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Dlamini W, Nunu WN, Ndlovu V, Nleya N, Mudonhi N, Sibula M. Molecular detection of Imbrasia belina proteins associated with allergic reactions on harvesters and consumers from selected districts in Matabeleland: a comparative study. Mol Biol Rep 2023; 50:8025-8034. [PMID: 37540454 DOI: 10.1007/s11033-023-08678-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 07/13/2023] [Indexed: 08/05/2023]
Abstract
BACKGROUND Harvesting and consuming insects (entomophagy), particularly Imbrasia belina is widespread in developing countries like Zimbabwe. Due to their extraordinary nutritional content, tastiness, ease of processing and storage, Imbrasia belina has become a delicacy, reachable nutritious complement, and money source for some people in Zimbabwean communities. However, some harvesters and consumers have become allergic to the Imbrasia belina, popularly known as Mopani worms. This has been attributed or associated with the changes in the genetic structure of Imbrasia belina. Therefore, this research sought to compare the presence of the genes associated with allergic reactions to mopane worms from Gwanda and Umguza districts in Zimbabwe. METHODS A lab-based observational study was conducted on collected Imbrasia belina samples from both districts. Fifteen samples of mopane worms were collected from each district, and DNA extraction was performed using DNeasy blood and tissue kit. The DNA extraction products were then amplified using a Polymerase chain reaction. The polymerase chain reaction products were run on agarose gel electrophoresis to determine the presence of the target genes. RESULTS Three of the five samples from Gwanda district were positive for the tropomyosin gene, whereas two samples from Umguza district were positive. All the samples from the two districts were negative for arginine kinase genes. CONCLUSION The study results highlighted that allergic reactions to Imbrasia belina reported in Gwanda district are associated with the presence of the tropomyosin gene, which has undergone polymorphism. Responsible authorities such as Gwanda local authority should develop bylaws that govern Imbrasia belina harvesting in the district.
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Affiliation(s)
- Witness Dlamini
- Department of Environmental Science, Faculty of Environmental Science, National University of Science and Technology, Bulawayo, Zimbabwe
| | - Wilfred Njabulo Nunu
- Office of the Executive Dean, Faculty of Environmental Science, National University of Science and Technology, Corner Gwanda Road and Cecil Avenue Ascot, P O Box AC 939, Bulawayo, Zimbabwe.
| | - Vuyelwa Ndlovu
- Department of Environmental Health, Faculty of Environmental Science, National University of Science and Technology, Bulawayo, Zimbabwe
| | - Nancy Nleya
- Department of Applied Biology and Biochemistry, Faculty of Applied Science, National University of Science and Technology, Bulawayo, Zimbabwe
| | - Nicholas Mudonhi
- Department of Environmental Health, Faculty of Environmental Science, National University of Science and Technology, Bulawayo, Zimbabwe
| | - Madeline Sibula
- Department of Applied Biology and Biochemistry, Faculty of Applied Science, National University of Science and Technology, Bulawayo, Zimbabwe
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Olagunju EA. Is the presence of mosquitoes an indicator of poor environmental sanitation? JOURNAL OF WATER AND HEALTH 2023; 21:385-401. [PMID: 37338318 PMCID: wh_2023_280 DOI: 10.2166/wh.2023.280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/21/2023]
Abstract
The World Health Organization has designated mosquitoes as the most lethal animal since they are known to spread pathogen-transmitting organisms. Understanding the many environmental elements that contribute to the spread of these vectors is one of the many strategies used to stop them. If there are mosquitoes around people, it may indicate that there is not an appropriate environmental sanitation program in place in the community or region. Environmental sanitation involves improving any elements of the physical environment that could have a negative impact on a person's survival, health, or physical environment. Keywords containing 'Aedes,' 'Culex,' 'Anopheles,' 'dengue,' 'malaria,' 'yellow fever,' 'Zika,' 'West Nile,' 'chikungunya,' 'resident,' 'environment,' 'sanitation,' 'mosquito control,' and 'breeding sites' of published articles on PubMed, Google Scholar, and ResearchGate were reviewed. It was discovered that the general population should be involved in mosquito and mosquito-borne disease control. Collaboration between health professionals and the general population is essential. The purpose of this paper is to increase public awareness of environmental health issues related to diseases carried by mosquitoes.
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Affiliation(s)
- Emmanuel Ajibola Olagunju
- Department of Crop and Environmental Protection, Faculty of Agricultural Sciences, Ladoke Akintola University of Technology, Ogbomoso, Nigeria E-mail:
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Graboyes M, Meta J, Clarke R. Mazingira and the malady of malaria: Perceptions of malaria as an environmental disease in contemporary Zanzibar. STUDIES IN HISTORY AND PHILOSOPHY OF SCIENCE 2022; 95:134-144. [PMID: 36027656 DOI: 10.1016/j.shpsa.2022.07.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2021] [Revised: 02/25/2022] [Accepted: 07/28/2022] [Indexed: 06/15/2023]
Abstract
This paper addresses how contemporary Zanzibaris perceive the relationship between the mazingira (roughly translated as "environment") and the malady of malaria. More broadly, this article presents data exploring Zanzibari conceptions of the mazingira, the relationship between the mazingira and malaria, and who Zanzibaris believe are responsible for acting on, or for, the mazingira in regards to malaria. We use the biomedical disease malaria-and the local syncretic understanding of it, which we recognize by referring to it as the "malady of malaria"-as a lens to investigate Zanzibari conceptions of the mazingira. We highlight the need to integrate local forms of knowledge, which we refer to as vernacular knowledge. 50 interviews show that Zanzibaris believe the mazingira can be modified in positive ways to cleaner, safer spaces that will also reduce malaria levels. People expressed widespread agreement that there is a clear relationship between the mazingira and the malady of malaria, though they differed in what exactly the relationship was.
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Ankrah DA, Kwapong NA, Boateng SD. Indigenous knowledge and science-based predictors reliability and its implication for climate adaptation in Ghana. AFRICAN JOURNAL OF SCIENCE, TECHNOLOGY, INNOVATION AND DEVELOPMENT 2021. [DOI: 10.1080/20421338.2021.1923394] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Daniel Adu Ankrah
- Department of Agricultural Extension, College of Basic and Applied Sciences (CBAS), School of Agriculture, University of Ghana, Ghana
| | - Nana Afranaa Kwapong
- Department of Agricultural Extension, College of Basic and Applied Sciences (CBAS), School of Agriculture, University of Ghana, Ghana
| | - Seth Dankyi Boateng
- Department of Agricultural Extension, College of Basic and Applied Sciences (CBAS), School of Agriculture, University of Ghana, Ghana
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Climate and climate-sensitive diseases in semi-arid regions: a systematic review. Int J Public Health 2020; 65:1749-1761. [PMID: 32876770 DOI: 10.1007/s00038-020-01464-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 08/04/2020] [Accepted: 08/18/2020] [Indexed: 12/19/2022] Open
Abstract
OBJECTIVES We aim to describe the relationships between climate variables and climate-sensitive diseases (CSDs) in semi-arid regions, highlighting the different main groups of CSDs and their climate patterns. METHODS This systematic review considered Medline, Science Direct, Scopus and Web of Science. The data collection period was August and September 2019 and included studies published between 2008 and 2019. This study followed a protocol based on the PRISMA statement. Data analysis was done in a qualitative way. RESULTS The most of works were from Africa, Asia and Iran (71%), where temperature was the main climatic variable. Although the studies provide climatic conditions that are more favorable for the incidence of vector-borne and respiratory diseases, the influence of seasonal patterns on the onset, development and end of CSDs is still poorly understood, especially for gastrointestinal disorders. Moreover, little is known about the impact of droughts on CSDs. CONCLUSIONS This review summarized the state of art of the relationship between climate and CSDs in semi-arid regions. Moreover, a research agenda was provided, which is fundamental for health policy development, priority setting and public health management.
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Nunu WN, Makhado L, Mabunda JT, Lebese RT. Strategies to facilitate safe sexual practices in adolescents through integrated health systems in selected districts of Zimbabwe: a mixed method study protocol. Reprod Health 2020; 17:20. [PMID: 32005263 PMCID: PMC6995095 DOI: 10.1186/s12978-020-0862-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Accepted: 01/14/2020] [Indexed: 01/08/2023] Open
Abstract
Background Zimbabwe has the highest teenage pregnancy rate in Sub Saharan Africa. Human Immunodeficiency Virus (HIV) and Acquired Immunodeficiency Syndrome (AIDS) prevalence in adolescents that are from tribes that perform cultural initiations and subscribe to certain norms are higher than the national prevalence which is estimated at 12% (18 and 13.6% respectively) in Zimbabwe. Indigenous Health Systems (IHSs) and Modern Health Systems (MHSs) in Zimbabwe run parallel thereby introducing challenges in the management of adolescent sexual health due to conflicts. This study seeks to develop strategies that will facilitate the integration of IHSs and MHS in Mberengwa and Umguza districts. Methods This research will be conducted in two phases. The first phase would utilise a concurrent triangulation mixed methods design with both qualitative and quantitative approaches. The findings from the qualitative and quantitative approaches would be merged through a comparison of findings side by side. The second phase would focus on the development and validation of strategies that would facilitate the integration of IHSs and MHSs. The Strength, Weakness, Opportunity and Threat (SWOT) analysis would be applied on interfaced findings from phase one. The Basic Logic and the Build, Overcome, Explore and Minimise (BOEM) models would then be used to develop strategies based on the SWOT findings. The developed strategies would be validated through the application of Delphi technique and administration of checklist to selected key stakeholders through organised workshops. Discussion There have been no known studies found in the literature that explores the possibility and developed strategies of integrating IHSs and MHSs so as to promote safe sexual practices in adolescents. Most programs on sexual health have ignored the role of IHSs and MHSs in influencing safe sexual practices leading to them failing to attain desired goals. A lot of emphases has been targeted at minimising the spread of Sexually Transmitted Infections (STIs) through advocating for utilisation MHSs rather than focussing on an integrating systems that are meant to manage Adolescent Sexual Health (ASH) related issues. The study protocol was approved by the University of Venda Ethics Committee Registration (SHS/19/PH/17/2608) on the 26th of August 2019.
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Affiliation(s)
- Wilfred Njabulo Nunu
- Department of Public Health, School of Health Sciences, University of Venda, Thohoyandou, South Africa. .,Department of Environmental Science and Health, Faculty of Applied Sciences, National University of Science and Technology, Bulawayo, Zimbabwe.
| | - Lufuno Makhado
- Department of Public Health, School of Health Sciences, University of Venda, Thohoyandou, South Africa
| | - Jabu Tsakani Mabunda
- Department of Public Health, School of Health Sciences, University of Venda, Thohoyandou, South Africa
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Nutritional factors associated with distribution of Mopani Worms in Mopani woodlands in Tsholotsho and Gwanda Districts, Zimbabwe: A comparative survey. Sci Rep 2019; 9:17320. [PMID: 31754197 PMCID: PMC6872812 DOI: 10.1038/s41598-019-53923-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Accepted: 11/06/2019] [Indexed: 11/23/2022] Open
Abstract
Mopani worms are abundant in Gwanda and sporadic in Tsholotsho though the two areas have similar climatic conditions. The study sought to determine nutritional factors that could be associated with distribution of Mopani worms in these two districts. Ten sampling points in undisturbed Mopani woodlands were established in each district. Samples were collected and analysed in the lab to determine the levels of crude protein, tannin and natural detergent fibres levels in leaves and pH, Nitrates, Phosphates and Potassium levels in soil and Welch’s test, Wilcoxon-Mann-Whitney, Analysis of Variance and the Bonferroni Confidence Intervals were employed to test for significance in the observed differences. Findings showed differences in tree size and leaf length whilst the differences of all other variables (non-extractible tannis, extractible tannis crude protein levels and natural detergent fibres) relating to leaf sample analysis were not statistically significant. Findings on soil sample analysis pointed out that Gwanda had higher pH, Phosphorus and Potassium levels whilst Nitrates were significantly higher in Tsholotsho. Differences in the tree sizes and leaf sizes of the samples from the two sites show that there could be host selection based on these variables.
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Wilcox BA, Echaubard P, de Garine-Wichatitsky M, Ramirez B. Vector-borne disease and climate change adaptation in African dryland social-ecological systems. Infect Dis Poverty 2019; 8:36. [PMID: 31130141 PMCID: PMC6535848 DOI: 10.1186/s40249-019-0539-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Accepted: 04/05/2019] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND Drylands, which are among the biosphere's most naturally limiting and environmentally variable ecosystems, constitute three-quarters of the African continent. As a result, environmental sustainability and human development along with vector-borne disease (VBD) control historically have been especially challenging in Africa, particularly in the sub-Saharan and Sahelian drylands. Here, the VBD burden, food insecurity, environmental degradation, and social vulnerability are particularly severe. Changing climate can exacerbate the legion of environmental health threats in Africa, the social dimensions of which are now part of the international development agenda. Accordingly, the need to better understand the dynamics and complex coupling of populations and environments as exemplified by drylands is increasingly recognized as critical to the design of more sustainable interventions. MAIN BODY This scoping review examines the challenge of vector-borne disease control in drylands with a focus on Africa, and the dramatic, ongoing environmental and social changes taking place. Dryland societies persisted and even flourished in the past despite changing climates, extreme and unpredictable weather, and marginal conditions for agriculture. Yet intrusive forces largely out of the control of traditional dryland societies, along with the negative impacts of globalization, have contributed to the erosion of dryland's cultural and natural resources. This has led to the loss of resilience underlying the adaptive capacity formerly widely exhibited among dryland societies. A growing body of evidence from studies of environmental and natural resource management demonstrates how, in light of dryland system's inherent complexity, these factors and top-down interventions can impede sustainable development and vector-borne disease control. Strengthening adaptive capacity through community-based, participatory methods that build on local knowledge and are tailored to local ecological conditions, hold the best promise of reversing current trends. CONCLUSIONS A significant opportunity exists to simultaneously address the increasing threat of vector-borne diseases and climate change through methods aimed at strengthening adaptive capacity. The integrative framework and methods based on social-ecological systems and resilience theory offers a novel set of tools that allow multiple threats and sources of vulnerability to be addressed in combination. Integration of recent advances in vector borne disease ecology and wider deployment of these tools could help reverse the negative social and environmental trends currently seen in African drylands.
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Affiliation(s)
- Bruce A. Wilcox
- ASEAN Institute for Health Development, Mahidol University, 999 Salaya Phuttamonthon, Nakon Pathom, 73170 Thailand
| | - Pierre Echaubard
- ASEAN Institute for Health Development, Mahidol University, 999 Salaya Phuttamonthon, Nakon Pathom, 73170 Thailand
| | - Michel de Garine-Wichatitsky
- ASTRE, Université de Montpellier, CIRA, INRA, F-34398 Montpellier, France
- Faculty of Veterinary Sciences, Kasetsart University, Bangkok, Thailand
| | - Bernadette Ramirez
- Special Programme for Research and Training in Tropical Diseases, World Health Organization, Geneva, Switzerland
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Musesengwa R, Chimbari MJ, Mukaratirwa S. A Framework for Community and Stakeholder Engagement: Experiences From a Multicenter Study in Southern Africa. J Empir Res Hum Res Ethics 2018; 13:323-332. [PMID: 29701110 DOI: 10.1177/1556264618769002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Community and stakeholder engagement (CSE) are central to conducting multicenter health research. Multicenter studies are, however, considerably more complex because they involve a geographically diverse pool of participants and researchers, making uniform application of CSE strategies difficult. This article describes a framework to achieve CSE based on the experiences of a conducting a multicenter study in Southern Africa. The CSE framework is divided into three phases: before research commences, during, and after the study. This CSE framework offers a practical step-by-step guide on the operational aspects of CSE in a multicenter study. The framework shows the importance of consistent monitoring and evaluation during implantation of CSE.
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Mbereko A, Chimbari MJ, Mukaratirwa S. The political ecology of stakeholder-driven climate change adaptation: Case study from Ntalale ward, Gwanda district, in Zimbabwe. JAMBA (POTCHEFSTROOM, SOUTH AFRICA) 2018; 10:419. [PMID: 29955255 PMCID: PMC6013978 DOI: 10.4102/jamba.v10i1.419] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Accepted: 07/17/2017] [Indexed: 06/08/2023]
Abstract
Vulnerable rural communities face climate change-related shifts in rainfall patterns, particularly droughts and floods. The study investigated how Ntalale ward households in Gwanda district of Zimbabwe interpret climate change and adapt to its stressors in the context of the Zimbabwean political economy. Focus group discussions and interviews collected qualitative data. The community has experienced the following climate change-related risks: droughts, floods, heatwave and intra-seasonal rainfall variability. Droughts were reported to be occurring more frequent in the past 25 years as compared to the period before 1991. Ntalale area experienced floods in the 2002-2003 rainy season only. Respondents generally perceived that the rainy season had changed in the past 5 years, with the season now beginning in December and ending in March. The households have resorted to shifting cultivation practices, replanting, use of wetlands in preference to upland fields, changing of seed varieties or crops, selling of livestock and informal trading as coping strategies. Although non-governmental organisations have assisted the community to set up irrigation schemes, a few selected community members have benefited from the initiative. The Ntalale community has experienced four climate change-related risks and institutions have assisted the community. It is recommended that cooperation between households and institutions is key in developing stakeholder-driven adaptation strategies.
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Affiliation(s)
- Alexio Mbereko
- College of Health Sciences, University of KwaZulu-Natal, South Africa
| | - Moses J. Chimbari
- College of Health Sciences, University of KwaZulu-Natal, South Africa
| | - Samson Mukaratirwa
- School of Life Sciences, University of KwaZulu-Natal, Westville Campus, South Africa
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Musesengwa R, Chimbari MJ. Experiences of community members and researchers on community engagement in an Ecohealth project in South Africa and Zimbabwe. BMC Med Ethics 2017; 18:76. [PMID: 29237440 PMCID: PMC5729516 DOI: 10.1186/s12910-017-0236-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Accepted: 11/30/2017] [Indexed: 11/17/2022] Open
Abstract
Background Community engagement (CE) models have provided much needed guidance for researchers to conceptualise and design engagement strategies for research projects. Most of the published strategies, however, still show very limited contribution of the community to the engagement process. One way of achieving this is to document experiences of community members in the CE processes during project implementation. The aim of our study was to explore the experiences of two research naïve communities, regarding a CE strategy collaboratively developed by researchers and study communities in a multicountry study. Methods The study was carried out in two research naïve communities; Gwanda, Zimbabwe and uMkhanyakude, South Africa. The multicentre study was a community based participatory ecohealth multicentre study. A qualitative case study approach was used to explore the CE strategy. Data was collected through Focus Group Discussions, Key Informant Interviews and Direct Observations. Data presented in this paper was collected at three stages of the community engagement process; soon after community entry, soon after sensitisation and during study implementation. Data was analysed through thematic analysis. Results The communities generally had positive experiences of the CE process. They felt that the continuous solicitation of their advice and preferences enabled them to significantly contribute to shaping the engagement process. Communities also perceived the CE process as having been flexible, and that the researchers had presented an open forum for sharing responsibilities in all decision making processes of the engagement process. Conclusions This study has demonstrated that research naïve communities can significantly contribute to research processes if they are adequately engaged. The study also showed that if researchers put in maximum effort to demystify the research process, communities become empowered and participate as partners in research.
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Affiliation(s)
- Rosemary Musesengwa
- College of Health Sciences, University of KwaZulu Natal, 1st Floor George Campbell Building, King George V Ave, Durban, 4041, South Africa.
| | - Moses J Chimbari
- College of Health Sciences, University of KwaZulu Natal, 1st Floor George Campbell Building, King George V Ave, Durban, 4041, South Africa
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Ramirez B. Support for research towards understanding the population health vulnerabilities to vector-borne diseases: increasing resilience under climate change conditions in Africa. Infect Dis Poverty 2017; 6:164. [PMID: 29228976 PMCID: PMC5725740 DOI: 10.1186/s40249-017-0378-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Accepted: 11/23/2017] [Indexed: 11/10/2022] Open
Abstract
Background Diseases transmitted to humans by vectors account for 17% of all infectious diseases and remain significant public health problems. Through the years, great strides have been taken towards combatting vector-borne diseases (VBDs), most notably through large scale and coordinated control programmes, which have contributed to the decline of the global mortality attributed to VBDs. However, with environmental changes, including climate change, the impact on VBDs is anticipated to be significant, in terms of VBD-related hazards, vulnerabilities and exposure. While there is growing awareness on the vulnerability of the African continent to VBDs in the context of climate change, there is still a paucity of research being undertaken in this area, and impeding the formulation of evidence-based health policy change. Main body One way in which the gap in knowledge and evidence can be filled is for donor institutions to support research in this area. The collaboration between the WHO Special Programme for Research and Training in Tropical Diseases (TDR) and the International Centre for Research and Development (IDRC) builds on more than 10 years of partnership in research capacity-building in the field of tropical diseases. From this partnership was born yet another research initiative on VBDs and the impact of climate change in the Sahel and sub-Saharan Africa. This paper lists the projects supported under this research initiative and provides a brief on some of the policy and good practice recommendations emerging from the ongoing implementation of the research projects. Conclusion Data generated from the research initiative are expected to be uptaken by stakeholders (including communities, policy makers, public health practitioners and other relevant partners) to contribute to a better understanding of the impacts of social, environmental and climate change on VBDs(i.e. the nature of the hazard, vulnerabilities, exposure), and improve the ability of African countries to adapt to and reduce the effects of these changes in ways that benefit their most vulnerable populations. Electronic supplementary material The online version of this article (10.1186/s40249-017-0378-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Bernadette Ramirez
- Vectors, Environment and Society Unit, Special Programme for Research and Training in Tropical Diseases (TDR), World Health Organization (WHO), Geneva, Switzerland.
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Manyangadze T, Chimbari MJ, Macherera M, Mukaratirwa S. Micro-spatial distribution of malaria cases and control strategies at ward level in Gwanda district, Matabeleland South, Zimbabwe. Malar J 2017; 16:476. [PMID: 29162102 PMCID: PMC5697109 DOI: 10.1186/s12936-017-2116-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2017] [Accepted: 11/11/2017] [Indexed: 01/07/2023] Open
Abstract
Background Although there has been a decline in the number of malaria cases in Zimbabwe since 2010, the disease remains the biggest public health threat in the country. Gwanda district, located in Matabeleland South Province of Zimbabwe has progressed to the malaria pre-elimination phase. The aim of this study was to determine the spatial distribution of malaria incidence at ward level for improving the planning and implementation of malaria elimination in the district. Methods The Poisson purely spatial model was used to detect malaria clusters and their properties, including relative risk and significance levels at ward level. The geographically weighted Poisson regression (GWPR) model was used to explore the potential role and significance of environmental variables [rainfall, minimum and maximum temperature, altitude, Enhanced Vegetation Index (EVI), Normalized Difference Vegetation Index (NDVI), Normalized Difference Water Index (NDWI), rural/urban] and malaria control strategies [indoor residual spraying (IRS) and long-lasting insecticide-treated nets (LLINs)] on the spatial patterns of malaria incidence at ward level. Results Two significant clusters (p < 0.05) of malaria cases were identified: (1) ward 24 south of Gwanda district and (2) ward 9 in the urban municipality, with relative risks of 5.583 and 4.316, respectively. The semiparametric-GWPR model with both local and global variables had higher performance based on AICc (70.882) compared to global regression (74.390) and GWPR which assumed that all variables varied locally (73.364). The semiparametric-GWPR captured the spatially non-stationary relationship between malaria cases and minimum temperature, NDVI, NDWI, and altitude at the ward level. The influence of LLINs, IRS and rural or urban did not vary and remained in the model as global terms. NDWI (positive coefficients) and NDVI (range from negative to positive coefficients) showed significant association with malaria cases in some of the wards. The IRS had a protection effect on malaria incidence as expected. Conclusions Malaria incidence is heterogeneous even in low-transmission zones including those in pre-elimination phase. The relationship between malaria cases and NDWI, NDVI, altitude, and minimum temperature may vary at local level. The results of this study can be used in planning and implementation of malaria control strategies at district and ward levels.
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Affiliation(s)
- Tawanda Manyangadze
- Department of Public Health Medicine, School of Nursing and Public Health, University of KwaZulu-Natal, Durban, South Africa. .,Geography Department, Faculty of Science, Bindura University of Science Education, Bag 1020, Bindura, Zimbabwe.
| | - Moses J Chimbari
- Department of Public Health Medicine, School of Nursing and Public Health, University of KwaZulu-Natal, Durban, South Africa
| | - Margaret Macherera
- Department of Public Health Medicine, School of Nursing and Public Health, University of KwaZulu-Natal, Durban, South Africa.,Department of Environmental Science and Health, Faculty of Applied Sciences, National University of Science and Technology, Ascot, P O Box AC 939, Bulawayo, Zimbabwe
| | - Samson Mukaratirwa
- School of Life Sciences, University of KwaZulu-Natal, Durban, South Africa
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Abstract
Epidemiological mapping and risk profiling build on the idea that diseases are tied to social-ecological systems that govern the distribution and abundance of transmissible pathogens, vectors and hosts. This is the heart of the emerging field of ecohealth, which examines how biological, cultural, demographic, economic, physical, political and social environments change and how these changes affect the health and wellbeing of humans, animals and ecosystems and the services they provide. This paper is an overview of a special issue of Acta Tropica, whose 15 publications reflect a geographically and epidemiologically diverse landscape of ecohealth. Nowhere is an ecohealth approach better suited than in Africa and its myriad of landscapes that include contexts varying from profuse expanses of tropical rain forests to the world's greatest desert. The publication of African ecohealth-related projects displays a biological, cultural and social diversity in health system contexts and a wide variety of contributions pertaining to different, often neglected, tropical diseases, including brucellosis, Buruli ulcer, fascioliasis, malaria, Q fever, rabies, Rift Valley fever and schistosomiasis. Pursuing an ecohealth approach provides a platform that brings together community members, decision makers, scientists and other stakeholders with a view to understand how ecosystem changes affect health conditions. Taken together, the presentation of this variety of papers dealing with environmental variables associated with health inaugurates the vital concept of ecohealth. By emphasizing that all organisms are part of social-ecological systems, the long-term wellbeing of both people and animals depending on healthy and productive ecosystems is highlighted.
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Affiliation(s)
| | - Norbert W Brattig
- Tropical Medicine Section, Bernhard Nocht Institute for Tropical Medicine, Bernhard-Nocht-Str. 74, D-20359 Hamburg, Germany
| | - Moses J Chimbari
- University of KwaZulu-Natal, College of Health Sciences, School of Nursing and Public Health, Howard Campus, Durban, South Africa
| | - Jakob Zinsstag
- Swiss Tropical and Public Health Institute, P.O. Box, CH-4002 Basel, Switzerland; University of Basel, P.O. Box, CH-4003 Basel, Switzerland
| | - Jürg Utzinger
- Swiss Tropical and Public Health Institute, P.O. Box, CH-4002 Basel, Switzerland; University of Basel, P.O. Box, CH-4003 Basel, Switzerland
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