North Of Senegal Research Articles

Detection of Hepatitis E Virus (HEV) in Pork Sold in Saint-Louis, the North of Senegal.

The hepatitis E virus (HEV) is a zoonotic pathogen with various hosts, including pigs, which act as reservoirs. In industrialized countries, sporadic cases caused by genotype 3, contracted by ingesting contaminated uncooked or undercooked meat, have been reported. However, in developing countries, HEV infection is mainly dominated by genotype 2 and often associated with poor hygiene conditions and drinking water supplies. HEV infection and its circulation in domestic fauna in West Africa are poorly documented. This study aimed to assess the presence of HEV in pork sold in Saint-Louis, Senegal. Meat products (250 g samples, n = 74) were purchased in August 2022 from three locations. Then, 2 g/sample was minced to extract total nucleic acids using the Purelink™ Viral DNA/RNA kit. RT-PCR reactions were performed using the One-Taq™ One-Step RT-PCR kit targeting the HEV ORF2 genomic region. The products obtained were visualized on a 1% agarose gel. Of a total of 74 samples, divided into pork meat (n = 65) and pork liver (n = 9), 5.4% (n = 4) tested positive for HEV. In both cases, two samples were positive, representing a rate of 3.1% and 22.2% for meat and pork liver, respectively. All new viral sequences were obtained from a monophyletic group within HEV genotype 3. This study is the first to report the presence of HEV in pork sold in Senegal and the results reveal a potential circulation of HEV in the pig population. The high proportion of contamination in the pork liver samples highlights a major risk associated with their consumption.

Foresight study on dairy farming systems in Central Kenya and north of Senegal

Dairy farming activities play important roles in nutrition and health, livelihoods and employment, and culture, in Kenya and Senegal. Faced with various challenges such as climate change, increased populations, insecurity, and conflicts over (water, land, feed) resources, dairy production systems will have to undergo changes in the future that allow them to adapt. This study used a qualitative foresight approach that is mainly based on interviews with technical experts and key stakeholders, including dairy cattle herders, to identify the main evolution trends to be observed in dairy farming in Central Kenya and north of Senegal. It found that (semi)-intensification of production systems and increased settlement of herders who are nomad pastoralists are the prevailing trends. These trends are likely to persist into the future. For both countries, the key drivers of change and their potential environmental and socio-economic impacts were investigated. As dairy systems continue to confront challenges related to livestock feed and water availability, milk quality and safety, production costs, and market access, strategies are needed that can improve resilience of the systems while attaining the right balance between productivity and sustainability.

Epidemiological Aspects of Acute Coronary Syndromes in Saint-Louis, Senegal

Introduction: The prevalence of cardiovascular diseases has been rapidly increasing in developing countries, leading to an increasing incidence of acute coronary syndrome which is becoming a major health concern. Few studies have been conducted in hospital settings, which has led us to conduct this cross-sectional, descriptive study in Saint Louis in the north of Senegal, (250 km away from the capital) whose objective is to describe the epidemiological aspects of acute coronary syndrome (ACS) in hospital settings. Methodology: This is a cross-sectional descriptive and retrospective study lasting two years from January 1, 2018 to 31 December 2019 which included all patients hospitalized in the cardiology department of the regional hospital of salary for an ACS. Results: Out of 475 patients admitted to the department of cardiology, 47 presented with acute coronary syndrome which is a prevalence of 9.89%. The mean age was 63+/-13.14 years. There was a male predominance with a sex ratio of 1.5. The meantime between the beginnings of symptoms to hospitalization was 50 hours. The most frequent clinical presentation was acute coronary syndrome with ST segment elevation (STEMI: ST-segment Elevation Myocardial Infarction) in 39 patients. Hypertension was the most common cardiovascular risk factor in 23 patients and chest pain was the most common symptoms 72.3%. In STEMI patients, the ECG abnormalities were mainly in the anterior region and in NSTEMI (Non-ST-segment Elevation Myocardial Infarction) patients the ECG abnormalities were mainly in the inferior region. On echocardiography, 64% of patients had an altered left ventricular ejection function in STEMI patients whereas in NSTEMI patients, the left ventricular ejection function was preserved in 71% of cases. STEMI patients received within the first 12 hours represented 66% of our population of which 84% benefited from thrombolysis with streptokinase with a success rate of 52%. The mean time to thrombolysis was six hours. Six patients or 12.76% were sent for coronarography. The most common complication was cardiovascular collapse (11%), 15% of patients died. Conclusion: The prevalence of acute coronary syndrome is increasing in West Africa with a predominance of ST segment elevation acute coronary syndromes. The main issues encountered were long leading times between onset of symptoms and hospital admission along with limited availability of medical facilities.

Influence of Sea Level Pressure on Inter-Annual Rainfall Variability in Northern Senegal in the Context of Climate Change

This study examines the inter-annual variability of rainfall and Mean Sea Level Pressure (MSLP) over west Africa based on analysis of the Global Precipitation Climatology Project (GPCP) and National Center for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) Reanalysis respectively. An interconnection is found in this region, between Mean Sea Level Pressure (MSLP) anomaly (over Azores and St. Helena High) and monthly mean precipitation during summer (June to September: JJAS). We also found that over northern Senegal (15°N - 17°N; 17°W - 13°W) the SLP to the north is strong; the wind converges at 200 hPa corresponding to the position of the African Easterly Jet (AEJ) the rotational wind 700 hPa (corresponding to the position of the African Easterly Jet (AEJ) coming from the north-east is negative. In this region, the precipitation is related to the SLP to the north with the opposite sign. The Empirical Orthogonal Functions (EOF) of SLP is also presented, including the mean spectrum of precipitation and pressures to the north (15°N - 40°N and 50°W - 25°W) and south (40°S - 10°S and 40°W - 0°E). The dominant EOF of Sea Level Pressures north and south of the Atlantic Ocean for GPCP represents about 62.2% and 69.4% of the variance, respectively. The second and third EOFs of the pressure to the north account for 24.0% and 6.5% respectively. The second and third EOFs of the pressure to the south represent 12.5% and 8.9% respectively. Wet years in the north of Senegal were associated with anomalous low-pressure areas over the north Atlantic Ocean as opposed to the dry years which exhibited an anomalous high-pressure area in the same region. On the other hand, over the South Atlantic, an opposition is noted. The wavelet analysis method is applied to the SLP showings to the north, south and precipitation in our study area. The indices prove to be very consistent, especially during intervals of high variance.

Molecular epidemiology of Plasmodium falciparum by multiplexed amplicon deep sequencing in Senegal

BackgroundMolecular epidemiology can provide important information regarding the genetic diversity and transmission of Plasmodium falciparum, which can assist in designing and monitoring elimination efforts. However, malaria molecular epidemiology including understanding the genetic diversity of the parasite and performing molecular surveillance of transmission has been poorly documented in Senegal. Next Generation Sequencing (NGS) offers a practical, fast and high-throughput approach to understand malaria population genetics. This study aims to unravel the population structure of P. falciparum and to estimate the allelic diversity, multiplicity of infection (MOI), and evolutionary patterns of the malaria parasite using the NGS platform.MethodsMultiplex amplicon deep sequencing of merozoite surface protein 1 (PfMSP1) and merozoite surface protein 2 (PfMSP2) in fifty-three P. falciparum isolates from two epidemiologically different areas in the South and North of Senegal, was carried out.ResultsA total of 76 Pfmsp1 and 116 Pfmsp2 clones were identified and 135 different alleles were found, 56 and 79 belonged to the pfmsp1 and pfmsp2 genes, respectively. K1 and IC3D7 allelic families were most predominant in both sites. The local haplotype diversity (Hd) and nucleotide diversity (π) were higher in the South than in the North for both genes. For pfmsp1, a high positive Tajima’s D (TD) value was observed in the South (D = 2.0453) while negative TD value was recorded in the North (D = − 1.46045) and F-Statistic (Fst) was 0.19505. For pfmsp2, non-directional selection was found with a highly positive TD test in both areas and Fst was 0.02111. The mean MOI for both genes was 3.07 and 1.76 for the South and the North, respectively, with a statistically significant difference between areas (p = 0.001).ConclusionThis study revealed a high genetic diversity of pfmsp1 and pfmsp2 genes and low genetic differentiation in P. falciparum population in Senegal. The MOI means were significantly different between the Southern and Northern areas. Findings also showed that multiplexed amplicon deep sequencing is a useful technique to investigate genetic diversity and molecular epidemiology of P. falciparum infections.

Development of Allometric Models for Estimating the Biomass of <i>Sclerocarya birrea</i> (A.Rich) Hoscht and <i>Boscia senegalensis</i> (Pers.) Lam. ex Poir.

The objective of this study was to develop allometric models for estimating the biomass of Sclerocarya birrea (A.Rich) Hoscht and Boscia senegalensis (Pers.) Lam. ex Poir. The inventory of these ligneous was carried out at Widou Thiengoly (North of Senegal). The sample consists of 43 individuals of Boscia senegalensis and 15 individuals of Sclerocarya birrea. The selected individuals were dendrometrically characterized before being cut, compartmentalized (trunk, branches, and twigs) and weighed entirely. Simple regression tests were performed to examine the most explanatory dendrometric parameter (x) for biomass (y) according to two types of models: the linear model (y = ax + b) and the polynomial model of degrees 2 (y = ax2 + bx + c). The criteria for selection and validity of the models are based firstly on the tests of normality, nullity, heterogeneity and autocorrelation of the residues. The results showed that the most explanatory dendrometric parameter of the biomass was the crown surface for Boscia senegalensis and the 1.30 m diameter for Sclerocarya birrea of all the tests performed, the second-order Polynomial model is the best predictor of above ground biomass for these two species. Thus, the allometric models established to predict the biomass of these two species are: y = 0.0023x2 + 0.4851x - 0.0519 for Boscia senegalensis and y = 0.35x2 + 10.35x - 12.90 for S. birrea; with very significant correlation coefficients (R2) of 0.85 and 0.94 respectively. These results can be used for a sequestered carbon assessment study and will play a role in monitoring the carbon market in Africa.

Pluralizzare il capitalocene, pensare la transizione. Investimenti agricoli in Africa e nuova questione agraria

This paper aims to integrate the socio-ecological critique of capitalist valorization with some indications developed in the post-colonial debate and the neo-materialist perspectives. It builds on an analysis of the land grab phenomena and its connections with recent agricultural development policies, involving green and bio-economy promotion in Sub-Saharan Africa. It firstly expands on the relationships between the neoliberal ecological regime and the racialized pattern of colonial appropriation that inform current agrarian governance processes. Then, re-calling the results of a case study on a land-deal conflict in the north of Senegal, it discusses the interest of a political ecology approach focused on a post-colonial reading of world-ecology, able to include in the narrative of capitalocene the alternative and subaltern socio-ecological stories that inhabit it. This, it will be argued, offers a useful perspective to re-imagine socio-ecological transition as a plural and more-than-human process.

Migration and climate change in Senegal. The Matam region, an emblematic case study

ABSTRACTThe presented research, characterized as a case study, was conducted in the months of April and May 2018 in the Matam Region, north of Senegal, conducted by Centro Ricerche IDOS within the framework of a project of economic development and business creation, realized by the Italian branch of the Green Cross NGO and funded by the Italian Ministry of the Interior. The research activity envisaged by the project was focused, first of all, on the knowledge level of the risks associated with migration among the rural population of the region, but many of the hypotheses concerned the relations that had never been sufficiently thematized between migratory waves and climate changes that have affected the area in the last 50 years.

Preliminary Study of Fish Assemblage Structure of the Marine Protected Area of Cayar in Senegal

Preliminary Study of Fish Assemblage Structure of the Marine Protected Area of Cayar in Senegal Since its establishment in 2004, Cayar Marine Protected area (North of Senegal) is characterized by a lack of information on its fish fauna. Therefore, it becomes necessary to characterize the fish fauna of this MPA and its dynamics in time and space for a sustainable management of this conservation area. This present study investigated seasonal and spatial structure of the fish assemblage of Cayar MPA. This study consisted of collaborative seasonal sampling with local communities from six stations within the four main fishing areas with two types of fishing gears, purse seine and long line between 2015 and 2016. Ecological and trophic classification was performed in order to determine the fish fauna nature of this MPA. Multivariate analysis like factorial correspondence analysis and hierarchical classification analysis were carried out to study spatial and seasonal structure of fish assemblage of Cayar MPA. A total of 103 fish species from 45 families were reported. The most abundant species and the richest family were Pagellus bellottii and Carangidae, respectively. The fish assemblage was dominated by species of marine affinity and predators. Spatial and seasonal fish assemblages differed both in terms species richness and fish abundance. The highest and lowest species richness and abundance were recorded during the cold season and cold to warm transition period, respectively. A clear separation was found between stations where purse seine and long line were applied, in species composition and abundance. Results from this study might serve as the reference point of the fish assemblage in Cayar MPA. However, further investigation on the environmental variability is needed for a better understanding of the observed fish assemblage organization in time and space.

Comparative Effects of Natural and Synthetic Fungicides on the Pink Root Disease of Onion (<i>Allium cepa </i>L.), in Nursery

Onion is an important vegetable in Senegal horticulture, where it occupies the first place. However in the greatest areas production like the Gandiolais, in the North of Senegal, Pink root disease caused by a soil born fungus Pyrenochaeta terrestris (Hansen) Gorentz, Walker and Larson affects its productivity especially in nursery. On soil sterilized and inoculated by the fungus, we tested 5 natural fungicides and 2 synthetic fungicides, to measure their effectiveness on the Pink root disease on onion, in nursery. The device used is a split plot with 4 repetitions and 8 treatments. The measured variables are the emergence rates, the survival rates and the infestation rates. Our experimentations have shown that, for the emergence rates, there is no significant difference between thiophanate-methyl (Pelt 44), Carbendazim (Bavistine), Azadirachta indica A. Juss and Carica papaya L. It is the same between C. papaya and Moringa oleifera Lam, between M. oleifera and Cassia alata L. It is also the same between C. alata and Crotolaria retusa L. Regarding the survival rates, there is no significant difference between thiophanate-methyl, Azadirachta indica, Carbendazim, C. papaya and M. oleifera. The same is true between M. oleifera and Cassia alata, and between C. alata and C. retusa. Concerning the infestation rates, apart from the control check, all other treatments show no difference.

Cytokine responses to Schistosoma mansoni and Schistosoma haematobium in relation to infection in a co-endemic focus in northern Senegal.

BackgroundIn Africa, many areas are co-endemic for the two major Schistosoma species, S. mansoni and S. haematobium. Epidemiological studies have suggested that host immunological factors may play an important role in co-endemic areas. As yet, little is known about differences in host immune responses and possible immunological interactions between S. mansoni and S. haematobium in humans. The aim of this study was to analyze host cytokine responses to antigens from either species in a population from a co-endemic focus, and relate these to S. mansoni and S. haematobium infection.MethodologyWhole blood cytokine responses were investigated in a population in the north of Senegal (n = 200). Blood was stimulated for 72 h with schistosomal egg and adult worm antigens of either Schistosoma species. IL-10, IL-5, IFN-γ, TNF-α, and IL-2 production was determined in culture supernatants. A multivariate (i.e. multi-response) approach was used to allow a joint analysis of all cytokines in relation to Schistosoma infection.Principal Findings Schistosoma haematobium egg and worm antigens induced higher cytokine production, suggesting that S. haematobium may be more immunogenic than S. mansoni. However, both infections were strongly associated with similar, modified Th2 cytokine profiles.Conclusions/SignificanceThis study is the first to compare S. mansoni and S. haematobium cytokine responses in one population residing in a co-endemic area. These findings are in line with previous epidemiological studies that also suggested S. haematobium egg and worm stages to be more immunogenic than those of S. mansoni.

Une présentation atypique tumorale d’un mycétome actinomycosique dorsolombaire

Mycetomas are localized chronic inflammatory infectious diseases involving subcutaneous tissues, skin and bones. We report a case of mycetoma in a 40-year-old farmer from the north of Senegal. The clinical appearance of the lesions suggested primarily the diagnosis of a soft tissue malignant tumor. Mycetoma diagnosis was confirmed by histopathologic evidences and growth of Actinomadura pelletieri in cultured samples. The evolution was good under a triple antibiotic therapy combining cotrimoxazole, amoxicillin-clavulanic acid and streptomycin for 12 months.

First attempt to validate the gSG6-P1 salivary peptide as an immuno-epidemiological tool for evaluating human exposure to Anopheles funestus bites

The development of a biomarker of exposure based on the evaluation of the human antibody response specific to Anopheles salivary proteins seems promising in improving malaria control. The IgG response specific to the gSG6-P1 peptide has already been validated as a biomarker of An. gambiae exposure. This study represents a first attempt to validate the gSG6-P1 peptide as an epidemiological tool evaluating exposure to An. funestus bites, the second main malaria vector in sub-Saharan Africa. A multi-disciplinary survey was performed in a Senegalese village where An. funestus represents the principal anopheline species. The IgG antibody level specific to gSG6-P1 was evaluated and compared in the same children before, at the peak and after the rainy season. Two-thirds of the children developed a specific IgG response to gSG6-P1 during the study period and--more interestingly--before the rainy season, when An. funestus was the only anopheline species reported. The specific IgG response increased during the An. funestus exposure season, and a positive association between the IgG level and the level of exposure to An. funestus bites was observed. The results suggest that the evaluation of the IgG response specific to gSG6-P1 in children could also represent a biomarker of exposure to An. funestus bites. The availability of such a biomarker evaluating the exposure to both main Plasmodium falciparum vectors in Africa could be particularly relevant as a direct criterion for the evaluation of the efficacy of vector control strategies.

Islamic Mystical Readings of Cheikh Hamidou Kane's Ambiguous Adventure

Cheikh Hamidou Kane was born in 1928 into a noble, scholarly family from the north of Senegal. His father was educated in the Islamic sciences and familiar with the theological and philosophical thought of both the Islamic and European traditions. Cheikh Hamidou Kane later left Senegal to study philosophy at the Sorbonne.Ambiguous Adventure was written in the early 1950s, but was not published until 1961. It has often been seen as a philosophical novel that deals with the social and intellectual dilemmas of an African Muslim society having to submit to secular cultural norms imported with French rule; but the story is actually about something much more fundamental.This article tries to demonstrate that Ambiguous Adventure is about the devastating effect upon the protagonist, Samba Diallo, of losing the precious esoteric knowledge transmitted to him within the Islamic mystical tradition, which is erased with the imposition of the French educational system.Ambiguous Adventure has also been called a ‘tale of initiation’, much like the risāla from the Ishrāqī School. Examining the work in this light, the paper shows that Samba Diallo's journey is actually a tragic inversion of the classical model featured in tales of initiation. He moves from an environment in which he is able to experience knowledge to one in which he is only able to discuss knowledge—a state of ‘rootless intellectualism’ devoid of real meaning.

Interaction between malaria and intestinal helminthiasis in Senegal: influence of the carriage of intestinal parasites on the intensity of the malaria infection

Co-infection between intestinal parasites and Plasmodium falciparum is very frequent in inter tropical zone. Our study carried out in the North of Senegal (zone of high prevalence of schistosomiasis) aimed at measuring the influence of the carriage of intestinal parasites on the intensity of malaria infection. The Plasmodium falciparum densities were significantly higher during Plasmodium falciparum/Schistosoma mansoni and Plasmodium falciparum/Ascaris lumbricoides co-infection in children under 14 years old. Other intestinal parasites did not seem to have negative influence on the intensity of Plasmodium falciparum infection.

Research Note: Nodulation and Nitrogen Fixation of Stylosanthes hamata in Response to Induced Drought Stress

In the north of Senegal, the average annual rainfall has fallen to 300–400 mm because of the occurrence of drought. In addition, the soils are impoverished, with particularly low nitrogen content—less than 0.20 g N kg−1. Stylosanthes (Stylosanthes hamata) is a forage legume cover crop with high nitrogen fixing potential when inoculated with elite Bradyrhizobium strains such as strains ISRA 97 and ISRA 674 already selected in West Africa MIRCEN rhizobial culture collection. This species was used as a test plant to study the effect of drought stress on nodulation and nitrogen fixation, aiming at the recommendation of its cultivation in the north of Senegal. Use of S. hamata could therefore reach the objective to increase and to sustain soil productivity. A pot experiment was carried under greenhouse conditions to estimate the fixed nitrogen in stylosanthes after induced drought stress using the 15N isotope dilution technique. Maximum of fixation occurred when stylosanthes was inoculated with Bradyrhizobium strain ISRA 97 and watered every 2 days with 100 ml of distilled water. The strain ISRA 674 should be used, however, to inoculate S. hamata in view to maximize the process of biological nitrogen fixation for sustaining agriculture in north and central regions of Senegal. Indeed, no effect of drought was observed up to watering once every 4 days when this strain ISRA 674 was used for inoculating S. hamata.

Morphological Variability in Illex Coindetii (Cephalopoda: Ommastrephidae) Along the North-West Coast of Africa

This paper gives morphometric variations and dorsal mantle length–total weight (DML-TW) relationships for Illex coindetii in the eastern Central Atlantic area. Positive allometry was observed in males and negative in females of the species. The most variable body measurements between males and females were width and perimeter of the head. In the study area, divergence of morphometric measurement starts at 95 mm. The point of divergence, however, varies with latitude; fluctuating from 104 mm in the north (Morocco and Sahara) to 76 mm in the central area (Mauritania and north of Senegal) and 73 mm in the south (Gulf of Guinea).The relationships between DML and TW showed that sexual dimorphism due to differential growth between males and females starts to occur at 56 mm ML. The starting point of sexual dimorphism (56 mm) varies according to the zone; the higher the latitude, the later it occurs. Thus, sexual dimorphism occurs at 49 mm in the south (Gulf of Guinea), at 54 mm in the central area (Mauritania and north of Senegal) and at 74 mm in the north (Morocco and Sahara). Females grow larger than males, but males were heavier at any given length. As latitude decreased, a slow down in the increase in weight-at-length was observed in both sexes.

The epidemiology of human schistosomiasis in the Senegal river basin

Extensive water development has taken place in the north of Senegal over the last decade, resulting in a large increase in the amount of fresh water for irrigation. The objectives of the present study were to determine the prevalence and intensity of Schistosoma mansoni and S. haematobium in the Senegal river basin (SRB), and to ascertain the distribution of the snail species acting as intermediate hosts for both species of schistosomes. The schistosomiasis survey started in January 1994 and was completed in March 1995. Compared to studies before the construction of the Diama dam, there was a significant increase in both the prevalence and intensity of urinary and intestinal schistosomiasis in the human population in parts of the SRB. From the 9014 people who were registered from 180 villages and 4 towns (10 districts), 7750 were examined. S. mansoni was found in the lower valley (lower delta-Senegal river, lower delta-Lampsar river, upper delta, and diéré) but not in the middle valley. The mean prevalence ranged from 4.4% in the lower delta-Senegal River to 71.8% in the zone of Lac de Guiers, where prevalence and intensity of infection were higher on the eastern side of the lake (81.3% with a mean number of 2088 eggs/g of faeces) compared with the western side (50.3% with a mean 1111 eggs/g). S. haematobium was recorded throughout the area of study, ranging from a mean prevalence of 0.37% in diére (lower valley) to 41.5% in the lower valley (Lampsar river), where the mean egg count was 313/10 mL of urine. Physical and chemical changes to the environment have favoured the spread and increase in the populations of freshwater snails. The only snail involved in the transmission of S. mansoni was Biomphalaria pfeifferi. Five species of bulinid snails were present— Bulinus globosus, Bu. umbilicatus, Bu. senegalensis, Bu. forskalii and Bu. truncatus—but only the first 3 species were involved in the transmission of S. haematobium in the lower and middle valleys.