Biometric Relationships and Evaluation of the Density of Tagelus angulatus Gray, 1847 (Mollusca, Solecurtidae) on the West African Coasts in Three Villages of the Community Protected Area of Urok, Guinea-Bissau

Aims: This study aimed to examin the biometric relationships, size frequencies and density of Tagelus angulatus in the Community Marine Protected Area of the Bijagós Islands of Guinea Bissau. Methodology: Sampling was carried out in three villages (Formosa, Nago and TChediã) of the Community Marine Protected Area. A total of 1596 individuals were collected. On each mudflat, four random transects 30 m apart and oriented from the shore to the sea were established. On each transect, individuals of Tagelus angulatus were collected on 6 plots of 1m² that were separated by 10 m. Results: The length of the individuals sampled ranged from 12 mm to 69 mm in all three of the villages studied with an average length of 48.65 ± 9.53 mm and a main mode equal to 53 mm. The results showed a positive allometry. The length and width of the species are also strongly correlated. The mean density for all three villages was 16.63 individuals. Conclusion: Management of the shellfish industry generally requires the knowledge and use of biometric relationships to translate data collected in the field into indicators that can be used for the development of management plans. This study provided knowledges on biometric relationships and density of Tagelus angulatus

Vascular access in Senegalese patients starting chronic haemodialysis

Introduction: It is recommended that patients should start chronic haemodialysis using an arteriovenous fistula (AVF). We aimed to determine the proportion of Senegalese patients who used an AVF at the start of  haemodialysis and examined the factors associated with its use. Methods: We conducted a cross-sectional study from 1 June 2021 to 2 October 2021 among patients on chronic haemodialysis in 10 centres in the Dakar and Thiès regions. Clinical and laboratory data were collected from medical records and also via patient interviews. Results: The patients (n = 543) had a median age of 50 years [interquartile range (IQR) 40–62 years] and 50.6% were male. The socio-economic level was low in two-thirds of cases. The median duration of haemodialysis was 40 (IQR 17–76) months. Hypertension was noted in 92% and diabetes in 13%. Hypertensive kidney disease was the cause of kidney failure in 33%. Only 47 patients (9%) had started dialysis using an arteriovenous fistula. Factors associated with its use at haemodialysis initiation were socio-economic level (OR 0.48; 95% confidence interval (CI) 0.25–0.94 for low socio-economic level) and duration of pre-dialysis follow-up by a nephrologist for >4 months (OR 7.82; 95% CI 3.05–26.50). In 65% of prevalent patients, the vascular access used was an AVF, a tunnelled central venous catheter in 28%, an arteriovenous graft in 2% and a temporary central venous catheter in 4.4%. Conclusions: The proportion of Senegalese patients with an AVF at the start of haemodialysis was low. AVF use was associated with socio-economic level and pre-dialysis follow-up by a nephrologist for >4 months

Entomological impact of indoor residual spraying with pirimiphos-methyl: a pilot study in an area of low malaria transmission in Senegal.

BACKGROUND: Scaling-up of effective anti-malarial control strategies in Central-West region of Senegal has resulted in the sharp decline in malaria prevalence in this area. However, despite these strategies, residual malaria transmission has been observed in some villages (hot spots). The objective of this study was to assess the impact of indoor residual spraying (IRS) with pirimiphos-methyl on malaria transmission in hot spot areas. METHODS: The malaria vector population dynamics were monitored in each of the six selected villages (4 of which used IRS, 2 were unsprayed control areas) using overnight human landing catches (HLC) and pyrethrum spray catches (PSC). The host source of blood meals from freshly fed females collected using PSC was identified using the direct ELISA method. Females caught through HLC were tested by ELISA for the detection of Plasmodium falciparum circumsporozoite protein and Anopheles gambiae complex was identified using PCR. RESULTS: Preliminary data shown that the densities of Anopheles populations were significantly lower in the sprayed areas (179/702) compared to the control. Overall, malaria transmission risk was 14 times lower in the intervention zone (0.94) compared to the control zone (12.7). In the control areas, three Anopheles species belonging to the Gambiae complex (Anopheles arabiensis, Anopheles coluzzii and Anopheles melas) maintained the transmission, while only An. coluzzii was infective in the sprayed areas. CONCLUSION: The preliminary data from this pilot study showed that IRS with the CS formulation of pirimiphos-methyl is likely very effective in reducing malaria transmission risk. However, additional studies including further longitudinal entomological surveys as well as ecological and ethological and genetical characterization of vectors species and their populations are needed to better characterize the entomological impact of indoor residual spraying with pirimiphos-methyl in the residual transmission areas of Senegal

Caractérisation De La Flore Et De La Végétation Ligneuse Des Terroirs Villageois De Keur Birame (Kaffrine) Et Saré Yorobana (Kolda) Au Sénégal

Vegetation in sub-Saharan countries is under heavy pressure from anthropogenic activities and climatic deterioration. This study was carried out at Keur Birame and Saré Yorobana villages, which are two edaphoclimatically contrasting localities. The aim of this study is to characterize their flora and woody vegetation. In doing so, 178 vegetation survey of 2500m² each were carried out on all two sites consisting of nine facies of vegetation. The results show a flora of the two soils of 93 species belonging to 80 genera and distributed to 33 botanical families. Among this richness, 78 species belong to Saré Yorobana and 45 species to Keur Birame. Except for regeneration rates (37.30% and 94.04%), all structural parameters studied are higher at Saré Yorobana and the similarity index (0.48) indicates that the two vegetal communities are floristically different. The ligneous stems are generally young with small diameter that hides facies imbalances due to human activities. It would require the various actors synergy to keep trees and biodiversity in the fields and terroirs

Isonatraemic haemodialysis in the management of salt and water overload: a crossover trial at an academic hospital in Dakar, Senegal

Introduction: The aims of this study were to assess the impact of isonatraemic haemodialysis on reduction of interdialytic weight gain (IDWG) and blood pressure (BP) as well as its tolerability in our study population. Methods: This crossover trial, at the Aristide Le Dantec University Hospital in Senegal, was conducted on 32 patients with kidney failure who were stable on treatment with chronic haemodialysis. In the initial “control phase”, patients had nine haemodialysis sessions with a dialysate sodium (Na+) concentration (Na+ dialysate) of 138 mmol/L. The serum Na+ set point (SP) for each patient was calculated from three predialytic mid-week values. In the second phase, the “individualized phase”, patients had nine haemodialysis sessions with Na+ dialysate equal to their SP. Results: The mean age of the patients was 55.5 ± 12.1 years, with a male/female ratio of 1.3 and the most common cause of kidney disease was hypertension (47%). Mean predialytic serum Na+ concentration was 135.8 ± 1.9 mmol/L, with a mean intra-individual coefficient of variation of 2%. Mean interdialytic weight gain (IDWG) was 1.9 kg and 1.8 kg in the control and individualized phases, respectively (P = 0.75). A reduction in postdialytic systolic blood pressure (BP) was observed during the individualized phase (P = 0.04). A similar trend was noted in pre- and intradialytic BP but this was not statistically significant. Apart from headaches, which were more common in the individualized phase (P = 0.04), isonatraemic haemodialysis was well tolerated. Conclusions: IDWG as well as pre- and intradialytic BP were unaffected by isonatraemic haemodialysis. Postdialytic BP was significantly reduced. Introduction: Les objectifs de cette étude étaient d’évaluer l’impact de l’hémodialyse isonatrémique sur la réduction de la prise de poids inter-dialytique (PPID) et de la pression artérielle (PA) ainsi que sa tolérance dans notre population d’étude. Méthodes: Cet essai croisé a été mené au centre hospitalier universitaire Aristide Le Dantec de Dakar (Sénégal) chez des patients hémodialysés chroniques. Durant la première phase dite « phase contrôle », les patients ont eu neuf séances d’hémodialyse avec une concentration de sodium dans le dialysat (Na+ dialysat) de 138 mmol/L. Le set-point (SP) de la natrémie a été calculé pour chaque patient et correspondait à la moyenne de 3 natrémies pré-dialytiques en milieu de semaine. Durant la deuxième phase dite « phase individualisée », les patients ont eu neuf séances d’hémodialyse avec du Na+ dialysat égal à leur SP. Résultats: Trente-deux patients ont été inclus. L’âge moyen était de 55,5 ± 12,1 ans avec un ratio homme/femme de 1,3 et la néphropathie initiale la plus fréquente était l’hypertensive (47%). La natrémie pré-dialytique moyenne était de 135,8 ± 1,9 mmol/L, avec un coefficient de variation intra-individuel moyen de 2 %. La PPID moyenne était de 1,9 kg et 1,8 kg dans les phases de contrôle et individualisé, respectivement (P = 0,75). Une diminution de la PA systolique post-dialytique a été observée au cours de la phase individualisée (P = 0,04). Une tendance similaire sans significativité statistique a été notée sur les PA pré- et intra-dialytiques. Hormis les céphalées, plus fréquentes pendant la phase individualisée (P = 0,04), l’hémodialyse isonatrémique a été bien tolérée. Conclusions: La PPID, les PA pré- et intra-dialytiques n’ont pas été affectées par l’hémodialyse isonatrémique. La PA post-dialytique était significativement réduite

Evaluation de l’état hydrique chez les patients hémodialysés chroniques : une étude transversale monocentrique: Assessment of the hydration status in chronic hemodialysis patients: a single-center cross-sectional study

Context and objective. For many practitioners, blood pressure is the main indicator of the hydration status of the chronic hemodialysis patient. The objective of this study was to assess the extent to which bioimpedance analysis (BIA) can assist in determining acute changes in fluid volume during the hemodialysis session. Methods. This was a 9-week longitudinal study. The total body water (TBW) was measured with a BIA analyzer, before and after 6 successive sessions. The ΔWeight was compared to the ΔTBW by calculating the P/V ratio (ΔWeight/ΔTBW) with the assumption that the dry weight is reached when P/V = 1. Results. The measurements made in 22 patients (46.6 years, 54.5% men, 92.3 months on dialysis) were reproducible. There was no statistically significant difference between ΔTBW and ΔWeight. However, at the individual level, significant differences had been observed. Using hypertension as a marker for a state of hyperhydration, a 31.8% agreement was noted between the P/V ratio and hypertension. Conclusion. Although the loss of water predicted by the BIA did not always correspond to the weight loss, BIA is a technique that can be used to assess the variations in TBW during the hemodialysis session in patients. Contexte et objectif. La pression artérielle est pour de nombreux praticiens, l’indicateur principal du statut hydrique du patient hémodialysé chronique. L’objectif de la présente étude était d’évaluer dans quelle mesure l’analyse d’impédance bioélectrique (BIA) pourrait aider à la détermination des variations aigues du volume hydrique au cours de la séance d’hémodialyse. Méthodes. Il s’agissait d’une étude de suivi longitudinal sur 9 semaines. Le volume total d’eau (VTE) a été mesuré par BIA, avant et après 6 séances. Le ΔPoids a été comparé au ΔVTE par le calcul du ratio P/V (ΔPoids / ΔVTE) dans l’hypothèse que le poids sec est atteint lorsque P/V = 1. Résultats. Les mesures faites chez 22 patients (46,6 ans, 54,5% hommes, 92,3 mois en dialyse) étaient reproductibles. Il n’y avait pas de différence statistiquement significative entre le ΔVTE et le ΔPoids. Cependant à l’échelon individuel des différences importantes étaient observées. En utilisant l’hypertension artérielle (HTA) comme marqueur d’un état d’hyperhydratation, une concordance de 31,8% était notée entre le ratio P/V et l’HTA. Conclusion. Bien que la perte d’eau prédite par la BIA ne corresponde pas toujours à celle du poids, la BIA est une technique qui peut être utilisée pour évaluer les variations du VTE au cours de la séance d’hémodialys

Mass testing and treatment for malaria followed by weekly fever screening, testing and treatment in Northern Senegal: feasibility, cost and impact.

BACKGROUND NlmCategory: BACKGROUND content: Population-wide interventions using malaria testing and treatment might decrease the reservoir of Plasmodium falciparum infection and accelerate towards elimination. Questions remain about their effectiveness and evidence from different transmission settings is needed. - Label: METHODS NlmCategory: METHODS content: "A pilot quasi-experimental study to evaluate a package of population-wide test and treat interventions was conducted in six health facility catchment areas (HFCA) in the districts of Kanel, Lingu\xC3\xA8re, and Ran\xC3\xA9rou (Senegal). Seven adjacent HFCAs were selected as comparison. Villages within the intervention HFCAs were stratified according to the 2013 incidences of passively detected malaria cases, and those with an incidence\xE2\x80\x89\xE2\x89\xA5\xE2\x80\x8915 cases/1000/year were targeted for a mass test and treat (MTAT) in September 2014. All households were visited, all consenting individuals were tested with a rapid diagnostic test (RDT), and, if positive, treated with dihydroartemisinin-piperaquine. This was followed by weekly screening, testing and treatment of fever cases (PECADOM++) until the end of the transmission season in January 2015. Villages with lower incidence received only PECADOM++ or case investigation. To evaluate the impact of the interventions over that transmission season, the incidence of passively detected, RDT-confirmed malaria cases was compared between the intervention and comparison groups with a difference-in-difference analysis using negative binomial regression with random effects on HFCA." - Label: RESULTS NlmCategory: RESULTS content: "During MTAT, 89% (2225/2503) of households were visited and 86% (18,992/22,170) of individuals were tested, for a combined 77% effective coverage. Among those tested, 291 (1.5%) were RDT positive (range 0-10.8 by village), of whom 82% were\xE2\x80\x89<\xE2\x80\x8920\xC2\xA0years old and 70% were afebrile. During the PECADOM++ 40,002 visits were conducted to find 2784 individuals reporting fever, with an RDT positivity of 6.5% (170/2612). The combination of interventions resulted in an estimated 38% larger decrease in malaria case incidence in the intervention compared to the comparison group (adjusted incidence risk ratio\xE2\x80\x89=\xE2\x80\x890.62, 95% CI 0.45-0.84, p\xE2\x80\x89=\xE2\x80\x890.002). The cost of the MTAT was $14.3 per person." - Label: CONCLUSIONS NlmCategory: CONCLUSIONS content: It was operationally feasible to conduct MTAT and PECADOM++ with high coverage, although PECADOM++ was not an efficient strategy to complement MTAT. The modest impact of the intervention package suggests a need for alternative or complementary strategies

Residual malaria transmission and the role of Anopheles arabiensis and Anopheles melas in central Senegal

Understanding the behavior and ecology of local malaria vectors is essential for the effectiveness of the commonly used vector-targeted malaria control tools in areas of low malaria transmission. This study was conducted to determine species composition, biting behavior and infectivity of the major Anopheles vectors of Plasmodium falciparum in low transmission settings in central Senegal. Adult mosquitoes were collected using human landing catches during 2 consecutive nights and Pyrethrum Spray Catches in 30–40 randomly selected rooms, from July 2017 to December 2018 in 3 villages. Anopheline mosquitoes were morphologically identified using conventional keys; their reproductive status assessed by ovary dissections, and a sub-sample of Anopheles gambiae s.l. were identified to species level using polymerase chain reaction (PCR). Plasmodium sporozoite infections were detected using real-time quantitative PCR. During this study 3684 Anopheles were collected of which 97% were An. gambiae s.l., 0.6% were Anopheles funestus, and 2.4% were Anopheles pharoensis. Molecular identification of 1,877 An. gambiae s.l. revealed a predominance of Anopheles arabiensis (68.7%), followed by Anopheles melas (28.8%), and Anopheles coluzzii (2.1%). The overall human-biting rate of An. gambiae s.l. was highest in the inland site of Keur Martin with 4.92 bites per person per night, while it was similar in the deltaic site, Diofior (0.51) and the coastal site, Mbine Coly (0.67). Parity rates were similar in An. arabiensis (45%) and An. melas (42%). Sporozoite infections were detected in both An. arabiensis and An. melas with the respective infection rates of 1.39% (N = 8) and 0.41% (N = 1). Results suggest that low residual malaria in central Senegal is transmitted by An. arabiensis and An. melas. Consequently, both vectors will need to be targeted as part of malaria elimination efforts in this area of Senegal

Análisis de la situación de la pesca artesanal en el delta y valle bajo del río Senegal a partir del marco conceptual DPSIR

For over two decades, the delta and the lower valley of the Senegal River have suffered a severe drought. Weather conditions have had serious consequences on the hydrological functioning. In addition, the artificiality of the basin due to the construction of hydro-agricultural infrastructures has caused other impacts. Observations made during an annual fishing cycle allowed us to implement the conceptual framework “Driving forces, Pressures, State, Impacts, Responses” (DPSIR). This article intends to help generate natural and socioeconomic indicators applicable to artisanal fisheries and make proposals for an integrated fisheries management in the study area.<br><br>Durante más de dos décadas, el delta y el valle bajo del río Senegal han sufrido una grave sequía. Las condiciones climáticas han tenido graves consecuencias en el funcionamiento hidrológico. Además, la artificialización de la cuenca debido a la construcción de infraestructuras hidroagrícolas ha causado otros impactos. Las observaciones realizadas durante un ciclo anual de pesca nos permiten implementar el marco conceptual <em>«Driving forces, Pressures, State, Impacts, Responses”</em> (DPSIR). El artículo pretende contribuir a generar indicadores naturales y socioeconómicos aplicables a la pesca artesanal, así como realizar propuestas para una gestión integrada de la actividad pesquera en el área de estudio. [fr] Durant plus de deux décennies, le delta et la basse vallée du fleuve Sénégal est affecté par une grave sécheresse. Les conditions climatiques ont eu de graves conséquences sur le fonctionnement hydrologique. L’artificialisation du bassin consécutive à la construction d’infrastructures hydroagricoles ont engendré d’autres impacts. Les observations réalisées sur le terrain durant un cycle annuel de pêche ont permis d’analyser l’activité selon le cadre conceptuel <em>“Driving forces, Pressures, State, Impacts, Responses ” </em>(DPSIR). L’article a pour but de contribuer à générer des indicateurs naturels et socioeconomiques applicables à la pêche artisanale et de faire des propositions pour une gestion intégrée de l’activité de pêche dans la zone d’étude

Spatial and temporal dynamics of West Nile virus between Africa and Europe

It is unclear whether West Nile virus (WNV) circulates between Africa and Europe, despite numerous studies supporting an African origin and high transmission in Europe. We integrated genomic data with geographic observations and phylogenetic and phylogeographic inferences to uncover the spatial and temporal viral dynamics of WNV between these two continents. We focused our analysis towards WNV lineages 1 (L1) and 2 (L2), the most spatially widespread and pathogenic WNV lineages. Our study shows a Northern-Western African origin of L1, with back-and-forth exchanges between West Africa and Southern-Western Europe; and a Southern African origin of L2, with one main introduction from South Africa to Europe, and no back introductions observed. We also noticed a potential overlap between L1 and L2 Eastern and Western phylogeography and two Afro-Palearctic bird migratory flyways. Future studies linking avian and mosquito species susceptibility, migratory connectivity patterns, and phylogeographic inference are suggested to elucidate the dynamics of emerging viruse