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Mohan K, Kandasamy S, Rajarajeswaran J, Sundaram T, Bjeljac M, Surendran RP, Ganesan AR. Chitosan-based insecticide formulations for insect pest control management: A review of current trends and challenges. Int J Biol Macromol 2024; 280:135937. [PMID: 39313045 DOI: 10.1016/j.ijbiomac.2024.135937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2024] [Revised: 08/20/2024] [Accepted: 09/20/2024] [Indexed: 09/25/2024]
Abstract
Future agricultural practices necessitate green alternatives to replace hazardous insecticides while distinguishing between pests and beneficial insects. Chitosan, as a biological macromolecule derived from chitin, is biodegradable and exhibits low toxicity to non-target organisms, making it a sustainable alternative to synthetic pesticides. This review identifies chitosan-derivatives for insecticidal activity and highlights its efficacy including genotoxicity, defense mechanism, and disruption of insect's exoskeleton at different concentrations against several insect pests. Similarly, synergistic effects of chitosan in combination with natural extracts, essential oils, and plant-derived compounds, enhances insecticidal action against various pests was evaluated. The chitosan-based insecticide formulations (CHIF) in the form of emulsions, microcapsules, and nanoparticles showed efficient insecticide action on the targeted pests with less environmental impact. The current challenges associated with the field-trial application were also recognized, by optimizing potent CHIF-formulation parameters, scaling-up process, and regulatory hurdles addressed alongside potential solutions. These findings will provide insight into achieving the EU mission of reducing chemical pesticides by 50 %.
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Affiliation(s)
- Kannan Mohan
- PG and Research Department of Zoology, Sri Vasavi College, Erode, Tamil Nadu 638 316, India.
| | - Sabariswaran Kandasamy
- Department of Biotechnology, PSGR Krishnammal College for Women, Peelamedu, Coimbatore 641 004, India
| | - Jayakumar Rajarajeswaran
- Department of Nanobiomaterials, Saveetha School of Engineering, Saveetha Institute of Medical and Technical Sciences, Chennai 602105, Tamil Nadu, India
| | - Thanigaivel Sundaram
- Department of Biotechnology, Faculty of Science & Humanities, SRM Institute of Science and Technology, Kattankulathur, Chengalpattu District, Tamil Nadu 603203, India
| | - Marko Bjeljac
- Institute for Plant Health, Laimburg Research Centre, 39040 Auer (Ora), Italy; Faculty of Agricultural, Environmental and Food Sciences, Free University of Bozen-Bolzano, Piazza Università 1, 39100, Bolzano, Italy
| | | | - Abirami Ramu Ganesan
- Division of Food Production and Society, Biomarine Resource Valorisation, Norwegian Institute of Bioeconomy Research, Torggården, Kudalsveien 6, NO-8027 Bodø, Norway.
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2
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Blanford JI. Managing vector-borne diseases in a geoAI-enabled society. Malaria as an example. Acta Trop 2024:107406. [PMID: 39299478 DOI: 10.1016/j.actatropica.2024.107406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2024] [Revised: 09/13/2024] [Accepted: 09/13/2024] [Indexed: 09/22/2024]
Abstract
More than 17% of all infectious diseases are caused by vector-borne diseases resulting in more than 1 billion cases and over 1 million deaths each year. Of this malaria continues to be a global burden in over eighty countries. As societies become more digitalised, the availability of geospatially enabled health and disease information will become more abundant. With this, the ability to assess health and disease risks in real-time will become a reality. The purpose of this study was to examine how geographic information, geospatial technologies and spatial data science are being used to reduce the burden of vector-borne diseases such as malaria and explore the opportunities that lie ahead with GeoAI and other geospatial technology advancements. Malaria is a dynamic and complex system and as such a range of data and approaches are needed to tackle different parts of the malaria cycle at different local and global scales. Geospatial technologies provide an integrated framework vital for monitoring, analysing, managing vector-borne diseases. GeoAI and technological advancements are useful for enhancing real-time assessments, accelerating the decision making process and spatial targeting of interventions. Training is needed to enhance the use of geospatial information for the management of vector-borne diseases.
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Affiliation(s)
- Justine I Blanford
- Faculty of Geo-Information Science and Earth Observation, University of Twente, Enschede, Netherlands.
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3
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Iyaloo DP, Zohdy S, Carney RM, Mosawa VR, Elahee KB, Munglee N, Latchooman N, Puryag S, Bheecarry A, Bhoobun H, Rasamoelina-Andriamanivo H, Bedja SA, Spear J, Baldet T, Carter TE. A regional One Health approach to the risk of invasion by Anopheles stephensi in Mauritius. PLoS Negl Trop Dis 2024; 18:e0011827. [PMID: 39259766 DOI: 10.1371/journal.pntd.0011827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Accepted: 07/29/2024] [Indexed: 09/13/2024] Open
Abstract
BACKGROUND Anopheles stephensi is an invasive malaria vector in Africa that threatens to put an additional 126 million people at risk of malaria if it continues to spread. The island nation of Mauritius is highly connected to Asia and Africa and is at risk of introduction due to this connectivity. For early detection of An. stephensi, the Vector Biology and Control Division under the Ministry of Health in Mauritius, leveraged a well-established Aedes program, as An. stephensi is known to share Aedes habitats. These efforts triggered multisectoral coordination and cascading benefits of integrated vector and One Health approaches. METHODS Beginning June 2021, entomological surveys were conducted at points of entry (seaport, airport) and on ships transporting livestock in collaboration with the Civil Aviation Department, the Mauritian Port Authority and National Veterinary Services. A total of 18, 39, 723 mosquito larval surveys were respectively conducted in the airport, seaport, and other localities in Mauritius while two, 20, and 26 adult mosquito surveys were respectively conducted in the airport, seaport, and twenty-six animal assembly points. Alongside adult mosquito surveys, surveillance of vectors of veterinary importance (e.g.- Culicoides spp.) was also carried out in collaboration with National Parks and Conservation Service and land owners. RESULTS A total of 8,428 adult mosquitoes were collected and 1,844 larval habitats were positive for mosquitoes. All collected mosquitoes were morphologically identified and 151 Anopheles and 339 Aedes mosquitoes were also molecularly characterized. Mosquito species detected were Aedes albopictus, Anopheles arabiensis, An. coustani, An. merus, Culex quinquefasciatus, Cx. thalassius and Lutzia tigripes. Anopheles stephensi was not detected. The One Health approach was shared with the French Agricultural Research Centre for International Development (CIRAD), strengthening collaboration between Mauritius and Réunion Island on vector surveillance at entry points and insecticide resistance monitoring. The Indian Ocean Commission (IOC) was also alerted to the risk of An. stephensi, leading to regional efforts supporting trainings and development of a response strategy to An. stephensi bringing together stakeholders from Comoros, Madagascar, Mauritius, Réunion Island and Seychelles. CONCLUSIONS Mauritius is a model system showing how existing public health entomology capabilities can be used to enhance vector surveillance and control and create multisectoral networks to respond to any emerging public and veterinary health vector-borne disease threat.
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Affiliation(s)
- Diana P Iyaloo
- Vector Biology and Control Division, Ministry of Health and Wellness, Curepipe, Mauritius
- Surveillance Epidemiologique et Gestion des Alertes (SEGA) One Health network, Indian Ocean Commission, Ebene, Mauritius
| | - Sarah Zohdy
- US President's Malaria Initiative, US Centers for Disease Control and Prevention (CDC), Atlanta, Georgia, United States of America
| | - Ryan M Carney
- Department of Integrative Biology, College of Arts & Sciences, University of South Florida, Tampa, Florida, United States of America
| | - Varina Ramdonee Mosawa
- Vector Biology and Control Division, Ministry of Health and Wellness, Curepipe, Mauritius
- Surveillance Epidemiologique et Gestion des Alertes (SEGA) One Health network, Indian Ocean Commission, Ebene, Mauritius
| | - Khouaildi B Elahee
- Vector Biology and Control Division, Ministry of Health and Wellness, Curepipe, Mauritius
- Surveillance Epidemiologique et Gestion des Alertes (SEGA) One Health network, Indian Ocean Commission, Ebene, Mauritius
| | - Nabiihah Munglee
- Vector Biology and Control Division, Ministry of Health and Wellness, Curepipe, Mauritius
- Surveillance Epidemiologique et Gestion des Alertes (SEGA) One Health network, Indian Ocean Commission, Ebene, Mauritius
| | - Nilesh Latchooman
- Vector Biology and Control Division, Ministry of Health and Wellness, Curepipe, Mauritius
- Surveillance Epidemiologique et Gestion des Alertes (SEGA) One Health network, Indian Ocean Commission, Ebene, Mauritius
| | - Surendra Puryag
- Vector Biology and Control Division, Ministry of Health and Wellness, Curepipe, Mauritius
- Surveillance Epidemiologique et Gestion des Alertes (SEGA) One Health network, Indian Ocean Commission, Ebene, Mauritius
| | - Ambicadutt Bheecarry
- Vector Biology and Control Division, Ministry of Health and Wellness, Curepipe, Mauritius
- Surveillance Epidemiologique et Gestion des Alertes (SEGA) One Health network, Indian Ocean Commission, Ebene, Mauritius
| | - Hemant Bhoobun
- Surveillance Epidemiologique et Gestion des Alertes (SEGA) One Health network, Indian Ocean Commission, Ebene, Mauritius
- Livestock and Veterinary Division, Ministry of Agro Industry and Food Security, Reduit, Mauritius
| | - Harena Rasamoelina-Andriamanivo
- Surveillance Epidemiologique et Gestion des Alertes (SEGA) One Health network, Indian Ocean Commission, Ebene, Mauritius
- Indian Ocean Commission, Ebene, Mauritius
| | - Saïd Ahmed Bedja
- Surveillance Epidemiologique et Gestion des Alertes (SEGA) One Health network, Indian Ocean Commission, Ebene, Mauritius
- Indian Ocean Commission, Ebene, Mauritius
| | - Joseph Spear
- Department of Biology, College of Arts & Sciences, Baylor University, Waco, Texas, United States of America
| | - Thierry Baldet
- Surveillance Epidemiologique et Gestion des Alertes (SEGA) One Health network, Indian Ocean Commission, Ebene, Mauritius
- UMR ASTRE, Cirad, INRAe, Univ. Montpellier, Sainte-Clotilde, La Réunion, France
| | - Tamar E Carter
- Department of Biology, College of Arts & Sciences, Baylor University, Waco, Texas, United States of America
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4
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Rafferty C, Raise G, Scaife J, Abongo B, Omondi S, Milanoi S, Muchoki M, Onyango B, Ochomo E, Zohdy S. Loop-Mediated Isothermal Amplification Assay to Detect Invasive Malaria Vector Anopheles stephensi Mosquitoes. Emerg Infect Dis 2024; 30:1770-1778. [PMID: 38985536 PMCID: PMC11346999 DOI: 10.3201/eid3009.240444] [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] [Indexed: 07/12/2024] Open
Abstract
Spread of the Anopheles stephensi mosquito, an invasive malaria vector, threatens to put an additional 126 million persons per year in Africa at risk for malaria. To accelerate the early detection and rapid response to this mosquito species, confirming its presence and geographic extent is critical. However, existing molecular species assays require specialized laboratory equipment, interpretation, and sequencing confirmation. We developed and optimized a colorimetric rapid loop-mediated isothermal amplification assay for molecular An. stephensi species identification. The assay requires only a heat source and reagents and can be used with or without DNA extraction, resulting in positive color change in 30-35 minutes. We validated the assay against existing PCR techniques and found 100% specificity and analytical sensitivity down to 0.0003 ng of genomic DNA. The assay can successfully amplify single mosquito legs. Initial testing on samples from Marsabit, Kenya, illustrate its potential as an early vector detection and malaria mitigation tool.
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5
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Higgins M, Kristan M, Collins EL, Messenger LA, Dombrowski JG, Vanheer LN, Nolder D, Drakeley CJ, Stone W, Mahamar A, Bousema T, Delves M, Bandibabone J, N'Do S, Bantuzeko C, Zawadi B, Walker T, Sutherland CJ, Marinho CRF, Cameron MM, Clark TG, Campino S. A Pan Plasmodium lateral flow recombinase polymerase amplification assay for monitoring malaria parasites in vectors and human populations. Sci Rep 2024; 14:20165. [PMID: 39215071 PMCID: PMC11364753 DOI: 10.1038/s41598-024-71129-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Accepted: 08/26/2024] [Indexed: 09/04/2024] Open
Abstract
Robust diagnostic tools and surveillance are crucial for malaria control and elimination efforts. Malaria caused by neglected Plasmodium parasites is often underestimated due to the lack of rapid diagnostic tools that can accurately detect these species. While nucleic-acid amplification technologies stand out as the most sensitive methods for detecting and confirming Plasmodium species, their implementation in resource-constrained settings poses significant challenges. Here, we present a Pan Plasmodium recombinase polymerase amplification lateral flow (RPA-LF) assay, capable of detecting all six human infecting Plasmodium species in low resource settings. The Pan Plasmodium RPA-LF assay successfully detected low density clinical infections with a preliminary limit of detection between 10-100 fg/µl for P. falciparum. When combined with crude nucleic acid extraction, the assay can serve as a point-of-need tool for molecular xenomonitoring. This utility was demonstrated by screening laboratory-reared Anopheles stephensi mosquitoes fed with Plasmodium-infected blood, as well as field samples of An. funestus s.l. and An. gambiae s.l. collected from central Africa. Overall, our proof-of-concept Pan Plasmodium diagnostic tool has the potential to be applied for clinical and xenomonitoring field surveillance, and after further evaluation, could become an essential tool to assist malaria control and elimination.
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Affiliation(s)
- Matthew Higgins
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine (LSHTM), Keppel Street, London, WC1E 7HT, UK
| | - Mojca Kristan
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine (LSHTM), Keppel Street, London, WC1E 7HT, UK
- Human Malaria Transmission Facility, LSHTM, Keppel Street, London, WC1E 7HT, UK
| | - Emma L Collins
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine (LSHTM), Keppel Street, London, WC1E 7HT, UK
| | - Louisa A Messenger
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine (LSHTM), Keppel Street, London, WC1E 7HT, UK
- Environmental & Occupational Health, School of Public Health, University of Nevada, Las Vegas, USA
| | - Jamille G Dombrowski
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine (LSHTM), Keppel Street, London, WC1E 7HT, UK
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Leen N Vanheer
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine (LSHTM), Keppel Street, London, WC1E 7HT, UK
| | - Debbie Nolder
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine (LSHTM), Keppel Street, London, WC1E 7HT, UK
- Malaria Reference Laboratory, UK Health Security Agency, LSHTM, London, WC1E 7HT, UK
| | - Christopher J Drakeley
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine (LSHTM), Keppel Street, London, WC1E 7HT, UK
| | - William Stone
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine (LSHTM), Keppel Street, London, WC1E 7HT, UK
| | - Almahamoudou Mahamar
- Malaria Research & Training Center, Faculty of Medicine, Pharmacy and Dentistry, University of Science, Techniques and Technologies (USTT), Bamako, Mali
| | - Teun Bousema
- Department of Medical Microbiology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Michael Delves
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine (LSHTM), Keppel Street, London, WC1E 7HT, UK
| | - Janvier Bandibabone
- Laboratoire d'Entomologie Médicale Et Parasitologie, Centre de Recherche en Sciences Naturelles (CRSN/Lwiro), Sud‑Kivu, Democratic Republic of the Congo
| | - Sévérin N'Do
- Médecins Sans Frontières (MSF) OCBA, Barcelona, Spain
- Institut de Recherche en Sciences de La Santé (IRSS), Bobo-Dioulasso, Burkina Faso
| | - Chimanuka Bantuzeko
- Centre de Recherche en Sciences Naturelles de Lwiro, Sud-Kivu, Democratic Republic of the Congo
- Université Officielle de Bukavu (UOB), Bukavu, Democratic Republic of the Congo
| | - Bertin Zawadi
- Centre de Recherche en Sciences Naturelles de Lwiro, Sud-Kivu, Democratic Republic of the Congo
| | - Thomas Walker
- School of Life Sciences, University of Warwick, Coventry, UK
| | - Colin J Sutherland
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine (LSHTM), Keppel Street, London, WC1E 7HT, UK
- Human Malaria Transmission Facility, LSHTM, Keppel Street, London, WC1E 7HT, UK
- Malaria Reference Laboratory, UK Health Security Agency, LSHTM, London, WC1E 7HT, UK
| | - Claudio R F Marinho
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Mary M Cameron
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine (LSHTM), Keppel Street, London, WC1E 7HT, UK
| | - Taane G Clark
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine (LSHTM), Keppel Street, London, WC1E 7HT, UK
- Faculty of Epidemiology and Population Health, LSHTM, Keppel Street, London, WC1E 7HT, UK
| | - Susana Campino
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine (LSHTM), Keppel Street, London, WC1E 7HT, UK.
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Aranda-Díaz A, Vickers EN, Murie K, Palmer B, Hathaway N, Gerlovina I, Boene S, Garcia-Ulloa M, Cisteró P, Katairo T, Semakuba FD, Nsengimaana B, Gwarinda H, García-Fernández C, Da Silva C, Datta D, Kiyaga S, Wiringilimaana I, Fekele SM, Parr JB, Conrad M, Raman J, Tukwasibwe S, Ssewanyana I, Rovira-Vallbona E, Tato CM, Briggs J, Mayor A, Greenhouse B. Sensitive and modular amplicon sequencing of Plasmodium falciparum diversity and resistance for research and public health. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.22.609145. [PMID: 39229023 PMCID: PMC11370457 DOI: 10.1101/2024.08.22.609145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 09/05/2024]
Abstract
Targeted amplicon sequencing is a powerful and efficient tool to interrogate the P. falciparum genome and generate actionable data from infections to complement traditional malaria epidemiology. For maximum impact, genomic tools should be multi-purpose, robust, sensitive and reproducible. We developed, characterized, and implemented MAD4HatTeR, an amplicon sequencing panel based on Multiplex Amplicons for Drug, Diagnostic, Diversity, and Differentiation Haplotypes using Targeted Resequencing, along with a bioinformatic pipeline for data analysis. MAD4HatTeR targets 165 highly diverse loci, focusing on multiallelic microhaplotypes; key markers for drug and diagnostic resistance, including duplications and deletions; and csp and potential vaccine targets. In addition, it can detect non-falciparum Plasmodium species. We used laboratory control and field sample data to demonstrate the high sensitivity and robustness of the panel. The successful implementation of this method in five laboratories, including three in malaria-endemic African countries, showcases its feasibility in generating reproducible data across laboratories. Finally, we introduce an analytical approach to detect gene duplications and deletions from amplicon sequencing data. MAD4HatTeR is thus a powerful research tool and a robust resource for malaria public health surveillance and control.
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Affiliation(s)
- Andrés Aranda-Díaz
- EPPIcenter Research Program, Division of HIV, Infectious Diseases, and Global Medicine, Department of Medicine, University of California, San Francisco, California, USA
- Chan Zuckerberg Biohub, San Francisco, California, USA
| | - Eric Neubauer Vickers
- EPPIcenter Research Program, Division of HIV, Infectious Diseases, and Global Medicine, Department of Medicine, University of California, San Francisco, California, USA
| | - Kathryn Murie
- EPPIcenter Research Program, Division of HIV, Infectious Diseases, and Global Medicine, Department of Medicine, University of California, San Francisco, California, USA
| | - Brian Palmer
- EPPIcenter Research Program, Division of HIV, Infectious Diseases, and Global Medicine, Department of Medicine, University of California, San Francisco, California, USA
| | - Nicholas Hathaway
- EPPIcenter Research Program, Division of HIV, Infectious Diseases, and Global Medicine, Department of Medicine, University of California, San Francisco, California, USA
| | - Inna Gerlovina
- EPPIcenter Research Program, Division of HIV, Infectious Diseases, and Global Medicine, Department of Medicine, University of California, San Francisco, California, USA
| | - Simone Boene
- Centro de Investigação em Saúde de Manhiça, Maputo, Mozambique
| | | | | | - Thomas Katairo
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | | | | | - Hazel Gwarinda
- Laboratory for Antimalarial Resistance Monitoring and Malaria Operational Research (ARMMOR), Centre of Emerging Zoonotic and Parasitic Diseases, National Institute for Communicable Diseases, Johannesburg, South Africa
| | | | | | | | - Shahiid Kiyaga
- Infectious Diseases Research Collaboration, Kampala, Uganda
- Department of Immunology and Molecular Biology, College of Health Sciences, Makerere University, Kampala, Uganda
| | | | - Sindew Mekasha Fekele
- Ethiopian Public Health Institute, Addis Ababa, Ethiopia
- Department of Environment and Genetics, La Trobe University, Melbourne, Australia
| | - Jonathan B Parr
- Division of Infectious Diseases, University of North Carolina at Chapel Hill, North Carolina, USA
| | - Melissa Conrad
- Division of HIV, Infectious Diseases, and Global Medicine, Department of Medicine, University of California, San Francisco, California, USA
| | - Jaishree Raman
- Laboratory for Antimalarial Resistance Monitoring and Malaria Operational Research (ARMMOR), Centre of Emerging Zoonotic and Parasitic Diseases, National Institute for Communicable Diseases, Johannesburg, South Africa
- Wits Research Institute for Malaria, University of Witwatersrand, Johannesburg, South Africa
- University of Pretoria Institute for Sustainable Malaria Control (UPISMC), University of Pretoria, Pretoria, South Africa
| | | | | | | | | | - Jessica Briggs
- EPPIcenter Research Program, Division of HIV, Infectious Diseases, and Global Medicine, Department of Medicine, University of California, San Francisco, California, USA
| | - Alfredo Mayor
- Centro de Investigação em Saúde de Manhiça, Maputo, Mozambique
- ISGlobal, Barcelona, Spain
- Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona (UB), Barcelona, Spain
- Department of Physiologic Sciences, Faculty of Medicine, Universidade Eduardo Mondlane, Maputo, Mozambique
| | - Bryan Greenhouse
- EPPIcenter Research Program, Division of HIV, Infectious Diseases, and Global Medicine, Department of Medicine, University of California, San Francisco, California, USA
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7
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Taylor R, Messenger LA, Abeku TA, Clarke SE, Yadav RS, Lines J. Invasive Anopheles stephensi in Africa: insights from Asia. Trends Parasitol 2024; 40:731-743. [PMID: 39054167 DOI: 10.1016/j.pt.2024.06.008] [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: 04/17/2024] [Revised: 06/03/2024] [Accepted: 06/19/2024] [Indexed: 07/27/2024]
Abstract
Anopheles stephensi is a highly competent urban malaria vector species, endemic in South Asia and the Persian Gulf, which has colonised eight countries in sub-Saharan Africa (SSA) since 2013 and is now spreading uncontrollably. In urban areas of Africa, where malaria transmission has previously been low or non-existent, the invasion of An. stephensi represents a significant problem, particularly to immunologically naïve populations. Despite this rapidly advancing threat, there is a paucity of information regarding the bionomics of An. stephensi in SSA. Here, we offer a critical synthesis of literature from An. stephensi's native range, focusing on the future of An. stephensi in a rapidly urbanising Africa, and highlighting key questions that warrant prioritisation by the global malaria vector control community.
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Affiliation(s)
- Roz Taylor
- RAFT (Resilience Against Future Threats Through Vector Control) Consortium, Department of Disease Control, London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK.
| | - Louisa A Messenger
- Department of Environmental and Occupational Health, School of Public Health, University of Nevada, Las Vegas, NV 89154, USA; Parasitology and Vector Biology (PARAVEC) Laboratory, School of Public Health, University of Nevada, Las Vegas, NV 89154, USA
| | - Tarekegn A Abeku
- Malaria Consortium, Green House, 244-254 Cambridge Heath Road, London E2 9DA, UK
| | - Sian E Clarke
- RAFT (Resilience Against Future Threats Through Vector Control) Consortium, Department of Disease Control, London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK
| | - Rajpal S Yadav
- Academy of Public Health Entomology, Udaipur 313002, Rajasthan, India
| | - Jo Lines
- RAFT (Resilience Against Future Threats Through Vector Control) Consortium, Department of Disease Control, London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK.
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8
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Weng SC, Chen F, Li M, Lee S, Gerry C, Turksoy DC, Akbari OS. Establishing a Male-Positive Genetic Sexing Strain in the Asian Malaria Vector Anopheles stephensi. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.17.603997. [PMID: 39071362 PMCID: PMC11275880 DOI: 10.1101/2024.07.17.603997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/30/2024]
Abstract
Genetic biocontrol interventions targeting mosquito-borne diseases require the release of male mosquitoes exclusively, as only females consume blood and transmit human pathogens. This reduces the risk of spreading pathogens while enabling effective population control. Robust sex sorting methods to enable early larval sorting in mosquitoes need to be developed to allow for scalable sex sorting for genetic biocontrol interventions. This study applies the SEPARATOR (Sexing Element Produced by Alternative RNA-splicing of A Transgenic Observable Reporter) system, previously developed for Aedes aegypti, to the Asian malaria vector Anopheles stephensi. We hypothesized that the intron from the doublesex gene in Anopheles gambiae would function in An. stephensi due to evolutionary conservation. Our results confirm that the splicing module from An. gambiae operates effectively in An. stephensi, demonstrating evolutionary conservation in sex-specific splicing events between these species. This system enables reliable positive male selection from first instar larval to pupal stages. RT-PCR analysis demonstrates that male-specific EGFP expression is dependent on doublesex sex-specific splicing events. The SEPARATOR system's independence from sex-chromosome linkage confers resistance to meiotic recombination and chromosomal rearrangements. This approach may facilitate the mass release of males, and the cross-species portability of SEPARATOR establishes it as a valuable tool for genetic biocontrol interventions across various pest species.
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Affiliation(s)
- Shih-Che Weng
- School of Biological Sciences, Department of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Fangying Chen
- School of Biological Sciences, Department of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Ming Li
- School of Biological Sciences, Department of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Sammy Lee
- School of Biological Sciences, Department of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Connor Gerry
- School of Biological Sciences, Department of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Dylan Can Turksoy
- School of Biological Sciences, Department of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Omar S. Akbari
- School of Biological Sciences, Department of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA 92093, USA
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Mwalugelo YA, Mponzi WP, Muyaga LL, Mahenge HH, Katusi GC, Muhonja F, Omondi D, Ochieng AO, Kaindoa EW, Amimo FA. Livestock keeping, mosquitoes and community viewpoints: a mixed methods assessment of relationships between livestock management, malaria vector biting risk and community perspectives in rural Tanzania. Malar J 2024; 23:213. [PMID: 39020392 PMCID: PMC11253484 DOI: 10.1186/s12936-024-05039-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Accepted: 07/09/2024] [Indexed: 07/19/2024] Open
Abstract
BACKGROUND Livestock keeping is one of the potential factors related to malaria transmission. To date, the impact of livestock keeping on malaria transmission remains inconclusive, as some studies suggest a zooprophylactic effect while others indicate a zoopotentiation effect. This study assessed the impact of livestock management on malaria transmission risks in rural Tanzania. Additionally, the study explored the knowledge and perceptions of residents about the relationships between livestock keeping and malaria transmission risks in a selected village. METHODS In a longitudinal entomological study in Minepa village, South Eastern Tanzania, 40 households were randomly selected (20 with livestock, 20 without). Weekly mosquito collection was performed from January to April 2023. Indoor and outdoor collections used CDC-Light traps, Prokopack aspirators, human-baited double-net traps, and resting buckets. A subsample of mosquitoes was analysed using PCR and ELISA for mosquito species identification and blood meal detection. Livestock's impact on mosquito density was assessed using negative binomial GLMMs. Additionally, in-depth interviews explored community knowledge and perceptions of the relationship between livestock keeping and malaria transmission risks. RESULTS A total of 48,677 female Anopheles mosquitoes were collected. Out of these, 89% were Anopheles gambiae sensu lato (s.l.) while other species were Anopheles funestus s.l., Anopheles pharoensis, Anopheles coustani, and Anopheles squamosus. The findings revealed a statistically significant increase in the overall number of An. gambiae s.l. outdoors (RR = 1.181, 95%CI 1.050-1.862, p = 0.043). Also, there was an increase of the mean number of An. funestus s.l. mosquitoes collected in households with livestock indoors (RR = 2.866, 95%CI: 1.471-5.582, p = 0.002) and outdoors (RR = 1.579,95%CI 1.080-2.865, p = 0.023). The human blood index of Anopheles arabiensis mosquitoes from houses with livestock was less than those without livestock (OR = 0.149, 95%CI 0.110-0.178, p < 0.001). The majority of participants in the in-depth interviews reported a perceived high density of mosquitoes in houses with livestock compared to houses without livestock. CONCLUSION Despite the potential for zooprophylaxis, this study indicates a higher malaria transmission risk in livestock-keeping communities. It is crucial to prioritize and implement targeted interventions to control vector populations within these communities. Furthermore, it is important to enhance community education and awareness regarding covariates such as livestock that influence malaria transmission.
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Affiliation(s)
- Yohana A Mwalugelo
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, P. O. Box 53, Ifakara, Tanzania.
- Department of Biomedical Sciences, Jaramogi Oginga Odinga University of Science and Technology, P. O. Box 210, Bondo, 40601, Kenya.
| | - Winifrida P Mponzi
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, P. O. Box 53, Ifakara, Tanzania
| | - Letus L Muyaga
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, P. O. Box 53, Ifakara, Tanzania
- School of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Herieth H Mahenge
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, P. O. Box 53, Ifakara, Tanzania
- The Nelson Mandela, African Institution of Science and Technology, School of Life Sciences and BioEngineering, Tengeru, Arusha, United Republic of Tanzania
| | - Godfrey C Katusi
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, P. O. Box 53, Ifakara, Tanzania
| | - Faith Muhonja
- School of Public Health, Amref International University, P.O. Box 27691-00506, Nairobi, Kenya
| | - Dickens Omondi
- Department of Biomedical Sciences, Jaramogi Oginga Odinga University of Science and Technology, P. O. Box 210, Bondo, 40601, Kenya
| | - Alfred O Ochieng
- Department of Biological Sciences, Jaramogi Oginga Odinga University of Science and Technology, P.O. Box 210, Bondo, 40601, Kenya
| | - Emmanuel W Kaindoa
- Environmental Health and Ecological Sciences Department, Ifakara Health Institute, P. O. Box 53, Ifakara, Tanzania
- The Nelson Mandela, African Institution of Science and Technology, School of Life Sciences and BioEngineering, Tengeru, Arusha, United Republic of Tanzania
- Wits Research Institute for Malaria, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand and the Centre for Emerging Zoonotic and Parasitic Diseases, National Institute for Communicable Diseases, Johannesburg, South Africa
| | - Fred A Amimo
- Department of Biomedical Sciences, Jaramogi Oginga Odinga University of Science and Technology, P. O. Box 210, Bondo, 40601, Kenya
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Ishengoma DS, Gosling R, Martinez-Vega R, Beshir KB, Bailey JA, Chimumbwa J, Sutherland C, Conrad MD, Tadesse FG, Juliano JJ, Kamya MR, Mbacham WF, Ménard D, Rosenthal PJ, Raman J, Tatarsky A, Tessema SK, Fidock DA, Djimde AA. Urgent action is needed to confront artemisinin partial resistance in African malaria parasites. Nat Med 2024; 30:1807-1808. [PMID: 38710833 DOI: 10.1038/d41591-024-00028-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
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Assada M, Al-Hadi M, Esmail MA, Al-Jurban J, Alkawri A, Shamsan A, Terreri P, Samake JN, Aljasari A, Awash AA, Al Eryani SM, Carter TE. Molecular Confirmation of Anopheles stephensi Mosquitoes in the Al Hudaydah Governorate, Yemen, 2021 and 2022. Emerg Infect Dis 2024; 30:1467-1471. [PMID: 38916721 PMCID: PMC11210655 DOI: 10.3201/eid3007.240331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/26/2024] Open
Abstract
We detected malaria vector Anopheles stephensi mosquitoes in the Al Hudaydah governorate in Yemen by using DNA sequencing. We report 2 cytochrome c oxidase subunit I haplotypes, 1 previously found in Ethiopia, Somalia, Djibouti, and Yemen. These findings provide insight into invasive An. stephensi mosquitoes in Yemen and their connection to East Africa.
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Arif M, Rasheed SB, Ullah H, Shah TA, Rehman FU, Dawoud TM. Feeding Behavior and Plasmodium Detection in Anopheles stephensi, a Malaria Vector in District Khyber, Khyber Pakhtunkhwa, Pakistan. IRANIAN JOURNAL OF PARASITOLOGY 2024; 19:333-340. [PMID: 39318824 PMCID: PMC11417983 DOI: 10.18502/ijpa.v19i3.16393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/19/2024] [Accepted: 06/14/2024] [Indexed: 09/26/2024]
Abstract
Background Anopheles stephensi is a significant malaria vector in Pakistan, and understanding its feeding behavior is necessary to control the spread of malaria. However, limited information is available on the host preferences of A. stephensi in Pakistan. Therefore, we aimed to explore the feeding behavior of A. stephensi, a malaria vector, in the District Khyber, Khyber Pakhtunkhwa, Pakistan. Methods A total of 7462 mosquitoes were collected between March and September 2021, with 1674 (22.4%) identified as A. stephensi (952 female and 722 male). Among the female A. stephensi, 495 (52%) were blood-fed. DNA was extracted from the blood-fed female A. stephensi mosquitoes using the Ammonium Acetate Precipitation Method followed by PCR analysis, blood meal sources were identified. Nested PCR on 191 pooled samples was used to detect Plasmodium falciparum and Plasmodium vivax. Results Cattle blood meals were predominant (73%), followed by human (20%) and chicken (7%), with no dog blood meals detected. All individual mosquito samples were negative for Plasmodium falciparum, while two pooled samples (out of 191) tested positive for P. vivax. Conclusion A. stephensi in Khyber District primarily displayed anthropophagic feeding behavior, with a small portion of the population infected with P. vivax. The results underscore the importance of targeted vector control strategies, environmental management, community engagement and continuous monitoring to suppress malaria transmission.
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Affiliation(s)
- Mahnoor Arif
- Institute of Zoological Sciences, University of Peshawar, Peshawar, Pakistan
| | - Syed Basit Rasheed
- Institute of Zoological Sciences, University of Peshawar, Peshawar, Pakistan
| | - Habib Ullah
- Institute of Zoological Sciences, University of Peshawar, Peshawar, Pakistan
| | - Tawaf Ali Shah
- College of Agriculture Engineering and Food Science, Shandong University of Technology, Zibo, China
| | - Faiz Ur Rehman
- Department of Zoology, Government Superior Science College Peshawar, Khyber Pakhtunkhwa, Pakistan
| | - Turki M. Dawoud
- Department of Botany and Microbiology, College of Science, King Saud University, Riyadh, Saudi Arabia
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Belay AK, Asale A, Sole CL, Kinya F, Yusuf AA, Torto B, Mutero CM, Tchouassi DP. Vectorial drivers of malaria transmission in Jabi Tehnan district, Amhara Regional State, Ethiopia. Sci Rep 2024; 14:13669. [PMID: 38871839 PMCID: PMC11176308 DOI: 10.1038/s41598-024-64436-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2024] [Accepted: 06/10/2024] [Indexed: 06/15/2024] Open
Abstract
Among the factors affecting the effectiveness of malaria control is poor knowledge of the entomologic drivers of the disease. We investigated anopheline populations as part of a baseline study to implement house screening of windows and doors as a supplementary malaria control tool towards elimination in Jabi Tehnan district, Amhara Regional State of Ethiopia. The samples were surveyed monthly using CDC light traps between June 2020 and May 2021. Mosquito trap density (< 3 mosquitoes/trap) was low, however, with a high overall Plasmodium sporozoite rate (9%; indoor = 4.3%, outdoor = 13.1%) comprising P. falciparum (88.9%) and P. vivax (11.1%). Anopheles gambiae s.l., mostly An. arabiensis, comprised > 80% of total anopheline captures and contributed ~ 42% of Plasmodium-infected mosquitoes. On the other hand, morphologically scored Anopheles funestus s.l., constituting about 6% of anopheline collections, accounted for 50% of sporozoite-infected mosquitoes. Most of the infected An. funestus s.l. specimens (86.7%) were grouped with previously unknown or undescribed Anopheles species previously implicated as a cryptic malaria vector in the western Kenyan highlands, confirming its wider geographic distribution in eastern Africa. Other species with Plasmodium infection included An. longipalpis C, An. theileri, An. demillioni, and An. nili. Cumulatively, 77.8% of the infected mosquitoes occurred outdoors. These results suggest efficient malaria parasite transmission despite the low vector densities, which has implications for effective endpoint indicators to monitor malaria control progress. Additionally, the largely outdoor infection and discovery of previously unknown and cryptic vectors suggest an increased risk of residual malaria transmission and, thus, a constraint on effective malaria prevention and control.
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Affiliation(s)
- Aklilu K Belay
- International Centre of Insect Physiology and Ecology, P.O. Box 30772-00100, Nairobi, Kenya
- Department of Zoology and Entomology, University of Pretoria, Private Bag X0028, Pretoria, South Africa
| | - Abebe Asale
- International Centre of Insect Physiology and Ecology, P.O. Box 5689, Addis Ababa, Ethiopia
| | - Catherine L Sole
- Department of Zoology and Entomology, University of Pretoria, Private Bag X0028, Pretoria, South Africa
| | - Fiona Kinya
- International Centre of Insect Physiology and Ecology, P.O. Box 30772-00100, Nairobi, Kenya
| | - Abdullahi A Yusuf
- Department of Zoology and Entomology, University of Pretoria, Private Bag X0028, Pretoria, South Africa
| | - Baldwyn Torto
- International Centre of Insect Physiology and Ecology, P.O. Box 30772-00100, Nairobi, Kenya
- Department of Zoology and Entomology, University of Pretoria, Private Bag X0028, Pretoria, South Africa
| | - Clifford M Mutero
- International Centre of Insect Physiology and Ecology, P.O. Box 30772-00100, Nairobi, Kenya
- School of Health Systems and Public Health, University of Pretoria, Private Bag X0028, Pretoria, South Africa
| | - David P Tchouassi
- International Centre of Insect Physiology and Ecology, P.O. Box 30772-00100, Nairobi, Kenya.
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Tesfaye M, Assefa A, Hailgiorgis H, Gidey B, Mohammed H, Tollera G, Tasew G, Assefa G, Bekele W, Mamo H. Therapeutic efficacy and safety of artemether-lumefantrine for uncomplicated Plasmodium falciparum malaria treatment in Metehara, Central-east Ethiopia. Malar J 2024; 23:184. [PMID: 38867217 PMCID: PMC11170838 DOI: 10.1186/s12936-024-04991-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Accepted: 05/20/2024] [Indexed: 06/14/2024] Open
Abstract
BACKGROUND Malaria remains a major global health problem although there was a remarkable achievement between 2000 and 2015. Malaria drug resistance, along with several other factors, presents a significant challenge to malaria control and elimination efforts. Numerous countries in sub-Saharan Africa have documented the presence of confirmed or potential markers of partial resistance against artemisinin, the drug of choice for the treatment of uncomplicated Plasmodium falciparum malaria. The World Health Organization (WHO) recommends regular surveillance of artemisinin therapeutic efficacy to inform policy decisions. METHODS This study aimed to evaluate the therapeutic efficacy of artemether-lumefantrine (AL), which is the first-line treatment for uncomplicated P. falciparum malaria in Ethiopia since 2004. Using a single-arm prospective evaluation design, the study assessed the clinical and parasitological responses of patients with uncomplicated P. falciparum malaria in Metehara Health Centre, central-east Ethiopia. Out of 2332 malaria suspects (1187 males, 1145 females) screened, 80 (50 males, 30 females) were enrolled, followed up for 28 days, and 73 (44 males, 29 females) completed the follow up. The study was conducted and data was analysed by employing the per-protocol and Kaplan-Meier analyses following the WHO Malaria Therapeutic Efficacy Evaluation Guidelines 2009. RESULTS The results indicated rapid parasite clearance and resolution of clinical symptoms, with all patients achieving complete recovery from asexual parasitaemia and fever by day (D) 3. The prevalence of gametocytes decreased from 6.3% on D0 to 2.5% on D2, D3, D7, and ultimately achieving complete clearance afterward. CONCLUSION The overall cure rate for AL treatment was 100%, demonstrating its high efficacy in effectively eliminating malaria parasites in patients. No serious adverse events related to AL treatment were reported during the study, suggesting its safety and tolerability among the participants. These findings confirm that AL remains a highly efficacious treatment for uncomplicated P. falciparum malaria in the study site after 20 years of its introduction in Ethiopia.
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Affiliation(s)
- Mahelet Tesfaye
- Department of Microbial, Cellular and Molecular Biology, College of Natural and Computational Sciences, Addis Ababa University, Addis Ababa, Ethiopia
| | - Ashenafi Assefa
- Ethiopian Public Health Institute, Addis Ababa, Ethiopia
- Institute of Infectious Disease and Global Health, University of North Carolina, Chapel Hill, USA
| | | | | | | | | | - Geremew Tasew
- Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | | | - Worku Bekele
- World Health Organization, Addis Ababa, Ethiopia
| | - Hassen Mamo
- Department of Microbial, Cellular and Molecular Biology, College of Natural and Computational Sciences, Addis Ababa University, Addis Ababa, Ethiopia.
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Zhou G, Taffese HS, Zhong D, Wang X, Lee MC, Degefa T, Getachew D, Haileselassie W, Hawaria D, Yewhalaw D, Yan G. Resurgence of Clinical Malaria in Ethiopia in the Era of Anopheles stephensi Invasion. RESEARCH SQUARE 2024:rs.3.rs-4468361. [PMID: 38947038 PMCID: PMC11213191 DOI: 10.21203/rs.3.rs-4468361/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/02/2024]
Abstract
Background The invasion of Anopheles stephensi into Africa poses a potential threat to malaria control and elimination on the continent. However, it is not clear if the recent malaria resurgence in Ethiopia has linked to the expansion of An. stephensi. We aimed to summarize the major achievements and lesson learnt in malaria control in Ethiopia from 2001 to 2022, to assess the new challenges and prospects for the control of An. stephensi. Methods and findings We obtained the clinical malaria case reports, antimalarial drug treatment records, insecticide-treated and long-lasting insecticidal net (ITN/LLIN) distribution and utilization records, and indoor residual spraying (IRS) coverage data from the Ethiopian Ministry of Health (MoH) for the period 2001-2022. We analyzed clinical malaria hotspots using spatially optimized hotspot analysis. We investigated malaria outbreaks in 2022 and examined the potential role of An. stephensi in the outbreaks.Clinical malaria cases in Ethiopia decreased by 80%, from 5.2 million cases (11% confirmed) in 2004 to 1.0 million cases (92% confirmed) in 2018; however, cases increased steadily to 2.6 million confirmed cases (98% confirmed) in 2022. Plasmodium vivax cases and proportion have increased significantly in the past 5 years. Clinical malaria hotspots are concentrated along the western Ethiopian border areas and have grown significantly from 2017 to 2022. Major malaria outbreaks in 2022/23 were detected in multiple sites across Ethiopia, and An. stephensi was the predominant vector in some of these sites, however, it was absence from many of the outbreak sites. Conclusions The malaria burden has been significantly reduced in Ethiopia in the past two decades, but in recent years it has increased substantially, and the cause of such increase is a subject of further investigation. Major gaps exist in An. stephensi research, including vector ecology, surveillance, and control tools, especially for adult mosquito control.
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Waymire E, Samake JN, Gunarathna I, Carter TE. A decade of invasive Anopheles stephensi sequence-based identification: toward a global standard. Trends Parasitol 2024; 40:477-486. [PMID: 38755024 PMCID: PMC11381088 DOI: 10.1016/j.pt.2024.04.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Revised: 04/15/2024] [Accepted: 04/15/2024] [Indexed: 05/18/2024]
Abstract
Anopheles stephensi is an invasive malaria vector in Africa that has been implicated in malaria outbreaks in the Horn of Africa. In 10 years, it has been detected as far east as Djibouti and as far west as Ghana. Early detections were mostly incidental, but now active surveillance in Africa has been updated to include An. stephensi. Morphological identification of An. stephensi from native vectors can be challenging, thus, sequence-based assays have been used to confirm identification during initial detections. Methods of sequence-based identification of An. stephensi have varied across initial detections to date. Here, we summarize initial detections, make suggestions that could provide a standardized approach, and discuss how sequences can inform additional genomic studies beyond species identification.
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Hailemeskel E, Tebeje SK, Ramjith J, Ashine T, Lanke K, Behaksra SW, Emiru T, Tsegaye T, Gashaw A, Kedir S, Chali W, Esayas E, Tafesse T, Abera H, Bulto MG, Shumie G, Petros B, Mamo H, Drakeley C, Gadisa E, Bousema T, Tadesse FG. Dynamics of asymptomatic Plasmodium falciparum and Plasmodium vivax infections and their infectiousness to mosquitoes in a low transmission setting of Ethiopia: a longitudinal observational study. Int J Infect Dis 2024; 143:107010. [PMID: 38490637 DOI: 10.1016/j.ijid.2024.107010] [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: 09/29/2023] [Revised: 03/11/2024] [Accepted: 03/11/2024] [Indexed: 03/17/2024] Open
Abstract
OBJECTIVE A 15-month longitudinal study was conducted to determine the duration and infectivity of asymptomatic qPCR-detected Plasmodium falciparum and Plasmodium vivax infections in Ethiopia. METHOD Total parasite and gametocyte kinetics were determined by molecular methods; infectivity to Anopheles arabiensis mosquitoes by repeated membrane feeding assays. Infectivity results were contrasted with passively recruited symptomatic malaria cases. RESULTS For P. falciparum and P. vivax infections detected at enrolment, median durations of infection were 37 days (95% confidence interval [CI], 15-93) and 60 days (95% CI, 18-213), respectively. P. falciparum and P. vivax parasite densities declined over the course of infections. From 47 feeding assays on 22 asymptomatic P. falciparum infections, 6.4% (3/47) were infectious and these infected 1.8% (29/1579) of mosquitoes. No transmission was observed in feeding assays on asymptomatic P. vivax mono-infections (0/56); one mixed-species infection was highly infectious. Among the symptomatic cases, 4.3% (2/47) of P. falciparum and 73.3% (53/86) of P. vivax patients were infectious to mosquitoes. CONCLUSION The majority of asymptomatic infections were of short duration and low parasite density. Only a minority of asymptomatic individuals were infectious to mosquitoes. This contrasts with earlier findings and is plausibly due to the low parasite densities in this population.
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Affiliation(s)
- Elifaged Hailemeskel
- Armauer Hansen Research Institute, Addis Ababa, Ethiopia; Department of Medical Microbiology and Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, Netherlands; Department of Biology, College of Natural and Computational Sciences, Wollo university, Dessie, Ethiopia; Department of Microbial, Cellular and Molecular Biology, Addis Ababa University, Addis Ababa, Ethiopia
| | - Surafel K Tebeje
- Armauer Hansen Research Institute, Addis Ababa, Ethiopia; Department of Medical Microbiology and Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, Netherlands
| | - Jordache Ramjith
- Department of Medical Microbiology and Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, Netherlands
| | | | - Kjerstin Lanke
- Department of Medical Microbiology and Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, Netherlands
| | | | - Tadele Emiru
- Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | - Tizita Tsegaye
- Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | - Abrham Gashaw
- Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | - Soria Kedir
- Adama Regional Laboratory, Oromia Region Health Bureau, Adama, Ethiopia
| | - Wakweya Chali
- Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | | | | | - Haile Abera
- Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | | | - Girma Shumie
- Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | - Beyene Petros
- Department of Microbial, Cellular and Molecular Biology, Addis Ababa University, Addis Ababa, Ethiopia
| | - Hassen Mamo
- Department of Microbial, Cellular and Molecular Biology, Addis Ababa University, Addis Ababa, Ethiopia
| | - Chris Drakeley
- London School of Hygiene & Tropical Medicine, London, United Kingdom
| | | | - Teun Bousema
- Department of Medical Microbiology and Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, Netherlands
| | - Fitsum G Tadesse
- Armauer Hansen Research Institute, Addis Ababa, Ethiopia; Department of Medical Microbiology and Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, Netherlands; London School of Hygiene & Tropical Medicine, London, United Kingdom.
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Rosenthal PJ, Asua V, Conrad MD. Emergence, transmission dynamics and mechanisms of artemisinin partial resistance in malaria parasites in Africa. Nat Rev Microbiol 2024; 22:373-384. [PMID: 38321292 DOI: 10.1038/s41579-024-01008-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/02/2024] [Indexed: 02/08/2024]
Abstract
Malaria, mostly due to Plasmodium falciparum infection in Africa, remains one of the most important infectious diseases in the world. Standard treatment for uncomplicated P. falciparum malaria is artemisinin-based combination therapy (ACT), which includes a rapid-acting artemisinin derivative plus a longer-acting partner drug, and standard therapy for severe P. falciparum malaria is intravenous artesunate. The efficacy of artemisinins and ACT has been threatened by the emergence of artemisinin partial resistance in Southeast Asia, mediated principally by mutations in the P. falciparum Kelch 13 (K13) protein. High ACT treatment failure rates have occurred when resistance to partner drugs is also seen. Recently, artemisinin partial resistance has emerged in Rwanda, Uganda and the Horn of Africa, with independent emergences of different K13 mutants in each region. In this Review, we summarize our current knowledge of artemisinin partial resistance and focus on the emergence of resistance in Africa, including its epidemiology, transmission dynamics and mechanisms. At present, the clinical impact of emerging resistance in Africa is unclear and most available evidence suggests that the efficacies of leading ACTs remain excellent, but there is an urgent need to better appreciate the extent of the problem and its consequences for the treatment and control of malaria.
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Affiliation(s)
| | - Victor Asua
- Infectious Diseases Research Collaboration, Kampala, Uganda
- University of Tübingen, Tübingen, Germany
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Boresa K, Belay T, Biruksew A, Alemayehu E, Zemene E. Ten-year trend analysis of malaria prevalence in Gindabarat district, West Shawa Zone, Oromia Regional State, Western Ethiopia. Malar J 2024; 23:152. [PMID: 38755638 PMCID: PMC11100101 DOI: 10.1186/s12936-024-04975-2] [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: 02/06/2024] [Accepted: 05/03/2024] [Indexed: 05/18/2024] Open
Abstract
BACKGROUND Malaria is a major public health concern in Ethiopia, where more than half of the population lives in malaria risk areas. While several studies have been conducted in different eco-epidemiological settings in Ethiopia, there is a notable scarcity of data on the prevalence of malaria in the Gindabarat district. Therefore, this study aimed to analyse 10-year trend of malaria prevalence in Gindabarat district, West Shawa Zone of Oromia, Western Ethiopia. METHODS A retrospective laboratory record review was conducted at Gindabarat General Hospital and Gindabarat District Health Office from September 2011 to August 2020. The retrieved data included the date of examination, age, sex and laboratory results of the blood smears, including the Plasmodium species identified. Data were summarized and presented in the form of tables, figures, and frequencies to present the results. The data were analysed using SPSS (version 25.0) and Microsoft Excel. RESULTS Over the course of 10 years, a total of 11,478 blood smears were examined in the public health facilities in the district. Of the total blood smears examined, 1372 (11.95%) were microscopically confirmed malaria. Plasmodium falciparum, Plasmodium vivax and mixed infections (P. falciparum and P. vivax) accounted for 70.77%, 20.55% and 8.67% of the cases, respectively. Malaria prevalence was significantly higher among individuals aged ≥ 15 years (12.60%, x2 = 13.6, df = 2, p = 0.001) and males (14.21%, x2 = 59.7, df = 1, p = 0.001). The highest number of malaria cases was recorded from September to November. CONCLUSION Malaria remains a public health problem in the district. P. falciparum was the most predominant parasite species in the area. Malaria prevalence was significantly higher among individuals aged ≥ 15 years and males. There was a remarkable fluctuation in the number of malaria cases in different months and years. In the study area malaria cases peaked in 2015 and 2017 then decreasing from 2017 to 2019, with sharp increase in 2020. Moreover, this study showed malaria cases were reported in all seasons and months, but the highest was observed from September to November. Strengthening malaria control activities is essential to further reduce the burden of malaria and pave the way for the anticipated elimination.
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Affiliation(s)
- Kinfu Boresa
- Department of Medical Laboratory Sciences, Institute of Health Sciences, Wallaga University, Nekemte, Ethiopia.
| | - Tariku Belay
- School of Medical Laboratory Sciences, Institute of Health, Jimma University, Jimma, Ethiopia
| | - Abdissa Biruksew
- School of Medical Laboratory Sciences, Institute of Health, Jimma University, Jimma, Ethiopia
| | - Eshetu Alemayehu
- Department of Epidemiology and Biostatistics, Institute of Health, Jimma University, Jimma, Ethiopia
| | - Endalew Zemene
- School of Medical Laboratory Sciences, Institute of Health, Jimma University, Jimma, Ethiopia
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20
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Platon L, Leroy D, Fidock DA, Ménard D. Drug-induced stress mediates Plasmodium falciparum ring-stage growth arrest and reduces in vitro parasite susceptibility to artemisinin. Microbiol Spectr 2024; 12:e0350023. [PMID: 38363132 PMCID: PMC10986542 DOI: 10.1128/spectrum.03500-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Accepted: 01/15/2024] [Indexed: 02/17/2024] Open
Abstract
During blood-stage infection, Plasmodium falciparum parasites are constantly exposed to a range of extracellular stimuli, including host molecules and drugs such as artemisinin derivatives, the mainstay of artemisinin-based combination therapies currently used as first-line treatment worldwide. Partial resistance of P. falciparum to artemisinin has been associated with mutations in the propeller domain of the Pfkelch13 gene, resulting in a fraction of ring stages that are able to survive exposure to artemisinin through a temporary growth arrest. Here, we investigated whether the growth arrest in ring-stage parasites reflects a general response to stress. We mimicked a stressful environment in vitro by exposing parasites to chloroquine or dihydroartemisinin (DHA). We observed that early ring-stage parasites pre-exposed to a stressed culture supernatant exhibited a temporary growth arrest and a reduced susceptibility to DHA, as assessed by the ring-stage survival assay, irrespective of their Pfkelch13 genotype. These data suggest that temporary growth arrest of early ring stages may be a constitutive, Pfkelch13-independent survival mechanism in P. falciparum.IMPORTANCEPlasmodium falciparum ring stages have the ability to sense the extracellular environment, regulate their growth, and enter a temporary growth arrest state in response to adverse conditions such as drug exposure. This temporary growth arrest results in reduced susceptibility to artemisinin in vitro. The signal responsible for this process is thought to be small molecules (less than 3 kDa) released by stressed mature-stage parasites. These data suggest that Pfkelch13-dependent artemisinin resistance and the growth arrest phenotype are two complementary but unrelated mechanisms of ring-stage survival in P. falciparum. This finding provides new insights into the field of P. falciparum antimalarial drug resistance by highlighting the extracellular compartment and cellular communication as an understudied mechanism.
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Affiliation(s)
- Lucien Platon
- Malaria Genetics and Resistance Unit, INSERM U1201, Institut Pasteur, Université Paris Cité, Paris, France
- Sorbonne Université, Collège Doctoral ED 515 Complexité du Vivant, Paris, France
- Malaria Parasite Biology and Vaccines Unit, Institut Pasteur, Université Paris Cité, Paris, France
- Institute of Parasitology and Tropical Diseases, UR7292 Dynamics of Host–Pathogen Interactions, Université de Strasbourg, Strasbourg, France
| | - Didier Leroy
- Department of Drug Discovery, Medicines for Malaria Venture, Geneva, Switzerland
| | - David A. Fidock
- Department of Microbiology and Immunology, Columbia University Irving Medical Center, New York, New York, USA
- Center for Malaria Therapeutics and Antimicrobial Resistance, Division of Infectious Diseases, Department of Medicine, Columbia University Irving Medical Center, New York, New York, USA
| | - Didier Ménard
- Malaria Genetics and Resistance Unit, INSERM U1201, Institut Pasteur, Université Paris Cité, Paris, France
- Malaria Parasite Biology and Vaccines Unit, Institut Pasteur, Université Paris Cité, Paris, France
- Institute of Parasitology and Tropical Diseases, UR7292 Dynamics of Host–Pathogen Interactions, Université de Strasbourg, Strasbourg, France
- Laboratory of Parasitology and Medical Mycology, CHU Strasbourg, Strasbourg, France
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21
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Ashine T, Eyasu A, Asmamaw Y, Simma E, Zemene E, Epstein A, Brown R, Negash N, Kochora A, Reynolds AM, Bulto MG, Tafesse T, Dagne A, Lukus B, Esayas E, Behaksra SW, Woldekidan K, Kassa FA, Deressa JD, Assefa M, Dillu D, Assefa G, Solomon H, Zeynudin A, Massebo F, Sedda L, Donnelly MJ, Wilson AL, Weetman D, Gadisa E, Yewhalaw D. Spatiotemporal distribution and bionomics of Anopheles stephensi in different eco-epidemiological settings in Ethiopia. Parasit Vectors 2024; 17:166. [PMID: 38556881 PMCID: PMC10983662 DOI: 10.1186/s13071-024-06243-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Accepted: 03/11/2024] [Indexed: 04/02/2024] Open
Abstract
BACKGROUND Malaria is a major public health concern in Ethiopia, and its incidence could worsen with the spread of the invasive mosquito species Anopheles stephensi in the country. This study aimed to provide updates on the distribution of An. stephensi and likely household exposure in Ethiopia. METHODS Entomological surveillance was performed in 26 urban settings in Ethiopia from 2021 to 2023. A kilometer-by-kilometer quadrant was established per town, and approximately 20 structures per quadrant were surveyed every 3 months. Additional extensive sampling was conducted in 50 randomly selected structures in four urban centers in 2022 and 2023 to assess households' exposure to An. stephensi. Prokopack aspirators and CDC light traps were used to collect adult mosquitoes, and standard dippers were used to collect immature stages. The collected mosquitoes were identified to species level by morphological keys and molecular methods. PCR assays were used to assess Plasmodium infection and mosquito blood meal source. RESULTS Catches of adult An. stephensi were generally low (mean: 0.15 per trap), with eight positive sites among the 26 surveyed. This mosquito species was reported for the first time in Assosa, western Ethiopia. Anopheles stephensi was the predominant species in four of the eight positive sites, accounting for 75-100% relative abundance of the adult Anopheles catches. Household-level exposure, defined as the percentage of households with a peridomestic presence of An. stephensi, ranged from 18% in Metehara to 30% in Danan. Anopheles arabiensis was the predominant species in 20 of the 26 sites, accounting for 42.9-100% of the Anopheles catches. Bovine blood index, ovine blood index and human blood index values were 69.2%, 32.3% and 24.6%, respectively, for An. stephensi, and 65.4%, 46.7% and 35.8%, respectively, for An. arabiensis. None of the 197 An. stephensi mosquitoes assayed tested positive for Plasmodium sporozoite, while of the 1434 An. arabiensis mosquitoes assayed, 62 were positive for Plasmodium (10 for P. falciparum and 52 for P. vivax). CONCLUSIONS This study shows that the geographical range of An. stephensi has expanded to western Ethiopia. Strongly zoophagic behavior coupled with low adult catches might explain the absence of Plasmodium infection. The level of household exposure to An. stephensi in this study varied across positive sites. Further research is needed to better understand the bionomics and contribution of An. stephensi to malaria transmission.
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Affiliation(s)
- Temesgen Ashine
- Department of Biology, College of Natural and Computational Sciences, Arba Minch University, Arba Minch, Ethiopia.
- Malaria and NTD Research Division, Armauer Hansen Research Institute, Addis Ababa, Ethiopia.
| | - Adane Eyasu
- Tropical and Infectious Diseases Research Center, Jimma University, Jimma, Ethiopia
| | - Yehenew Asmamaw
- Malaria and NTD Research Division, Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | - Eba Simma
- Department of Biology, College of Natural Sciences, Jimma University, Jimma, Ethiopia
| | - Endalew Zemene
- School of Medical Laboratory Sciences, Institute of Health, Jimma University, Jimma, Ethiopia
| | - Adrienne Epstein
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Rebecca Brown
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Nigatu Negash
- Malaria and NTD Research Division, Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | - Abena Kochora
- Malaria and NTD Research Division, Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | - Alison M Reynolds
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | | | - Temesgen Tafesse
- Malaria and NTD Research Division, Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | - Alemayehu Dagne
- Tropical and Infectious Diseases Research Center, Jimma University, Jimma, Ethiopia
| | - Biniyam Lukus
- Tropical and Infectious Diseases Research Center, Jimma University, Jimma, Ethiopia
| | - Endashaw Esayas
- Malaria and NTD Research Division, Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | | | - Kidist Woldekidan
- Malaria and NTD Research Division, Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | | | - Jimma Dinsa Deressa
- Malaria and NTD Research Division, Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | - Muluken Assefa
- Malaria and NTD Research Division, Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | - Dereje Dillu
- Disease Prevention and Control Directorate, Ethiopian Federal Ministry of Health, Addis Ababa, Ethiopia
| | - Gudissa Assefa
- Disease Prevention and Control Directorate, Ethiopian Federal Ministry of Health, Addis Ababa, Ethiopia
| | - Hiwot Solomon
- Disease Prevention and Control Directorate, Ethiopian Federal Ministry of Health, Addis Ababa, Ethiopia
| | - Ahmed Zeynudin
- School of Medical Laboratory Sciences, Institute of Health, Jimma University, Jimma, Ethiopia
| | - Fekadu Massebo
- Department of Biology, College of Natural and Computational Sciences, Arba Minch University, Arba Minch, Ethiopia
| | - Luigi Sedda
- Lancaster Ecology and Epidemiology Group, Lancaster Medical School, Lancaster University, Lancaster, UK
| | - Martin James Donnelly
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Anne L Wilson
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - David Weetman
- Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK
| | - Endalamaw Gadisa
- Malaria and NTD Research Division, Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | - Delenasaw Yewhalaw
- Tropical and Infectious Diseases Research Center, Jimma University, Jimma, Ethiopia
- School of Medical Laboratory Sciences, Institute of Health, Jimma University, Jimma, Ethiopia
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22
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Holzschuh A, Ewnetu Y, Carlier L, Lerch A, Gerlovina I, Baker SC, Yewhalaw D, Haileselassie W, Berhane N, Lemma W, Koepfli C. Plasmodium falciparum transmission in the highlands of Ethiopia is driven by closely related and clonal parasites. Mol Ecol 2024; 33:e17292. [PMID: 38339833 DOI: 10.1111/mec.17292] [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: 07/12/2023] [Revised: 12/28/2023] [Accepted: 01/30/2024] [Indexed: 02/12/2024]
Abstract
Malaria cases are frequently recorded in the Ethiopian highlands even at altitudes above 2000 m. The epidemiology of malaria in the Ethiopian highlands, and, in particular, the role of importation by human migration from the highly endemic lowlands is not well understood. We sequenced 187 Plasmodium falciparum samples from two sites in the Ethiopian highlands, Gondar (n = 159) and Ziway (n = 28), using a multiplexed droplet digital PCR (ddPCR)-based amplicon sequencing method targeting 35 microhaplotypes and drug resistance loci. Here, we characterize the parasite population structure and genetic relatedness. We identify moderate parasite diversity (mean HE : 0.54) and low infection complexity (74.9% monoclonal). A significant percentage of infections share microhaplotypes, even across transmission seasons and sites, indicating persistent local transmission. We identify multiple clusters of clonal or near-clonal infections, highlighting high genetic relatedness. Only 6.3% of individuals diagnosed with P. falciparum reported recent travel. Yet, in clonal or near-clonal clusters, infections of travellers were frequently observed first in time, suggesting that parasites may have been imported and then transmitted locally. 31.1% of infections are pfhrp2-deleted and 84.4% pfhrp3-deleted, and 28.7% have pfhrp2/3 double deletions. Parasites with pfhrp2/3 deletions and wild-type parasites are genetically distinct. Mutations associated with resistance to sulphadoxine-pyrimethamine or suggested to reduce sensitivity to lumefantrine are observed at near-fixation. In conclusion, genomic data corroborate local transmission and the importance of intensified control in the Ethiopian highlands.
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Affiliation(s)
- Aurel Holzschuh
- Department of Biological Sciences, Eck Institute for Global Health, University of Notre Dame, Notre Dame, Indiana, USA
| | - Yalemwork Ewnetu
- Department of Medical Biotechnology, University of Gondar, Gondar, Ethiopia
| | - Lise Carlier
- Trinity Centre for Global Health, Trinity College Dublin, Dublin, Ireland
- Noul Inc., Seoul, Republic of Korea
| | - Anita Lerch
- Department of Biological Sciences, Eck Institute for Global Health, University of Notre Dame, Notre Dame, Indiana, USA
| | - Inna Gerlovina
- Department of Medicine, Division of HIV, ID and Global Medicine, EPPIcenter Research Program, University of California, San Francisco, California, USA
| | - Sarah Cate Baker
- Trinity Centre for Global Health, Trinity College Dublin, Dublin, Ireland
| | - Delenasaw Yewhalaw
- Tropical and Infectious Disease Research Center, Jimma University, Jimma, Ethiopia
| | | | - Nega Berhane
- Department of Medical Biotechnology, University of Gondar, Gondar, Ethiopia
| | - Wossenseged Lemma
- Department of Medical Biotechnology, University of Gondar, Gondar, Ethiopia
| | - Cristian Koepfli
- Department of Biological Sciences, Eck Institute for Global Health, University of Notre Dame, Notre Dame, Indiana, USA
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Ebhodaghe FI, Sanchez-Vargas I, Isaac C, Foy BD, Hemming-Schroeder E. Sibling species of the major malaria vector Anopheles gambiae display divergent preferences for aquatic breeding sites in southern Nigeria. Malar J 2024; 23:60. [PMID: 38413961 PMCID: PMC10900747 DOI: 10.1186/s12936-024-04871-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Accepted: 02/06/2024] [Indexed: 02/29/2024] Open
Abstract
BACKGROUND When integrated with insecticide-treated bed nets, larval control of Anopheles mosquitoes could fast-track reductions in the incidence of human malaria. However, larval control interventions may deliver suboptimal outcomes where the preferred breeding places of mosquito vectors are not well known. This study investigated the breeding habitat choices of Anopheles mosquitoes in southern Nigeria. The objective was to identify priority sites for mosquito larval management in selected urban and periurban locations where malaria remains a public health burden. METHODS: Mosquito larvae were collected in urban and periurban water bodies during the wet-dry season interface in Edo, Delta, and Anambra States. Field-collected larvae were identified based on PCR gel-electrophoresis and amplicon sequencing, while the associations between Anopheles larvae and the properties and locations of water bodies were assessed using a range of statistical methods. RESULTS Mosquito breeding sites were either man-made (72.09%) or natural (27.91%) and mostly drainages (48.84%) and puddles (25.58%). Anopheles larvae occurred in drainages, puddles, stream margins, and a concrete well, and were absent in drums, buckets, car tires, and a water-holding iron pan, all of which contained culicine larvae. Wild-caught Anopheles larvae comprised Anopheles coluzzii (80.51%), Anopheles gambiae sensu stricto (s.s.) (11.54%), and Anopheles arabiensis (7.95%); a species-specific PCR confirmed the absence of the invasive urban malaria vector Anopheles stephensi among field-collected larvae. Anopheles arabiensis, An. coluzzii, and An. gambiae s.s. displayed preferences for turbid, lowland, and partially sunlit water bodies, respectively. Furthermore, An. arabiensis preferred breeding sites located outside 500 m of households, whereas An. gambiae s.s. and An. coluzzii had increased detection odds in sites within 500 m of households. Anopheles gambiae s.s. and An. coluzzii were also more likely to be present in natural water bodies; meanwhile, 96.77% of An. arabiensis were in man-made water bodies. Intraspecific genetic variations were little in the dominant vector An. coluzzii, while breeding habitat choices of populations made no statistically significant contributions to these variations. CONCLUSION Sibling malaria vectors in the An. gambiae complex display divergent preferences for aquatic breeding habitats in southern Nigeria. The findings are relevant for planning targeted larval control of An. coluzzii whose increasing evolutionary adaptations to urban ecologies are driving the proliferation of the mosquito, and An. arabiensis whose adults typically evade the effects of treated bed nets due to exophilic tendencies.
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Affiliation(s)
- Faith I Ebhodaghe
- Center for Vector-Borne Infectious Diseases, Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO, USA
| | - Irma Sanchez-Vargas
- Center for Vector-Borne Infectious Diseases, Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO, USA
| | - Clement Isaac
- Department of Zoology, Faculty of Life Sciences, Ambrose Alli University, Ekpoma, Edo State, Nigeria
| | - Brian D Foy
- Center for Vector-Borne Infectious Diseases, Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO, USA
| | - Elizabeth Hemming-Schroeder
- Center for Vector-Borne Infectious Diseases, Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO, USA.
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24
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Zhou G, Zhong D, Yewhalaw D, Yan G. Anopheles stephensi ecology and control in Africa. Trends Parasitol 2024; 40:102-105. [PMID: 38142196 DOI: 10.1016/j.pt.2023.11.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 11/29/2023] [Accepted: 11/30/2023] [Indexed: 12/25/2023]
Abstract
The encroachment and rapid spread of Anopheles stephensi across Africa presents a significant challenge to malaria control and elimination efforts. Understanding the ecology and behavior of An. stephensi will critically inform control measures and provide prerequisite knowledge for exploring new larval and adult control tools to contain its spread.
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Affiliation(s)
- Guofa Zhou
- Program in Public Health, University of California, Irvine, CA 92697, USA.
| | - Daibin Zhong
- Program in Public Health, University of California, Irvine, CA 92697, USA
| | - Delenasaw Yewhalaw
- Tropical and Infectious Diseases Research Centre, Jimma University, Jimma, Ethiopia
| | - Guiyun Yan
- Program in Public Health, University of California, Irvine, CA 92697, USA
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Assefa A, Fola AA, Tasew G. Emergence of Plasmodium falciparum strains with artemisinin partial resistance in East Africa and the Horn of Africa: is there a need to panic? Malar J 2024; 23:34. [PMID: 38273360 PMCID: PMC10809756 DOI: 10.1186/s12936-024-04848-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2023] [Accepted: 01/10/2024] [Indexed: 01/27/2024] Open
Abstract
The emergence and spread of artemisinin partial resistance in East and Horn of Africa is alarming. However, artemisinin-based combination therapy (ACT) generally remains efficacious for the treatment of falciparum malaria. The emergence of partial artemisinin resistance does not currently meet the criteria to initiate change on treatment guidelines nor affect ACT routine procurement and distribution. It is high time for scientists and transitional researchers to be more critical and vigilant on further changes so that national programmes will be able to make informed decisions as well as remain alert and prepared for any change that may be required in the future.
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Affiliation(s)
- Ashenafi Assefa
- Ethiopian Public Health Institute, Addis Ababa, Ethiopia.
- Institute of Global Health and Infectious Diseases, University of North Carolina School of Medicine, Chapel Hill, NC, USA.
| | - Abebe A Fola
- Center for Computational Molecular Biology, Brown University, Providence, RI, USA
| | - Geremew Tasew
- Ethiopian Public Health Institute, Addis Ababa, Ethiopia
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26
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Du Toit A. Urban malaria. Nat Rev Microbiol 2024; 22:1. [PMID: 37963975 DOI: 10.1038/s41579-023-00994-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2023]
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27
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Ménard D, Mihreteab S, Fidock DA. Artemisinin-Resistant HRP2-Negative Malaria in Eritrea. Reply. N Engl J Med 2023; 389:2497-2498. [PMID: 38157513 DOI: 10.1056/nejmc2312559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2024]
Affiliation(s)
- Didier Ménard
- Centre Hospitalier Universitaire Strasbourg, Strasbourg, France
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