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Abubakr M, Sami H, Mahdi I, Altahir O, Abdelbagi H, Mohamed NS, Ahmed A. The Phylodynamic and Spread of the Invasive Asian Malaria Vectors, Anopheles stephensi, in Sudan. BIOLOGY 2022; 11:409. [PMID: 35336783 PMCID: PMC8945054 DOI: 10.3390/biology11030409] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/22/2022] [Revised: 02/14/2022] [Accepted: 02/17/2022] [Indexed: 11/28/2022]
Abstract
Anopheles stephensi is an invasive Asian malaria vector that initially emerged in Africa in 2012 and was reported in Sudan in 2019. We investigated the distribution and population structure of An. stephensi throughout Sudan by using sequencing and molecular tools. We confirmed the presence of An. stephensi in eight border-states, identifying both natural and human-made breeding sites. Our analysis revealed the presence of 20 haplotypes with different distributions per state. This study revealed a countrywide spread of An. stephensi in Sudan, with confirmed presence in borders states with Chad, Egypt, Eritrea, Ethiopia, Libya, Republic of Central Africa, and South Sudan. Detection of An. stephensi at points of entry with these countries, particularly Chad, Libya, and South Sudan, indicates the rapid previously undetected spread of this invasive vector. Our phylogenetic and haplotype analysis suggested local establishment and evolutionary adaptation of the vector to different ecological and environmental conditions in Sudan. Urgent engagement of the global community is essential to control and prevent further spread into Africa.
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Affiliation(s)
- Mustafa Abubakr
- Directorate of the Integrated Vector Management (IVM), Federal Ministry of Health, Khartoum 11111, Sudan; (M.A.); (H.S.); (I.M.)
| | - Hamza Sami
- Directorate of the Integrated Vector Management (IVM), Federal Ministry of Health, Khartoum 11111, Sudan; (M.A.); (H.S.); (I.M.)
| | - Isam Mahdi
- Directorate of the Integrated Vector Management (IVM), Federal Ministry of Health, Khartoum 11111, Sudan; (M.A.); (H.S.); (I.M.)
| | - Omnia Altahir
- Molecular Biology Unit, Sirius Training and Research Centre, Khartoum 11111, Sudan; (O.A.); (H.A.); (N.S.M.)
| | - Hanadi Abdelbagi
- Molecular Biology Unit, Sirius Training and Research Centre, Khartoum 11111, Sudan; (O.A.); (H.A.); (N.S.M.)
| | - Nouh Saad Mohamed
- Molecular Biology Unit, Sirius Training and Research Centre, Khartoum 11111, Sudan; (O.A.); (H.A.); (N.S.M.)
| | - Ayman Ahmed
- Directorate of the Integrated Vector Management (IVM), Federal Ministry of Health, Khartoum 11111, Sudan; (M.A.); (H.S.); (I.M.)
- Molecular Biology Unit, Sirius Training and Research Centre, Khartoum 11111, Sudan; (O.A.); (H.A.); (N.S.M.)
- Institute of Endemic Diseases, University of Khartoum, Khartoum 11111, Sudan
- Swiss Tropical and Public Health Institute (Swiss TPH), 4123 Allschwil, Switzerland
- Faculty of Science, University of Basel, Petersplatz 1, 4001 Basel, Switzerland
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Suhr F, Steinert JI. Epidemiology of floods in sub-Saharan Africa: a systematic review of health outcomes. BMC Public Health 2022; 22:268. [PMID: 35144560 PMCID: PMC8830087 DOI: 10.1186/s12889-022-12584-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 01/17/2022] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND Floods have affected 2.3 billion people worldwide in the last 20 years, and are associated with a wide range of negative health outcomes. Climate change is projected to increase the number of people exposed to floods due to more variable precipitation and rising sea levels. Vulnerability to floods is highly dependent on economic wellbeing and other societal factors. Therefore, this systematic review synthesizes the evidence on health effects of flood exposure among the population of sub-Saharan Africa. METHODS We systematically searched two databases, Web of Science and PubMed, to find published articles. We included studies that (1) were published in English from 2010 onwards, (2) presented associations between flood exposure and health indicators, (3) focused on sub-Saharan Africa, and (4) relied on a controlled study design, such as cohort studies, case-control studies, cross-sectional studies, or quasi-experimental approaches with a suitable comparator, for instance individuals who were not exposed to or affected by floods or individuals prior to experiencing a flood. RESULTS Out of 2306 screened records, ten studies met our eligibility criteria. We included studies that reported the impact of floods on water-borne diseases (n = 1), vector-borne diseases (n = 8) and zoonotic diseases (n = 1). Five of the ten studies assessed the connection between flood exposure and malaria. One of these five evaluated the impact of flood exposure on malaria co-infections. The five non-malaria studies focused on cholera, scabies, taeniasis, Rhodesian sleeping sickness, alphaviruses and flaviviruses. Nine of the ten studies reported significant increases in disease susceptibility after flood exposure. CONCLUSION The majority of included studies of the aftermath of floods pointed to an increased risk of infection with cholera, scabies, taeniasis, Rhodesian sleeping sickness, malaria, alphaviruses and flaviviruses. However, long-term health effects, specifically on mental health, non-communicable diseases and pregnancy, remain understudied. Further research is urgently needed to improve our understanding of the health risks associated with floods, which will inform public policies to prevent and reduce flood-related health risks.
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Affiliation(s)
- Friederike Suhr
- School of Social Sciences and Technology, Technical University of Munich, Richard-Wagner Str. 1, 80333, Munich, Germany.
| | - Janina Isabel Steinert
- School of Social Sciences and Technology, Technical University of Munich, Richard-Wagner Str. 1, 80333, Munich, Germany
- Department of Social Policy and Intervention, University of Oxford, Oxford, UK
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Coalson JE, Anderson EJ, Santos EM, Madera Garcia V, Romine JK, Luzingu JK, Dominguez B, Richard DM, Little AC, Hayden MH, Ernst KC. The Complex Epidemiological Relationship between Flooding Events and Human Outbreaks of Mosquito-Borne Diseases: A Scoping Review. ENVIRONMENTAL HEALTH PERSPECTIVES 2021; 129:96002. [PMID: 34582261 PMCID: PMC8478154 DOI: 10.1289/ehp8887] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 08/10/2021] [Accepted: 08/19/2021] [Indexed: 06/13/2023]
Abstract
BACKGROUND Climate change is expected to increase the frequency of flooding events. Although rainfall is highly correlated with mosquito-borne diseases (MBD) in humans, less research focuses on understanding the impact of flooding events on disease incidence. This lack of research presents a significant gap in climate change-driven disease forecasting. OBJECTIVES We conducted a scoping review to assess the strength of evidence regarding the potential relationship between flooding and MBD and to determine knowledge gaps. METHODS PubMed, Embase, and Web of Science were searched through 31 December 2020 and supplemented with review of citations in relevant publications. Studies on rainfall were included only if the operationalization allowed for distinction of unusually heavy rainfall events. Data were abstracted by disease (dengue, malaria, or other) and stratified by post-event timing of disease assessment. Studies that conducted statistical testing were summarized in detail. RESULTS From 3,008 initial results, we included 131 relevant studies (dengue n = 45 , malaria n = 61 , other MBD n = 49 ). Dengue studies indicated short-term (< 1 month ) decreases and subsequent (1-4 month) increases in incidence. Malaria studies indicated post-event incidence increases, but the results were mixed, and the temporal pattern was less clear. Statistical evidence was limited for other MBD, though findings suggest that human outbreaks of Murray Valley encephalitis, Ross River virus, Barmah Forest virus, Rift Valley fever, and Japanese encephalitis may follow flooding. DISCUSSION Flooding is generally associated with increased incidence of MBD, potentially following a brief decrease in incidence for some diseases. Methodological inconsistencies significantly limit direct comparison and generalizability of study results. Regions with established MBD and weather surveillance should be leveraged to conduct multisite research to a) standardize the quantification of relevant flooding, b) study nonlinear relationships between rainfall and disease, c) report outcomes at multiple lag periods, and d) investigate interacting factors that modify the likelihood and severity of outbreaks across different settings. https://doi.org/10.1289/EHP8887.
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Affiliation(s)
- Jenna E. Coalson
- Center for Insect Science, University of Arizona, Tucson, Arizona, USA
| | | | - Ellen M. Santos
- Department of Epidemiology and Biostatistics, University of Arizona Mel and Enid Zuckerman College of Public Health, Tucson, Arizona, USA
| | - Valerie Madera Garcia
- Department of Epidemiology and Biostatistics, University of Arizona Mel and Enid Zuckerman College of Public Health, Tucson, Arizona, USA
| | - James K. Romine
- Department of Epidemiology and Biostatistics, University of Arizona Mel and Enid Zuckerman College of Public Health, Tucson, Arizona, USA
| | - Joy K. Luzingu
- Department of Epidemiology and Biostatistics, University of Arizona Mel and Enid Zuckerman College of Public Health, Tucson, Arizona, USA
| | - Brian Dominguez
- Department of Epidemiology and Biostatistics, University of Arizona Mel and Enid Zuckerman College of Public Health, Tucson, Arizona, USA
| | - Danielle M. Richard
- Department of Epidemiology and Biostatistics, University of Arizona Mel and Enid Zuckerman College of Public Health, Tucson, Arizona, USA
| | - Ashley C. Little
- Department of Epidemiology and Biostatistics, University of Arizona Mel and Enid Zuckerman College of Public Health, Tucson, Arizona, USA
| | - Mary H. Hayden
- National Institute for Human Resilience, University of Colorado Colorado Springs, Colorado Springs, Colorado, USA
| | - Kacey C. Ernst
- Department of Epidemiology and Biostatistics, University of Arizona Mel and Enid Zuckerman College of Public Health, Tucson, Arizona, USA
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Ashton RA, Prosnitz D, Andrada A, Herrera S, Yé Y. Evaluating malaria programmes in moderate- and low-transmission settings: practical ways to generate robust evidence. Malar J 2020; 19:75. [PMID: 32070357 PMCID: PMC7027277 DOI: 10.1186/s12936-020-03158-z] [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: 12/05/2019] [Accepted: 02/09/2020] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Many countries have made substantial progress in scaling-up and sustaining malaria intervention coverage, leading to more focalized and heterogeneous transmission in many settings. Evaluation provides valuable information for programmes to understand if interventions have been implemented as planned and with quality, if the programme had the intended impact on malaria burden, and to guide programmatic decision-making. Low-, moderate-, and heterogeneous-transmission settings present unique evaluation challenges because of dynamic and targeted intervention strategies. This paper provides illustration of evaluation approaches and methodologies for these transmission settings, and suggests how to answer evaluation questions specific to the local context. METHODS The Roll Back Malaria Monitoring and Evaluation Reference Group formed a task force in October 2017 to lead development of this framework. The task force includes representatives from National Malaria Programmes, funding agencies, and malaria research and implementing partners. The framework builds on existing guidance for process and outcome evaluations and impact evaluations specifically in high transmission settings. RESULTS The theory of change describes how evaluation questions asked by national malaria programmes in different contexts influence evaluation design. The transmission setting, existing stratification, and data quality and availability are also key considerations. The framework is intended for adaption by countries to their local context, and use for evaluation at sub-national level. Confirmed malaria incidence is recommended as the primary impact indicator due to its sensitivity to detect changes in low-transmission settings. It is expected that process evaluations provide sufficient evidence for programme monitoring and improvement, while impact evaluations are needed following adoption of new mixes of interventions, operational strategies, tools or policies, particularly in contexts of changing malaria epidemiology. Impact evaluations in low-, moderate-, or heterogeneous-transmission settings will likely use plausibility designs, and methods highlighted by the framework include interrupted time series, district-level dose-response analyses, and constructed control methods. Triangulating multiple data sources and analyses is important to strengthen the plausibility argument. CONCLUSIONS This framework provides a structure to assist national malaria programmes and partners to design evaluations in low-, moderate- or heterogeneous-transmission settings. Emphasizing a continuous cycle along the causal pathway linking process evaluation to impact evaluation and then programmatic decision-making, the framework provides practical guidance in evaluation design, analysis, and interpretation to ensure that the evaluation meets national malaria programme priority questions and guides decision-making at national and sub-national levels.
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Affiliation(s)
- Ruth A Ashton
- MEASURE Evaluation, Center for Applied Malaria Research and Evaluation, Tulane School of Public Health and Tropical Medicine, Tulane University, 1440 Canal Street, Suite 2300, New Orleans, LA, USA.
| | | | | | - Samantha Herrera
- MEASURE Evaluation, ICF, Rockville, MD, USA.,Save the Children, Washington, DC, USA
| | - Yazoumé Yé
- MEASURE Evaluation, ICF, Rockville, MD, USA
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