintl
- UCD School of Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland;
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Modelling the distribution of Rhipicephalus microplus and R. decoloratus in Zimbabwe. VETERINARY PARASITOLOGY- REGIONAL STUDIES AND REPORTS 2018; 14:41-49. [PMID: 31014735 DOI: 10.1016/j.vprsr.2018.08.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2018] [Revised: 08/26/2018] [Accepted: 08/28/2018] [Indexed: 10/28/2022]
Abstract
Species distribution modelling is a very useful tool in vector management. Ticks are vectors of various pathogens which cause serious problems in livestock production in tropical countries. They have a high dispersal potential which is mainly facilitated by the movement of animals from one area to another. In light of the observed geographic expansion of Rhipicephalus microplus in Zimbabwe, we used species distribution modelling techniques to identify areas which may provide suitable habitats for the occurrence of this invasive tick species as well as the autochthonous Rhipicephalus decoloratus. Our results suggest that, despite the geographic expansion of R. microplus, climate will continue to be a limiting factor for the further expansion of this tick species. We expect its distribution to be restricted to the most favourable areas in the eastern and northern parts. The greater part of Zimbabwe is suitable for R. decoloratus, although in areas where R. microplus occurs, displacement of the former by the latter will be expected to occur. A heterogeneous climate, unregulated movement of cattle and episodic droughts are suggested to be possible factors for the continued existence of R. microplus and R. decoloratus in Zimbabwe and the partial displacement.
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14
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Prevalence, risk factors, and genetic diversity of veterinary important tick-borne pathogens in cattle from Rhipicephalus microplus-invaded and non-invaded areas of Benin. Ticks Tick Borne Dis 2018; 9:450-464. [DOI: 10.1016/j.ttbdis.2017.12.015] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 11/13/2017] [Accepted: 12/21/2017] [Indexed: 01/08/2023]
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15
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Boka OM, Achi L, Adakal H, Azokou A, Yao P, Yapi YG, Kone M, Dagnogo K, Kaboret YY. Review of cattle ticks (Acari, Ixodida) in Ivory Coast and geographic distribution of Rhipicephalus (Boophilus) microplus, an emerging tick in West Africa. EXPERIMENTAL & APPLIED ACAROLOGY 2017; 71:355-369. [PMID: 28497303 DOI: 10.1007/s10493-017-0129-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2016] [Accepted: 04/02/2017] [Indexed: 06/07/2023]
Abstract
The exotic tick Rhipicephalus (Boophilus) microplus was discovered in Ivory Coast in 2007 and then gradually in other countries in West Africa. It is known to induce significant losses in farming and to replace other species of the same genus. In order to contribute to improve health and productivity of cattle in Ivory Coast regarding the emergence of this dreaded tick, a study was conducted to determine the current geographic distribution of the tick R. (B.) microplus and review cattle ticks in general. To this end, 23,460 ticks were collected from 180 farms located throughout the country. Ten species of ticks belonging to the genus Rhipicephalus (including those of the subgenus Boophilus), Hyalomma and Ambyomma were identified. It was found that the exotic tick R. (B.) microplus has invaded the entire Ivorian territory and is now the main cattle tick (63.6% of ticks collected), followed by Amblyomma variegatum that remains still dominant in the North. The population of indigenous species of Rhipicephalus (Boophilus) is in drastic decline.
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Affiliation(s)
- O M Boka
- Centre d'Entomologie Médicale et Vétérinaire (CEMV), Université Alassane Ouattara (UAO), Bouaké, Ivory Coast.
- Projet d'Amélioration de la Santé Animale et de l'Hygiène Publique Vétérinaire (PASA-HPV), Abidjan, Ivory Coast.
| | - L Achi
- Ecole de Spécialisation en Elevage et Métiers de la Viande de Bingerville(ESEMVB), Institut National de la Formation Professionnelle Agricole (INFPA), Abidjan, Ivory Coast
- Centre Suisse de Recherches Scientifiques en Côte d'Ivoire (CSRS), Abidjan, Ivory Coast
| | - H Adakal
- Université de Maradi, Maradi, Niger
| | - A Azokou
- Université Nangui Abrogoua, Abidjan, Ivory Coast
| | - P Yao
- Faculté de Biosciences, Université Félix Houphouët Boigny (UFHB), Abidjan, Ivory Coast
| | - Y G Yapi
- Centre d'Entomologie Médicale et Vétérinaire (CEMV), Université Alassane Ouattara (UAO), Bouaké, Ivory Coast
| | - M Kone
- Université Nangui Abrogoua, Abidjan, Ivory Coast
| | - K Dagnogo
- Projet d'Amélioration de la Santé Animale et de l'Hygiène Publique Vétérinaire (PASA-HPV), Abidjan, Ivory Coast
| | - Y Y Kaboret
- Ecole Inter-états des Sciences et Médecine Vétérinaire (EISMV), Dakar, Senegal
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Xing X, Slabbekoorn H, Campbell J, Li F, Ma J. Distinct song parts of the endemic marsh grassbird of China vary with latitude and climate among migratory and sedentary populations. Evol Ecol 2017. [DOI: 10.1007/s10682-016-9879-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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17
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Sindato C, Stevens KB, Karimuribo ED, Mboera LEG, Paweska JT, Pfeiffer DU. Spatial Heterogeneity of Habitat Suitability for Rift Valley Fever Occurrence in Tanzania: An Ecological Niche Modelling Approach. PLoS Negl Trop Dis 2016; 10:e0005002. [PMID: 27654268 PMCID: PMC5031441 DOI: 10.1371/journal.pntd.0005002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Accepted: 08/24/2016] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Despite the long history of Rift Valley fever (RVF) in Tanzania, extent of its suitable habitat in the country remains unclear. In this study we investigated potential effects of temperature, precipitation, elevation, soil type, livestock density, rainfall pattern, proximity to wild animals, protected areas and forest on the habitat suitability for RVF occurrence in Tanzania. MATERIALS AND METHODS Presence-only records of 193 RVF outbreak locations from 1930 to 2007 together with potential predictor variables were used to model and map the suitable habitats for RVF occurrence using ecological niche modelling. Ground-truthing of the model outputs was conducted by comparing the levels of RVF virus specific antibodies in cattle, sheep and goats sampled from locations in Tanzania that presented different predicted habitat suitability values. PRINCIPAL FINDINGS Habitat suitability values for RVF occurrence were higher in the northern and central-eastern regions of Tanzania than the rest of the regions in the country. Soil type and precipitation of the wettest quarter contributed equally to habitat suitability (32.4% each), followed by livestock density (25.9%) and rainfall pattern (9.3%). Ground-truthing of model outputs revealed that the odds of an animal being seropositive for RVFV when sampled from areas predicted to be most suitable for RVF occurrence were twice the odds of an animal sampled from areas least suitable for RVF occurrence (95% CI: 1.43, 2.76, p < 0.001). CONCLUSION/SIGNIFICANCE The regions in the northern and central-eastern Tanzania were more suitable for RVF occurrence than the rest of the regions in the country. The modelled suitable habitat is characterised by impermeable soils, moderate precipitation in the wettest quarter, high livestock density and a bimodal rainfall pattern. The findings of this study should provide guidance for the design of appropriate RVF surveillance, prevention and control strategies which target areas with these characteristics.
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Affiliation(s)
- Calvin Sindato
- National Institute for Medical Research, Tabora, Tanzania
- Department of Veterinary Medicine and Public Health, Sokoine University of Agriculture, Morogoro, Tanzania
- Southern African Centre for Infectious Disease Surveillance, Morogoro, Tanzania
- * E-mail:
| | - Kim B. Stevens
- Veterinary Epidemiology, Economics & Public Health Group, Department of Production & Population Health, Royal Veterinary College, London, United Kingdom
| | - Esron D. Karimuribo
- Department of Veterinary Medicine and Public Health, Sokoine University of Agriculture, Morogoro, Tanzania
- Southern African Centre for Infectious Disease Surveillance, Morogoro, Tanzania
| | | | - Janusz T. Paweska
- Center for Emerging and Zoonotic Diseases, National Institute for Communicable Diseases, of the National Health Laboratory Service, Sandringham, South Africa
- School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Dirk U. Pfeiffer
- Veterinary Epidemiology, Economics & Public Health Group, Department of Production & Population Health, Royal Veterinary College, London, United Kingdom
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Walter M, Brugger K, Rubel F. The ecological niche of Dermacentor marginatus in Germany. Parasitol Res 2016; 115:2165-74. [PMID: 26993325 PMCID: PMC4863919 DOI: 10.1007/s00436-016-4958-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Accepted: 02/12/2016] [Indexed: 11/28/2022]
Abstract
The ixodid tick Dermacentor marginatus (Sulzer, 1776) is endemic throughout southern Europe in the range of 33-51 (°) N latitude. In Germany, however, D. marginatus was exclusively reported in the Rhine valley and adjacent areas. Its northern distribution limit near Giessen is located at the coordinates 8.32 (°) E/50.65 (°) N. Particularly with regard to the causative agents of rickettsioses, tularemia, and Q fever, the observed locations as well as the potential distribution of the vector D. marginatus in Germany are of special interest. Applying a dataset of 118 georeferenced tick locations, the ecological niche for D. marginatus was calculated. It is described by six climate parameters based on temperature and relative humidity and another six environmental parameters including land cover classes and altitude. The final ecological niche is determined by the frequency distributions of these 12 parameters at the tick locations. Main parameters are the mean annual temperature (frequency distribution characterized by the minimum, median, and maximum of 6.1, 9.9, and 12.2 (°)C), the mean annual relative humidity (73.7, 76.7, and 80.9 %), as well as the altitude (87, 240, 1108 m). The climate and environmental niche is used to estimate the habitat suitability of D. marginatus in Germany by applying the BIOCLIM model. Finally, the potential spatial distribution of D. marginatus was calculated and mapped by determining an optimal threshold value of the suitability index, i.e., the maximum of sensitivity and specificity (Youden index). The model performance is expressed by AUC = 0.91.
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Affiliation(s)
- Melanie Walter
- Institute for Veterinary Public Health, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210, Vienna, Austria
| | - Katharina Brugger
- Institute for Veterinary Public Health, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210, Vienna, Austria
| | - Franz Rubel
- Institute for Veterinary Public Health, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210, Vienna, Austria.
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Marcantonio M, Metz M, Baldacchino F, Arnoldi D, Montarsi F, Capelli G, Carlin S, Neteler M, Rizzoli A. First assessment of potential distribution and dispersal capacity of the emerging invasive mosquito Aedes koreicus in Northeast Italy. Parasit Vectors 2016; 9:63. [PMID: 26842546 PMCID: PMC4739402 DOI: 10.1186/s13071-016-1340-9] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Accepted: 01/26/2016] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Invasive alien species represent a growing threat for natural systems, economy and human health. Active surveillance and responses that readily suppress newly established colonies are effective actions to mitigate the noxious consequences of biological invasions. However, when an exotic species establishes a viable population in a new area, predicting its potential spread is the most effective way to implement adequate control actions. Emerging invasive species, despite monitoring efforts, are poorly known in terms of behaviour and capacity to adapt to the new invaded range. Therefore, tools that provide information on their spread by maximising the available data, are critical. METHODS We apply three different approaches to model the potential distribution of an emerging invasive mosquito, Aedes koreicus, in Northeast Italy: 1) an automatic statistical approach based on information theory, 2) a statistical approach integrated with prior knowledge, and 3) a GIS physiology-based approach. Each approach possessed benefits and limitations, and the required ecological information increases on a scale from 1 to 3. We validated the model outputs using the only other known invaded area in Europe. Finally, we applied a road network analysis to the suitability surface with the highest prediction power to highlight those areas with the highest likelihood of invasion. RESULTS The GIS physiological-based model had the highest prediction power. It showed that localities currently occupied by Aedes koreicus represent only a small fraction of the potentially suitable area. Furthermore, the modelled niche included areas as high as 1500 m a.s.l., only partially overlapping with Aedes albopictus distribution. CONCLUSIONS The simulated spread indicated that all of the suitable portion of the study area is at risk of invasion in a relatively short period of time if no control policies are implemented. Stochastic events may further boost the invasion process, whereas competition with Aedes albopictus may limit it. According to our analysis, some of the major cities in the study area may have already been invaded. Further monitoring is needed to confirm this finding. The developed models and maps represent valuable tools to inform policies aimed at eradicating or mitigating Aedes koreicus invasion in Northeast Italy and Central Europe.
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Affiliation(s)
- Matteo Marcantonio
- Department of Biodiversity and Molecular Ecology, Research and Innovation Centre, Fondazione Edmund Mach, Via E. Mach 1, 38010, S. Michele all'Adige, Italy.
| | - Markus Metz
- Department of Biodiversity and Molecular Ecology, Research and Innovation Centre, Fondazione Edmund Mach, Via E. Mach 1, 38010, S. Michele all'Adige, Italy.
| | - Frédéric Baldacchino
- Department of Biodiversity and Molecular Ecology, Research and Innovation Centre, Fondazione Edmund Mach, Via E. Mach 1, 38010, S. Michele all'Adige, Italy.
| | - Daniele Arnoldi
- Department of Biodiversity and Molecular Ecology, Research and Innovation Centre, Fondazione Edmund Mach, Via E. Mach 1, 38010, S. Michele all'Adige, Italy.
| | - Fabrizio Montarsi
- Istituto Zooprofilattico Sperimentale delle Venezie, Viale dell'Università, 10, 35020, Legnaro, Padova, Italy.
| | - Gioia Capelli
- Istituto Zooprofilattico Sperimentale delle Venezie, Viale dell'Università, 10, 35020, Legnaro, Padova, Italy.
| | - Sara Carlin
- Istituto Zooprofilattico Sperimentale delle Venezie, Viale dell'Università, 10, 35020, Legnaro, Padova, Italy.
| | - Markus Neteler
- Department of Biodiversity and Molecular Ecology, Research and Innovation Centre, Fondazione Edmund Mach, Via E. Mach 1, 38010, S. Michele all'Adige, Italy.
| | - Annapaola Rizzoli
- Department of Biodiversity and Molecular Ecology, Research and Innovation Centre, Fondazione Edmund Mach, Via E. Mach 1, 38010, S. Michele all'Adige, Italy.
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The Necessity of Mobile Phone Technologies for Public Health Surveillance in Benin. ADVANCES IN PUBLIC HEALTH 2016. [DOI: 10.1155/2016/5692480] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
A cross-sectional study was conducted in March 2016 to assess the need of mobile phone technologies for health surveillance and interventions in Benin. Questionnaires were administered to 130 individuals comprising 25 medical professionals, 33 veterinarians, and 72 respondents from the public. All respondents possess cell phones and 75%, 84%, and 100% of the public, medical professionals, and veterinarians, respectively, generally use them for medical purposes. 75% of respondents including 68% of medics, 84.8% of veterinarians, and 72.2% of the public acknowledged that the current surveillance systems are ineffective and do not capture and share real-time information. More than 92% of the all respondents confirmed that mobile phones have the potential to improve health surveillance in the country. All respondents reported adhering to a nascent project of mobile phone-based health surveillance and confirmed that there is no existing similar approach in the country. The most preferred methods by all respondents for effective implementation of such platform are phone calls (96.92%) followed by SMS (49.23%) and smart phone digital forms (41.53%). This study revealed urgent needs of mobile phone technologies for health surveillance and interventions in Benin for real-time surveillance and efficient disease prevention.
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Cianci D, Hartemink N, Ibáñez-Justicia A. Modelling the potential spatial distribution of mosquito species using three different techniques. Int J Health Geogr 2015; 14:10. [PMID: 25888755 PMCID: PMC4349312 DOI: 10.1186/s12942-015-0001-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 01/31/2015] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Models for the spatial distribution of vector species are important tools in the assessment of the risk of establishment and subsequent spread of vector-borne diseases. The aims of this study are to define the environmental conditions suitable for several mosquito species through species distribution modelling techniques, and to compare the results produced with the different techniques. METHODS Three different modelling techniques, i.e., non-linear discriminant analysis, random forest and generalised linear model, were used to investigate the environmental suitability in the Netherlands for three indigenous mosquito species (Culiseta annulata, Anopheles claviger and Ochlerotatus punctor). Results obtained with the three statistical models were compared with regard to: (i) environmental suitability maps, (ii) environmental variables associated with occurrence, (iii) model evaluation. RESULTS The models indicated that precipitation, temperature and population density were associated with the occurrence of Cs. annulata and An. claviger, whereas land surface temperature and vegetation indices were associated with the presence of Oc. punctor. The maps produced with the three different modelling techniques showed consistent spatial patterns for each species, but differences in the ranges of the predictions. Non-linear discriminant analysis had lower predictions than other methods. The model with the best classification skills for all the species was the random forest model, with specificity values ranging from 0.89 to 0.91, and sensitivity values ranging from 0.64 to 0.95. CONCLUSIONS We mapped the environmental suitability for three mosquito species with three different modelling techniques. For each species, the maps showed consistent spatial patterns, but the level of predicted environmental suitability differed; NLDA gave lower predicted probabilities of presence than the other two methods. The variables selected as important in the models were in agreement with the existing knowledge about these species. All model predictions had a satisfactory to excellent accuracy; best accuracy was obtained with random forest. The insights obtained can be used to gain more knowledge on vector and non-vector mosquito species. The output of this type of distribution modelling methods can, for example, be used as input for epidemiological models of vector-borne diseases.
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Affiliation(s)
- Daniela Cianci
- Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.
| | - Nienke Hartemink
- Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.
| | - Adolfo Ibáñez-Justicia
- Centre for Monitoring of Vectors, Food and Consumer Product Safety Authority, Wageningen, The Netherlands.
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