Abstract
Chikungunya virus (CHIKV) is a major public health concern worldwide. However, infection levels are rarely known, especially in Africa. We recruited individuals from Ouagadougou, Burkina ...Faso and Lambaréné, Gabon (age range, 1–55 years), tested their blood for CHIKV antibodies, and used serocatalytic models to reconstruct epidemiological histories. In Ouagadougou, 291 of 999 (29.1%) individuals were seropositive, ranging from 2% among those aged <10 years to 66% in those aged 40–55 years. We estimated there were 7 outbreaks since the 1970s but none since 2001, resulting in 600 000 infections in the city, none of which were reported. However, we could not definitively conclude whether infections were due to CHIKV or o’nyong-nyong, another alphavirus. In Lambaréné, 117 of 427 (27%) participants were seropositive. Our model identified a single outbreak sometime since 2007, consistent with the only reported CHIKV outbreak in the country. These findings suggest sporadic outbreaks in these settings and that the burden remains undetected or incorrectly attributed.
We conducted chikungunya virus serostudies and used models to reconstruct past circulation. In Burkina Faso, we identified 7 outbreaks, compared to a single outbreak in Gabon. Serostudies with models have a key role in supporting disease surveillance.
•New hybrid intelligent (ANFIS-FA) model is proposed for evapotranspiration prediction.•A regional semi-arid environment at the west of Africa, Burkina Faso is investigated.•The application of the ...hybrid ANFIS-FA model authenticated against ANFIS-based model.•The developed models are conducted using numerous climatological variables.•In conclusion, the proposed method provides an excellent and sophisticated outcome.
Reference Evapotranspiration (ETo) is one of the major components of the hydrological cycle that is very essential in water resources planning, irrigation and drainage management and several other hydrology processes. In irrigation system and design, the prediction of ETo is vital and indispensable for the quantification of crop water needs. This study investigates the capabilities of hybridized fuzzy model with firefly algorithm (ANFIS-FA) for predicting daily reference evapotranspiration over Burkina Faso region. Metrological information at Bobo Dioulasso, Bur Dedougou, and Ouahigouya stations, in Sahelian, Sudano-Sahelian, and Sudanian zone, are used for modelling development. Six different climatic input variable combinations corresponding to 6 models are inspected. The daily Penman-Monteith reference evapotranspiration for the time-period (1998–2012) are used to train and test the models. Several numerical indicators in addition to Taylor diagram are considered to evaluate the performance of the models. Results indicated that the hybrid ANFIS-FA model outperformed the classical ANFIS-based model for all three stations and the model with full inputs climatic data gave the best results. Furthermore, ANFIS-FA is performed the best for Bur Dedougou (Sahalian-Soudanian region) and less at Ouahigouya (sahalian region). In quantitative terms and for instance Bur Dedougou station, ANFIS-FA model increased the prediction accuracy remarkably (SI = 0.043, R2 = 0.97, MAPE = 0.035 and RMSE = 0.24) compared with ANFIS-based model (SI = 0.068, R2 = 0.89, MAPE = 0.037 and RMSE = 0.378). Results revealed the influence of utilizing nature-inspired firefly algorithm to substantially improve performance of the classical ANFIS model optimization for the applied application. Also, the applied modelling strategy can bring a trustful expert intelligent system for predicting reference evapotranspiration at the west desert of Africa.
Cet article analyse la problimatique de la crise sicuritaire au Burkina Faso a partir des perceptions des populations de la ville de Djibo. Depuis 2016, Djibo est considiri comme 1'ipicentre de cette ...crise avec les actions armies revendiquies par le groupe terroriste Ansarul Islam du pridicateur radical Malam Ibrahim Dicko. Llarticle trace les principales raisons de 1'imergence de 1'insicuriti dans la ville de Djibo a travers les perceptions des acteurs au niveau local. Nous dimontrons que 1'origine de cette crise sicuritaire est liie a 1'instrumentalisah'on des clivages sociaux et religieux, et a une crise de gouvernance qui se manifeste notamment par les hierarchies et inigalitis sociales productrices de frustrations, le sentiment de l'absence de l'Etat et la difficile collaboration entre les populations et certaines forces de difense et de sicuriti. MCCTS-CLES : Ansarul Islam, Burkina Faso, Insicuriti, Islam, Peul, Soum. This article examines the security crisis in Burkina Faso through the perceptions of people in the town of Djibo. Since 2016, Djibo has been an epicenter of this crisis amid acts of armed violence claimed by terrorist group Ansarul Islam, led by radical preacher Malam Ibrahim Dicko. The article considers the primary reasons behind the rise of insecurity in the town of Djibo through the lens of local actors. It demonstrates that the origin of the security crisis is linked to the exploitation of social and religious cleavages, and to a governance crisis stemming from frustration over social hierarchies and inequalities, the sentiment of state absence, and the problematic relationship between local populations and elements ofthe government security forces. KEYWORDS: Ansarul Islam, Burkina Faso, Insecurity, Islam, Peul, Soum.
La majorité des AVC est attribuable aux facteurs de risque modifiables. De plus en plus de cas d’AVC lié à la consommation de cannabis ont été décrite dans la littérature.
Décrire les aspects ...épidemiocliniques des AVC liés à la consommation de cannabis, de tabac et d’alcool au CHU Yalgado Ouédraogo au Burkina Faso.
Il s’est agi d’une étude à collecte rétrospective chez les patients atteints d’AVC hospitalisés dans le service de neurologie du CHU Yalgado Ouédraogo durant la période allant du 1er janvier 2015 au 31 décembre 2018. Seuls les patients consommateurs d’alcool, de tabac et de cannabis ont été inclus. L’analyse des données a été faite grâce au logiciel Epi-Info version 7.2.1.0.
Trente deux patients ont été inclus dans l’étude. Les d’AVC ischémiques représentaient 81,7 % des cas. L’âge moyen des patients était de 41,9 ans avec une prédominance masculine. La majorité des patients (56,2 %) était agé de moins de 45 ans. Les principales substances étaient le tabac (75 %), l’alcool (68,8 %) et le cannabis (9,4 %). Un dépistage toxicologique a été réalisé dans 18,7 % des cas.La durée de séjour était de 12,12±9,7jours. La mortalité était de 3,1 %.
Les AVC liés à la consommation de substance psychoactive sont rares dans notre contexte. Cette rareté est due à l’insuffisance des dosages toxicologiques.
Les AVC liés à la consommation de substances psychoactives ne sont pas rares dans notre contexte. Une politique de prévention sur les drogues s’avère nécessaire.
•Land use and land cover change over the past 25years was assessed.•Savannah areas are continuously converted to cropland and settlements.•A multivariate validation of a process based hydrological ...model was achieved.•Land use change potentially affects available water resources and flood risk.
This study investigates the impacts of land use change on water resources in the Dano catchment, Burkina Faso, using a physically based hydrological simulation model and land use scenarios. Land use dynamic in the catchment was assessed through the analysis of four land use maps corresponding to the land use status in 1990, 2000, 2007, and 2013. A reclassification procedure levels out differences between the classification schemes of the four maps. The land use maps were used to build five land use scenarios corresponding to different levels of land use change in the catchment. Water balance was simulated by applying the Water flow and balance Simulation Model (WaSiM) using observed discharge, soil moisture, and groundwater level for model calibration and validation. Model statistical quality measures (R2, NSE and KGE) achieved during calibration and validation ranged between 0.6 and 0.9 for total discharge, soil moisture, and groundwater level, indicating a good agreement between observed and simulated variables. After a successful multivariate validation the model was applied to the land use scenarios.
The land use assessment exhibited a decrease of savannah at an annual rate of 2% since 1990. Conversely, cropland and urban areas have increased. Since urban areas occupy only 3% of the catchment it can be assumed that savannah was mainly converted to cropland. The conversion rate of savannah was lower than the annual population growth of 3%.
A clear increase in total discharge (+17%) and decrease in evapotranspiration (−5%) was observed following land use change in the catchment. A strong relationship was established between savannah degradation, cropland expansion, discharge increase and reduction of evapotranspiration. The increase in total discharge is related to high peak flow, suggesting (i) an increase in water resources that are not available for plant growth and human consumption and (ii) an alteration of flood risk for both the population within and downstream of the catchment.
After its initial detection in Wuhan, China, in December 2019, SARS-CoV-2 has spread rapidly, causing successive epidemic waves worldwide. This study aims to provide a genomic epidemiology of ...SARS-CoV-2 in Burkina Faso.
Three hundred and seventy-seven SARS-CoV-2 genomes obtained from PCR-positive nasopharyngeal samples (PCR cycle threshold score < 35) collected between 5 May 2020, and 31 January 2022 were analyzed. Genomic sequences were assigned to phylogenetic clades using NextClade and to Pango lineages using pangolin. Phylogenetic and phylogeographic analyses were performed to determine the geographical sources and time of virus introduction in Burkina Faso.
The analyzed SARS-CoV-2 genomes can be assigned to 10 phylogenetic clades and 27 Pango lineages already described worldwide. Our analyses revealed the important role of cross-border human mobility in the successive SARS-CoV-2 introductions in Burkina Faso from neighboring countries.
This study provides additional insights into the genomic epidemiology of SARS-CoV-2 in West Africa. It highlights the importance of land travel in the spread of the virus and the need to rapidly implement preventive policies. Regional cross-border collaborations and the adherence of the general population to government policies are key to prevent new epidemic waves.
Malaria is a leading cause of morbidity and mortality worldwide. We previously reported the efficacy of the R21/Matrix-M malaria vaccine, which reached the WHO-specified goal of 75% or greater ...efficacy over 12 months in the target population of African children. Here, we report the safety, immunogenicity, and efficacy results at 12 months following administration of a booster vaccination.
This double-blind phase 1/2b randomised controlled trial was done in children aged 5–17 months in Nanoro, Burkina Faso. Eligible children were enrolled and randomly assigned (1:1:1) to receive three vaccinations of either 5 μg R21/25 μg Matrix-M, 5 μg R21/50 μg Matrix-M, or a control vaccine (the Rabivax-S rabies vaccine) before the malaria season, with a booster dose 12 months later. Children were eligible for inclusion if written informed consent could be provided by a parent or guardian. Exclusion criteria included any existing clinically significant comorbidity or receipt of other investigational products. A random allocation list was generated by an independent statistician by use of block randomisation with variable block sizes. A research assistant from the University of Oxford, independent of the trial team, prepared sealed envelopes using this list, which was then provided to the study pharmacists to assign participants. All vaccines were prepared by the study pharmacists by use of the same type of syringe, and the contents were covered with an opaque label. Vaccine safety, efficacy, and a potential correlate of efficacy with immunogenicity, measured as anti-NANP antibody titres, were evaluated over 1 year following the first booster vaccination. The population in which the efficacy analyses were done comprised all participants who received the primary series of vaccinations and a booster vaccination. Participants were excluded from the efficacy analysis if they withdrew from the trial within the first 2 weeks of receiving the booster vaccine. This trial is registered with ClinicalTrials.gov (NCT03896724), and is continuing for a further 2 years to assess both the potential value of additional booster vaccine doses and longer-term safety.
Between June 2, and July 2, 2020, 409 children returned to receive a booster vaccine. Each child received the same vaccination for the booster as they received in the primary series of vaccinations; 132 participants received 5 μg R21 adjuvanted with 25 μg Matrix-M, 137 received 5 μg R21 adjuvanted with 50 μg Matrix-M, and 140 received the control vaccine. R21/Matrix-M had a favourable safety profile and was well tolerated. Vaccine efficacy remained high in the high adjuvant dose (50 μg) group, similar to previous findings at 1 year after the primary series of vaccinations. Following the booster vaccination, 67 (51%) of 132 children who received R21/Matrix-M with low-dose adjuvant, 54 (39%) of 137 children who received R21/Matrix-M with high-dose adjuvant, and 121 (86%) of 140 children who received the rabies vaccine developed clinical malaria by 12 months. Vaccine efficacy was 71% (95% CI 60 to 78) in the low-dose adjuvant group and 80% (72 to 85) in the high-dose adjuvant group. In the high-dose adjuvant group, vaccine efficacy against multiple episodes of malaria was 78% (95% CI 71 to 83), and 2285 (95% CI 1911 to 2568) cases of malaria were averted per 1000 child-years at risk among vaccinated children in the second year of follow-up. Among these participants, at 28 days following their last R21/Matrix-M vaccination, titres of malaria-specific anti-NANP antibodies correlated positively with protection against malaria in both the first year of follow-up (Spearman's ρ –0·32 95% CI –0·45 to –0·19; p=0·0001) and second year of follow-up (–0·20 –0·34 to –0·06; p=0·02).
A booster dose of R21/Matrix-M at 1 year following the primary three-dose regimen maintained high efficacy against first and multiple episodes of clinical malaria. Furthermore, the booster vaccine induced antibody concentrations that correlated with vaccine efficacy. The trial is ongoing to assess long-term follow-up of these participants and the value of further booster vaccinations.
European and Developing Countries Clinical Trials Partnership 2 (EDCTP2), Wellcome Trust, and NIHR Oxford Biomedical Research Centre.
For the French translation of the abstract see Supplementary Materials section.
In this book Ousman Kobo provides a fresh understanding of the indigenous origins of Islamic reforms sympathetic to "Wahhabi" ideas in two West African countries, Burkina Faso and Ghana, and connects ...these movements to Muslim's search for religious purity in modern contexts.
Burkina Faso experienced an epidemic resurgence of dengue in 2016, which led to the implementation of several control strategies. In order to allow a better adaptation of these strategies, we studied ...the spatio-temporal distribution of dengue.
Monthly dengue cases from 2016 to 2019, aggregated at the health district level, were used to map the crude incidence, excess risk, and smoothed incidence of dengue in Burkina Faso with GeoDa software. A Kulldoff scan on Satscan software was then used to identify spatio-temporal clustering of cases.
The results show that the distribution of dengue fever across the health districts of Burkina Faso is heterogeneous. Dengue was considered non-endemic in 9 out of the 70 health districts, minimally endemic in 45 districts (< 10 incidences), moderately endemic (10-100 incidences) in 12 districts, and highly endemic (> 100 incidences) in 4 districts. The main cluster covered the health districts of Baskuy, Nongr-massom, Sig-noghin, Boulmiougou, and Bogodogo. The months of October and November corresponded to the peak of cases and a significant temporal cluster in 2017.
This study identified the spatial and temporal clustering of dengue cases in Burkina Faso. These results may help to develop better preventive strategies.
Although the evaluation of soil organic carbon (SOC) stocks across different types of land use and major reference soil groups is essential for mitigating climate change, there remains, to date, ...limited comprehensive understanding of whole tropical soil profiles. Therefore, this study aimed to explain the amount of SOC stocks in different land-use systems and across various soil groups, as well as its spatial pattern in the topsoil (0–30 cm) and subsoil (30–100 cm) within the savannah zone of Burkina Faso. Roughly 70 soil profiles were considered along with additional auger sampling to account for spatial variation in both cropland (CR) and savannah (SA). The machine learning technique random forest regression (RFR) and multiple linear regression (MLR) were used for modeling the surface and subsurface SOC stocks. For model calibration, covariates including land use, topographic, texture, and climatic data were considered as surrogate for soil forming factors. The prediction maps produced by the calibrated models were validated by an independent dataset. The results indicated that about 53% of the SOC stock over 1 m depth was held in the upper 30 cm. Only a marginal difference was recorded between the topsoil SOC stock in SA (41.4 t C ha−1) and CR (39.1 t C ha−1) soils. For the subsoil, a significant difference (p < 0.05) was observed between the SOC stock of CR soils recording about 40.2 t C ha−1 and SA soils with 26.3 t C ha−1. Among the reference soil groups, the Gleysols located at lower elevation positions revealed the highest SOC stocks over 0–30 cm (44 t C ha−1) and 100 cm depth (86.6 t C ha−1). The Stagnosols (45.2 t C ha−1) followed by the Gleysols (42.7 t C ha−1) recorded the highest SOC stocks over 30–100 cm. The variability of SOC stock in the topsoil was primarily related to site-specific elements, such as particle-size fraction and wetness index, while its distribution in the subsoil was mainly associated with the topographical orientation represented by the slope aspect. Compared to the MLR, RFR estimated mean top- and subsoil SOC stocks of the catchment fairly well, along with lower statistical error metrics, though extreme values were not covered. Nevertheless, the findings on SOC stocks reinforce the view that the semi-arid ecosystems of West Africa still offer a significant opportunity for carbon sequestration for both topsoil and subsoil, and these results represent a baseline for future modeling of SOC dynamics in the region.
•Difference in organic carbon stock for topsoil savannah and cropland was marginal.•Particle-size fraction mainly affects the topsoil carbon stock distribution.•Random Forest predicted fairly well the mean top- and subsoil organic carbon stocks.
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