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Orish VN, Kyeremateng C, Appiah BP, Addei IB, Ayaba MA, Kwadzokpui PK, Marinkovic A, Prakash S, Okorie C, Izurieta R, Sanyaolu A. Knowledge and perception of asymptomatic malaria in the Volta region of Ghana. Trans R Soc Trop Med Hyg 2024; 118:33-43. [PMID: 37534813 DOI: 10.1093/trstmh/trad049] [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: 03/17/2023] [Revised: 06/19/2023] [Accepted: 07/17/2023] [Indexed: 08/04/2023] Open
Abstract
BACKGROUND The control of asymptomatic malaria is considered a key aspect of malaria control. This study aimed to assess the knowledge and perception of asymptomatic malaria among people in Ho municipality of the Volta region. METHODS A descriptive cross-sectional study involving questionnaire administration was conducted among randomly sampled residents of the Ho municipality of the Volta region of Ghana. Using SPSS version 25 statistical software, frequency distributions and proportions were computed for sociodemographic variables while knowledge and perception about asymptomatic malaria were computed into percentages and categorized into three levels based on Bloom's cut-off for further analysis. Findings with p-values <0.05 were considered statistically significant. RESULTS Among the 200 participants, 197 (98.5%) were aware of malaria. The majority (116 [58.0%]) of the study participants agreed to the possibility of asymptomatic infection, but most (133 [66.5%]) of the community members did not know that asymptomatic individuals can still transmit infections. The majority of the participants (184 [92.0%]) showed interest in getting further education on asymptomatic malaria and a significant majority (180 [90.0%]) expressed a willingness to take treatment after testing positive without showing any symptoms. CONCLUSIONS Asymptomatic malaria control can be achieved through a mass testing and treatment strategy, therefore improving the knowledge and perception about asymptomatic malaria might improve malaria control.
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Affiliation(s)
- Verner N Orish
- Department of Microbiology and Immunology, School of Medicine, University of Health and Allied Sciences, Ho, Volta Region, Ghana
| | - Caleb Kyeremateng
- School of Medicine, University of Health and Allied Sciences, Ho, Ghana
| | - Baffoe P Appiah
- Department of Medical Laboratory Sciences, School of Allied Health Sciences, University of Health and Allied Sciences, Ho, Ghana
| | - Isaac B Addei
- School of Medicine, University of Health and Allied Sciences, Ho, Ghana
| | - Moses A Ayaba
- School of Medicine, University of Health and Allied Sciences, Ho, Ghana
| | | | | | | | - Chuku Okorie
- Department of Allied Health Sciences, Union College of Union County, Plainfield Campus, NJ, USA
| | - Ricardo Izurieta
- Department of Global Communicable Diseases, College of Public Health, University of South Florida, Tampa, FL, USA
| | - Adekunle Sanyaolu
- Department of Public Health, Federal Ministry of Health, Abuja, Nigeria
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Aidoo EK, Aboagye FT, Agginie GE, Botchway FA, Osei-Adjei G, Appiah M, Takyi RD, Sakyi SA, Amoah L, Arthur G, Lawson BW, Asmah RH, Boateng P, Ansah O, Krogfelt KA. Malaria elimination in Ghana: recommendations for reactive case detection strategy implementation in a low endemic area of Asutsuare, Ghana. Malar J 2024; 23:5. [PMID: 38167067 PMCID: PMC10759473 DOI: 10.1186/s12936-023-04792-z] [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: 10/01/2023] [Accepted: 11/15/2023] [Indexed: 01/05/2024] Open
Abstract
BACKGROUND Progress toward malaria elimination is increasing as many countries near zero indigenous malaria cases. In settings nearing elimination, interventions will be most effective at interrupting transmission when targeted at the residual foci of transmission. These foci may be missed due to asymptomatic infections. To solve this problem, the World Health Organization recommends reactive case detection (RACD). This case study was conducted to identify individuals with asymptomatic malaria, their predisposing risk factors and recommend RACD in Asutsuare, Ghana based on literature review and a cross sectional study. METHODS The study involved a search on PubMed and Google Scholar of literature published between 1st January, 2009-14th August, 2023 using the search terms "malaria" in "Asutsuare". Furthermore, structured questionnaires were administered to one hundred individuals without symptoms of malaria and screened using rapid diagnostic test (RDT) kits, microscopy and real-time polymerase chain reaction (rt-PCR). Malaria prevalence based on the three diagnostic techniques as well as potential malaria risk factors were assessed through questionnaires in a cross-sectional study. RESULTS Cumulatively, sixty-four (64) studies (Google Scholar, 57 and PubMed, 7) were reviewed and 22 studies included in the literature on malaria in Asutsuare, Ghana. Significant risk factors were occupation, distance from a house to a waterbody, age group and educational level. Out of the 100 samples, 3 (3%) were positive by RDT, 6 (6%) by microscopy and 9 (9%) by rt-PCR. Ages 5-14.9 years had the highest mean malaria parasite densities of 560 parasites/µl with Plasmodium falciparum as the dominant species in 4 participants. Moreover, in the age group ≥ 15, 2 participants (1 each) harboured P. falciparum and Plasmodium malariae parasites. RDT had a higher sensitivity (76.54%; CI95 66.82-85.54) than rt-PCR (33.33%; CI95 4.33-77.72), while both rt-PCR and RDT were observed to have a higher specificity (92.55; CI95 85.26-96.95) and (97.30; CI95 93.87-99.13), respectively in the diagnosis of malaria. CONCLUSION In Asutsuare, Ghana, a low endemic area, the elimination of malaria may require finding individuals with asymptomatic infections. Given the low prevalence of asymptomatic individuals identified in this study and as repleted in the literature review, which favours RACD, Asutsuare is a possible setting receptive for RACD implementation.
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Affiliation(s)
| | - Frank Twum Aboagye
- Bio-Medical and Public Health Research Unit, Council for Scientific and Industrial Research - Water Research Institute, Accra, Ghana
| | - George Edem Agginie
- Department of Medical Laboratory Technology, Accra Technical University, Accra, Ghana
| | - Felix Abekah Botchway
- Department of Medical Laboratory Technology, Accra Technical University, Accra, Ghana
| | - George Osei-Adjei
- Department of Medical Laboratory Technology, Accra Technical University, Accra, Ghana
| | - Michael Appiah
- Department of Medical Laboratory Technology, Accra Technical University, Accra, Ghana
| | - Ruth Duku Takyi
- Department of Medical Laboratory Technology, Accra Technical University, Accra, Ghana
| | - Samuel Asamoah Sakyi
- Department of Molecular Medicine, Kwame Nkrumah University of Science & Technology, University Post Office, Kumasi, Ghana
| | - Linda Amoah
- Department of Immunology, Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
| | - George Arthur
- Department of Medical Laboratory, Accra Psychiatric Hospital, Accra, Ghana
| | - Bernard Walter Lawson
- Department of Theoretical & Applied Biology, Kwame Nkrumah University of Science & Technology, University Post Office, Kumasi, Ghana
| | - Richard Harry Asmah
- Department of Biomedical Sciences, School of Basic and Biomedical Science, University of Health & Allied Sciences, Ho, Ghana
| | - Paul Boateng
- National Malaria Elimination Programme, Accra, Ghana
| | - Otubea Ansah
- National Malaria Elimination Programme, Accra, Ghana
| | - Karen Angeliki Krogfelt
- Department of Science and Environment, Unit of Molecular and Medical Biology, The PandemiX Center, Roskilde University, 4000, Roskilde, Denmark
- Department of Virus and Microbiological Special Diagnostics, Statens Serum Institut, 2300, Copenhagen, Denmark
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Mshani IH, Siria DJ, Mwanga EP, Sow BB, Sanou R, Opiyo M, Sikulu-Lord MT, Ferguson HM, Diabate A, Wynne K, González-Jiménez M, Baldini F, Babayan SA, Okumu F. Key considerations, target product profiles, and research gaps in the application of infrared spectroscopy and artificial intelligence for malaria surveillance and diagnosis. Malar J 2023; 22:346. [PMID: 37950315 PMCID: PMC10638832 DOI: 10.1186/s12936-023-04780-3] [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: 03/04/2023] [Accepted: 11/01/2023] [Indexed: 11/12/2023] Open
Abstract
Studies on the applications of infrared (IR) spectroscopy and machine learning (ML) in public health have increased greatly in recent years. These technologies show enormous potential for measuring key parameters of malaria, a disease that still causes about 250 million cases and 620,000 deaths, annually. Multiple studies have demonstrated that the combination of IR spectroscopy and machine learning (ML) can yield accurate predictions of epidemiologically relevant parameters of malaria in both laboratory and field surveys. Proven applications now include determining the age, species, and blood-feeding histories of mosquito vectors as well as detecting malaria parasite infections in both humans and mosquitoes. As the World Health Organization encourages malaria-endemic countries to improve their surveillance-response strategies, it is crucial to consider whether IR and ML techniques are likely to meet the relevant feasibility and cost-effectiveness requirements-and how best they can be deployed. This paper reviews current applications of IR spectroscopy and ML approaches for investigating malaria indicators in both field surveys and laboratory settings, and identifies key research gaps relevant to these applications. Additionally, the article suggests initial target product profiles (TPPs) that should be considered when developing or testing these technologies for use in low-income settings.
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Affiliation(s)
- Issa H Mshani
- Ifakara Health Institute, Environmental Health, and Ecological Sciences Department, Morogoro, United Republic of Tanzania.
- School of Biodiversity, One Health and Veterinary Medicine, University of Glasgow, Glasgow, UK.
| | - Doreen J Siria
- Ifakara Health Institute, Environmental Health, and Ecological Sciences Department, Morogoro, United Republic of Tanzania
- School of Biodiversity, One Health and Veterinary Medicine, University of Glasgow, Glasgow, UK
| | - Emmanuel P Mwanga
- Ifakara Health Institute, Environmental Health, and Ecological Sciences Department, Morogoro, United Republic of Tanzania
- School of Biodiversity, One Health and Veterinary Medicine, University of Glasgow, Glasgow, UK
| | - Bazoumana Bd Sow
- Department of Medical Biology and Public Health, Institut de Recherche en Sciences de la Santé (IRSS), Bobo-Dioulasso, Burkina Faso
| | - Roger Sanou
- Department of Medical Biology and Public Health, Institut de Recherche en Sciences de la Santé (IRSS), Bobo-Dioulasso, Burkina Faso
| | - Mercy Opiyo
- Centro de Investigação em Saúde de Manhiça (CISM), Maputo, Mozambique
- Malaria Elimination Initiative (MEI), Institute for Global Health Sciences, University of California, San Francisco, USA
| | - Maggy T Sikulu-Lord
- Faculty of Science, School of the Environment, The University of Queensland, Brisbane, QLD, Australia
| | - Heather M Ferguson
- Ifakara Health Institute, Environmental Health, and Ecological Sciences Department, Morogoro, United Republic of Tanzania
- School of Biodiversity, One Health and Veterinary Medicine, University of Glasgow, Glasgow, UK
| | - Abdoulaye Diabate
- Department of Medical Biology and Public Health, Institut de Recherche en Sciences de la Santé (IRSS), Bobo-Dioulasso, Burkina Faso
| | - Klaas Wynne
- School of Chemistry, The University of Glasgow, Glasgow, G12 8QQ, UK
| | - Mario González-Jiménez
- School of Biodiversity, One Health and Veterinary Medicine, University of Glasgow, Glasgow, UK
- School of Chemistry, The University of Glasgow, Glasgow, G12 8QQ, UK
| | - Francesco Baldini
- School of Biodiversity, One Health and Veterinary Medicine, University of Glasgow, Glasgow, UK
| | - Simon A Babayan
- School of Biodiversity, One Health and Veterinary Medicine, University of Glasgow, Glasgow, UK.
| | - Fredros Okumu
- Ifakara Health Institute, Environmental Health, and Ecological Sciences Department, Morogoro, United Republic of Tanzania.
- School of Biodiversity, One Health and Veterinary Medicine, University of Glasgow, Glasgow, UK.
- School of Life Sciences and Biotechnology, Nelson Mandela African Institution of Science and Technology, Arusha, United Republic of Tanzania.
- School of Public Health, The University of the Witwatersrand, Park Town, South Africa.
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Gehlot P, Vyas VK. Recent advances on patents of Plasmodium falciparum dihydroorotate dehydrogenase ( PfDHODH) inhibitors as antimalarial agents. Expert Opin Ther Pat 2023; 33:579-596. [PMID: 37942637 DOI: 10.1080/13543776.2023.2280596] [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: 06/26/2023] [Accepted: 11/03/2023] [Indexed: 11/10/2023]
Abstract
INTRODUCTION Pyrimidine nucleotides are essential for the parasite's growth and replication. Parasites have only a de novo pathway for the biosynthesis of pyrimidine nucleotides. Dihydroorotate dehydrogenase (DHODH) enzyme is involved in the rate-limiting step of the pyrimidine biosynthesis pathway. DHODH is a biochemical target for the discovery of new antimalarial agents. AREA COVERED This review discussed the development of patented PfDHODH inhibitors published between 2007 and 2023 along with their chemical structures and activities. EXPERT OPINION PfDHODH enzyme is involved in the rate-limiting fourth step of the pyrimidine biosynthesis pathway. Thus, inhibition of PfDHODH using species-selective inhibitors has drawn much attention for treating malaria because they inhibit parasite growth without affecting normal human functions. Looking at the current scenario of antimalarial drug resistance with most of the available antimalarial drugs, there is a huge need for targeted newer agents. Newer agents with unique mechanisms of action may be devoid of drug toxicity, adverse effects, and the ability of parasites to quickly gain resistance, and PfDHODH inhibitors can be those newer agents. Many PfDHODH inhibitors were patented in the past, and the dependency of Plasmodium on de novo pyrimidine provided a new approach for the development of novel antimalarial agents.
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Affiliation(s)
- Pinky Gehlot
- Department of Pharmaceutical Chemistry, Institute of Pharmacy, Nirma University, Ahmedabad, India
| | - Vivek K Vyas
- Department of Pharmaceutical Chemistry, Institute of Pharmacy, Nirma University, Ahmedabad, India
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Alemayehu A. Biology and epidemiology of Plasmodium falciparum and Plasmodium vivax gametocyte carriage: Implication for malaria control and elimination. Parasite Epidemiol Control 2023; 21:e00295. [PMID: 36950502 PMCID: PMC10025134 DOI: 10.1016/j.parepi.2023.e00295] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 01/01/2023] [Accepted: 02/27/2023] [Indexed: 03/09/2023] Open
Abstract
Malaria is among the leading public health problems worldwide. Female anopheles mosquito orchestrates the transmission of malaria by taking gametocytes and introducing sporozoite while taking blood meals. Interrupting transmission is the major strategy for malaria elimination. The gametocyte stage is essential for the onward transmission of malaria. Thus, understanding its basic biology and epidemiology is key to malaria control and elimination. Therefore, the current review focuses on revealing the biology, prevalence, and determinants of gametocyte carriage as well as its implication on mitigation of malaria. It also illustrates the role of asymptomatic and sub-microscopic Plasmodium infections and G-6-PD deficiency in gametocyte carriage and hence malaria transmission. Gametocytogenesis is initiated at committed merozoites and gives rise to the development of gametocytes. The trigger for gametocytogenesis depends on the host, parasite, and intervention factors. Gametocytes pass through five developmental stages identifiable by molecular markers. A considerable number of malaria patients carry gametocytes at a sub-microscopic level, thereby serving as a potential infectious reservoir of transmission. Factors involving the human host, Plasmodium parasite, and intervention parameters play a critical role in gametocyte biology and prevalence. The contribution of asymptomatic and sub-microscopic infections to malaria transmission is unknown. The clear impact of G-6-PD deficiency on malaria control and elimination remains unclear. Lack of clarity on such issues might impede the success of interventions. Basic science and epidemiological studies should continue to overcome the challenges and cope with the ever-evolving parasite and guide interventions.
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Affiliation(s)
- Aklilu Alemayehu
- School of Medical Laboratory Sciences, Institute of Health, Jimma University, Jimma, Ethiopia
- Department of Medical Laboratory Sciences, College of Medicine and Health Sciences, Arba Minch University, Arba Minch, Ethiopia
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Andolina C, Ramjith J, Rek J, Lanke K, Okoth J, Grignard L, Arinaitwe E, Briggs J, Bailey J, Aydemir O, Kamya MR, Greenhouse B, Dorsey G, Staedke SG, Drakeley C, Jonker M, Bousema T. Plasmodium falciparum gametocyte carriage in longitudinally monitored incident infections is associated with duration of infection and human host factors. Sci Rep 2023; 13:7072. [PMID: 37127688 PMCID: PMC10150352 DOI: 10.1038/s41598-023-33657-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 04/17/2023] [Indexed: 05/03/2023] Open
Abstract
Malaria transmission depends on the presence of Plasmodium gametocytes that are the only parasite life stage that can infect mosquitoes. Gametocyte production varies between infections and over the course of infections. Infection duration is highly important for gametocyte production but poorly quantified. Between 2017 and 2019 an all-age cohort of individuals from Tororo, eastern Uganda was followed by continuous passive and routine assessments. We longitudinally monitored 104 incident infections from 98 individuals who were sampled once every 28 days and on any day of symptoms. Among infections that lasted ≥ 3 months, gametocyte appearance was near-universal with 96% of infections having detectable gametocytes prior to clearance. However, most infections were of much shorter duration; 55.7% of asymptomatic infections were detected only once. When considering all asymptomatic infections, regardless of their duration, only 36.3% had detectable gametocytes on at least one time-point prior to parasite clearance. Infections in individuals with sickle-cell trait (HbAS) were more likely to have gametocytes detected (Hazard Rate (HR) = 2.68, 95% CI 1.12, 6.38; p = 0.0231) and had gametocytes detected at higher densities (Density Ratio (DR) = 9.19, 95% CI 2.79, 30.23; p = 0.0002) compared to infections in wildtype (HbAA) individuals. Our findings suggest that a large proportion of incident infections is too short in duration and of too low density to contribute to onward transmission.
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Affiliation(s)
- Chiara Andolina
- Department of Medical Microbiology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Jordache Ramjith
- Department of Medical Microbiology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
- Department for Health Evidence, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - John Rek
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Kjerstin Lanke
- Department of Medical Microbiology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Joseph Okoth
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Lynn Grignard
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, UK
| | | | - Jessica Briggs
- Department of Medicine, San Francisco General Hospital, University of California, San Francisco, USA
| | - Jeffrey Bailey
- Department of Pathology and Laboratory Medicine, Brown University, Providence, RI, USA
| | - Ozkan Aydemir
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, USA
| | - Moses R Kamya
- Infectious Diseases Research Collaboration, Kampala, Uganda
- Department of Medicine, Makerere University College of Health Sciences, Kampala, Uganda
| | - Bryan Greenhouse
- Department of Medicine, San Francisco General Hospital, University of California, San Francisco, USA
| | - Grant Dorsey
- Department of Medicine, San Francisco General Hospital, University of California, San Francisco, USA
| | - Sarah G Staedke
- Department of Clinical Research, London School of Hygiene and Tropical Medicine, London, UK
| | - Chris Drakeley
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, UK
| | - Marianne Jonker
- Department for Health Evidence, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Teun Bousema
- Department of Medical Microbiology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands.
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, UK.
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Opoku Afriyie S, Addison TK, Gebre Y, Mutala AH, Antwi KB, Abbas DA, Addo KA, Tweneboah A, Ayisi-Boateng NK, Koepfli C, Badu K. Accuracy of diagnosis among clinical malaria patients: comparing microscopy, RDT and a highly sensitive quantitative PCR looking at the implications for submicroscopic infections. Malar J 2023; 22:76. [PMID: 36870966 PMCID: PMC9985253 DOI: 10.1186/s12936-023-04506-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 02/18/2023] [Indexed: 03/06/2023] Open
Abstract
BACKGROUND The World Health Organization recommends parasitological confirmation of all suspected malaria cases by microscopy or rapid diagnostic tests (RDTs) before treatment. These conventional tools are widely used for point-of-care diagnosis in spite of their poor sensitivity at low parasite density. Previous studies in Ghana have compared microscopy and RDT using standard 18S rRNA PCR as reference with varying outcomes. However, how these conventional tools compare with ultrasensitive varATS qPCR has not been studied. This study, therefore, sought to investigate the clinical performance of microscopy and RDT assuming highly sensitive varATS qPCR as gold standard. METHODS 1040 suspected malaria patients were recruited from two primary health care centers in the Ashanti Region of Ghana and tested for malaria by microscopy, RDT, and varATS qPCR. The sensitivity, specificity, and predictive values were assessed using varATS qPCR as gold standard. RESULTS Parasite prevalence was 17.5%, 24.5%, and 42.1% by microscopy, RDT, and varATS qPCR respectively. Using varATS qPCR as the standard, RDT was more sensitive (55.7% vs 39.3%), equally specific (98.2% vs 98.3%), and reported higher positive (95.7% vs 94.5%) and negative predictive values (75.3% vs 69.0%) than microscopy. Consequently, RDT recorded better diagnostic agreement (kappa = 0.571) with varATS qPCR than microscopy (kappa = 0.409) for clinical detection of malaria. CONCLUSIONS RDT outperformed microscopy for the diagnosis of Plasmodium falciparum malaria in the study. However, both tests missed over 40% of infections that were detected by varATS qPCR. Novel tools are needed to ensure prompt diagnosis of all clinical malaria cases.
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Affiliation(s)
- Stephen Opoku Afriyie
- Department of Theoretical and Applied Biology, Kwame Nkrumah University of Science and Technology (KNUST), Kumasi, Ghana
| | - Thomas Kwame Addison
- Department of Theoretical and Applied Biology, Kwame Nkrumah University of Science and Technology (KNUST), Kumasi, Ghana
| | - Yilekal Gebre
- Department of Biological Sciences, University of Notre Dame, South Bend, IN, USA
| | - Abdul-Hakim Mutala
- Department of Theoretical and Applied Biology, Kwame Nkrumah University of Science and Technology (KNUST), Kumasi, Ghana
| | - Kwasi Baako Antwi
- Department of Theoretical and Applied Biology, Kwame Nkrumah University of Science and Technology (KNUST), Kumasi, Ghana
| | - Dawood Ackom Abbas
- Department of Theoretical and Applied Biology, Kwame Nkrumah University of Science and Technology (KNUST), Kumasi, Ghana
| | - Kofi Agyapong Addo
- Department of Theoretical and Applied Biology, Kwame Nkrumah University of Science and Technology (KNUST), Kumasi, Ghana
| | - Austine Tweneboah
- Department of Theoretical and Applied Biology, Kwame Nkrumah University of Science and Technology (KNUST), Kumasi, Ghana
| | | | - Cristian Koepfli
- Department of Biological Sciences, University of Notre Dame, South Bend, IN, USA.
| | - Kingsley Badu
- Department of Theoretical and Applied Biology, Kwame Nkrumah University of Science and Technology (KNUST), Kumasi, Ghana.
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Structure- and ligand-based drug design methods for the modeling of antimalarial agents: a review of updates from 2012 onwards. J Biomol Struct Dyn 2022; 40:10481-10506. [PMID: 34129805 DOI: 10.1080/07391102.2021.1932598] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Malaria still persists as one of the deadliest infectious disease having a huge morbidity and mortality affecting the higher population of the world. Structure and ligand-based drug design methods like molecular docking and MD simulations, pharmacophore modeling, QSAR and virtual screening are widely used to perceive the accordant correlation between the antimalarial activity and property of the compounds to design novel dominant and discriminant molecules. These modeling methods will speed-up antimalarial drug discovery, selection of better drug candidates for synthesis and to achieve potent and safer drugs. In this work, we have extensively reviewed the literature pertaining to the use and applications of various ligand and structure-based computational methods for the design of antimalarial agents. Different classes of molecules are discussed along with their target interactions pattern, which is responsible for antimalarial activity. Communicated by Ramaswamy H. Sarma.
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Epidémiology of malaria from 2019 to 2021 in the southeastern city of Franceville, Gabon. BMC Public Health 2022; 22:2313. [PMID: 36496354 PMCID: PMC9739344 DOI: 10.1186/s12889-022-14765-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 11/29/2022] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND In Gabon, a new national malaria control policy was implemented in 2003. It resulted in a decrease in the number of malaria cases in the country. In March 2020, the disruption of routine health services due to the COVID-19 pandemic has led to an increase in cases and deaths due to malaria. However, in Franceville, south-east Gabon, no data on malaria cases recorded before, during and after the COVID-19 epidemic has been published. Thus, the objective of this study was to determine the epidemiological characteristics of malaria in Franceville from 2019 to 2021. METHODS A retrospectively study of malaria cases was performed at the Hôpital de l'Amitié Sino-Gabonaise (HASG). Information regarding age, gender, malaria diagnosis by microscopy and hematology cell count were collected from laboratory registers from June 2019 to December 2021. Malaria data were analyzed and correlated with seasonal variations. RESULTS The data of 12,695 febrile patients were collected from the laboratory registers of the HASG, among which 4252 (33.5%) patients were found positive for malaria. The malaria prevalence was 37.5% in 2020 year. This prevalence was highest compared to the 2019 (29.6%) and 2021 (31.5%) year (p < 0.001). During the short rainy season (October to December), a large increase in malaria cases was observed all three year, from 2019 to 2021 (p > 0.05). CONCLUSION The prevalence of malaria in Franceville was very high during COVID-19 pandemic. It is therefore necessary to strengthen existing interventions and implement more effective interventions.
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Ikegbunam MN, Uba C, Flügge J, Abone H, Ezeagwuna D, Ushie S, Esimone C. Malaria surveillance amongst pregnant women attending antenatal care in private hospitals in Onitsha metropolis, South Eastern Nigeria. MALARIAWORLD JOURNAL 2022; 13:2. [PMID: 35813272 PMCID: PMC9242532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Background Recent reports suggest that pregnant women living in holoendemic regions of sub-Sahara Africa die in great numbers annually due to malaria disease resulting from their higher susceptibility, reduced immunity and demographic associated factors. This work investigated the prevalence of Plasmodium falciparum in pregnant women attending antenatal care (ANC) in selected private hospitals in Onitsha metropolis South East Nigeria. Methods Venous blood samples were collected from 270 pregnant women during ANC visits between October 2016 and December 2017. A questionnaire was used to collect demographic data, gestational age, knowledge of malaria and preventive measures while clinical presentations and symptoms were extracted from the physician's clerking form. Laboratory diagnosis was done using microscopy. The effect of the demographic variables and other associated factors on prevalence and parasite densities was studied using Chi-square and ANOVA tests. Results The overall P. falciparum prevalence was 42.6%. Prevalence varied with the maternal age, gestational age, preventive measures adopted by the pregnant women and clinical presentations. 27.8 % of the infected women were highly parasitized (>5000 parasites/μl); 67% had a moderate parasite density (1,000-4,999 parasites/μl) and 5.2% showed a low parasite density (1-999 parasites/μl). We observed that 35.2%, 30%, 18.9% and 5.2% of the study cohorts preferred and used treated bed nets, insecticides, windows and door screening and non-treated bed nets respectively as malaria preventive measures. 5.9% did not use any protection. Conclusions The findings of this study revealed high prevalence of malaria among pregnant women living in Onitsha metropolis with high mean parasite densities despite strong adherence to use of sulphadoxine-pyrimethamine (SP) for intermittent preventive treatment in pregnancy (IPTp) and other malaria preventive measures.
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Affiliation(s)
- Moses N. Ikegbunam
- Department of Pharmaceutical Microbiology and Biotechnology, Nnamdi Azikiwe University, Awka, Nigeria,Molecular Research Foundation for Students and Scientists, Nnamdi Azikiwe University, Awka, Nigeria,Institute for Tropical Medicine, Tübingen, Germany,,
| | - Chibuzo Uba
- Department of Pharmaceutical Microbiology and Biotechnology, Nnamdi Azikiwe University, Awka, Nigeria
| | | | - Harrison Abone
- Department of Pharmaceutical Microbiology and Biotechnology, Nnamdi Azikiwe University, Awka, Nigeria
| | - Dorothy Ezeagwuna
- Department of Parasitology and Entomology, Nnamdi Azikiwe University, Awka, Nigeria
| | - Simeon Ushie
- Department of Medical Microbiology and Parasitology, Nnamdi Azikiwe University, Awka, Nigeria
| | - Charles Esimone
- Department of Pharmaceutical Microbiology and Biotechnology, Nnamdi Azikiwe University, Awka, Nigeria,Molecular Research Foundation for Students and Scientists, Nnamdi Azikiwe University, Awka, Nigeria
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Chaudhury S, Bolton JS, Eller LA, Robb M, Ake J, Ngauy V, Regules JA, Kamau E, Bergmann-Leitner ES. Assessing Prevalence and Transmission Rates of Malaria through Simultaneous Profiling of Antibody Responses against Plasmodium and Anopheles Antigens. J Clin Med 2022; 11:jcm11071839. [PMID: 35407447 PMCID: PMC9000160 DOI: 10.3390/jcm11071839] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 03/12/2022] [Accepted: 03/23/2022] [Indexed: 01/23/2023] Open
Abstract
Reliably assessing exposure to mosquitoes carrying malaria parasites continues to be a challenge due to the lack of reliable, highly sensitive diagnostics with high-throughput potential. Here, we describe an approach that meets these requirements by simultaneously measuring immune responses to both disease vector and pathogen, using an electro-chemiluminescence-based multiplex assay platform. While using the same logistical steps as a classic ELISA, this platform allows for the multiplexing of up to ten antigens in a single well. This simple, reproducible, quantitative readout reports the magnitude, incidence, and prevalence of malaria infections in residents of malaria-endemic areas. By reporting exposure to both insect vectors and pathogen, the approach also provides insights into the efficacy of drugs and/or other countermeasures deployed against insect vectors aimed at reducing or eliminating arthropod-borne diseases. The high throughput of the assay enables the quick and efficient screening of sera from individuals for exposure to Plasmodium even if they are taking drug prophylaxis. We applied this assay to samples collected from controlled malaria infection studies, as well as those collected in field studies in malaria-endemic regions in Uganda and Kenya. The assay was sensitive to vector exposure, malaria infection, and endemicity, demonstrating its potential for use in malaria serosurveillance.
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Affiliation(s)
- Sidhartha Chaudhury
- Center Enabling Capabilities, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA;
| | - Jessica S. Bolton
- Biologics Research & Development, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA; (J.S.B.); (V.N.); (J.A.R.)
| | - Leigh Anne Eller
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD 20817, USA; (L.A.E.); (M.R.)
| | - Merlin Robb
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD 20817, USA; (L.A.E.); (M.R.)
| | - Julie Ake
- U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA; (J.A.); (E.K.)
| | - Viseth Ngauy
- Biologics Research & Development, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA; (J.S.B.); (V.N.); (J.A.R.)
| | - Jason A. Regules
- Biologics Research & Development, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA; (J.S.B.); (V.N.); (J.A.R.)
| | - Edwin Kamau
- U.S. Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA; (J.A.); (E.K.)
- Laboratory Medicine, Department of Pathology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
| | - Elke S. Bergmann-Leitner
- Biologics Research & Development, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA; (J.S.B.); (V.N.); (J.A.R.)
- Correspondence:
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12
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Agbana HB, Rogier E, Lo A, Abukari Z, Jones S, Gyan B, Aidoo M, Amoah LE. Detecting asymptomatic carriage of Plasmodium falciparum in southern Ghana: utility of molecular and serological diagnostic tools. Malar J 2022; 21:57. [PMID: 35183178 PMCID: PMC8858553 DOI: 10.1186/s12936-022-04078-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Accepted: 02/06/2022] [Indexed: 12/04/2022] Open
Abstract
Background Asymptomatic malaria infections can serve as potential reservoirs for malaria transmission. The density of parasites contained in these infections range from microscopic to submicroscopic densities, making the accurate detection of asymptomatic parasite carriage highly dependent on the sensitivity of the tools used for the diagnosis. This study sought to evaluate the sensitivities of a variety of molecular and serological diagnostic tools at determining the prevalence of asymptomatic Plasmodium falciparum parasite infections in two communities with varying malaria parasite prevalence. Methods Whole blood was collected from 194 afebrile participants aged between 6 and 70 years old living in a high (Obom) and a low (Asutsuare) malaria transmission setting of Ghana. Thick and thin blood smears, HRP2 based malaria rapid diagnostic test (RDT) and filter paper dried blood spots (DBS) were prepared from each blood sample. Genomic DNA was extracted from the remaining blood and used in Plasmodium specific photo-induced electron transfer polymerase chain reaction (PET-PCR) and Nested PCR, whilst the HRP2 antigen content of the DBS was estimated using a bead immunoassay. A comparison of malaria parasite prevalence as determined by each method was performed. Results Parasite prevalence in the high transmission site of Obom was estimated at 71.4%, 61.9%, 60%, 37.8% and 19.1% by Nested PCR, the HRP2 bead assay, PET-PCR, HRP2-RDT and microscopy respectively. Parasite prevalence in the low transmission site of Asutsuare was estimated at 50.1%, 11.2%, 5.6%, 0% and 2.2% by Nested PCR, the HRP2 bead assay, PET-PCR, RDT and microscopy, respectively. The diagnostic performance of Nested PCR, PET-PCR and the HRP2 bead assay was similar in Obom but in Asutsuare, Nested PCR had a significantly higher sensitivity than PET-PCR and the HRP2 bead assay, which had similar sensitivity. Conclusions Nested PCR exhibited the highest sensitivity by identifying the highest prevalence of asymptomatic P. falciparum in both the high and low parasite prevalence settings. However, parasite prevalence estimated by the HRP2 bead assay and PET-PCR had the highest level of inter-rater agreement relative to all the other tools tested and have the advantage of requiring fewer processing steps relative to Nested PCR and producing quantitative results. Supplementary Information The online version contains supplementary material available at 10.1186/s12936-022-04078-w.
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13
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Osarfo J, Ampofo GD, Tagbor H. Trends of malaria infection in pregnancy in Ghana over the past two decades: a review. Malar J 2022; 21:3. [PMID: 34983534 PMCID: PMC8725495 DOI: 10.1186/s12936-021-04031-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Accepted: 12/17/2021] [Indexed: 02/07/2023] Open
Abstract
Background There has been a global decline in malaria transmission over the past decade. However, not much is known of the impact of this observation on the burden of malaria infection in pregnancy in endemic regions including Ghana. A narrative review was undertaken to help describe trends in malaria infection in pregnancy in Ghana. Among others, such information is important in showing any progress made in malaria in pregnancy control. Methods To describe trends in pregnancy-associated malaria infection in Ghana, a search and review of literature reporting data on the prevalence of asymptomatic Plasmodium falciparum infection in pregnancy was conducted. Results Thirty-six (36) studies, conducted over 1994–2019, were included in the review. In the northern savannah zone with largely seasonal malaria transmission, prevalence appeared to reduce from about 50–60% in 1994–2010 to 13–26% by 2019. In the middle transitional/forest zone, where transmission is perennial with peaks in the rainy season, prevalence apparently reduced from 60% in the late 1990 s to about 5–20% by 2018. In the coastal savannah area, there was apparent reduction from 28 to 35% in 2003–2010 to 5–11% by 2018–2019. The burden of malaria infection in pregnancy continues to be highest among teenagers and younger-aged pregnant women and paucigravidae. Conclusions There appears to be a decline in asymptomatic parasite prevalence in pregnancy in Ghana though this has not been uniform across the different transmission zones. The greatest declines were noticeably in urban settings. Submicroscopic parasitaemia remains a challenge for control efforts. Further studies are needed to evaluate the impact of the reduced parasite prevalence on maternal anaemia and low birthweight and to assess the local burden of submicroscopic parasitaemia in relation to pregnancy outcomes. Supplementary Information The online version contains supplementary material available at 10.1186/s12936-021-04031-3.
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Affiliation(s)
- Joseph Osarfo
- Department of Community Medicine, School of Medicine, University of Health and Allied Sciences, Ho, Volta Region, Ghana.
| | - Gifty Dufie Ampofo
- Department of Community Medicine, School of Medicine, University of Health and Allied Sciences, Ho, Volta Region, Ghana
| | - Harry Tagbor
- Department of Community Medicine, School of Medicine, University of Health and Allied Sciences, Ho, Volta Region, Ghana
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14
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Broni FK, Acquah FK, Obiri-Yeboah D, Obboh EK, Sarpong E, Amoah LE. Profiling the Quality and Quantity of Naturally Induced Antibody Responses Against Pfs230 and Pfs48/45 Among Non-Febrile Children Living in Southern Ghana: A Longitudinal Study. Front Cell Infect Microbiol 2021; 11:770821. [PMID: 34900755 PMCID: PMC8656302 DOI: 10.3389/fcimb.2021.770821] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2021] [Accepted: 11/03/2021] [Indexed: 11/15/2022] Open
Abstract
A clear understanding of the properties of naturally induced antibody responses against transmission-blocking vaccine candidates can accelerate the understanding of the development of transmission-blocking immunity. This study characterized the naturally induced IgG responses against two leading transmission-blocking vaccine antigens, Pfs230 and Pfs48/45, in non-febrile children living in Simiw, Ghana. Consecutive sampling was used to recruit 84 non-febrile children aged from 6 to 12 years old into the 6-month (November 2017 until May 2018) longitudinal study. Venous blood (1 ml) was collected once every 2 months and used to determine hemoglobin levels, P. falciparum prevalence using microscopy and polymerase chain reaction, and the levels and relative avidity of IgG responses against Pfs230 and Pfs48/45 using indirect ELISA. IgG levels against Pfs230 and Pfs48/45 decreased from the start (November) to the middle (January) and end (March) of the dry season respectively, then they began to increase. Participants, especially older children (10-12 years old) with active infections generally had lower antibody levels against both antigens. The relative avidities of IgG against both antigens followed the trend of IgG levels until the middle of the dry season, after which the relative avidities of both antigens correlated inversely with the antibody levels. In conclusion, although IgG antibody levels against both Pfs48/45 and Pfs230 began to increase by the early rainy season, they were inversely correlated to their respective relative avidities.
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Affiliation(s)
- Fermin K. Broni
- Department of Microbiology and Immunology, School of Medical Sciences, University of Cape Coast, Cape Coast, Ghana
| | - Festus K. Acquah
- Immunology Department, Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
- West African Centre for Cell Biology of Infectious Pathogens, University of Ghana, Accra, Ghana
| | - Dorcas Obiri-Yeboah
- Department of Microbiology and Immunology, School of Medical Sciences, University of Cape Coast, Cape Coast, Ghana
- Directorate of Research, Innovation and Consultancy, University of Cape Coast, Cape Coast, Ghana
| | - Evans K. Obboh
- Department of Microbiology and Immunology, School of Medical Sciences, University of Cape Coast, Cape Coast, Ghana
| | - Esther Sarpong
- Department of Molecular Biology and Biotechnology, School of Biological Sciences, University of Cape Coast, Cape Coast, Ghana
| | - Linda E. Amoah
- Immunology Department, Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
- West African Centre for Cell Biology of Infectious Pathogens, University of Ghana, Accra, Ghana
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15
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Whittaker C, Slater H, Nash R, Bousema T, Drakeley C, Ghani AC, Okell LC. Global patterns of submicroscopic Plasmodium falciparum malaria infection: insights from a systematic review and meta-analysis of population surveys. LANCET MICROBE 2021; 2:e366-e374. [PMID: 34382027 PMCID: PMC8332195 DOI: 10.1016/s2666-5247(21)00055-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Background Adoption of molecular techniques to detect Plasmodium falciparum infection has revealed many previously undetected (by microscopy) yet transmissible low-density infections. The proportion of these infections is typically highest in low transmission settings, but drivers of submicroscopic infection remain unclear. Here, we updated a previous systematic review of asexual P falciparum prevalence by microscopy PCR in the same population. We aimed to explore potential drivers of submicroscopic infection and to identify the locations where submicroscopic infections are most common. Methods In this systematic review and meta-analysis we searched PubMed and Web of Science from Jan 1, 2010, until Oct 11, 2020, for cross-sectional studies reporting data on asexual P falciparum prevalence by both microscopy and PCR. Surveys of pregnant women, surveys in which participants had been chosen based on symptoms or treatment, or surveys that did not involve a population from a defined location were excluded. Both the number of individuals tested and the number of individuals who tested positive by microscopy or PCR, or both, for P falciparum infection were extracted. Bayesian regression modelling was used to explore determinants of the size of the submicroscopic reservoir including geographical location, seasonality, age, methodology, and current or historical patterns of transmission. Findings Of 4893 identified studies, we retained 121 after screening and removal of duplicates. 45 studies from a previous systematic review were included giving 166 studies containing 551 cross-sectional survey microscopy and PCR prevalence pairs. Our results show that submicroscopic infections predominate in low-transmission settings across all regions, but also reveal marked geographical variation, with the proportion of infections that are submicroscopic being highest in South American surveys and lowest in west African surveys. Although current transmission levels partly explain these results, we find that historical transmission intensity also represents a crucial determinant of the size of the submicroscopic reservoir, as does the demographic structure of the infected population (with submicroscopic infection more likely to occur in adults than in children) and the PCR or microscopy methodology used. We also observed a small yet significant influence of seasonality, with fewer submicroscopic infections observed in the wet season than the dry season. Integrating these results with estimates of infectivity in relation to parasite density suggests the contribution of submicroscopic infections to transmission across different settings is likely to be highly variable. Interpretation Significant variation in the prevalence of submicroscopic infection exists even across settings characterised by similar current levels of transmission. These differences in submicroscopic epidemiology potentially warrant different approaches to targeting this infected subgroup across different settings to eliminate malaria. Funding Bill & Melinda Gates Foundation, The Royal Society, and the UK Medical Research Council.
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Affiliation(s)
- Charles Whittaker
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, UK
| | - Hannah Slater
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, UK.,PATH, Seattle, WA, USA
| | - Rebecca Nash
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, UK
| | - Teun Bousema
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, Netherlands
| | - Chris Drakeley
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
| | - Azra C Ghani
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, UK
| | - Lucy C Okell
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, UK
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16
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Touray AO, Mobegi VA, Wamunyokoli F, Butungi H, Herren JK. Prevalence of asymptomatic P. falciparum gametocyte carriage among school children in Mbita, Western Kenya and assessment of the association between gametocyte density, multiplicity of infection and mosquito infection prevalence. Wellcome Open Res 2021; 5:259. [PMID: 33959684 PMCID: PMC8078214 DOI: 10.12688/wellcomeopenres.16299.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/29/2021] [Indexed: 12/02/2022] Open
Abstract
Background: Asymptomatic Plasmodium falciparum gametocyte carriers are reservoirs for sustaining transmission in malaria endemic regions. Gametocyte presence in the host peripheral blood is a predictor of capacity to transmit malaria. However, it does not always directly translate to mosquito infectivity. Factors that affect mosquito infectivity include, gametocyte sex-ratio and density, multiplicity of infection (MOI), and host and vector anti-parasite immunity. We assess the prevalence of gametocyte carriage and some of its associated risk factors among asymptomatic schoolchildren in Western Kenya and to further analyse the association between gametocyte density, multiplicity of infection (MOI) and mosquito infection prevalence. Methods: P. falciparum parasite infections were detected by RDT (Rapid Diagnostic Test) and microscopy among schoolchildren (5-15 years old). Blood from 37 microscopy positive gametocyte carriers offered to laboratory reared An. gambiae s.l. mosquitoes. A total of 3395 fully fed mosquitoes were screened for Plasmodium sporozoites by ELISA. P. falciparum was genotyped using 10 polymorphic microsatellite markers. The association between MOI and gametocyte density and mosquito infection prevalence was investigated. Results: A significantly higher prevalence of P. falciparum infection was found in males 31.54% (764/2422) ( p-value < 0.001) compared to females 26.72% (657/2459). The microscopic gametocyte prevalence among the study population was 2% (84/4881). Children aged 5-9 years have a higher prevalence of gametocyte carriage (odds ratios = 2.1 [95% CI = 1.3-3.4], P = 0.002) as compared to children aged 10-15 years. After offering gametocyte positive blood to An. gambiae s.l. by membrane feeding assay, our results indicated that 68.1% of the variation in mosquito infection prevalence was accounted for by gametocyte density and MOI (R-SQR. = 0.681, p < 0.001). Conclusions: We observed a higher risk of gametocyte carriage among the younger children (5-9 years). Gametocyte density and MOI significantly predicted mosquito infection prevalence.
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Affiliation(s)
- Abdoulie O. Touray
- Department of Molecular Biology and Biotechnology, Institute of Basic Sciences, Technology and Innovation, Pan African University (PAUSTI), Nairobi, Kenya
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
| | - Victor A. Mobegi
- Department of Biochemistry, School of Medicine, University of Nairobi, Nairobi, Kenya
| | - Fred Wamunyokoli
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology (JKUAT), Nairobi, Kenya
| | - Hellen Butungi
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
- Wits Research Institute for Malaria, School of Pathology, Faculty of Health Sciences, University of the Witswatersrand, Johannesburg, South Africa
| | - Jeremy K. Herren
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
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17
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Tandoh KZ, Amenga-Etego L, Quashie NB, Awandare G, Wilson M, Duah-Quashie NO. Plasmodium falciparum Malaria Parasites in Ghana Show Signatures of Balancing Selection at Artemisinin Resistance Predisposing Background Genes. Evol Bioinform Online 2021; 17:1176934321999640. [PMID: 33746510 PMCID: PMC7940735 DOI: 10.1177/1176934321999640] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Accepted: 02/05/2021] [Indexed: 11/16/2022] Open
Abstract
Sub-Saharan Africa is courting the risk of artemisinin resistance (ARTr) emerging in Plasmodium falciparum malaria parasites. Current molecular surveillance efforts for ARTr have been built on the utility of P. falciparum kelch13 (pfk13) validated molecular markers. However, whether these molecular markers will serve the purpose of early detection of artemisinin-resistant parasites in Ghana is hinged on a pfk13 dependent evolution. Here, we tested the hypothesis that the background pfk13 genome may be present before the pfk13 ARTr-conferring variant(s) is selected and that signatures of balancing selection on these genomic loci may serve as an early warning signal of ARTr. We analyzed 12 198 single nucleotide polymorphisms (SNPs) in Ghanaian clinical isolates in the Pf3K MalariaGEN dataset that passed a stringent filtering regimen. We identified signatures of balancing selection in 2 genes (phosphatidylinositol 4-kinase and chloroquine resistance transporter) previously reported as background loci for ARTr. These genes showed statistically significant and high positive values for Tajima's D, Fu and Li's F, and Fu and Li's D. This indicates that the biodiversity required to establish a pfk13 background genome may have been primed in clinical isolates of P. falciparum from Ghana as of 2010. Despite the absence of ARTr in Ghana to date, our finding supports the current use of pfk13 for molecular surveillance of ARTr in Ghana and highlights the potential utility of monitoring malaria parasite populations for balancing selection in ARTr precursor background genes as early warning molecular signatures for the emergence of ARTr.
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Affiliation(s)
- Kwesi Z Tandoh
- West African Centre for Cell Biology of Infectious Pathogens, Department of Biochemistry, Cell and Molecular Biology, College of Basic and Applied Sciences, University of Ghana, Accra, Ghana
| | - Lucas Amenga-Etego
- West African Centre for Cell Biology of Infectious Pathogens, Department of Biochemistry, Cell and Molecular Biology, College of Basic and Applied Sciences, University of Ghana, Accra, Ghana
| | - Neils B Quashie
- Department of Epidemiology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Accra, Ghana.,Centre for Tropical Clinical Pharmacology and Therapeutics, School of Medicine and Dentistry, College of Health Sciences, University of Ghana, Accra, Ghana
| | - Gordon Awandare
- West African Centre for Cell Biology of Infectious Pathogens, Department of Biochemistry, Cell and Molecular Biology, College of Basic and Applied Sciences, University of Ghana, Accra, Ghana
| | - Michael Wilson
- Department of Parasitology, Noguchi Memorial Institute for Medical Research, College of Health sciences, University of Ghana, Accra, Ghana
| | - Nancy O Duah-Quashie
- Department of Epidemiology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Accra, Ghana
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18
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Brown CA, Pappoe-Ashong PJ, Duah N, Ghansah A, Asmah H, Afari E, Koram KA. High frequency of the Duffy-negative genotype and absence of Plasmodium vivax infections in Ghana. Malar J 2021; 20:99. [PMID: 33596926 PMCID: PMC7888148 DOI: 10.1186/s12936-021-03618-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Accepted: 02/02/2021] [Indexed: 01/01/2023] Open
Abstract
Background Recent studies from different malaria-endemic regions including western Africa have now shown that Plasmodium vivax can infect red blood cells (RBCs) and cause clinical disease in Duffy-negative people, though the Duffy-negative phenotype was thought to confer complete refractoriness against blood invasion with P. vivax. The actual prevalence of P. vivax in local populations in Ghana is unknown and little information is available about the distribution of Duffy genotypes. The aim of this study was to assess the prevalence of P. vivax in both asymptomatic and symptomatic outpatients and the distribution of Duffy genotypes in Ghana. Methods DNA was extracted from dried blood spots (DBS) collected from 952 subjects (845 malaria patients and 107 asymptomatic persons) from nine locations in Ghana. Plasmodium species identification was carried out by nested polymerase chain reaction (PCR) amplification of the small-subunit (SSU) rRNA genes. For P. vivax detection, a second PCR of the central region of the Pvcsp gene was carried out. Duffy blood group genotyping was performed by allele-specific PCR to detect the presence of the FYES allele. Results No cases of P. vivax were detected in any of the samples by both PCR methods used. Majority of infections (542, 94.8%) in the malaria patient samples were due to P. falciparum with only 1 infection (0.0017%) due to Plasmodium malariae, and 2 infections (0.0034%) due to Plasmodium ovale. No case of mixed infection was identified. Of the samples tested for the FYES allele from all the sites, 90.5% (862/952) had the FYES allele. All positive samples were genotyped as FY*B-33/FY*B-33 (Duffy-negative homozygous) and therefore classified as Fy(a−b−). Conclusions No cases of P. vivax were detected by both PCRs and majority of the subjects tested carried the FYES allele. The lack of P. vivax infections observed can be attributed to the high frequency of the FYES allele that silences erythroid expression of the Duffy. These results provide insights on the host susceptibility for P. vivax infections that had not been investigated in Ghana before.
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Affiliation(s)
- Charles A Brown
- School of Biomedical and Allied Health Sciences, College of Health Sciences, University of Ghana, Legon, Ghana.
| | - Prince J Pappoe-Ashong
- School of Biomedical and Allied Health Sciences, College of Health Sciences, University of Ghana, Legon, Ghana
| | - Nancy Duah
- Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
| | - Anita Ghansah
- Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
| | - Harry Asmah
- School of Biomedical and Allied Health Sciences, College of Health Sciences, University of Ghana, Legon, Ghana
| | - Edwin Afari
- School of Public Health, College of Health Sciences, University of Ghana, Legon, Ghana
| | - Kwadwo A Koram
- Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
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19
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Sondo P, Bihoun B, Tahita MC, Derra K, Rouamba T, Nakanabo Diallo S, Kazienga A, Ilboudo H, Valea I, Tarnagda Z, Sorgho H, Lefèvre T, Tinto H. Plasmodium falciparum gametocyte carriage in symptomatic patients shows significant association with genetically diverse infections, anaemia, and asexual stage density. Malar J 2021; 20:31. [PMID: 33413393 PMCID: PMC7791700 DOI: 10.1186/s12936-020-03559-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 12/18/2020] [Indexed: 11/17/2022] Open
Abstract
Background Multi-genotype malaria infections are frequent in endemic area, and people commonly harbour several genetically distinct Plasmodium falciparum variants. The influence of genetic multiplicity and whether some specific genetic variants are more or less likely to invest into gametocyte production is not clearly understood. This study explored host and parasite-related risk factors for gametocyte carriage, and the extent to which some specific P. falciparum genetic variants are associated with gametocyte carriage. Methods Gametocytes and asexual forms were detected by light microscopy on thick smears collected between 2010 and 2012 in Nanoro, Burkina Faso. Merozoite surface protein 1 and 2 were genotyped by nested PCR on clinical samples. Associations between gametocyte carriage and factors, including multiplicity of infection, parasite density, patient age, gender, haemoglobin (Hb) level, and body temperature were assessed. The relationship between the presence of a particular msp1 and msp2 genetic variants and gametocyte carriage was also explored. Results Of the 724 samples positive to P. falciparum and successfully genotyped, gametocytes were found in 48 samples (6.63%). There was no effect of patient gender, age and body temperature on gametocyte carriage. However, the probability of gametocyte carriage significantly increased with increasing values of multiplicity of infection (MOI). Furthermore, there was a negative association between parasite density and gametocyte carriage. MOI decreased with parasite density in gametocyte-negative patients, but increased in gametocyte carriers. The probability of gametocyte carriage decreased with Hb level. Finally, the genetic composition of the infection influenced gametocyte carriage. In particular, the presence of RO33 increased the odds of developing gametocytes by 2 while the other allelic families K1, MAD20, FC27, and 3D7 had no significant impact on the occurrence of gametocytes in infected patients. Conclusion This study provides insight into potential factors influencing gametocyte production in symptomatic patients. The findings contribute to enhance understanding of risk factors associated with gametocyte carriage in humans. Trial registration NCT01232530.
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Affiliation(s)
- Paul Sondo
- Institut de Recherche en Sciences de La Santé/ Clinical Research Unit of Nanoro (IRSS-URCN), Nanoro, Burkina Faso.
| | - Biebo Bihoun
- Institut de Recherche en Sciences de La Santé/ Clinical Research Unit of Nanoro (IRSS-URCN), Nanoro, Burkina Faso
| | - Marc Christian Tahita
- Institut de Recherche en Sciences de La Santé/ Clinical Research Unit of Nanoro (IRSS-URCN), Nanoro, Burkina Faso
| | - Karim Derra
- Institut de Recherche en Sciences de La Santé/ Clinical Research Unit of Nanoro (IRSS-URCN), Nanoro, Burkina Faso
| | - Toussaint Rouamba
- Institut de Recherche en Sciences de La Santé/ Clinical Research Unit of Nanoro (IRSS-URCN), Nanoro, Burkina Faso
| | - Seydou Nakanabo Diallo
- Institut de Recherche en Sciences de La Santé/ Clinical Research Unit of Nanoro (IRSS-URCN), Nanoro, Burkina Faso.,Institut National de Santé Publique/Centre Muraz de Bobo-Dioulasso, Bobo-Dioulasso, Burkina Faso
| | - Adama Kazienga
- Institut de Recherche en Sciences de La Santé/ Clinical Research Unit of Nanoro (IRSS-URCN), Nanoro, Burkina Faso
| | - Hamidou Ilboudo
- Institut de Recherche en Sciences de La Santé/ Clinical Research Unit of Nanoro (IRSS-URCN), Nanoro, Burkina Faso
| | - Innocent Valea
- Institut de Recherche en Sciences de La Santé/ Clinical Research Unit of Nanoro (IRSS-URCN), Nanoro, Burkina Faso.,Institut National de Santé Publique/Centre Muraz de Bobo-Dioulasso, Bobo-Dioulasso, Burkina Faso
| | - Zekiba Tarnagda
- Institut de Recherche en Sciences de La Santé/ Clinical Research Unit of Nanoro (IRSS-URCN), Nanoro, Burkina Faso
| | - Hermann Sorgho
- Institut de Recherche en Sciences de La Santé/ Clinical Research Unit of Nanoro (IRSS-URCN), Nanoro, Burkina Faso
| | - Thierry Lefèvre
- Laboratoire Mixte International Sur Les Vecteurs (LAMIVECT), Bobo Dioulasso, Burkina Faso.,MIVEGEC, Université de Montpellier, IRD, CNRS, Montpellier, France.,Centre de Recherche en Écologie Et Évolution de La Santé (CREES), Montpellier, France
| | - Halidou Tinto
- Institut de Recherche en Sciences de La Santé/ Clinical Research Unit of Nanoro (IRSS-URCN), Nanoro, Burkina Faso
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Na-Bangchang K, Martviset P, Kitvatanachai S, Tarasuk M, Muhamad P. Pretreatment gametocyte carriage in symptomatic patients with Plasmodium falciparum and Plasmodium vivax infections on the Thai-Myanmar border. J Vector Borne Dis 2021; 58:257-264. [DOI: 10.4103/0972-9062.316274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
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21
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Kitojo C, Chacky F, Kigadye ES, Mugasa JP, Lusasi A, Mohamed A, Walker P, Reaves EJ, Gutman JR, Ishengoma DS. Evaluation of a single screen and treat strategy to detect asymptomatic malaria among pregnant women from selected health facilities in Lindi region, Tanzania. Malar J 2020; 19:438. [PMID: 33256758 PMCID: PMC7708125 DOI: 10.1186/s12936-020-03513-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Accepted: 11/19/2020] [Indexed: 02/07/2023] Open
Abstract
Background In areas of high transmission, malaria in pregnancy (MiP) primarily causes asymptomatic infections; these infections nonetheless increase the risk of adverse maternal and fetal outcomes. In 2014, Tanzania initiated a single screening and treatment (SST) strategy for all pregnant women at their first antenatal care (ANC) visit using malaria rapid diagnostic tests (RDT) for surveillance purposes. However, there is paucity of data on the effectiveness of SST in the prevention of MiP. The objective of this study was to estimate the number of asymptomatic infections among pregnant women detected by SST, which would have been missed in the absence of the policy. Methods Data from pregnant women attending their first ANC visits between October 2017 and June 2018, including gestational age, history of fever, and RDT results, were abstracted from ANC registers in eight health centres in two randomly selected districts, Kilwa and Lindi, in Lindi Region. The proportion of symptomatic (with history of fever in the past 48 h) and asymptomatic pregnant women with positive RDTs were calculated and stratified by trimester (first, second and third). The study areas were categorized as low transmission with prevalence < 10% or moderate/high with ≥ 10%. Results Over the study period, 1,845 women attended their first ANC visits; 22.1% were in the first trimester (< 12 weeks gestation age). Overall 15.0% of the women had positive RDTs, and there was a trend towards higher malaria prevalence in the first (15.9%) and second (15.2%) trimesters, compared to the third (7.1%), although the differences were not statistically significant (p = 0.07). In total, 6.9% of women reported fever within the past 48 h and, of these, 96.1% were RDT positive. For every 100 pregnant women in the moderate/high and low transmission areas, SST identified 60 and 26 pregnant women, respectively, with asymptomatic infections that would have otherwise been missed. Among the 15.9% of women detected in the first trimester, 50.7% were asymptomatic. Conclusion In areas of moderate/high transmission, many infected women were asymptomatic, and would have been missed in the absence of SST. The benefits on maternal and fetal birth outcomes of identifying these infections depend heavily on the protection afforded by treatment, which is likely to be greatest for women presenting in the first trimester when intermittent preventive treatment (IPTp) with sulfadoxine-pyrimethamine (SP) is contraindicated, and in areas with high SP resistance, such as most parts of Tanzania. An evaluation of the impact and cost-effectiveness of SST across different transmission strata is warranted.
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Affiliation(s)
- Chonge Kitojo
- US President's Malaria Initiative, United States Agency for International Development, Dar es Salaam, United Republic of Tanzania. .,The Open University of Tanzania, Dar es Salaam, United Republic of Tanzania.
| | - Frank Chacky
- National Malaria Control Programme, Dodoma, United Republic of Tanzania
| | - Emmanuel S Kigadye
- The Open University of Tanzania, Dar es Salaam, United Republic of Tanzania
| | - Joseph P Mugasa
- USAID Boresha Afya Southern Zone, FHI 360, Dar es Salaam, United Republic of Tanzania
| | - Abdallah Lusasi
- National Malaria Control Programme, Dodoma, United Republic of Tanzania
| | - Ally Mohamed
- National Malaria Control Programme, Dodoma, United Republic of Tanzania
| | - Patrick Walker
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, UK
| | - Erik J Reaves
- Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention and US President's Malaria Initiative, Dar es Salaam, United Republic of Tanzania.,Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, USA
| | - Julie R Gutman
- Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, USA
| | - Deus S Ishengoma
- National Institute for Medical Research, Dar Es Salaam, United Republic of Tanzania.,Faculty of Pharmaceutical Sciences, Monash University, Melbourne, Australia.,Harvard T.H. Chan School of Public Health, Boston, MA, USA
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22
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Oppong M, Lamptey H, Kyei-Baafour E, Aculley B, Ofori EA, Tornyigah B, Kweku M, Ofori MF. Prevalence of sickle cell disorders and malaria infection in children aged 1-12 years in the Volta Region, Ghana: a community-based study. Malar J 2020; 19:426. [PMID: 33228681 PMCID: PMC7684914 DOI: 10.1186/s12936-020-03500-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Accepted: 11/15/2020] [Indexed: 11/18/2022] Open
Abstract
Background Alterations in the structure of haemoglobin (Hb) are usually brought about by point mutations affecting one or, in some cases, two codons encoding amino acids of the globin chains. One in three Ghanaians are said to have sickle cell disorders, whereas malaria continues to be one of the leading causes of mortality among children. This study determined the prevalence of sickle cell disorders and malaria infection among children aged 1–12 years in the Volta Region. Methods This was a community-based cross-sectional survey that involved 938 children aged 1–12 years selected from three districts, one each from the 3 geographical zones of the Volta Region using a multistage sampling method. Demographic information was collected using a standard questionnaire and anthropometric indices were measured. Isoelectric focusing (IEF) electrophoresis was used to determine the Hb genotypes and sub-microscopic parasites were determined by PCR. Results The prevalence of sickling screening positive was 16.0% with an overall prevalence of sickle cell disorders being 2.0%. Among the individual genotypes making up the sickle cell disorders, genotype HbSF was the highest (0.9% as compared to 0.2%; HbSS, 0.6%; HbSC and 0.3%; HbSCF). Microscopic Plasmodium falciparum parasitaemia was detected among 5.5% of the children and 14.2% sub-microscopic prevalence by PCR. Children with sickle cell disorders were more likely to have sub-microscopic parasitaemia (AOR = 5.51 95%CI (2.15, 14.10), p < 0.001) as well as anaemia (AOR = 3.03 95% CI (1.04, 8.82), p = 0.042), compared to those with normal genotypes. There was no significant difference observed between sickle cell disorders and growth and development of the children screened. Conclusions Sickle cell disorders were significantly associated with sub-microscopic parasitaemia as well as anaemia in this study. Establishment of sickle cell clinics in the district and regional hospitals will help in the management of children with the disorder and also generate a national database on sickle cell disorders. National neonatal screening policies must also be put in place to help in early detection and management of these disorders.
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Affiliation(s)
- Mavis Oppong
- Department of Epidemiology and Biostatistics, School of Public Health, University of Health and Allied Sciences, Hohoe, Ghana
| | - Helena Lamptey
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Accra, Ghana
| | - Eric Kyei-Baafour
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Accra, Ghana
| | - Belinda Aculley
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Accra, Ghana
| | - Ebenezer Addo Ofori
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Accra, Ghana
| | - Bernard Tornyigah
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Accra, Ghana
| | - Margaret Kweku
- Department of Epidemiology and Biostatistics, School of Public Health, University of Health and Allied Sciences, Hohoe, Ghana
| | - Michael F Ofori
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Accra, Ghana.
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Touray AO, Mobegi VA, Wamunyokoli F, Butungi H, Herren JK. Prevalence of asymptomatic P. falciparum gametocyte carriage in schoolchildren and assessment of the association between gametocyte density, multiplicity of infection and mosquito infection prevalence. Wellcome Open Res 2020; 5:259. [PMID: 33959684 PMCID: PMC8078214 DOI: 10.12688/wellcomeopenres.16299.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/22/2020] [Indexed: 07/22/2023] Open
Abstract
Background: Malaria is a major public health threat in sub-Saharan Africa. Asymptomatic Plasmodium falciparum gametocyte carriers are potential infectious reservoirs for sustaining transmission in many malaria endemic regions. The aim of the study was to assess the prevalence of gametocyte carriage and some of its associated risk factors among asymptomatic schoolchildren in Western Kenya and further analyse the association between gametocyte density, multiplicity of infection (MOI) and mosquito infection prevalence. Methods: Rapid diagnostic tests were used to screen for P. falciparum parasite infection among schoolchildren (5-15 years old) and the results were verified using microscopy. Microscopy positive gametocyte carriers were selected to feed laboratory reared An. gambiae s.l. mosquitoes using membrane feeding method. Genomic DNA was extracted from dry blood spot samples and P. falciparum populations were genotyped using 10 polymorphic microsatellite markers. Assessment of the association between MOI and gametocyte density and mosquito infection prevalence was conducted. Results: A significantly higher prevalence of P. falciparum infection was found in males 31.54% (764/2422) ( p-value < 0.001) compared to females 26.72% (657/2459). The microscopy gametocyte prevalence among the study population was 2% (84/4881). Children aged 5-9 years have a higher prevalence of gametocyte carriage (odds ratios = 2.1 [95% CI = 1.3-3.4], P = 0.002) as compared to children aged 10-15 years. After challenging An. gambiae s.l. by membrane feeding assay on gametocyte positive patient blood, our results indicate that 68.1% of the variation in mosquito infection prevalence is accounted for by gametocyte density and MOI (R-SQR. = 0.681, p < 0.001). Conclusions: Age was a significant risk factor for gametocyte carriage, as indicated by the higher risk of gametocyte carriage among the younger children (5-9 years). Gametocyte density and MOI statistically significantly predicted mosquito infection prevalence. Both of the variables added significantly to the prediction ( p < 0.05).
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Affiliation(s)
- Abdoulie O. Touray
- Department of Molecular Biology and Biotechnology, Institute of Basic Sciences, Technology and Innovation, Pan African University (PAUSTI), Nairobi, Kenya
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
| | - Victor A. Mobegi
- Department of Biochemistry, School of Medicine, University of Nairobi, Nairobi, Kenya
| | - Fred Wamunyokoli
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology (JKUAT), Nairobi, Kenya
| | - Hellen Butungi
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
- Wits Research Institute for Malaria, School of Pathology, Faculty of Health Sciences, University of the Witswatersrand, Johannesburg, South Africa
| | - Jeremy K. Herren
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
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24
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Kalinjuma AV, Darling AM, Mugusi FM, Abioye AI, Okumu FO, Aboud S, Masanja H, Hamer DH, Hertzmark E, Fawzi WW. Factors associated with sub-microscopic placental malaria and its association with adverse pregnancy outcomes among HIV-negative women in Dar es Salaam, Tanzania: a cohort study. BMC Infect Dis 2020; 20:796. [PMID: 33109111 PMCID: PMC7590608 DOI: 10.1186/s12879-020-05521-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Accepted: 10/16/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Malaria infection during pregnancy has negative health consequences for both mothers and offspring. Sub-microscopic malaria infection during pregnancy is common in most African countries. We sought to identify factors associated with sub-microscopic placental malaria, and its association with adverse pregnancy outcomes among HIV-negative pregnant women in Dar es Salaam, Tanzania. METHODS We recruited a cohort of pregnant women during their first trimester and assessed for the occurrence of placental malaria and pregnancy outcomes. The follow-up was done monthly from recruitment until delivery. Histopathology placental malaria positive results were defined as the presence of malaria pigment or parasitized erythrocytes on the slide (histology-positive (HP)), and the sub-microscopic placental infection was defined as positive Plasmodium falciparum DNA by polymerase chain reaction (DNA PCR) amplification in a negative histopathology test. Adverse pregnancy outcomes investigated included low birth weight (birth weight below 2.5 kg), prematurity (live birth below 37 weeks), and small-for-gestational-age (SGA) (live born with a birth weight below 10th percentile for gestational age and sex). Weighted baseline category logit, log-binomial, and log-Poisson models were used to assess factors associated with placental malaria, and its association with adverse pregnancy outcomes. RESULTS Among 1115 women who had histopathology and DNA PCR performed, 93 (8%) had HP placental infection, and 136 (12%) had the sub-microscopic placental infection. The risk of sub-microscopic placental malaria was greater in women who did not use mosquito prevention methods such as bed nets, fumigation, or mosquito coils (odds ratio (OR) = 1.75; 95% confidence interval (CI): 1.05-2.92; P = 0.03) and in women who were anemic (OR = 1.59; 95% CI: 1.20-2.11; P = 0.001). Women who were underweight had reduced odds of sub-microscopic placental malaria infection (OR = 0.33; 95% CI: 0.17-0.62; P = 0.001). Women who were overweight/obese had 1.48 times higher the odds of HP placental malaria compared to normal weight (OR = 1.48; 95% CI: 1.03-2.11; P = 0.03). HP placental malaria infection was associated with an increased risk of SGA births (RR = 1.30, 95% CI: 0.98-1.72, P = 0.07). In contrast, the sub-microscopic infection was associated with a reduced risk of SGA births (RR = 0.61, 95% CI: 0.43-0.88, P = 0.01). Placental malaria was not associated with low birth weight or prematurity. CONCLUSION Malaria prevention methods and maternal nutrition status during early pregnancy were important predictors of sub-microscopic placental malaria. More research is needed to understand sub-microscopic placental malaria and the possible mechanisms mediating the association between placental malaria and SGA.
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Affiliation(s)
- Aneth Vedastus Kalinjuma
- Department of Intervention and Clinical Trials, Ifakara Health Institute, P.O. Box 53, Ifakara, Morogoro, Tanzania.
- Department of Global Health and Population, Harvard T.H. Chan School of Public Health, Boston, MA, USA.
| | - Anne Marie Darling
- Department of Global Health and Population, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Ferdinand M Mugusi
- Departments of Internal Medicine; and Microbiology and Immunology, School of Medicine, Muhimbili University of Health and Allied Sciences, Dar-es-Salaam, Tanzania
| | - Ajibola Ibraheem Abioye
- Department of Global Health and Population, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Fredros O Okumu
- Department of Intervention and Clinical Trials, Ifakara Health Institute, P.O. Box 53, Ifakara, Morogoro, Tanzania
| | - Said Aboud
- Departments of Internal Medicine; and Microbiology and Immunology, School of Medicine, Muhimbili University of Health and Allied Sciences, Dar-es-Salaam, Tanzania
| | - Honorati Masanja
- Department of Intervention and Clinical Trials, Ifakara Health Institute, P.O. Box 53, Ifakara, Morogoro, Tanzania
| | - Davidson H Hamer
- Department of Global Health, Boston University School of Public Health, Boston, MA, USA
- Section of Infectious Diseases, Department of Medicine, Boston University School of Medicine, Boston, MA, USA
| | - Ellen Hertzmark
- Department of Global Health and Population, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Wafaie W Fawzi
- Department of Global Health and Population, Harvard T.H. Chan School of Public Health, Boston, MA, USA
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Makenga G, Menon S, Baraka V, Minja DT, Nakato S, Delgado-Ratto C, Francis F, Lusingu JP, Van Geertruyden JP. Prevalence of malaria parasitaemia in school-aged children and pregnant women in endemic settings of sub-Saharan Africa: A systematic review and meta-analysis. Parasite Epidemiol Control 2020; 11:e00188. [PMID: 33145445 PMCID: PMC7591779 DOI: 10.1016/j.parepi.2020.e00188] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2019] [Revised: 10/15/2020] [Accepted: 10/18/2020] [Indexed: 12/05/2022] Open
Abstract
Despite increased malaria control efforts, school-aged children (5–14 years) have higher a malaria prevalence compared to children under-five. In high-transmission settings, up to 70% of school-aged children harbour malaria parasitaemia and therefore contribute significantly to the reservoir for transmission. A systematic review was performed to explore the correlation between the malaria parasite carriage in pregnant women and school-aged children living in similar endemic settings of sub Saharan Africa to inform strategies to improve targeted malaria control. In order to obtain data on malaria prevalence in pregnant women and school-aged children living in the same endemic setting, we searched the Malaria in Pregnancy Library, PubMed, Cochrane library and Web of Science in December 2018. We fit a fixed effect model to obtain a pooled risk ratio (PRR) of malaria in school-aged children versus pregnant women and used Poisson regression to estimate risk ratios in school-aged children for every increase in prevalence in pregnant women. We used data from six (out of 1096) sources that included 10 data points. There was a strong linear relation between the prevalence of malaria infection in pregnant women and school-aged children (r = 0·93, p < 0·0001). School-aged children were nearly twice at risk to carry parasites compared to pregnant women (RR = 1.95, 95% CI: 1·69–2.25, p < 0.01). Poisson regression showed that a 1% increase in prevalence of malaria infection in pregnant women was significantly associated with increase in risk in school-aged children by 4%. Malaria infection prevalence in school-aged children is strongly correlated with the prevalence in pregnant women living in the same community, and may be considered as alternative indicators to track temporal and spatial trends in malaria transmission intensity. Chemoprevention strategies targeting school-aged children should be explored to reduce malaria burden and transmission in school-aged children and its potential impact on communities.
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Affiliation(s)
- Geofrey Makenga
- National Institute for Medical Research, Tanga Centre, P. O. Box 5004, Tanga, Tanzania
- Global Health Institute, University of Antwerp, Antwerp, Belgium
- Corresponding author at.: National Institute for Medical Research, Tanga Centre, P. O. Box 5004, Tanga, Tanzania.
| | - Sonia Menon
- Global Health Institute, University of Antwerp, Antwerp, Belgium
| | - Vito Baraka
- National Institute for Medical Research, Tanga Centre, P. O. Box 5004, Tanga, Tanzania
| | - Daniel T.R. Minja
- National Institute for Medical Research, Tanga Centre, P. O. Box 5004, Tanga, Tanzania
| | - Swabra Nakato
- Global Health Institute, University of Antwerp, Antwerp, Belgium
| | | | - Filbert Francis
- National Institute for Medical Research, Tanga Centre, P. O. Box 5004, Tanga, Tanzania
| | - John P.A. Lusingu
- National Institute for Medical Research, Tanga Centre, P. O. Box 5004, Tanga, Tanzania
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Fagbemi KA, Adebusuyi SA, Nderu D, Adedokun SA, Pallerla SR, Amoo AOJ, Thomas BN, Velavan TP, Ojurongbe O. Analysis of sulphadoxine-pyrimethamine resistance-associated mutations in Plasmodium falciparum isolates obtained from asymptomatic pregnant women in Ogun State, Southwest Nigeria. INFECTION GENETICS AND EVOLUTION 2020; 85:104503. [PMID: 32805431 DOI: 10.1016/j.meegid.2020.104503] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 08/04/2020] [Accepted: 08/11/2020] [Indexed: 12/19/2022]
Abstract
Intermittent preventive treatment in pregnancy with sulphadoxine-pyrimethamine (IPTp-SP) is one of the main strategies for protecting pregnant women, fetus, and their new-born against adverse effects of P. falciparum infection. The development of the drug resistance linked to mutations in P. falciparum dihydrofolate reductase gene (pfdhfr) and P. falciparum dihydropteroate synthase gene (pfdhps), is currently threatening the IPTp-SP approach. This study determined the prevalence of pfdhfr and pfdhps mutations in isolates obtained from pregnant women with asymptomatic P. falciparum infection in Nigerian. Additionally, P. falciparum genetic diversity and multiplicity of infection (MOI) was assessed by genotyping the P. falciparum merozoite surface Protein 1 and 2 (pfmsp-1 and pfmsp-2) genes. The pfdhfr and pfdhps were genotyped by direct sequencing, and the pfmsp-1 and pfmsp-2 fragment analysis by polymerase chain reaction was used to determine P. falciparum genetic diversity. Of the 406 pregnant women recruited, 123 had P. falciparum infection by PCR, and of these, 52 were successfully genotyped for pfdhfr and 42 for pfdhps genes. The pfdhfr triple-mutant parasites (N51I, C59R, and S108N) or the IRN haplotype were predominant (98%), whereas pfdhfr mutations C50R and I164L did not occur. For pfdhps gene, the prevalence of A437G, A581G, A436A, and A613S mutations were 98, 71, 55, and 36%, respectively. Nineteen (44%) isolates with quintuple mutations (CIRNI- SGKGA) had the highest combined pfdhfr-pfdhps haplotype. Isolates with sextuple mutants; CIRNI- AGKAS and CIRNI- AGKGA had a prevalence of 29 and 14%, respectively. High genetic diversity (7 pfmsp-1 alleles and 10 pfmsp-2 alleles) and monoclonal infection rate (76%) was observed. This study demonstrated a continuous high prevalence of pfdhfr mutation and an increase in pfdhps mutations associated with SP-resistance in southwest Nigeria. Continuous surveillance of IPTp-SP effectiveness and consideration of alternative IPTp strategies is recommended.
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Affiliation(s)
- Kaossarath A Fagbemi
- Institute of Tropical Medicine, University of Tübingen, Germany; Department of Biomedical Sciences, Laboratory of Cytogenetics and Medical Genetics, Faculty of Health Sciences, University of Abomey-Calavi, Benin
| | - Sunday A Adebusuyi
- Department of Medical Microbiology & Parasitology, Olabisi Onabanjo University, Ago-Iwoye, Nigeria
| | - David Nderu
- Institute of Tropical Medicine, University of Tübingen, Germany; School of Health Sciences, Kirinyaga University, Kirinyaga, Kenya
| | - Samuel A Adedokun
- Institute of Tropical Medicine, University of Tübingen, Germany; Department of Medical Microbiology & Parasitology, Ladoke Akintola University of Technology, Osogbo, Nigeria
| | | | - Abimbola O J Amoo
- Department of Medical Microbiology & Parasitology, Olabisi Onabanjo University, Ago-Iwoye, Nigeria
| | - Bolaji N Thomas
- Department of Biomedical Sciences, College of Health Sciences and Technology, Rochester Institute of Technology, Rochester, NY, USA
| | - Thirumalaisamy P Velavan
- Institute of Tropical Medicine, University of Tübingen, Germany; Duy Tan University, Da Nang, Viet Nam
| | - Olusola Ojurongbe
- Institute of Tropical Medicine, University of Tübingen, Germany; Department of Medical Microbiology & Parasitology, Ladoke Akintola University of Technology, Osogbo, Nigeria.
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Lufungulo Bahati Y, Delanghe J, Bisimwa Balaluka G, Sadiki Kishabongo A, Philippé J. Asymptomatic Submicroscopic Plasmodium Infection Is Highly Prevalent and Is Associated with Anemia in Children Younger than 5 Years in South Kivu/Democratic Republic of Congo. Am J Trop Med Hyg 2020; 102:1048-1055. [PMID: 32124722 DOI: 10.4269/ajtmh.19-0878] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
One of the most important problems in controlling malaria is the limited access to effective and accurate diagnosis of malaria parasitemia. In the Democratic Republic of Congo (DRC), malaria is one of the leading causes of morbidity and mortality. The purpose of this study was to assess the prevalence of anemia and the relationship with asymptomatic submicroscopic Plasmodium infection. A cross-sectional study was carried out among 1,088 apparently healthy children aged between 6 and 59 months selected at random in the health zone of Miti Murhesa in South Kivu/DRC. Capillary blood was obtained for hemoglobin (Hb) concentration measurement by Hemocue® Hb 301. Malaria detection was performed by microscopy and the loop-mediated isothermal amplification (LAMP) assay. Anemia was defined as Hb < 11g/dL. We applied the chi-square test for comparisons, and multiple logistic regression was used to identify the risk factors for anemia and submicroscopic Plasmodium infection. The prevalence of anemia was 39.6%, and the prevalence of parasitemia was 15.9% and 34.0% using microscopy and LAMP test, respectively. Submicroscopic Plasmodium infection was found in 22.3% of the children. The independent risk factors for anemia are Plasmodium infection, children younger than 24 months, low middle-upper arm circumference, and history of illness two weeks before. Otherwise, children with submicroscopic malaria infection have a significantly increased risk for anemia, with a need of transfusion. The prevalence of malaria infection was underestimated, when microscopy was used to diagnose malaria. Children with low parasitemia detected by LAMP but not by microscopy showed a significantly increased prevalence of anemia.
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Affiliation(s)
- Yvette Lufungulo Bahati
- Department of Diagnostic Sciences, Ghent University, Ghent, Belgium.,Department of Pediatrics, Catholic University of Bukavu, Bukavu, Democratic Republic of Congo
| | - Joris Delanghe
- Department of Diagnostic Sciences, Ghent University, Ghent, Belgium
| | | | | | - Jan Philippé
- Department of Diagnostic Sciences, Ghent University, Ghent, Belgium
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28
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Makenga G, Baraka V, Francis F, Nakato S, Gesase S, Mtove G, Madebe R, Kyaruzi E, Minja DTR, Lusingu JPA, Van Geertruyden JP. Effectiveness and safety of intermittent preventive treatment for malaria using either dihydroartemisinin-piperaquine or artesunate-amodiaquine in reducing malaria related morbidities and improving cognitive ability in school-aged children in Tanzania: A study protocol for a controlled randomised trial. Contemp Clin Trials Commun 2020; 17:100546. [PMID: 32382685 PMCID: PMC7201189 DOI: 10.1016/j.conctc.2020.100546] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Revised: 02/14/2020] [Accepted: 02/17/2020] [Indexed: 11/05/2022] Open
Abstract
BACKGROUND In high transmission settings, up to 70% of school-aged children harbour malaria parasites without showing any clinical symptoms. Thus, epidemiologically, school aged children act as a substantial reservoir for malaria transmission. Asymptomatic Plasmodium infections induce inflammation leading to iron deficiency anaemia. Consequently, anaemia retards child growth, predisposes children to other diseases and reduces cognitive potential that could lead to poor academic performance. School aged children become increasingly more vulnerable as compared to those aged less than five years due to delayed acquisition of protective immunity. None of the existing Intermittent Preventive Treatment (IPT) strategies is targeting school-aged children. Here, we describe the study protocol of a clinical trial conducted in north-eastern Tanzania to expand the IPT by assessing the effectiveness and safety of two antimalarial drugs, Dihydroartemisinin-Piperaquine (DP) and Artesunate-Amodiaquine (ASAQ) in preventing malaria related morbidities in school-aged children (IPTsc) living in a high endemic area. METHODS/DESIGN The trial is a phase IIIb, individual randomized, open label, controlled trial enrolling school children aged 5-15 years, who receive either DP or ASAQ or control (no drug), using a "balanced block design" with the "standard of care" arm as reference. The interventional treatments are given three times a year for the first year. A second non-interventional year will assess possible rebound effects. Sample size was estimated to 1602 school children (534 per group) from selected primary schools in an area with high malaria endemicity. Thick and thin blood smears (to measure malaria parasitaemia using microscope) were obtained prior to treatment at baseline, and will be obtained again at month 12 and 20 from all participants. Haemoglobin concentration using a haemoglobinometer (HemoCue AB, Sweden) will be measured four monthly. Finger-prick blood (dried bloodspot-DBS) prepared on Whatman 3 M filter paper, will be used for sub-microscopic malaria parasite detection usingPCR, detect markers of drug resistance (using next generation sequencing (NGS) technology), and malaria serological assays (using enzyme-linked immunosorbent assay, ELISA). To determine the benefit of IPTsc on cognitive and psychomotor ability test of everyday attention for children (TEA-Ch) and a '20 m Shuttle run' respectively, will be conducted at baseline, month 12 and 20. The primary endpoints are change in mean haemoglobin from baseline concentration and reduction in clinical malaria incidence at month 12 and 20 of follow up. Mixed design methods are used to assess the acceptability, cost-effectiveness and feasibility of IPTsc as part of a more comprehensive school children health package. Statistical analysis will be in the form of multilevel modelling, owing to repeated measurements and clustering effect of participants. DISCUSSION Malaria intervention using IPTsc strategy may be integrated in the existing national school health programme. However, there is limited systematic evidence to assess the effectiveness and operational feasibility of this approach. School-aged children are easily accessible in most endemic malaria settings. The evidence from this study will guide the implementation of the strategy to provide complementary approach to reduce malaria related morbidity, anaemia and contribute to the overall burden reduction. TRIAL REGISTRATION Clinicaltrials.gov: NCT03640403, registered on Aug 21, 2018, prospectively registered.Url https://www.clinicaltrials.gov/ct2/show/NCT03640403?term=NCT03640403&rank=1.
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Affiliation(s)
- Geofrey Makenga
- National Institute for Medical Research, Tanga Centre, Tanga, Tanzania
- Global Health Institute, University of Antwerp, Antwerp, Belgium
| | - Vito Baraka
- National Institute for Medical Research, Tanga Centre, Tanga, Tanzania
| | - Filbert Francis
- National Institute for Medical Research, Tanga Centre, Tanga, Tanzania
| | - Swabra Nakato
- Global Health Institute, University of Antwerp, Antwerp, Belgium
| | - Samwel Gesase
- National Institute for Medical Research, Tanga Centre, Tanga, Tanzania
| | - George Mtove
- National Institute for Medical Research, Tanga Centre, Tanga, Tanzania
| | - Rashid Madebe
- National Institute for Medical Research, Tanga Centre, Tanga, Tanzania
| | - Edna Kyaruzi
- College of Education (DUCE), University of Dar Es Salaam, Dar Es Salaam, Tanzania
| | - Daniel T R Minja
- National Institute for Medical Research, Tanga Centre, Tanga, Tanzania
| | - John P A Lusingu
- National Institute for Medical Research, Tanga Centre, Tanga, Tanzania
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Acquah FK, Lo AC, Akyea-Mensah K, Abagna HB, Faye B, Theisen M, Gyan BA, Amoah LE. Stage-specific Plasmodium falciparum immune responses in afebrile adults and children living in the Greater Accra Region of Ghana. Malar J 2020; 19:64. [PMID: 32041620 PMCID: PMC7011432 DOI: 10.1186/s12936-020-3146-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Accepted: 01/30/2020] [Indexed: 12/02/2022] Open
Abstract
Background Asymptomatic carriage of Plasmodium falciparum is widespread in adults and children living in malaria-endemic countries. This study identified the prevalence of malaria parasites and the corresponding levels of naturally acquired anti-parasite antibody levels in afebrile adults living in two communities in the Greater Accra Region of Ghana. Methods Two cross-sectional studies conducted in January and February 2016 and repeated in July and August 2016 recruited subjects aged between 6 and 75 years from high parasite prevalence (Obom) and low parasite prevalence (Asutsuare) communities. Whole blood (5 ml) was collected from each volunteer, plasma was aliquoted and frozen until needed. An aliquot (10 µl) of the blood was used to prepare thick and thin blood smears, 100 µl was preserved in Trizol and the rest was separated into plasma and blood cells and each stored at − 20 °C until needed. Anti-MSP3 and Pfs230 antibody levels were measured using ELISA. Results Asexual parasite and gametocyte prevalence were higher in Obom than Asutsuare. Antibody (IgG, IgG1, IgG3, IgM) responses against the asexual parasite antigen MSP3 and gametocyte antigen Pfs230 were higher in Obom during the course of the study except for IgM responses against Pfs230, which was higher in Asutsuare than in Obom during the rainy season. Antibody responses in Asutsuare were more significantly associated with age than the responses measured in Obom. Conclusion The pattern of antibody responses measured in people living in the high and low malaria transmission setting was similar. All antibody responses measured against the asexual antigen MSP3 increased, however, IgG and IgG1 responses against gametocyte antigen Pfs230 decreased in moving from the dry to the peak season in both sites. Whilst asexual and gametocyte prevalence was similar between the seasons in the low transmission setting, in the high transmission setting asexual parasite prevalence increased but gametocyte prevalence decreased in the rainy season relative to the dry season.
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Affiliation(s)
- Festus K Acquah
- Immunology Department, Noguchi Memorial Institute for Medical Research (NMIMR), University of Ghana, Accra, Ghana.,West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), University of Ghana, Accra, Ghana
| | - Aminata C Lo
- Immunology Department, Noguchi Memorial Institute for Medical Research (NMIMR), University of Ghana, Accra, Ghana.,Parasitology Department, University Cheikh Anta Diop, Dakar, Senegal
| | - Kwadwo Akyea-Mensah
- Immunology Department, Noguchi Memorial Institute for Medical Research (NMIMR), University of Ghana, Accra, Ghana
| | - Hamza B Abagna
- Immunology Department, Noguchi Memorial Institute for Medical Research (NMIMR), University of Ghana, Accra, Ghana
| | - Babacar Faye
- Parasitology Department, University Cheikh Anta Diop, Dakar, Senegal
| | - Michael Theisen
- Department for Congenital Disorders, Statens Serum Institut, Copenhagen, Denmark.,Centre for Medical Parasitology at Department of International Health, Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Ben A Gyan
- Immunology Department, Noguchi Memorial Institute for Medical Research (NMIMR), University of Ghana, Accra, Ghana
| | - Linda E Amoah
- Immunology Department, Noguchi Memorial Institute for Medical Research (NMIMR), University of Ghana, Accra, Ghana. .,West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), University of Ghana, Accra, Ghana.
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30
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Muthui MK, Kamau A, Bousema T, Blagborough AM, Bejon P, Kapulu MC. Immune Responses to Gametocyte Antigens in a Malaria Endemic Population-The African falciparum Context: A Systematic Review and Meta-Analysis. Front Immunol 2019; 10:2480. [PMID: 31695697 PMCID: PMC6817591 DOI: 10.3389/fimmu.2019.02480] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 10/04/2019] [Indexed: 11/13/2022] Open
Abstract
Background: Malaria elimination remains a priority research agenda with the need for interventions that reduce and/or block malaria transmission from humans to mosquitoes. Transmission-blocking vaccines (TBVs) are in development, most of which target the transmission stage (i.e., gametocyte) antigens Pfs230 and Pfs48/45. For these interventions to be implemented, there is a need to understand the naturally acquired immunity to gametocytes. Several studies have measured the prevalence of immune responses to Pfs230 and Pfs48/45 in populations in malaria-endemic areas. Methods: We conducted a systematic review of studies carried out in African populations that measured the prevalence of immune responses to the gametocyte antigens Pfs230 and Pfs48/45. We assessed seroprevalence of antibody responses to the two antigens and investigated the effects of covariates such as age, transmission intensity/endemicity, season, and parasite prevalence on the prevalence of these antibody responses by meta-regression. Results: We identified 12 studies covering 23 sites for inclusion in the analysis. We found that the range of reported seroprevalence to Pfs230 and Pfs48/45 varied widely across studies, from 0 to 64% for Pfs48/45 and from 6 to 72% for Pfs230. We also found a modest association between increased age and increased seroprevalence to Pfs230: adults were associated with higher seroprevalence estimates in comparison to children (β coefficient 0.21, 95% CI: 0.05-0.38, p = 0.042). Methodological factors were the most significant contributors to heterogeneity between studies which prevented calculation of pooled prevalence estimates. Conclusions: Naturally acquired sexual stage immunity, as detected by antibodies to Pfs230 and Pfs48/45, was present in most studies analyzed. Significant between-study heterogeneity was seen, and methodological factors were a major contributor to this, and prevented further analysis of epidemiological and biological factors. This demonstrates a need for standardized protocols for conducting and reporting seroepidemiological analyses.
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Affiliation(s)
- Michelle K Muthui
- Department of Biosciences, KEMRI-Wellcome Trust Programme, Kilifi, Kenya
| | - Alice Kamau
- Department of Biosciences, KEMRI-Wellcome Trust Programme, Kilifi, Kenya
| | - Teun Bousema
- Immunology and Infection Department, London School of Hygiene and Tropical Medicine, London, United Kingdom.,Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Andrew M Blagborough
- Department of Life Sciences, Imperial College London, London, United Kingdom.,Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Philip Bejon
- Department of Biosciences, KEMRI-Wellcome Trust Programme, Kilifi, Kenya.,Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, United Kingdom
| | - Melissa C Kapulu
- Department of Biosciences, KEMRI-Wellcome Trust Programme, Kilifi, Kenya.,Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, United Kingdom
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31
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Amaral LC, Robortella DR, Guimarães LFF, Limongi JE, Fontes CJF, Pereira DB, de Brito CFA, Kano FS, de Sousa TN, Carvalho LH. Ribosomal and non-ribosomal PCR targets for the detection of low-density and mixed malaria infections. Malar J 2019; 18:154. [PMID: 31039781 PMCID: PMC6492410 DOI: 10.1186/s12936-019-2781-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Accepted: 04/13/2019] [Indexed: 01/01/2023] Open
Abstract
Background The unexpected high proportion of submicroscopic malaria infections in areas with low transmission intensity challenges the control and elimination of malaria in the Americas. The current PCR-based assays present limitations as most protocols still rely on amplification of few-copies target gene. Here, the hypothesis was that amplification of different plasmodial targets—ribosomal (18S rRNA) and non-ribosomal multi-copy sequences (Pvr47 for Plasmodium vivax and Pfr364 for Plasmodium falciparum)—could increase the chances of detecting submicroscopic malaria infection. Methods A non-ribosomal real-time PCR assay targeting Pvr47/Pfr364 (NR-qPCR) was established and compared with three additional PCR protocols, two of them based on 18S rRNA gene amplification (Nested-PCR and R-qPCR) and one based on Pvr47/Pfr364 targets (NR-cPCR). The limit of detection of each PCR protocol, at single and artificial mixed P. vivax/P. falciparum infections, was determined by end-point titration curves. Field samples from clinical (n = 110) and subclinical (n = 324) malaria infections were used to evaluate the impact of using multiple molecular targets to detect malaria infections. Results The results demonstrated that an association of ribosomal and non-ribosomal targets did not increase sensitivity to detect submicroscopic malaria infections. Despite of that, artificial mixed-malaria infections demonstrated that the NR-qPCR was the most sensitive protocol to detect low-levels of P. vivax/P. falciparum co-infections. Field studies confirmed that submicroscopic malaria represented a large proportion (up to 77%) of infections among asymptomatic Amazonian residents, with a high proportion of infections (~ 20%) identified only by the NR-qPCR. Conclusions This study presents a new species-specific non-ribosomal PCR assay with potential to identify low-density P. vivax and P. falciparum infections. As the majority of subclinical infections was caused by P. vivax, the commonest form of malaria in the Amazon area, future studies should investigate the potential of Pvr47/Pfr364 to detect mixed-malaria infections in the field. Electronic supplementary material The online version of this article (10.1186/s12936-019-2781-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Lara Cotta Amaral
- Instituto René Rachou, Fundação Oswaldo Cruz, FIOCRUZ-MINAS, Belo Horizonte, MG, Brazil
| | - Daniela Rocha Robortella
- Instituto René Rachou, Fundação Oswaldo Cruz, FIOCRUZ-MINAS, Belo Horizonte, MG, Brazil.,Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | | | | | | | - Dhelio Batista Pereira
- Centro de Pesquisas em Medicina Tropical de Rondônia (CEPEM), Porto Velho, Rondônia, Brazil
| | | | - Flora Satiko Kano
- Instituto René Rachou, Fundação Oswaldo Cruz, FIOCRUZ-MINAS, Belo Horizonte, MG, Brazil
| | - Taís Nóbrega de Sousa
- Instituto René Rachou, Fundação Oswaldo Cruz, FIOCRUZ-MINAS, Belo Horizonte, MG, Brazil.
| | - Luzia Helena Carvalho
- Instituto René Rachou, Fundação Oswaldo Cruz, FIOCRUZ-MINAS, Belo Horizonte, MG, Brazil. .,Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil.
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Essangui E, Eboumbou Moukoko CE, Nguedia N, Tchokwansi M, Banlanjo U, Maloba F, Fogang B, Donkeu C, Biabi M, Cheteug G, Kemleu S, Elanga-Ndille E, Lehman L, Ayong L. Demographical, hematological and serological risk factors for Plasmodium falciparum gametocyte carriage in a high stable transmission zone in Cameroon. PLoS One 2019; 14:e0216133. [PMID: 31022294 PMCID: PMC6483257 DOI: 10.1371/journal.pone.0216133] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Accepted: 04/15/2019] [Indexed: 01/22/2023] Open
Abstract
Presence of mature gametocyte forms of malaria parasites in peripheral blood is a key requirement for malaria transmission. Yet, studies conducted in most malaria transmission zones report the absence of gametocyte in the majority of patients. We therefore sought to determine the risk factors of both all-stage and mature gametocyte carriage in an area with high stable transmission of Plasmodium falciparum in Cameroon. Gametocyte positivity was determined using three complementary methods: thick blood smear microscopy, RT-PCR and RT-LAMP, whereas exposure to the infection was assessed by enzyme-linked immunosorbent assay. Of 361 malaria endemic residents randomly included in the study (mean age: 28±23 years, age range: 2–100 years, male/female sex ratio: 1.1), 87.8% were diagnosed with P. falciparum infection, of whom 45.7% presented with fever (axillary body temperature ≥37.5°C). Mature gametocyte positivity was 1.9% by thick blood smear microscopy and 8.9% by RT-PCR targeting the mature gametocyte transcript, Pfs25. The gametocyte positivity rate was 24.1% and 36.3% by RT-PCR or RT-LAMP, respectively, when targeting the sexual stage marker, Pfs16. Multivariate analyses revealed anemia as a common independent risk factor for both mature and all-stage gametocyte carriage, whereas fever and low anti-gametocyte antibody levels were independently associated with all-stage gametocyte carriage only. Taken together, the data suggest important differences in risk factors of gametocyte carriage depending on stage analyzed, with anemia, fever and low antiplasmodial plasma antibody levels representing the major contributing risk factors.
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Affiliation(s)
- Estelle Essangui
- Malaria Research Unit, Centre Pasteur Cameroon, Yaounde, Cameroon
- Faculty of Sciences, University of Douala, Douala, Cameroon
| | - Carole Else Eboumbou Moukoko
- Malaria Research Unit, Centre Pasteur Cameroon, Yaounde, Cameroon
- Faculty of Medicine and Pharmaceutical Sciences, University of Douala, Douala, Cameroon
| | - Niels Nguedia
- Malaria Research Unit, Centre Pasteur Cameroon, Yaounde, Cameroon
| | | | - Umaru Banlanjo
- Malaria Research Unit, Centre Pasteur Cameroon, Yaounde, Cameroon
| | - Franklin Maloba
- Malaria Research Unit, Centre Pasteur Cameroon, Yaounde, Cameroon
- Faculty of Sciences, University of Buea, Buea, Cameroon
| | - Balotin Fogang
- Malaria Research Unit, Centre Pasteur Cameroon, Yaounde, Cameroon
- Faculty of Sciences, University of Yaounde, Yaounde, Cameroon
| | - Christiane Donkeu
- Malaria Research Unit, Centre Pasteur Cameroon, Yaounde, Cameroon
- Faculty of Sciences, University of Yaounde, Yaounde, Cameroon
| | - Marie Biabi
- Malaria Research Unit, Centre Pasteur Cameroon, Yaounde, Cameroon
- Faculty of Sciences, University of Douala, Douala, Cameroon
| | - Glwadys Cheteug
- Malaria Research Unit, Centre Pasteur Cameroon, Yaounde, Cameroon
- Faculty of Sciences, University of Buea, Buea, Cameroon
| | - Sylvie Kemleu
- Malaria Research Unit, Centre Pasteur Cameroon, Yaounde, Cameroon
- Faculty of Health Sciences, University of Buea, Buea, Cameroon
| | - Emmanuel Elanga-Ndille
- Malaria Research Unit, Centre Pasteur Cameroon, Yaounde, Cameroon
- Centre for Research in Infectious Diseases, Yaounde, Cameroon
| | - Léopold Lehman
- Faculty of Sciences, University of Douala, Douala, Cameroon
| | - Lawrence Ayong
- Malaria Research Unit, Centre Pasteur Cameroon, Yaounde, Cameroon
- * E-mail:
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Lamptey H, Ofori MF, Adu B, Kusi KA, Dickson EK, Quakyi I, Alifrangis M. Association between alpha-thalassaemia trait, Plasmodium falciparum asexual parasites and gametocyte carriage in a malaria endemic area in Southern Ghana. BMC Res Notes 2019; 12:134. [PMID: 30867026 PMCID: PMC6417235 DOI: 10.1186/s13104-019-4181-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Accepted: 03/11/2019] [Indexed: 11/29/2022] Open
Abstract
Objective The alpha-thalassaemia trait has been associated with protection against severe malaria but its role in Plasmodium falciparum asexual parasite and gametocyte carriage remains unclear. This study examined association between prevalence of α-thalassaemia and P. falciparum asexual stage parasitaemia and gametocytaemia in children, pregnant women and adults, which was part of a bigger study that investigated some key factors that influence gametocyte carriage. Results Overall prevalence of heterozygous α-thalassaemia trait among all the groups was 39.0%, while 8.2% were homozygous alpha thalassaemia. Asexual parasite prevalence was significantly higher in children (P = 0.008) compared to adults and pregnant women. Of the asexual P. falciparum positive individuals, gametocyte prevalence was 38.5% (15/39) in children, 29.7% (11/37) in pregnant women and 17.4% (4/23) in adults. Heterozygous α-thalassaemic children were less likely to harbour asexual parasites, compared with normal and those deficient (OR = 0.52; 95% CI 0.28–0.97; P = 0.037) under the dominant model. These heterozygous children were also associated with reduced risk of parasitaemia compared to heterozygous adults and pregnant women. Children with heterozygous α-thalassaemia trait had reduced risk of asexual parasite carriage. There was however, no association between α-thalassaemia trait and risk of gametocyte carriage.
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Affiliation(s)
- Helena Lamptey
- Immunology Department, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana.
| | - Michael Fokuo Ofori
- Immunology Department, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
| | - Bright Adu
- Immunology Department, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
| | - Kwadwo Asamoah Kusi
- Immunology Department, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
| | - Emmanuel Kakra Dickson
- Immunology Department, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
| | - Isabella Quakyi
- Department of Biological, Environmental and Occupational Health Sciences, School of Public Health, College of Health Sciences, University of Ghana, Legon, Ghana
| | - Michael Alifrangis
- Centre for Medical Parasitology, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark.,Department of Infectious Disease, National University Hospital (Rigshospitalet), Copenhagen, Denmark
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