Émissions de dioxyde de carbone et de méthane des termitières de Macrotermes bellicosus au Burkina Faso

Cette étude a pour but d’évaluer les émissions de gaz carbonique (CO2) et de méthane (CH4) à partir des termitières de Macrotermes bellicosus appartenant à la famille des Termitidae qui occupe plus de 2/3 des sols tropicaux. Deux différentes termitières (T1 et T2) ont fait l’objet de cette étude. Des échantillons gazeux ont été prélevés des termitières puis analysés par chromatographie en phase gazeuse. Des concentrations variables de CO2 ont été enregistrées de chaque termitière durant la nuit (22368 et 12803 ppm respectivement pour T1 et T2) et le jour (21397 et 9985 ppm respectivement pour T1 et T2). Selon l’activité des termites, l’architecture des termitières et le gradient de température entre l’intérieur et l’extérieur des termitières, des mécanismes de ventilation sont élaborés par ces termites pour diffuser les gaz. Des traces de CH4 (<0,5 ppm CH4/jour) ont été aussi détectées tout au long de l’étude quelle que soit la température des termitières. Par contre, la transition saisonnière (sèche à pluvieuse) a marqué une très légère augmentation d’émission de CH4 (0,5 ppm CH4 / jour). En plus de ces facteurs, bien d’autres paramètres sont à intégrer pour une étude ultérieure plus complète.Mots clés: Gaz à effet de serre, termites, structure des termitières, température, cycle journalie

Evaluation de l’effet d’un extrait aqueux de Bridelia ferruginea Benth. (Euphorbiaceae) sur les activités spontanée et locomotrice chez le rat

L’objectif de ce travail est d’évaluer l’effet d’un extrait aqueux de l’écorce de tige de Bridelia ferruginea (SEA) sur le système nerveux central chez le rat. L’extrait aqueux de cette plante est administré aux animaux par la voie intrapéritonéale 30 minutes avant l’évaluation. L’actographe a permis de quantifier l’activité spontanée alors que l’activité locomotrice a été évaluée grâce à la roue d’activité et la traction. SEA, à la dose de 10 mg/kg de poids corporel réduit de manière significative l’activité spontanée de 63,26% (

Effets pharmacologiques d’un extrait aqueux de Costus afer (Zingiberaceae) sur l’activité cardiaque et la pression artérielle couplée à la respiration de mammifères

Costus afer, couramment utilisée pour ses vertus médicinales, est une plante de la pharmacopée traditionnelle africaine. Elle intervient dans le traitement de nombreuses maladies telles que le paludisme, la diarrhée et l’hypertension. L’objectif de la présente étude a été d’évaluer les effets de l’extrait aqueux de cette plante sur le système cardiovasculaire et l’activité respiratoire chez les mammifères. L’étude des effets pharmacologiques de l’extrait aqueux total de Costus afer (Caf) sur l’activité cardiaque et la pression artérielle couplée à la respiration a révélé que Caf aux doses comprises entre 2,94.10-3 et 4,71.10-2 g/kg de poids corporel (PC) induit une diminution de l’amplitude des ondes P et QRS ainsi que la fréquence cardiaque du Lapin. Cet extrait aux doses comprises entre 2,94.10-3 et 3,82.10-2 g/kg de PC provoque une hypotension et une baisse de l’amplitude de l’activité respiratoire chez le lapin. En présence de l’atropine (10-6 mg/ml), l’effet inotrope négatif de Caf est aboli. La persistance de l’effet chronotrope négatif en présence de cet antagoniste des récepteurs cholinergiques de type muscarinique, suggère également la présence de substances cardioinhibitrices non cholinergiques. Pour des concentrations comprises entre 10-12 et 10-6 mg/ml, Caf induit sur le coeur isolé de rat des effets inotropes positifs qui seraient dus à la présence de substances cardiotoniques. Caf, aux concentrations supérieures à 10-6 mg/ml,  provoque des effets inotrope et chronotrope négatifs sur l’activité contractile du coeur isolé de rat. Les résultats obtenus lors de cette étude suggèrent donc que cet extrait brut contiendrait des principes actifs  cholinomimétiques et non cholinomimétiques et des principes actifsadrénomimétiques. Mots clés : Costus afer, Atropine, Propranolol, récepteur muscarinique

Composition and antimicrobial activities of the leaf and flower essential oils of Lippia chevalieri and Ocimum canum from Burkina Faso

The essential oils of the air dried leaves and flowers of Lippia chevalieri Moldenke and Ocimum canum Sims from Burkina Faso were analysed by GC-MS. Essential oil of the leaves of L. chevalieri is composed mainly of thymol (27.4%), p-cymene (21.1%), and 2-phenyl-ethyl-propionate (12.6%), whilethe oils from flower is composed of b-elemene (33%), ethyl cinnamate (30.3%) and a-amorphene (12.4%). O. canum leaves and flowers oils consisted mainly in 1,8-cineole (60.1%) and cis, transpiperitol (68.5%), respectively. The antimicrobial activities of the essential oils were evaluated against 9 bacteria by agar diffusion method. The leaves of both plants showed higher activity than their flowers. The leaves of L. chevalieri were active against Gram negative and Gram positive bacteria whereas only Gram positive bacteria were sensitive to the essential oil of the O. canum leaves. Flower essential oilsdid not show any significant activity

Polymerase Chain Reaction (PCR) provides a superior tool for the diagnosis of Pneumococcal Infection in Burkina Faso

Purpose of study: The aim of this study was to determine the value of real-time Polymerase Chain Reaction (rt-PCR) in the routine surveillance of pneumococcal meningitis in Burkina Faso, compared to standard methods of culture, Gram stain and latex agglutination assay.Materiel and methods: A total of 385 specimens of cerebrospinal fluid were analyzed by the three standard bacteriological methods (Gram stain, latex agglutination assay, and culture) and real-time Polymerase Chain Reaction.Results: Of 385 specimens analyzed by these methods, 204 S. pneumoniae were detected by one or more  methods. Gram stain detected 36.4% (140/385) Gram positive encapsulated diplococci; 37.7% (145/385) and 20.8% (80/385) of the specimens were positive for pneumococci by latex agglutination assay and culture. These specimens were tested with rt-PCR, which confirmed 51.2% (197/385) S. pneumoniae positive. The sensitivity and specificity of culture were 54.4% and 31.5%, respectively, and the sensitivity and specificity of rt-PCR were 96.6% and 100%, respectively. These results showed that rt-PCR was more sensitive than Gram stain (p=0.0235), latex agglutination assay (p=0.0442)and culture (p=0.0006).The culture is the gold standard method; however, the result showed that rt-PCR had specificity and was as specific as Gram stain (p=0.3405) and latex agglutination assay (p=0.7745).Conclusion: rt-PCR was highly sensitive and specific. It could be used as a complementary diagnostic tool to  mprove case confirmation of bacterial meningitis. However,its high cost, the qualification of the technical staff and infrastructures required for its implementation, constitute obstacles to its widened use in countries with limited resources.Keywords: Streptococcus pneumoniae, meningitis, rt-PCR, standard bacteriological methods Objectif: Le but de cette étude était de déterminer la place de la rt-PCR dans la surveillance de routine deméningitespneumococciquesau Burkina Faso et la comparée avec les méthodes de la bactériologie classique: Culture, coloration de Gram et l’agglutination au latex.Matériel etméthodes: Au total, 385 échantillons deliquides céphalorachidiens (LCR)étaient analysés par les trois méthodes de la bactériologie classique (coloration de Gram, agglutination au latex, culture) et la PCR en temps réel.RESULTATS: Parmi 385 échantillons analysés, 204 cas de Streptococcuspneumoniae étaient détectés par une ou plusieurs méthodes. La coloration de Gram adétecté 36,4% (140/385) diplocoques encapsulés à Gram positif (DGP); 37,7% (145/385) et 20,8% (80/385) d’échantillons étaient positifs aux pneumocoques par l’agglutination au latex et la culture. Ces échantillons étaient aussi testés par rt-PCR qui a confirmé 51,2% (197/385) cas positifs de S. pneumoniae. La sensibilité et la spécificité de la culture étaient respectivement de 54,4% et 31,5%, et la sensibilité et la spécificité de rt-PCR étaient respectivement de 96,6% et 100%. Ces résultats ont montré que la rt-PCR était plus sensible que la coloration de Gram (p=0,0235), l’agglutination au latex (p=0,0442) et la  culture(p=0,0006).La culture est une méthode de référence; cependant, le résultat a montré que rt-PCR était plus sensibleet aussi spécifique que la coloration de Gram ((p=0,3405)et l’agglutination au latex (p=0,7745).Conclusion : :rt-PCR était plus sensible et plus spécifique. Elle pourrait être utilisée comme un outil de diagnosticcomplémentaire pour améliorer les cas de confirmation de méningites bactériennes. Cependant, ces coûts de réalisation, la qualification de techniciens et les matériels pour son application constituent des obstacles pour sa vulgarisation dans les pays à ressources limités.Keywords: Streptococcus pneumoniae, méningites, rt-PCR, méthodes de la bactériologie classique Article in English

Mortality from HIV-associated meningitis in sub-Saharan Africa: a systematic review and meta-analysis.

INTRODUCTION: HIV-associated cryptococcal, TB and pneumococcal meningitis are the leading causes of adult meningitis in sub-Saharan Africa (SSA). We performed a systematic review and meta-analysis with the primary aim of estimating mortality from major causes of adult meningitis in routine care settings, and to contrast this with outcomes from clinical trial settings. METHODS: We searched PubMed, EMBASE and the Cochrane Library for published clinical trials (defined as randomized-controlled trials (RCTs) or investigator-managed prospective cohorts) and observational studies that evaluated outcomes of adult meningitis in SSA from 1 January 1990 through 15 September 2019. We performed random effects modelling to estimate pooled mortality, both in clinical trial and routine care settings. Outcomes were stratified as short-term (in-hospital or two weeks), medium-term (up to 10 weeks) and long-term (up to six months). RESULTS AND DISCUSSION: Seventy-nine studies met inclusion criteria. In routine care settings, pooled short-term mortality from cryptococcal meningitis was 44% (95% confidence interval (95% CI):39% to 49%, 40 studies), which did not differ between amphotericin (either alone or with fluconazole) and fluconazole-based induction regimens, and was twofold higher than pooled mortality in clinical trials using amphotericin based treatment (21% (95% CI:17% to 25%), 17 studies). Pooled short-term mortality of TB meningitis was 46% (95% CI: 33% to 59%, 11 studies, all routine care). For pneumococcal meningitis, pooled short-term mortality was 54% in routine care settings (95% CI:44% to 64%, nine studies), with similar mortality reported in two included randomized-controlled trials. Few studies evaluated long-term outcomes. CONCLUSIONS: Mortality rates from HIV-associated meningitis in SSA are very high under routine care conditions. Better strategies are needed to reduce mortality from HIV-associated meningitis in the region

QUARITE (quality of care, risk management and technology in obstetrics): a cluster-randomized trial of a multifaceted intervention to improve emergency obstetric care in Senegal and Mali

<p>Abstract</p> <p>Background</p> <p>Maternal and perinatal mortality are major problems for which progress in sub-Saharan Africa has been inadequate, even though childbirth services are available, even in the poorest countries. Reducing them is the aim of two of the main Millennium Development Goals. Many initiatives have been undertaken to remedy this situation, such as the Advances in Labour and Risk Management (ALARM) International Program, whose purpose is to improve the quality of obstetric services in low-income countries. However, few interventions have been evaluated, in this context, using rigorous methods for analyzing effectiveness in terms of health outcomes. The objective of this trial is to evaluate the effectiveness of the ALARM International Program (AIP) in reducing maternal mortality in referral hospitals in Senegal and Mali. Secondary goals include evaluation of the relationships between effectiveness and resource availability, service organization, medical practices, and satisfaction among health personnel.</p> <p>Methods/Design</p> <p>This is an international, multi-centre, controlled cluster-randomized trial of a complex intervention. The intervention is based on the concept of evidence-based practice and on a combination of two approaches aimed at improving the performance of health personnel: 1) Educational outreach visits; and 2) the implementation of facility-based maternal death reviews.</p> <p>The unit of intervention is the public health facility equipped with a functional operating room. On the basis of consent provided by hospital authorities, 46 centres out of 49 eligible were selected in Mali and Senegal. Using randomization stratified by country and by level of care, 23 centres will be allocated to the intervention group and 23 to the control group. The intervention will last two years. It will be preceded by a pre-intervention one-year period for baseline data collection. A continuous clinical data collection system has been set up in all participating centres. This, along with the inventory of resources and the satisfaction surveys administered to the health personnel, will allow us to measure results before, during, and after the intervention. The overall rate of maternal mortality measured in hospitals during the post-intervention period (Year 4) is the primary outcome. The evaluation will also include cost-effectiveness.</p> <p>Trial Registration</p> <p>The QUARITE trial is registered on the Current Controlled Trials website under the number ISRCTN46950658 <url>http://www.controlled-trials.com/</url>.</p

Landscape Ecology of Sylvatic Chikungunya Virus and Mosquito Vectors in Southeastern Senegal

The risk of human infection with sylvatic chikungunya (CHIKV) virus was assessed in a focus of sylvatic arbovirus circulation in Senegal by investigating distribution and abundance of anthropophilic Aedes mosquitoes, as well as the abundance and distribution of CHIKV in these mosquitoes. A 1650 km2 area was classified into five land cover classes: forest, barren, savanna, agriculture and village. A total of 39,799 mosquitoes was sampled from all classes using human landing collections between June 2009 and January 2010. Mosquito diversity was extremely high, and overall vector abundance peaked at the start of the rainy season. CHIKV was detected in 42 mosquito pools. Our data suggest that Aedes furcifer, which occurred abundantly in all land cover classes and landed frequently on humans in villages outside of houses, is probably the major bridge vector responsible for the spillover of sylvatic CHIKV to humans

An operational approach to high resolution agro-ecological zoning in West-Africa

Research ArticleThe objective of this work is to develop a simple methodology for high resolution crop suitability analysis under current and future climate, easily applicable and useful in Least Developed Countries. The approach addresses both regional planning in the context of climate change projections and pre-emptive short-term rural extension interventions based on same-year agricultural season forecasts, while implemented with off-the-shelf resources. The developed tools are applied operationally in a case-study developed in three regions of Guinea-Bissau and the obtained results, as well as the advantages and limitations of methods applied, are discussed. In this paper we show how a simple approach can easily generate information on climate vulnerability and how it can be operationally used in rural extension servicesinfo:eu-repo/semantics/publishedVersio