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Sarley D, Hwang A, Fenton Hall B, Ford A, Giersing B, Kaslow DC, Wahl B, Friede M. Accelerating access for all through research and innovation in immunization: Recommendations from Strategic Priority 7 of the Immunization Agenda 2030. Vaccine 2024; 42 Suppl 1:S82-S90. [PMID: 36529593 DOI: 10.1016/j.vaccine.2022.11.041] [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: 04/19/2021] [Revised: 06/08/2022] [Accepted: 11/17/2022] [Indexed: 12/23/2022]
Abstract
Research and innovation have been fundamental to many of the successes in immunization thus far, and will play important roles in the future success of Immunization Agenda 2030 (IA2030). Strategic Priority 7 (SP7) of IA2030, which addresses research and innovation, is explicitly informed by country needs and priorities, and aims to strengthen the innovation ecosystem through capacity building and collaboration at country, regional, and global levels. SP7 identifies four key focus areas: (1) "needs-based innovation", (2) "new and improved products, services, and practices", (3) "evidence for implementation", and (4) "local capacity". Strategic interventions in these key focus areas apply the lessons of the Global Vaccine Action Plan and the "Decade of Vaccines" to emphasize local innovation, promote the use of research by countries to improve program performance and impact, and encourage capacity building for the development and implementation of innovations. The proposed approach will maintain a focus on the development of new vaccines and the improvement of existing vaccines, and increase attention to innovation in service delivery. Monitoring and evaluation will foster evidence-based priority setting at the country level and help to ground the global research and development (R&D) agenda in the needs of communities. Together, these approaches are intended to harness the power of research and innovation more effectively, to meet the challenges of the future and achieve the ambitious goals of IA2030.
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Affiliation(s)
- David Sarley
- Bill & Melinda Gates Foundation, Seattle, WA, USA
| | | | - B Fenton Hall
- Division of Microbiology and Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Andrew Ford
- Division of Microbiology and Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | | | | | - Brian Wahl
- International Vaccine Access Center, Johns Hopkins Bloomberg School of Public Health, Baltimore, USA; Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, USA
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Alga A, Wasihun Y, Ayele T, Endawkie A, Feleke SF, Kebede N. Factors influencing delay in malaria treatment seeking at selected public health facilities in South Gonder, Ethiopia. Sci Rep 2024; 14:6648. [PMID: 38503838 PMCID: PMC10951229 DOI: 10.1038/s41598-024-56413-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 03/06/2024] [Indexed: 03/21/2024] Open
Abstract
Early and prompt treatment-seeking for malaria is necessary to reduce the progression of the disease to its severe forms and the associated mortality. Various studies have indicated that treatments sought for malaria were not always within the recommended timeframe. Therefore, this study aims to assess factors influencing delay in malaria treatment seeking at public health facilities in South Gonder, Ethiopia. An unmatched case-control study was conducted among 322 individuals, comprising 161 cases and 161 controls, who were randomly selected malaria patients visiting public health facilities in South Gonder District, Ethiopia, from May 20/2022 to June 25/2022. An interviewer-administered questionnaire was used to collect data, which were subsequently cleaned and entered into Epi data. Descriptive statistics were performed, and variables with a p-value of ≤ 0.25 from the bivariate analysis were included in a multivariable logistic regression model. Significant variables with a p-value of < 0.05 were retained in the multivariable model. Patients who were unable to read and write [AOR = 3.47 (1.01-11.9)], fear of side effects of malaria treatment drugs [AOR = 1.89 (1.04-3.42)], lack of access to health education malaria disease and its treatment [AOR = 1.93 (1.02-3.65)], lack of transportation access [AOR = 4.70 (1.73-12.7)], not membership of community-based health insurance [AOR = 2.5 (1.3-4.82)] and lack of confidence on malaria care health facility providing [AOR = 2.14 (1.06-4.29)], were found to be determinants of treatment-seeking delay among malaria patients. In Summary, this study revealed significant associations between delays in seeking malaria treatment and factors such as educational status (those who were unable to read and write), malaria drug side effects, health education on malaria, transportation access, CBHI membership, and confidence in health malaria care. it is recommended that targeted interventions and awareness campaigns be implemented to address these determinants, promoting prompt and effective malaria treatment-seeking behavior in the studied population.
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Affiliation(s)
- Adimasu Alga
- Department of Reproductive and Family Health, School of Public Health, College of Medicine Health Sciences, Wollo University, Dessie, Ethiopia
| | - Yitbarek Wasihun
- Department of Health Promotion, School of Public Health, College of Medicine Health Sciences, Wollo University, Dessie, Ethiopia
| | - Tiruneh Ayele
- Department of Epidemiology and Biostatics, School of Public Health, College of Medicine Health Sciences, Wollo University, Dessie, Ethiopia
| | - Abel Endawkie
- Department of Epidemiology and Biostatics, School of Public Health, College of Medicine Health Sciences, Wollo University, Dessie, Ethiopia
| | | | - Natnael Kebede
- Department of Health Promotion, School of Public Health, College of Medicine Health Sciences, Wollo University, Dessie, Ethiopia.
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Jiang A, Lee M, Selvaraj P, Degefa T, Getachew H, Merga H, Yewhalaw D, Yan G, Hsu K. Investigating the Impact of Irrigation on Malaria Vector Larval Habitats and Transmission Using a Hydrology-Based Model. GEOHEALTH 2023; 7:e2023GH000868. [PMID: 38089068 PMCID: PMC10711417 DOI: 10.1029/2023gh000868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Revised: 10/13/2023] [Accepted: 11/20/2023] [Indexed: 02/01/2024]
Abstract
A combination of accelerated population growth and severe droughts has created pressure on food security and driven the development of irrigation schemes across sub-Saharan Africa. Irrigation has been associated with increased malaria risk, but risk prediction remains difficult due to the heterogeneity of irrigation and the environment. While investigating transmission dynamics is helpful, malaria models cannot be applied directly in irrigated regions as they typically rely only on rainfall as a source of water to quantify larval habitats. By coupling a hydrologic model with an agent-based malaria model for a sugarcane plantation site in Arjo, Ethiopia, we demonstrated how incorporating hydrologic processes to estimate larval habitats can affect malaria transmission. Using the coupled model, we then examined the impact of an existing irrigation scheme on malaria transmission dynamics. The inclusion of hydrologic processes increased the variability of larval habitat area by around two-fold and resulted in reduction in malaria transmission by 60%. In addition, irrigation increased all habitat types in the dry season by up to 7.4 times. It converted temporary and semi-permanent habitats to permanent habitats during the rainy season, which grew by about 24%. Consequently, malaria transmission was sustained all-year round and intensified during the main transmission season, with the peak shifted forward by around 1 month. Lastly, we evaluated the spatiotemporal distribution of adult vectors under the effect of irrigation by resolving habitat heterogeneity. These findings could help larval source management by identifying transmission hotspots and prioritizing resources for malaria elimination planning.
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Affiliation(s)
- Ai‐Ling Jiang
- Department of Civil and Environmental EngineeringCenter for Hydrometeorology and Remote SensingUniversity of California IrvineIrvineCAUSA
| | - Ming‐Chieh Lee
- Department of Population Health and Disease PreventionSchool of Public HealthSusan and Henry Samueli College of Health SciencesUniversity of California IrvineIrvineCAUSA
| | - Prashanth Selvaraj
- Institute for Disease ModelingBill and Melinda Gates FoundationSeattleWAUSA
| | - Teshome Degefa
- School of Medical Laboratory SciencesInstitute of HealthJimma UniversityJimmaEthiopia
- Tropical and Infectious Diseases Research Center (TIDRC)Jimma UniversityJimmaEthiopia
| | - Hallelujah Getachew
- School of Medical Laboratory SciencesInstitute of HealthJimma UniversityJimmaEthiopia
- Tropical and Infectious Diseases Research Center (TIDRC)Jimma UniversityJimmaEthiopia
- Department of Medical Laboratory TechnologyArbaminch College of Health SciencesArba MinchEthiopia
| | - Hailu Merga
- Department of EpidemiologyInstitute of HealthJimma UniversityJimmaEthiopia
| | - Delenasaw Yewhalaw
- School of Medical Laboratory SciencesInstitute of HealthJimma UniversityJimmaEthiopia
- Tropical and Infectious Diseases Research Center (TIDRC)Jimma UniversityJimmaEthiopia
| | - Guiyun Yan
- Department of Population Health and Disease PreventionSchool of Public HealthSusan and Henry Samueli College of Health SciencesUniversity of California IrvineIrvineCAUSA
| | - Kuolin Hsu
- Department of Civil and Environmental EngineeringCenter for Hydrometeorology and Remote SensingUniversity of California IrvineIrvineCAUSA
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Hamilton A, Haghpanah F, Hasso-Agopsowicz M, Frost I, Lin G, Schueller E, Klein E, Laxminarayan R. Modeling of malaria vaccine effectiveness on disease burden and drug resistance in 42 African countries. COMMUNICATIONS MEDICINE 2023; 3:144. [PMID: 37833540 PMCID: PMC10576074 DOI: 10.1038/s43856-023-00373-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 09/27/2023] [Indexed: 10/15/2023] Open
Abstract
BACKGROUND The emergence of antimalarial drug resistance poses a major threat to effective malaria treatment and control. This study aims to inform policymakers and vaccine developers on the potential of an effective malaria vaccine in reducing drug-resistant infections. METHODS A compartmental model estimating cases, drug-resistant cases, and deaths averted from 2021 to 2030 with a vaccine against Plasmodium falciparum infection administered yearly to 1-year-olds in 42 African countries. Three vaccine efficacy (VE) scenarios and one scenario of rapidly increasing drug resistance are modeled. RESULTS When VE is constant at 40% for 4 years and then drops to 0%, 235.7 (Uncertainty Interval [UI] 187.8-305.9) cases per 1000 children, 0.6 (UI 0.4-1.0) resistant cases per 1000, and 0.6 (UI 0.5-0.9) deaths per 1000 are averted. When VE begins at 80% and drops 20 percentage points each year, 313.9 (UI 249.8-406.6) cases per 1000, 0.9 (UI 0.6-1.3) resistant cases per 1000, and 0.9 (UI 0.6-1.2) deaths per 1000 are averted. When VE remains 40% for 10 years, 384.7 (UI 311.7-496.5) cases per 1000, 1.0 (0.7-1.6) resistant cases per 1000, and 1.1 (UI 0.8-1.5) deaths per 1000 are averted. Assuming an effective vaccine and an increase in current levels of drug resistance to 80% by 2030, 10.4 (UI 7.3-15.8) resistant cases per 1000 children are averted. CONCLUSIONS Widespread deployment of a malaria vaccine could substantially reduce health burden in Africa. Maintaining VE longer may be more impactful than a higher initial VE that falls rapidly.
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Affiliation(s)
| | | | | | - Isabel Frost
- World Health Organization, Geneva, Switzerland
- Imperial College London, London, UK
| | - Gary Lin
- One Health Trust, Washington, D.C., USA
| | | | - Eili Klein
- One Health Trust, Washington, D.C., USA
- Johns Hopkins University, Department of Emergency Medicine, Baltimore, MD, USA
| | - Ramanan Laxminarayan
- One Health Trust, Washington, D.C., USA.
- One Health Trust, New Delhi, India.
- Princeton University, Princeton, NJ, USA.
- University of Washington, Seattle, WA, USA.
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Runge M, Stahlfeld A, Ambrose M, Toh KB, Rahman S, Omoniwa OF, Bever CA, Oresanya O, Uhomoibhi P, Galatas B, Tibenderana JK, Gerardin J. Perennial malaria chemoprevention with and without malaria vaccination to reduce malaria burden in young children: a modelling analysis. Malar J 2023; 22:133. [PMID: 37095480 PMCID: PMC10124689 DOI: 10.1186/s12936-023-04564-9] [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: 03/19/2023] [Accepted: 04/18/2023] [Indexed: 04/26/2023] Open
Abstract
BACKGROUND A recent WHO recommendation for perennial malaria chemoprevention (PMC) encourages countries to adapt dose timing and number to local conditions. However, knowledge gaps on the epidemiological impact of PMC and possible combination with the malaria vaccine RTS,S hinder informed policy decisions in countries where malaria burden in young children remains high. METHODS The EMOD malaria model was used to predict the impact of PMC with and without RTS,S on clinical and severe malaria cases in children under the age of two years (U2). PMC and RTS,S effect sizes were fit to trial data. PMC was simulated with three to seven doses (PMC-3-7) before the age of eighteen months and RTS,S with three doses, shown to be effective at nine months. Simulations were run for transmission intensities of one to 128 infectious bites per person per year, corresponding to incidences of < 1 to 5500 cases per 1000 population U2. Intervention coverage was either set to 80% or based on 2018 household survey data for Southern Nigeria as a sample use case. The protective efficacy (PE) for clinical and severe cases in children U2 was calculated in comparison to no PMC and no RTS,S. RESULTS The projected impact of PMC or RTS,S was greater at moderate to high transmission than at low or very high transmission. Across the simulated transmission levels, PE estimates of PMC-3 at 80% coverage ranged from 5.7 to 8.8% for clinical, and from 6.1 to 13.6% for severe malaria (PE of RTS,S 10-32% and 24.6-27.5% for clinical and severe malaria, respectively. In children U2, PMC with seven doses nearly averted as many cases as RTS,S, while the combination of both was more impactful than either intervention alone. When operational coverage, as seen in Southern Nigeria, increased to a hypothetical target of 80%, cases were reduced beyond the relative increase in coverage. CONCLUSIONS PMC can substantially reduce clinical and severe cases in the first two years of life in areas with high malaria burden and perennial transmission. A better understanding of the malaria risk profile by age in early childhood and on feasible coverage by age, is needed for selecting an appropriate PMC schedule in a given setting.
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Affiliation(s)
- Manuela Runge
- Department of Preventive Medicine, Institute for Global Health, Northwestern University, Chicago, IL USA
| | - Anne Stahlfeld
- Department of Preventive Medicine, Institute for Global Health, Northwestern University, Chicago, IL USA
| | - Monique Ambrose
- Institute for Disease Modeling, Bill and Melinda Gates Foundation, Seattle, USA
| | - Kok Ben Toh
- Department of Preventive Medicine, Institute for Global Health, Northwestern University, Chicago, IL USA
| | - Semiu Rahman
- Malaria Consortium Nigeria, 33 Pope John Paul Street, Off Gana Street, Maitama, Abuja-FCT Nigeria
| | - Omowunmi F. Omoniwa
- Malaria Consortium Nigeria, 33 Pope John Paul Street, Off Gana Street, Maitama, Abuja-FCT Nigeria
| | - Caitlin A. Bever
- Institute for Disease Modeling, Bill and Melinda Gates Foundation, Seattle, USA
| | - Olusola Oresanya
- Malaria Consortium Nigeria, 33 Pope John Paul Street, Off Gana Street, Maitama, Abuja-FCT Nigeria
| | - Perpetua Uhomoibhi
- National Malaria Elimination Programme, Federal Ministry of Health, Abuja, Nigeria
| | - Beatriz Galatas
- Global Malaria Programme, World Health Organization, Geneva, Switzerland
| | | | - Jaline Gerardin
- Department of Preventive Medicine, Institute for Global Health, Northwestern University, Chicago, IL USA
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Kwapong SS, Asare KK, Kusi KA, Pappoe F, Ndam N, Tahar R, Poinsignon A, Amoah LE. Mosquito bites and stage-specific antibody responses against Plasmodium falciparum in southern Ghana. Malar J 2023; 22:126. [PMID: 37061695 PMCID: PMC10105943 DOI: 10.1186/s12936-023-04557-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Accepted: 04/07/2023] [Indexed: 04/17/2023] Open
Abstract
BACKGROUND The human host elicits specific immune responses after exposure to various life stages of the malaria parasite as well as components of mosquito saliva injected into the host during a mosquito bite. This study describes differences in IgG responses against antigens derived from the sporozoite (PfCSP), asexual stage parasite (PfEBA175) and the gametocyte (Pfs230), in addition to an Anopheles gambiae salivary gland antigen (gSG6-P1), in two communities in Ghana with similar blood stage malaria parasite prevalence. METHODS This study used archived plasma samples collected from an earlier cross-sectional study that enrolled volunteers aged from 6 months to 70 years from Simiw, peri-urban community (N = 347) and Obom, rural community (N = 291). An archived thick and thin blood smear for microscopy was used for the estimation of Plasmodium parasite density and species and DNA extraction from blood spots and P. falciparum confirmation was performed using PCR. This study used the stored plasma samples to determine IgG antibody levels to P. falciparum and Anopheles salivary antigens using indirect ELISA. RESULTS Individuals from Simiw had significantly higher levels of IgG against mosquito gSG6-P1 [median (95%CI)] [2.590 (2.452-2.783) ng/mL] compared to those from Obom [2.119 (1.957-2.345) ng/mL], p < 0.0001. Both IgG responses against Pfs230proC (p = 0.0006), and PfCSP (p = 0.002) were significantly lower in volunteers from Simiw compared to the participants from Obom. The seroprevalence of PfEBA-175.5R (p = 0.8613), gSG6-P1 (p = 0.0704), PfCSP (p = 0.7798) IgG were all similar in Obom and Simiw. However, Pfs230 seroprevalence was significantly higher at Obom compared to Simiw (p = 0.0006). Spearman correlation analysis showed no significant association between IgG responses against gSG6-P1, PfCSP, Pfs230proC and PfEBA-175.5R and parasite density at both Obom and Simiw (p > 0.05). CONCLUSION In conclusion, the study showed that participants from Simiw had higher concentrations of circulating gSG6-P1 IgG antibodies but lower concentrations of P. falciparum antibodies, PfCSP IgG and Pfs230proC IgG compared to participants from Obom.
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Affiliation(s)
- Sebastian Shine Kwapong
- Department of Microbiology and Immunology, School of Medical Sciences, University of Cape Coast, Cape Coast, Ghana
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Accra, Ghana
| | - Kwame Kumi Asare
- Department of Biomedical Science, School of Allied Health Sciences, University of Cape Coast, Cape Coast, Ghana
- Biomedical and Clinical Research Centre, College of Allied Health Sciences, University of Cape Coast, Cape Coast, Ghana
| | - Kwadwo Asamoah Kusi
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Accra, Ghana
| | - Faustina Pappoe
- Department of Microbiology and Immunology, School of Medical Sciences, University of Cape Coast, Cape Coast, Ghana
| | - Nicaise Ndam
- MERIT, IRD, Université de Paris Cité, 75006, Paris, France
| | - Rachida Tahar
- MERIT, IRD, Université de Paris Cité, 75006, Paris, France
| | - Anne Poinsignon
- IRD, CNRS, MIVEGEC, University of Montpellier, 34000, Montpellier, France
| | - Linda Eva Amoah
- Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Accra, Ghana.
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Tchoumi SY, Chukwu CW, Diagne ML, Rwezaura H, Juga ML, Tchuenche JM. Optimal control of a two-group malaria transmission model with vaccination. NETWORK MODELING AND ANALYSIS IN HEALTH INFORMATICS AND BIOINFORMATICS 2023; 12:7. [PMID: 36575768 PMCID: PMC9780107 DOI: 10.1007/s13721-022-00403-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 11/28/2022] [Accepted: 12/06/2022] [Indexed: 12/24/2022]
Abstract
Malaria is a vector-borne disease that poses major health challenges globally, with the highest burden in children less than 5 years old. Prevention and treatment have been the main interventions measures until the recent groundbreaking highly recommended malaria vaccine by WHO for children below five. A two-group malaria model structured by age with vaccination of individuals aged below 5 years old is formulated and theoretically analyzed. The disease-free equilibrium is globally asymptotically stable when the disease-induced death rate in both human groups is zero. Descarte's rule of signs is used to discuss the possible existence of multiple endemic equilibria. By construction, mathematical models inherit the loss of information that could make prediction of model outcomes imprecise. Thus, a global sensitivity analysis of the basic reproduction number and the vaccination class as response functions using Latin-Hypercube Sampling in combination with partial rank correlation coefficient are graphically depicted. As expected, the most sensitive parameters are related to children under 5 years old. Through the application of optimal control theory, the best combination of interventions measures to mitigate the spread of malaria is investigated. Simulations results show that concurrently applying the three intervention measures, namely: personal protection, treatment, and vaccination of childreen under-five is the best strategy for fighting against malaria epidemic in a community, relative to using either single or any dual combination of intervention(s) at a time.
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Affiliation(s)
- S. Y. Tchoumi
- Department of Mathematics and Computer Sciences ENSAI, University of NGaoundere, P. O. Box 455, Ngaoundere, Cameroon ,Department of Mathematics and Applied Mathematics, University of Pretoria, Pretoria, South Africa
| | - C. W. Chukwu
- Department of Mathematics, Wake Forest University, Winston-Salem, NC 27109 USA
| | - M. L. Diagne
- Departement de Mathematiques, UFR des Sciences et Technologies, Universite de Thies, Thies, Senegal
| | - H. Rwezaura
- Mathematics Department, University of Dar es Salaam, P.O. Box 35062, Dar es Salaam, Tanzania
| | - M. L. Juga
- Department of Mathematics and Applied Mathematics, University of Johannesburg, Auckland Park, 2006 South Africa
| | - J. M. Tchuenche
- School of Computer Science and Applied Mathematics, University of the Witwatersrand, Private Bag 3, Wits 2050, Johannesburg, South Africa ,School of Computational and Communication Sciences and Engineering, Nelson Mandela African Institution of Science and Technology, P.O. Box 447, Arusha, Tanzania
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