Nodulation and nitrogen fixation of field grown common bean (Phaseolus vulgaris) as influenced by fungicide seed treatment

A field experiment was conducted at Bel Air station, in Dakar using 15N isotope dilution technique and the non nodulating soybean (Glycine max) variety m129 as reference plant to test the compatibility of Dichlorofenthion-thiram (DCT) fungicide to the inoculation of common bean (Phaseolus vulgaris) Paulista variety with both Rhizobium etli ISRA 353 and R. tropici strain ISRA 554. Nodulation was not induced with R. etli ISRA 353 and nitrogen fixation did not occur. With R. tropici ISRA 554, a decrease in nodulation was observed, but nitrogen fixation was not significantly different compared to that of the non DCT-treated common bean. (African Journal of Biotechnology: 2003 2(7): 198-201

Étude in vitro de l’effet antifalcémiant des globules rouges et de l’activité antioxydante d’extraits de la poudre de racines de Maytenus senegalensis Lam (Celestraceae)

La drépanocytose est une hémoglobinopathie largement répandue chez les populations africaines noires. Actuellement, très peu de traitements conventionnels existent sur le marché, d’où le recours à la médecine traditionnelle. Maytenus senegalensis est une plante prescrite par les tradipraticiens dans la prise en charge de la drépanocytose. L’activité antifalcémiante des extraits de la poudre de racines de Maytenus senegalensis a été étudiée dans ce travail. Après obtention de l’extrait hexanique par extraction à l’aide d’un Soxhlet, le marc est macéré dans de l’acétate d’éthyle puis dans du méthanol pour donner les extraits correspondants. L’activité des fractions a été évaluée sur des drépanocytes de type SS. Les activités antifalcémiantes les plus importantes ont été observées pour les fractions polaires du méthanol et de l’acétate d’éthyle avec des taux d’inversion de la falciformation respectivement de 77% et de 65% à 10 mg/mL. Les activités antioxydantes de M. senegalensis (CI50 = 0,195 ± 0,004 mg/mL) et de l’acide ascorbique (CI50 = 0,078 ± 0,002 mg/mL) ont été déterminées. Les pouvoirs antioxydants (PA) montrent que l’activité antiradicalaire de l’acide ascorbique (PA = 12,85) est 2,5 fois meilleure que celle de M. senegalensis (PA = 5,14). Les résultats de l’étude justifient l’utilisation traditionnelle des racines de Maytenus senegalensis dans la prise en charge de la drépanocytose.Mots clés : Hémoglobine, drépanocytose, Maytenus senegalensis, activité antifalcémiante, stress oxydant, radicaux libres, activité antioxydante

Measles and Rubella Incidence and Molecular Epidemiology in Senegal: Temporal and Regional Trends during Twelve Years of National Surveillance, 2010-2021.

We investigated the epidemiology of measles and rubella infections in Senegal based on data from twelve consecutive years of laboratory-based surveillance (2010-2021) and conducted phylogenetic analyses of circulating measles viruses. Sera from measles-suspected cases were collected and tested for measles and rubella-specific IgM antibodies using enzyme-linked immunosorbent assays (ELISA). Throat swabs were collected from patients with clinically diagnosed measles for confirmation by reverse-transcription polymerase chain reaction (RT-PCR) and viral genotyping. Among 8082 laboratory-tested specimens from measles-suspected cases, serological evidence of measles and rubella infection was confirmed in 1303/8082 (16.1%) and 465/6714 (6.9%), respectively. The incidence of rubella is now low-0.8 (95% CI 0.4-1.3) cases per million people in 2021-whereas progress towards measles pre-elimination targets (<1.0 case per million people per year) appears to have stalled; there were 10.8 (95% CI 9.3-12.5) cases per million people in 2021. Phylogenetic analyses revealed that all Senegalese measles strains belonged to genotype B3. The rubella virus sequence obtained in this study was consistent with genotype 1C. Our national surveillance data suggest that despite their low incidence both measles and rubella remain endemic in Senegal with a concerning stagnation in the decline of measles infections that represents a significant challenge to the goal of regional elimination

A Multicentre Randomized Controlled Trial of the Efficacy and Safety of Single-Dose Praziquantel at 40 mg/kg vs. 60 mg/kg for Treating Intestinal Schistosomiasis in the Philippines, Mauritania, Tanzania and Brazil

Control of urinary and intestinal schistosomiasis is based on mass administration of praziquantel at the World Health Organization (WHO) recommended dose of 40 mg/kg, though some countries use 60 mg/kg. This multi-country randomized clinical trial compared the efficacy (cure and egg reduction rates three weeks post-treatment) and safety of these two doses for treating intestinal schistosomiasis in 856 patients in Brazil, Mauritania and Tanzania (Schistosoma mansoni), and The Philippines (S. japonicum). Transmission and infection intensities varied across the sites, but there was no bias or heterogeneity in efficacy outcomes. The two doses are equally effective in curing intestinal schistosomiasis; the higher dose may be less well tolerated, though effects are generally mild and transient. In endemic areas people can be re-infected; one year post-treatment patients on 60 mg/kg had fewer re-infections but this finding is difficult to explain. This study was conducted to respond to the demand for evidence about the dose of praziquantel when deployed in endemic countries. The results, along with those of systematic reviews, support the current WHO recommendation for using praziquantel at 40 mg/kg and should inform policy decisions in countries. The Philippines has already changed from 60 to 40 mg/kg after this study

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

The appropriation of health huts according populations' perspective.

Au Sénégal, la case de santé (CdS), fruit d’un processus socio-historique et de l’évolution de la politique sanitaire, constitue la base de la pyramide sanitaire où elle est intégrée. Paradoxalement, les communautés arrivent difficilement à se l’approprier. Elle doit sa survie à l’accompagnement des ONG. La compréhension de l’appropriation communautaire fait défaut et a motivé cette recherche, d’où son originalité. La recherche est basée sur l’hypothèse selon laquelle les dynamiques de participation communautaire influencent l’appropriation de la CdS.Au moyen d’une étude qualitative, empirique et exploratoire utilisant une stratégie d’étude de cas multiples, 3 cas ont été sélectionnés dans la région de Thiès. Nous avons collecté quatre types de données qualitatives : entretiens approfondis, focus groups, entretiens semi-structurés et observation directe. Une perspective relationnelle opérationnalisée par un cadre conceptuel large empruntant des concepts de la théorie Bourdieusienne et une approche socio-historique Eliasienne balisent la recherche.Les données ont été analysées au moyen de la théorisation ancrée utilisant un codage par niveaux d’abstraction progressive, duquel ont émergé les catégories ayant servi à l’élaboration d’un cadre logique.Les résultats de l’étude indiquent que les mécanismes du processus d’appropriation s’expriment par la capacité des communautés à gérer les événements critiques et par l’insertion de la CdS dans le tissu social.La pouvoir d’agir de la communauté, le sens communautaire de ses membres et leur capacité à mobiliser les pratiques sociales de participation constituent les moteurs de l’appropriation qui est entretenue par des interrelations entre les capitaux culturel, social et symbolique. Ce dernier s’exprime au niveau communautaire, en entrant en jeu dans la construction de l’appropriation comme processus et non finalité, en renforçant l’identité et en renouvelant l’espace de confiance et de réciprocité, essentiel pour l’action collective. La construction discursive de l’identité communautaire, de la reconnaissance et de l’espace de confiance de réciprocité apparait comme une originalité.Les discussions portent sur des aspects méthodologiques et sur l’opérationnalité du concept d’appropriation. Entres autres, l’appropriation apparait comme processus de reconnaissance et non comme finalité.Cette étude ouvre des pistes de recherches dans le cadre d’un élargissement de l’aire de recherche et en tenant compte des facteurs supra-communautaires. Elle recommande un changement de regard des agents de développement qui devraient considérer les communautés comme des unités de participation, des systèmes regorgeant de potentialités et de solutions nécessitant d’être stimulés et mobilisés ; et non comme des nids de problèmes à résoudre, avec des solutions importées.The health hut model in Senegal is the result of a socio-historical process as well as the health policy evolution. It underpins the health pyramid and is integrated into the health system. Paradoxically, communities struggle to appropriate their health huts. The lack of understanding of the community appropriation process justified this research, which makes it original.The research hypothesis is that the dynamics of community participation influence the health hut appropriation.Through a qualitative, empirical and exploratory research using a multiple case study strategy, three cases were selected in the Thiès region. Four types of qualitative data were collected: in-depth interviews, focus groups, semi-structured interviews and direct observation.A relational perspective based on flexible conceptual framework inspired by Bourdieu’s theory and an Eliasian socio-historical approach guided the research.Data were analyzed by means of the grounded theory method using a coding based on progressive abstraction; which allowed the emerging of categories used to develop the theoretical framework.Results show that the appropriation process mechanisms are expressed through the capacity of communities to manage critical events; and the immersion of the health hut in the social fabric.The agency of action, the sense of community and the capacity of community members to mobilize their social practices of participation are the driving forces of the appropriation process, that is sustained by the interrelations between the cultural, social and symbolic capitals. The latter displays at the community level by coming into play in the appropriation construction as process and not as an aim, and by renewing the trust and reciprocity space that is essential for collective actions. Of originality, is the discursive building of identity, recognition; and space of trust and reciprocity.Are discussed, methodological aspects and the operationability of the appropriation concept: among others, appropriation appears as a process and not as an aim.The study opens new research paths as it relates to the widening of the geographical area of such type of study; and by taking into account the supra-community level factors. It recommends a paradigm shift from the part of development agents who need to consider communities as unit of participation, as systems full of potential and solutions that wait to be stimulated and mobilized; and not as problem nets to be addressed using imported solutions

L’appropriation communautaire des cases de santé selon la perspective des populations.

The health hut model in Senegal is the result of a socio-historical process as well as the health policy evolution. It underpins the health pyramid and is integrated into the health system. Paradoxically, communities struggle to appropriate their health huts. The lack of understanding of the community appropriation process justified this research, which makes it original.The research hypothesis is that the dynamics of community participation influence the health hut appropriation.Through a qualitative, empirical and exploratory research using a multiple case study strategy, three cases were selected in the Thiès region. Four types of qualitative data were collected: in-depth interviews, focus groups, semi-structured interviews and direct observation.A relational perspective based on flexible conceptual framework inspired by Bourdieu’s theory and an Eliasian socio-historical approach guided the research.Data were analyzed by means of the grounded theory method using a coding based on progressive abstraction; which allowed the emerging of categories used to develop the theoretical framework.Results show that the appropriation process mechanisms are expressed through the capacity of communities to manage critical events; and the immersion of the health hut in the social fabric.The agency of action, the sense of community and the capacity of community members to mobilize their social practices of participation are the driving forces of the appropriation process, that is sustained by the interrelations between the cultural, social and symbolic capitals. The latter displays at the community level by coming into play in the appropriation construction as process and not as an aim, and by renewing the trust and reciprocity space that is essential for collective actions. Of originality, is the discursive building of identity, recognition; and space of trust and reciprocity.Are discussed, methodological aspects and the operationability of the appropriation concept: among others, appropriation appears as a process and not as an aim.The study opens new research paths as it relates to the widening of the geographical area of such type of study; and by taking into account the supra-community level factors. It recommends a paradigm shift from the part of development agents who need to consider communities as unit of participation, as systems full of potential and solutions that wait to be stimulated and mobilized; and not as problem nets to be addressed using imported solutions.Au Sénégal, la case de santé (CdS), fruit d’un processus socio-historique et de l’évolution de la politique sanitaire, constitue la base de la pyramide sanitaire où elle est intégrée. Paradoxalement, les communautés arrivent difficilement à se l’approprier. Elle doit sa survie à l’accompagnement des ONG. La compréhension de l’appropriation communautaire fait défaut et a motivé cette recherche, d’où son originalité. La recherche est basée sur l’hypothèse selon laquelle les dynamiques de participation communautaire influencent l’appropriation de la CdS.Au moyen d’une étude qualitative, empirique et exploratoire utilisant une stratégie d’étude de cas multiples, 3 cas ont été sélectionnés dans la région de Thiès. Nous avons collecté quatre types de données qualitatives : entretiens approfondis, focus groups, entretiens semi-structurés et observation directe. Une perspective relationnelle opérationnalisée par un cadre conceptuel large empruntant des concepts de la théorie Bourdieusienne et une approche socio-historique Eliasienne balisent la recherche.Les données ont été analysées au moyen de la théorisation ancrée utilisant un codage par niveaux d’abstraction progressive, duquel ont émergé les catégories ayant servi à l’élaboration d’un cadre logique.Les résultats de l’étude indiquent que les mécanismes du processus d’appropriation s’expriment par la capacité des communautés à gérer les événements critiques et par l’insertion de la CdS dans le tissu social.La pouvoir d’agir de la communauté, le sens communautaire de ses membres et leur capacité à mobiliser les pratiques sociales de participation constituent les moteurs de l’appropriation qui est entretenue par des interrelations entre les capitaux culturel, social et symbolique. Ce dernier s’exprime au niveau communautaire, en entrant en jeu dans la construction de l’appropriation comme processus et non finalité, en renforçant l’identité et en renouvelant l’espace de confiance et de réciprocité, essentiel pour l’action collective. La construction discursive de l’identité communautaire, de la reconnaissance et de l’espace de confiance de réciprocité apparait comme une originalité.Les discussions portent sur des aspects méthodologiques et sur l’opérationnalité du concept d’appropriation. Entres autres, l’appropriation apparait comme processus de reconnaissance et non comme finalité.Cette étude ouvre des pistes de recherches dans le cadre d’un élargissement de l’aire de recherche et en tenant compte des facteurs supra-communautaires. Elle recommande un changement de regard des agents de développement qui devraient considérer les communautés comme des unités de participation, des systèmes regorgeant de potentialités et de solutions nécessitant d’être stimulés et mobilisés ; et non comme des nids de problèmes à résoudre, avec des solutions importées