scholarly journals Spatial and spatio-temporal methods for mapping malaria risk: a systematic review

2020 ◽  
Vol 5 (10) ◽  
pp. e002919 ◽  
Author(s):  
Julius Nyerere Odhiambo ◽  
Chester Kalinda ◽  
Peter M Macharia ◽  
Robert W Snow ◽  
Benn Sartorius
Keyword(s):  
Spatial Clustering ◽  
Malaria Incidence ◽  
Data Extraction ◽  
Malaria Risk ◽  
Risk Mapping ◽  
Data Availability ◽  
Sub Saharan Africa ◽  
Clustering Methods ◽  
Manual Search ◽  
Geostatistical Models

BackgroundApproaches in malaria risk mapping continue to advance in scope with the advent of geostatistical techniques spanning both the spatial and temporal domains. A substantive review of the merits of the methods and covariates used to map malaria risk has not been undertaken. Therefore, this review aimed to systematically retrieve, summarise methods and examine covariates that have been used for mapping malaria risk in sub-Saharan Africa (SSA).MethodsA systematic search of malaria risk mapping studies was conducted using PubMed, EBSCOhost, Web of Science and Scopus databases. The search was restricted to refereed studies published in English from January 1968 to April 2020. To ensure completeness, a manual search through the reference lists of selected studies was also undertaken. Two independent reviewers completed each of the review phases namely: identification of relevant studies based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, data extraction and methodological quality assessment using a validated scoring criterion.ResultsOne hundred and seven studies met the inclusion criteria. The median quality score across studies was 12/16 (range: 7–16). Approximately half (44%) of the studies employed variable selection techniques prior to mapping with rainfall and temperature selected in over 50% of the studies. Malaria incidence (47%) and prevalence (35%) were the most commonly mapped outcomes, with Bayesian geostatistical models often (31%) the preferred approach to risk mapping. Additionally, 29% of the studies employed various spatial clustering methods to explore the geographical variation of malaria patterns, with Kulldorf scan statistic being the most common. Model validation was specified in 53 (50%) studies, with partitioning data into training and validation sets being the common approach.ConclusionsOur review highlights the methodological diversity prominent in malaria risk mapping across SSA. To ensure reproducibility and quality science, best practices and transparent approaches should be adopted when selecting the statistical framework and covariates for malaria risk mapping. Findings underscore the need to periodically assess methods and covariates used in malaria risk mapping; to accommodate changes in data availability, data quality and innovation in statistical methodology.

scholarly journals Pediatric Malaria Incidence and Risk Mapping With and Without Clinical Data in Sussundenga Municipality, Mozambique

2021 ◽  
Author(s):  
Joao Luis Ferrao ◽  
Robert Mendes ◽  
Alberto Tungadza ◽  
Bernado Franque Bernardo ◽  
Kelly M. Searle
Keyword(s):  
Malaria Incidence ◽  
Relevant Information ◽  
Malaria Risk ◽  
Risk Mapping ◽  
Landsat 8 ◽  
Residential Areas ◽  
Correct Treatment ◽  
Socioeconomic Impacts ◽  
Need To Evaluate ◽  
Age Category

Abstract BackgroundMalaria is a parasitic borne disease that affects red blood cells. The disease is preventable, detectable and treatable and more common in poor resource settings. It causes socioeconomic impacts, representing a large burden on the revenue of countries where it is endemic. Malaria is undoubtedly one of the main public health concerns impacting on families and the economy in Mozambique. Although the entire population of Mozambique is at risk of malaria, children and pregnant women have higher risk owing to lower immunity. Age category plays a significant important role in malaria occurrence and can affect the course and progression of the disease and correct treatment. Very few studies in pediatric malaria exists in Mozambique and the existing uses a simplistic and coarse grouping. Malaria risk is rarely uniform, whether considering households in a village, villages in a district or districts in a country. The knowledge of malaria pediatric incidence and, the need to evaluate the local heterogeneity by generating malaria risk maps can improve the understanding of pediatric malaria being the objective of this study. Materials and MethodsA retrospective study was conducted using existing malaria positive data from 2018 to 2019 at Rural Sussundenga Hospital (RSH) in Sussundenga municipality. Attributable factor of the disease and incidence were calculated. Proportion of gender, age category and location were tested using G test. For malaria risk mapping, ten malaria factors (anthropic, sociodemographic, climatic and clinic) were used to produce two maps one using malaria incidence and other without. Bioclimatic, Diva GIS 7.4.0 and, Landsat 8 image were used to produce the map.Results and conclusionThe findings revealed that of the, 42,248 patients who visited the local hospital f, 51.2 % tested positive for malaria with an incidence of 45.7 per 100 persons. There is a difference between residential areas in malaria incidence, with both maps showing malaria risk in Nhamazara, Nhamarenza and Unidade communities. This implies that malaria high risk areas seem to be located in high populated areas and areas close to water bodies. Relevant information is provided for effective planning in malaria intervention.

scholarly journals Intersectional stigma and its impact on HIV prevention and care among MSM and WSW in sub-Saharan African countries: a protocol for a scoping review

BMJ Open ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. e047280
Author(s):  
Gamji M’Rabiu Abubakari ◽  
Debbie Dada ◽  
Jemal Nur ◽  
DeAnne Turner ◽  
Amma Otchere ◽  
...  
Keyword(s):  
Hiv Prevention ◽  
Data Extraction ◽  
Grey Literature ◽  
Secondary Data ◽  
Well Being ◽  
Sub Saharan Africa ◽  
African Countries ◽  
Scoping Reviews ◽  
Sub Saharan ◽  
Meta Analyses

IntroductionResearch has established that various forms of stigma (HIV stigma, gender non-conforming stigma and same-gender sex stigma) exist across Sub-Saharan Africa and have consequences for the utilisation of HIV prevention and care services. Stigmas are typically investigated in HIV literature individually or through investigating individual populations and the various stigmas they may face. The concept of intersectionality highlights the interconnected nature of social categorisations and their ability to create interdependent systems of discrimination based on gender, race, sexuality and so on. Drawing from perspectives on intersectionality, intersectional stigma denotes the convergence of multiple marginalised identities within an individual or a group, the experiences of stigma associated with these identities as well as the synergistic impact of these experiences on health and well-being. With respect to HIV, public health scholars can examine the impacts of intersectional stigmas on HIV prevention and care utilisation.Methods and analysisReviewers will search systematically through MEDLINE, Global Health, Embase, Scopus, Web of Science Core Collection and Africa Index Medicus and citations for quantitative studies, qualitative studies and grey literature that include data on stigma and HIV among men who have sex with men and women who have sex with women in Sub-Saharan Africa. Eligible studies will include primary or secondary data on stigma related to HIV risk factors experienced by this population. Studies will be written in French or English and be published between January 1991 and November 2020. All screening and data extraction will be performed in duplicate, and if discrepancies arise, they will be settled by GM’RA, LEN, DD or AO. Findings from this study will be reported according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews.Ethics and disseminationEthics approval is not required as there will be no human participants and no protected data will be used in this study. We will disseminate findings through peer-reviewed manuscripts, conferences and webinars.

scholarly journals Applicability Evaluation of Several Spatial Clustering Methods in Spatiotemporal Data Mining of Floating Car Trajectory

2021 ◽  
Vol 10 (3) ◽  
pp. 161
Author(s):  
Hao-xuan Chen ◽  
Fei Tao ◽  
Pei-long Ma ◽  
Li-na Gao ◽  
Tong Zhou
Keyword(s):  
Spatial Analysis ◽  
Spatial Clustering ◽  
Heat Index ◽  
Operating Efficiency ◽  
Clustering Methods ◽  
Clustering Method ◽  
Trajectory Mining ◽  
Density Peaks ◽  
Analysis Methods ◽  
Taxi Trajectory

Spatial analysis is an important means of mining floating car trajectory information, and clustering method and density analysis are common methods among them. The choice of the clustering method affects the accuracy and time efficiency of the analysis results. Therefore, clarifying the principles and characteristics of each method is the primary prerequisite for problem solving. Taking four representative spatial analysis methods—KMeans, Density-Based Spatial Clustering of Applications with Noise (DBSCAN), Clustering by Fast Search and Find of Density Peaks (CFSFDP), and Kernel Density Estimation (KDE)—as examples, combined with the hotspot spatiotemporal mining problem of taxi trajectory, through quantitative analysis and experimental verification, it is found that DBSCAN and KDE algorithms have strong hotspot discovery capabilities, but the heat regions’ shape of DBSCAN is found to be relatively more robust. DBSCAN and CFSFDP can achieve high spatial accuracy in calculating the entrance and exit position of a Point of Interest (POI). KDE and DBSCAN are more suitable for the classification of heat index. When the dataset scale is similar, KMeans has the highest operating efficiency, while CFSFDP and KDE are inferior. This paper resolves to a certain extent the lack of scientific basis for selecting spatial analysis methods in current research. The conclusions drawn in this paper can provide technical support and act as a reference for the selection of methods to solve the taxi trajectory mining problem.

scholarly journals Evidence for rapid avoidance of rockfish habitat under reduced quota and comprehensive at-sea monitoring in the British Columbia Pacific halibut fishery

2020 ◽  
Vol 77 (8) ◽  
pp. 1409-1420
Author(s):  
Robyn E. Forrest ◽  
Ian J. Stewart ◽  
Cole C. Monnahan ◽  
Katherine H. Bannar-Martin ◽  
Lisa C. Lacko
Keyword(s):  
British Columbia ◽  
Spatial Clustering ◽  
Clustering Methods ◽  
Quota System ◽  
Encounter Rates ◽  
System A ◽  
Pacific Halibut ◽  
Hippoglossus Stenolepis ◽  
Footprint Area ◽  
Management Changes

The British Columbia longline fishery for Pacific halibut (Hippoglossus stenolepis) has experienced important recent management changes, including the introduction of comprehensive electronic catch monitoring on all vessels; an integrated transferable quota system; a reduction in Pacific halibut quotas; and, beginning in 2016, sharp decreases in quota for yelloweye rockfish (Sebastes ruberrimus, an incidentally caught species). We describe this fishery before integration, after integration, and after the yelloweye rockfish quota reduction using spatial clustering methods to define discrete fishing opportunities. We calculate the relative utilization of these fishing opportunities and their overlap with areas with high encounter rates of yelloweye rockfish during each of the three periods. The spatial footprint (area fished) increased before integration, then decreased after integration. Each period showed shifts in utilization among four large fishing areas. Immediately after the reductions in yelloweye rockfish quota, fishing opportunities with high encounter rates of yelloweye rockfish had significantly lower utilization than areas with low encounter rates, implying rapid avoidance behaviour.

scholarly journals A simple clustering technique to extract subsets of data for function approximation

2015 ◽  
Vol 17 (5) ◽  
pp. 719-732
Author(s):  
Dulakshi Santhusitha Kumari Karunasingha ◽  
Shie-Yui Liong
Keyword(s):  
Function Approximation ◽  
Prediction Models ◽  
Data Extraction ◽  
Single Parameter ◽  
Subtractive Clustering ◽  
Data Sets ◽  
Clustering Methods ◽  
Clustering Method ◽  
Data Set ◽  
Functional Relationships

A simple clustering method is proposed for extracting representative subsets from lengthy data sets. The main purpose of the extracted subset of data is to use it to build prediction models (of the form of approximating functional relationships) instead of using the entire large data set. Such smaller subsets of data are often required in exploratory analysis stages of studies that involve resource consuming investigations. A few recent studies have used a subtractive clustering method (SCM) for such data extraction, in the absence of clustering methods for function approximation. SCM, however, requires several parameters to be specified. This study proposes a clustering method, which requires only a single parameter to be specified, yet it is shown to be as effective as the SCM. A method to find suitable values for the parameter is also proposed. Due to having only a single parameter, using the proposed clustering method is shown to be orders of magnitudes more efficient than using SCM. The effectiveness of the proposed method is demonstrated on phase space prediction of three univariate time series and prediction of two multivariate data sets. Some drawbacks of SCM when applied for data extraction are identified, and the proposed method is shown to be a solution for them.

scholarly journals Factors associated with oral cavity cancers in Sub-Saharan Africa: Summary of the literature

2021 ◽  
Vol 1 (2) ◽  
pp. 34-41
Author(s):  
A Dieng ◽  
AD Faye ◽  
MM Ndiaye ◽  
G Diop ◽  
A Bouazé ◽  
...  
Keyword(s):  
Oral Cavity ◽  
Public Health Problem ◽  
Epidemiological Data ◽  
Sub Saharan Africa ◽  
Factors Associated ◽  
Manual Search ◽  
African Populations ◽  
Localization Strategy ◽  
Sub Saharan ◽  
Oral Cavity Cancers

INTRODUCTION: Oral cavity cancers are now a public health problem according to WHO epidemiological data. There are several risk factors or factors associated with cancers of the oral cavity but they vary according to geographic regions. OBJECTIVE: The objective of this study was to identify factors associated with cancers of the oral cavity in Sub-Saharan African populations through a systematic literature review. METHODOLOGY: Using the data available for the period from January 1980 to December 2019, a synthesis of the literature was carried out. The literature localization strategy included an electronic search of the MEDLINE, EMBASE and GOOGLE SCHOLAR databases from 1980 to 2019 and a manual search of the list of references of articles identified by snowballing. The data were extracted independently by two researchers on an Excel© spreadsheet. Parameters collected from each study were author, country, type of study, period of study, size, age, gender, and factors studied. RESULTS: Out of 1,318 articles found, 24 were selected. The data contained 17,290 patients including 8,229 men, i.e. a male / female sex-ratio of 0.91. Factors studied were tobacco, alcohol, diet, infection, genetics and social factors. CONCLUSION: The results reported showed that several factors are associated with the occurrence of oral cavity cancers in Sub-Saharan Africa. There is a need to conduct further studies with more structured methodologies for more convincing results.

scholarly journals Novel Use of Hydroxyurea in an African Region with Malaria (NOHARM): A Randomized Controlled Trial

Blood ◽  
2017 ◽  
Vol 130 (Suppl_1) ◽  
pp. 759-759
Author(s):  
Robert Opoka ◽  
Christopher Ndugwa ◽  
Teresa S. Latham ◽  
Adam Lane ◽  
Heather Ann Hume ◽  
...  
Keyword(s):  
Adverse Events ◽  
Sickle Cell ◽  
Research Funding ◽  
Malaria Incidence ◽  
Controlled Trial ◽  
Sub Saharan Africa ◽  
Number Needed To Treat ◽  
Hydroxyurea Treatment ◽  
Sub Saharan ◽  
Double Blinded

Abstract Background. Hydroxyurea treatment is recommended for children with sickle cell anemia (SCA) living in high-resource malaria-free regions, but its safety and efficacy in malaria-endemic settings such as sub-Saharan Africa, where the greatest sickle cell burden exists, remain unknown. In vitro studies suggest hydroxyurea could increase malaria severity, through upregulation of intracellular adhesion molecule 1 (ICAM-1) that facilitates parasite adhesion to endothelium. In addition, hydroxyurea-associated neutropenia could worsen infections that occur in low-resource settings. Methods. NOHARM (NCT01976416) was a randomized, double-blinded, placebo-controlled trial conducted in malaria-endemic Uganda. Children between the ages of 1.00-3.99 years were enrolled, and then received 12-months of blinded treatment with either hydroxyurea or placebo at 20 ± 2.5 mg/kg/day, with dose adjustments in both arms for weight gain and hematological toxicities. All participants received standard care for SCA including folic acid, penicillin prophylaxis, and pneumococcal vaccination. For malaria prophylaxis, children received insecticide-treated mosquito nets and monthly sulphadoxine-pyrimethamine. The primary outcome was incidence of clinical malaria. Secondary outcomes included SCA-related adverse events, clinical and laboratory effects, and hematological toxicities. After completing the blinded treatment phase, all participants were offered open-label hydroxyurea, as per local Ethics Committee recommendations. Results. Study participants (median age 2.2 years) received either hydroxyurea (N=104) or placebo (N=103) for 12-months. Malaria occurred at a low rate throughout the study. The malaria incidence did not differ between children on hydroxyurea [0.05 episodes/child/year, 95% CI (0.02, 0.13)] versus placebo [0.07 episodes/child/year (0.03, 0.16)]. The hydroxyurea/placebo malaria incidence rate ratio was 0.7 [(0.2, 2.7), p=0.61], and time to infection did not differ significantly between treatment arms. A composite SCA-related clinical outcome (vaso-occlusive painful crisis, dactylitis, acute chest syndrome, splenic sequestration, or blood transfusion) was less frequent with hydroxyurea (45%) than placebo (69%, p=0.001). For individual clinical events, vaso-occlusive pain and hospitalizations were significantly less frequent with hydroxyurea than placebo; the number needed to treat to prevent one hospitalization was 6.4, while the number needed to treat to prevent a SCA-related event was 2.5. Serious adverse events, sepsis episodes, and dose-limiting toxicities were similar between treatment arms. Specifically, low hemoglobin (<6.0 g/dL) occurred more frequently in children receiving placebo than hydroxyurea, while the frequencies of neutropenia, thrombocytopenia and reticulocytopenia did not differ significantly between treatment arms. Three deaths occurred (two hydroxyurea, one placebo, none from malaria). Children receiving hydroxyurea had significantly increased hemoglobin concentration and fetal hemoglobin, along with decreased leukocytes, neutrophils, and reticulocytes. Conclusions. In this prospective randomized double-blinded placebo-controlled trial of young children with SCA living in Uganda, hydroxyurea therapy was both safe and efficacious. Based on these NOHARM data, hydroxyurea treatment appears safe for children with SCA living in malaria-endemic sub-Saharan Africa, without increased risk for severe malaria, infections, or adverse events. Hydroxyurea provides predicted SCA-related laboratory and clinical efficacy, but the optimal dosing and monitoring regimens for affected children in Africa remain undefined. Disclosures Ware: Agios: Membership on an entity's Board of Directors or advisory committees; Bristol Myers Squibb: Research Funding; Addmedica: Research Funding; Nova Laboratories: Consultancy; Global Blood Therapeutics: Consultancy.

scholarly journals Impact of insecticide resistance in Anopheles arabiensis on malaria incidence and prevalence in Sudan and the costs of mitigation

2017 ◽  
Vol 114 (52) ◽  
pp. E11267-E11275 ◽  
Author(s):  
Hmooda Toto Kafy ◽  
Bashir Adam Ismail ◽  
Abraham Peter Mnzava ◽  
Jonathan Lines ◽  
Mogahid Shiekh Eldin Abdin ◽  
...  
Keyword(s):  
Insecticide Resistance ◽  
Pyrethroid Resistance ◽  
Malaria Incidence ◽  
Disease Incidence ◽  
Indoor Residual Spraying ◽  
Sub Saharan Africa ◽  
Malaria Vectors ◽  
Incidence And Mortality ◽  
Additional Protection ◽  
The Impact

Insecticide-based interventions have contributed to ∼78% of the reduction in the malaria burden in sub-Saharan Africa since 2000. Insecticide resistance in malaria vectors could presage a catastrophic rebound in disease incidence and mortality. A major impediment to the implementation of insecticide resistance management strategies is that evidence of the impact of resistance on malaria disease burden is limited. A cluster randomized trial was conducted in Sudan with pyrethroid-resistant and carbamate-susceptible malaria vectors. Clusters were randomly allocated to receive either long-lasting insecticidal nets (LLINs) alone or LLINs in combination with indoor residual spraying (IRS) with a pyrethroid (deltamethrin) insecticide in the first year and a carbamate (bendiocarb) insecticide in the two subsequent years. Malaria incidence was monitored for 3 y through active case detection in cohorts of children aged 1 to <10 y. When deltamethrin was used for IRS, incidence rates in the LLIN + IRS arm and the LLIN-only arm were similar, with the IRS providing no additional protection [incidence rate ratio (IRR) = 1.0 (95% confidence interval [CI]: 0.36–3.0; P = 0.96)]. When bendiocarb was used for IRS, there was some evidence of additional protection [interaction IRR = 0.55 (95% CI: 0.40–0.76; P < 0.001)]. In conclusion, pyrethroid resistance may have had an impact on pyrethroid-based IRS. The study was not designed to assess whether resistance had an impact on LLINs. These data alone should not be used as the basis for any policy change in vector control interventions.

Modafinil Augmentation for Residual Symptoms of Fatigue in Patients with a Partial Response to Antidepressants

2007 ◽  
Vol 41 (6) ◽  
pp. 1005-1012 ◽  
Author(s):  
Jenny Y Lam ◽  
Maisha Kelly Freeman ◽  
Marshall E Cates
Keyword(s):  
Clinical Trials ◽  
Data Extraction ◽  
Controlled Clinical Trials ◽  
Open Label ◽  
Double Blind ◽  
Residual Symptoms ◽  
Randomized Controlled ◽  
Manual Search ◽  
Number Of Patients ◽  
Residual Fatigue

OBJECTIVE: To evaluate the literature discussing the use of modafinil in the treatment of residual symptoms of fatigue in patients with depression. DATA SOURCES: PubMed (1966–March 2007) and International Pharmaceutical Abstracts(1970–March 2007) were searched using the key words modafinil and depression. A manual search of the reference section of the articles retrieved was conducted to identify articles not indexed in either of these sources. STUDY SELECTION AND DATA EXTRACTION: All articles published in English were evaluated. Studies were included if modafinil was used to treat patients with residual fatigue from depression and the effects were measured with validated fatigue subscales. DATA SYNTHESIS: One retrospective study, 5 open-label trials, and 2 randomized controlled clinical trials met the inclusion criteria for assessment of residual symptoms of fatigue as assessed by commonly used fatigue subscales after modafinil administration. Although improvement with fatigue has occurred with modafinil therapy, literature regarding the topic is limited by the lack of well-controlled clinical trials. Modafinil does appear to improve residual fatigue with depression as evidenced by open-label trials; however, the efficacy of this agent has not been duplicated in randomized controlled trials. The open-label trials that have been conducted often had no comparator and a small number of patients. In addition, outcome measures used in the studies were not consistent between trials. Modafinil appears to be well tolerated, with the main adverse effects being headache and nausea. CONCLUSIONS: Open-label trials indicate that modafinil may be effective in ameliorating fatigue associated with depression; however, this effect has not been reproduced in randomized, double-blind, placebo-controlled clinical trials. Therefore, the use of modafinil for the treatment of residual fatigue is not recommended due to the lack of reproducible data of its efficacy. Long-term, adequately powered clinical trials should be conducted to determine its place in therapy.

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