SWV determination of glyphosate in Burkina Faso soils using carbon fiber microelectrode

This paper presents an evaluation using carbon fiber microelectrode (CFME) for the determination of glyphosate in soils from Burkina Faso treated with Glyphonet SL 360 by square wave voltammetry (SWV).The maximum intensity of the electrochemical response signal of  glyphosate has been optimized and conditions using a 0.2 M of phosphate buffer solution at pH 5.2 as supporting electrolyte and the SWV parameters frequency of 60 Hz, a scan increment of 10 mV and a pulse height of 60 mV. The limit of detection for glyphosate in the Glyphonet SL 360 formulation was 25 ìg L-1 while the quantification limit was 83 ìgL-1with a linear dynamic range up to 50 ìg L-1. In these conditions, a sequence of experiments led to recoveries in the range 88.5 to 102.3% for soil samples spiked with 50, 100 and 200 ìgL-1 of glyphosate with a standard deviation of 11.5, 4.2 and 2.3% respectively indicating the precision of the method. The optimized method was successfully applied to determine the residues of glyphosate in soils collected in the fields in two different dates from the application period.Keywords: Glyphosate, Glyphonet SL 360, carbon fiber microelectrode, square wave voltammetry, sensitivit

Allelic and genotypic frequencies of ASIP and MC1R genes in four West African sheep populations

In West Africa, consumers pay a major attention on the coat colour of the sheep due to religious and cultural reasons. White coated individuals reach selling prices up to three-fold higher than black coated sheep. The aim of this study was to ascertain the genotypic and allelic frequencies of MC1R and ASIP genes in order to assess possible implementation of breeding programmes focusing on the increase of the white coated sheep frequencies. A total of 113 individuals belonging to three Burkina Faso sheep breeds (Burkina-Sahel, Djallonké and Mossi) and one Niger sheep breed (Touareg) were genotyped for the MC1R and ASIP genes. The wild allele of the ASIP gene (Awt; 54.30%) was the most frequent in the four West African sheep, particularly in Burkina-Sahel (85%) and Touareg breeds (80%). The dominant black ED allele was not identified in Burkina-Sahel and Touareg. Most of the analysed individuals were homozygous for wild MC1R allele (E+/E+) with 100, 73.5, 59 and 100% frequency in Burkina-Sahel, Djallonké, Mossi and Touareg, respectively. The Awt/Awt was the most frequent genotype on the ASIP gene in the four West African breeds (80.53%). No individuals were homozygous for the deletion (allele Adel). Although, no routine methods for detection of the genetic basis of the recessive black coat colour patterns can be easily implemented, the current results suggest the feasibility of a selection programme aiming at decreasing the frequencies of the dominant black ED allele in Burkina Faso sheep breeds.Key words: Sheep, coat colour, MC1R gene, ASIP gene, Burkina Faso, Niger

Stakeholder perceptions on the deployment of multiple first-line therapies for uncomplicated malaria: a qualitative study in the health district of Kaya, Burkina Faso

BACKGROUND: In Burkina Faso, malaria remains the first cause of medical consultation and hospitalization in health centres. First-line case management of malaria in the country's health facilities is based on the use of artemisinin-based combination therapy (ACT). To optimize the use of these anti-malarial drugs in the perspective of mitigating the emergence of artemisinin resistance, which is a serious threat to malaria control and elimination, a pilot programme using multiple first-line therapies (MFTs) [three artemisinin-based combinations-pyronaridine-artesunate, dihydroartemisinin-piperaquine and artemether-lumefantrine] has been designed for implementation. As the success of this MFT pilot programme depends on the perceptions of key stakeholders in the health system and community members, the study aimed to assess their perceptions on the implementation of this strategy. METHODS: Semi-structured interviews, including 27 individual in-depth interviews and 41 focus groups discussions, were conducted with key stakeholders including malaria control policymakers and implementers, health system managers, health workers and community members. Volunteers from targets stakeholder groups were randomly selected. All interviews were recorded, transcribed and translated. Content analysis was performed using the qualitative software programme QDA Miner. RESULTS: The interviews revealed a positive perception of stakeholders on the implementation of the planned MFT programme. They saw the strategy as an opportunity to strengthen the supply of anti-malarial drugs and improve the management of fever and malaria. However, due to lack of experience with the products, health workers and care givers expressed some reservations about the effectiveness and side-effect profiles of the two anti-malarial drugs included as first-line therapy in the MFT programme (pyronaridine-artesunate, dihydroartemisinin-piperaquine). Questions were raised about the appropriateness of segmenting the population into three groups and assigning a specific drug to each group. CONCLUSION: The adherence of both populations and key stakeholders to the MFT implementation strategy will likely depend on the efficacy of the proposed drugs, the absence of, or low frequency of, side-effects, the cost of drugs and availability of the different combinations

Feasibility and acceptability of a strategy deploying multiple first-line artemisinin-based combination therapies for uncomplicated malaria in the health district of Kaya, Burkina Faso

(1) Background: Effective malaria case management relies on World Health Organization (WHO) recommended artemisinin-based combination therapies (ACTs), but partial resistance to artemisinin has emerged and is spreading, threatening malaria control and elimination efforts. The strategy of deploying multiple first-line therapies (MFT) may help mitigate this threat and extend the therapeutic life of current ACTs. (2) Methods: A district-wide pilot quasi-experimental study was conducted, deploying three different ACTs at the public health facility (PHF) level for uncomplicated malaria treatment from December 2019 to December 2020 in the health district (HD) of Kaya, Burkina Faso. Mixed methods, including household and health facility-based quantitative and qualitative surveys, were used to evaluate the pilot programme. (3) Results: A total of 2008 suspected malaria patients were surveyed at PHFs, of which 79.1% were tested by rapid diagnostic test (RDT) with 65.5% positivity rate. In total, 86.1% of the confirmed cases received the appropriate ACT according to the MFT strategy. The adherence level did not differ by study segment (p = 0.19). Overall, the compliance level of health workers (HWs) with MFT strategy was 72.7% (95% CI: 69.7-75.5). The odds of using PHF as the first source of care increased after the intervention (aOR = 1.6; 95% CI, 1.3-1.9), and the reported adherence to the 3-day treatment regimen was 82.1%; (95% CI: 79.6-84.3). Qualitative results showed a high acceptance of the MFT strategy with positive opinions from all stakeholders. (4) Conclusions: Implementing an MFT strategy is operationally feasible and acceptable by stakeholders in the health systems in Burkina Faso. This study provides evidence to support the simultaneous use of multiple first-line artemisinin combination therapies in malaria-endemic countries such as Burkina Faso

Developing reference criteria for the ecological status of West African rivers

Awareness of sustainable management of water and its biological resources is rising in West Africa, but application of effective tools for biomonitoring and detecting habitats at risk in aquatic ecosystems is limited. In this study, we provide key environmental descriptors to characterize reference sites by applying the following "a priori criteria" (physical and chemical, hydro-morphological, and land use parameters) by exploring their potential to determine suitable reference sites. Using data collected from 44 sites, we identified 37 criteria that reliably identify reference conditions in semi-arid rivers by reflecting the impacts of multiple pressures ranging from low to very high intensity of human uses and impairments. We integrated all these impacts in an overall pressures index, which showed that protected areas can reasonably be considered as credible reference sites as far as they show low overall impact levels from cumulative pressures. We recommend that development of bio-indicator standards should be based on the collection and integration of all the available information, especially quantitative, spatially-explicit data, from benthic macroinvertebrates and fish. Rigorous standardization of bio-indicator protocols will make them more easily applicable for management and conservation of aquatic ecosystem resources in semi-arid zones of Africa

Attitudes, practices, and determinants of community care-seeking behaviours for fever/malaria episodes in the context of the implementation of multiple first-line therapies for uncomplicated malaria in the health district of Kaya, Burkina Faso

BACKGROUND: Malaria case management relies on World Health Organization (WHO)-recommended artemisinin-based combination therapy (ACT), and a continuous understanding of local community knowledge, attitudes, and practices may be a great support for the success of malaria disease control efforts. In this context, this study aimed to identify potential facilitators or barriers at the community level to inform a health district-wide implementation of multiple first-line therapies (MFT) as a new strategy for uncomplicated malaria case management. METHODS: A community-based cross-sectional study using a mixed-method design was carried out from November 2018 to February 2019, in the health district (HD) of Kaya in Burkina Faso. Quantitative data were collected using a standardized questionnaire from 1394 individuals who had fever/malaria episodes four weeks prior to the survey. In addition, 23 focus group discussions (FGDs) were conducted targeting various segments of the community. Logistic regression models were used to assess the predictors of community care-seeking behaviours. RESULTS: Overall, 98% (1366/1394) of study participants sought advice or treatment, and 66.5% did so within 24 h of fever onset. 76.4% of participants preferred to seek treatment from health centres as the first recourse to care, 5.8% were treated at home with remaining drug stock, and 2.3% preferred traditional healers. Artemether-lumefantrine (AL) was by far the most used anti-malarial drug (98.2%); reported adherence to the 3-day treatment regimen was 84.3%. Multivariate analysis identified less than 5 km distance travelled for care (AOR = 2.7; 95% CI 2.1-3.7) and education/schooling (AOR = 1.8; 95% CI 1.3-2.5) as determinants of prompt care-seeking for fever. Geographical proximity (AOR = 1.5, 95% CI 1.2-2.1), having a child under five (AOR = 4.6, 95% CI 3.2-6.7), being pregnant (AOR = 6.5, 95% CI 1.9-22.5), and living in an urban area (AOR = 2.8, 95% CI 1.8-4.2) were significant predictors for visiting health centres. The FGDs showed that participants had good knowledge about malaria symptoms, prevention tools, and effective treatment. Behaviour change regarding malaria treatment and free medication for children under five were the main reasons for participants to seek care at health centres. CONCLUSIONS: The study showed appropriate knowledge about malaria and positive community care-seeking behaviour at health centres for fever/malaria episodes. This could potentially facilitate the implementation of a MFT pilot programme in the district. CLINICALTRIALS: gov Identifier: NCT04265573

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

Effets de traitements herbicides sur Rhamphicarpa fistulosa (Hochst.) Benth. Une plante parasite facultative

Objectif: La dispersion et le maintien des mauvaises herbes annuelles dépendent de la production de leurs semences et de leur dissémination. Rhamphicarpa fistulosa, une plante parasite facultative n’échappe pas à cette règle. La lutte chimique, entre autres est préconisée. L’objectif étant d’optimaliser les traitements en déterminant les meilleures périodes ainsi que les meilleures conditions d’application des herbicides.Méthodologie et résultats: L’expérimentation a été réalisée au Burkina Faso avec les herbicides : acide 2,4- D sous sa forme amine et Rilof. Une étude cytologique des graines du parasite soumises à des traitements herbicides couplée à l’étude embryologique du parasite est effectuée. Les capsules de Rhamphicarpa possèdent un tégument peu coriace avec quelques poly embryons. Deux traitements au 2,4D à la dose de 360 g m.a. ha-1 donnent les meilleurs résultats. Le Rilof détruit les graines et embryons contenus dans les capsules à un niveau moindre que le 2, 4-D ; il élimine les plants de Rhamphicarpa de 78 % à 92 % comparativement au 2.4-D qui est à 100%. En général le succès d’un traitement herbicide dépend largement du moment d'application de l'herbicide : - destruction des nouveaux plants de Rhamphicarpa émergés depuis le premier traitement et qui sont encore à l'état végétatif ou en tout début de floraison ; - empêcher la floraison de nouveaux axes florifères mis en place par les bourgeons axillaires du reste des tiges de Rhamphicarpa encore vivantes après le premier traitement. Cette étude a permis de recueillir un grand nombre de données ayant un impact agronomique, ce qui permet ainsi de minimiser la pollution des produits chimiques et de diminuer la quantité de graines produites et à terme, aboutir à une diminution du stock de graines dans le sol.Conclusion et application des résultats: L'approche chimique doit être retenue comme une des composantes de la lutte intégrée recherchée pour contenir ce type de parasite dans des limites acceptables.Mots-clés: lutte chimique, Rhamphicarpa fistulosa, efficacité, cytologie, graines, embryonsEnglish Title: Effects of chemical treatments on Rhamphicarpa fistulosa (Hochst.) BenthEnglish AbstractObjective: The dispersal and maintenance of annual weeds depend on the production and dissemination of their seeds. Rhamphicarpa fistulosa does not escape this rule. Chemical control is, among others, recommended. The objective is to optimize the treatments by determining the best periods and the best conditions for application of herbicides.Methodology and results: The experiment was carried out in Burkina Faso with herbicides: 2,4-D acid in its amine form and Rilof. A cytological study of the parasite seeds subjected to herbicidal treatments coupled with the embryological study of the parasite is carried out. Rhamphicarpa capsules have a slightly tough seed coat with some poly embryos. Two treatments of 2,4D at the dose of 360 g a. i. ha-1 gave better results. The Rilof destroys the seeds and embryos contained in the capsules to a level lower than 2,4-D; it eliminates Rhamphicarpa plants from 78% to 92% comparated to 2.4-D which is 100%. In general, the success of a herbicide treatment depends largely on the time of application of the herbicide: - destruction of new Rhamphicarpa plants emerging from the first treatment and still in the vegetative state or at the beginning of flowering; - to prevent the flowering of new flowering axes established by the axillary buds of the rest of the stems of Rhamphicarpa still alive after the first treatment. This study resulted in a large amount of data having an agronomic impact, thus minimizing pollution of chemicals and decreasing the amount of seed produced and ultimately resulting in a decrease in the seed stock in the soil.Conclusion and application of the results: The chemical approach should be retained as one of the components of integrated pest management to contain this type of parasite within acceptable limits.Keyworld: chemical control, Rhamphicarpa fistulosa, efficacity, cytology, seeds, embryo