Prévalence de la démence dans une population de personnes âgées sénégalaises

Description Avec le vieillissement de la population, survient la démence dans la population de personnes âgées. Objectif. L’objectif de cette étude était d’estimer la prévalence de cette affection dans une population de personnes âgées sénégalaises. Méthodes Par une étude transversale qui s’est déroulée du 01 mars 2004 au 31 décembre 2005, des personnes âgées de 55 ans et plus venant consulter pour un problème de santé au Centre Médico-Social et Universitaire de l’IPRES (Sénégal) ont été évaluées sur le plan clinique et neuropsychologique. Des données sur les caractéristiques sociodémographiques, les antécédents médico-chirurgicaux et familiaux, le mode de vie, le réseau social ont été collectées à l’aide d’un questionnaire structuré avec des réponses fermées. Résultat La population à l’étude était composée de 872 personnes. Elles avaient un âge moyen de 67,2 ans ± 7,5.Elles étaient de sexe masculin (62,6%), mariées (79%), non instruites (50,7%). Dans les antécédents, l’HTA, le diabète, les affections respiratoires, les affections rhumatismales, la cataracte et les troublesdigestifs étaient les plus fréquents. Le tabagisme et l’alcoolisme était faible alors que la marche constituait la principale activité physique. Les personnes âgées vivaient en famille avec un bon réseau social.Cinquante huit (58) personnes ont présenté une démence (6,6%). La prévalence de la maladie variait de manière significative avec l’âge et l’instruction. Conclusion Ce résultat confirme que la prévalence de la démence varie en fonction de l’âge et de l’instruction de la personne âgée

Dermatomyosite avec atteinte cardiaque : A propos d’un cas observe au Senegal

Introduction : La dermatomyosite est une myopathie inflammatoire chronique caractérisée essentiellement par une faiblesse musculaire associée à des lésions cutanées caractéristiques.Cas clinique : Nous rapportons l‘observation d‘une patiente de 20 ans qui a présenté 6 mois auparavant une faiblesse musculaire d‘installation progressive associée à des troubles de la déglutition. L‘examen clinique retrouvait un déficit moteur des 4 membres à 1/5 en proximal et 3/5 en distal avec des lésions dermatologiques érythématosquameuses, et une tachyarythmie à l‘auscultation cardiaque. L‘électroneuromyogramme a montré des potentiels d‘unités motrices polyphasiques, d‘amplitude et de durée limitée, avec des vitesses de  conduction nerveuse motrice et sensitive normales. L‘écho-Doppler cardiaque a montré une fraction d‘éjection systolique à 40%. Le dosage des enzymes musculaires révélait une élévation des CPK à 1200 UI/L, LDH à 1284 UI/L et des aldolases à 35 UI/L. Le diagnostic de dermatomyosite associée à une atteinte cardiaque a été  retenu. La patiente a été traitée par corticothérapie avec une bonne évolution clinique.Conclusion : Notre observation souligne l‘intérêt de rechercher systématiquement une atteinte cardiaque chez les patients présentant un tableau de dermatomyosite. English title: Introduction : Dermatomyositis associated with cardiac involvement: A case observed in Senegal Background: Dermatomyositis is a chronic inflammatory myopathy characterized by muscle weakness associated with characteristic skin lesions.Case report: We report the case of a 20-year-old woman who presented 6 months before muscle weakness and swallowing disorders. Clinical examination showed a motor deficit of four limbs (1/5 proximal and 3/5 distal)  with dermatological lesions and tachyarrhythmia in cardiac auscultation. Electromyography showed multiphase motor unit potentials, with decreased amplitude and duration, and normal motor and sensory nerve   conduction velocities. Echocardiography showed a reduced left ventricular ejection of 40%. The dosage of the muscle enzymes revealed a high rate of Creatine Phosphokinase at 1200 IU/L, LDH at 1284 UI/L and aldolase at 35 UI/L. Diagnosis of dermatomyositis associated with cardiac involvement was retained. The patient was   treated with steroids with a good clinical response.Conclusion: Our observation underlines the value of systematically looking at cardiac involvement in patients with dermatomyositis

Hepatitis B virus (HBV) infection amongst children in Senegal: current prevalence and seroprotection level

Introduction: hepatitis B virus (HBV) infection is highly endemic in Senegal. HBV vaccine of all children has been introduced in 1999 and included in the Expanded Programme on Immunization in 2004. The aim of this study was to assess the HBV prevalence and immunity status against HBV amongst children in Senegal. Methods: between March and August 2016, consecutive children aged from 6 months to 16 years old were recruited in outpatient department of three main children hospitals in Senegal. Serum samples were analyzed for HBV serology (HBsAg, HBcAb, HBsAb) using ARCHITECT analyzer. Children with HBsAb levels ≥ 10 IU/l) were considered as seroprotected against HBV. Results: during the study period, 295 children fulfilled the criteria for the study and were further analyzed. Three children were HBsAg positive giving a seroprevalence at 1.1% (95% CI: 0.2-3.3), 12/267 (4.5%, 95% CI=2.3-7.7) had positive HBcAb and 226/295 (76.6%, 71.4-81.3) had positive HBsAb including 191 (77.3%, 71.6-82.4) with isolated HBsAb related to previous active immunization. However only 165 children (56%, CI 50-62) had seroprotective HBsAb levels (HBsAb ≥ 10 UI/L) and 63 (21.4, 16.8-26) had a strong seroprotectiondefined by HBsAb ≥ 100 IU/L. Conclusion: our results suggest that although HBV prevalence has significantly decreased in children in Senegal following a better HBV vaccine coverage, the number of children correctly seroprotected is insufficient (56%). Assessing the levels of HBsAb and providing HBV vaccine boosters should be considered in children in Senegal

The Origin and Evolutionary History of HIV-1 Subtype C in Senegal

Background: The classification of HIV-1 strains in subtypes and Circulating Recombinant Forms (CRFs) has helped in tracking the course of the HIV pandemic. In Senegal, which is located at the tip of West Africa, CRF02_AG predominates in the general population and Female Sex Workers (FSWs). In contrast, 40% of Men having Sex with Men (MSM) in Senegal are infected with subtype C. In this study we analyzed the geographical origins and introduction dates of HIV-1 C in Senegal in order to better understand the evolutionary history of this subtype, which predominates today in the MSM population Methodology/Principal Findings: We used a combination of phylogenetic analyses and a Bayesian coalescent-based approach, to study the phylogenetic relationships in pol of 56 subtype C isolates from Senegal with 3,025 subtype C strains that were sampled worldwide. Our analysis shows a significantly well supported cluster which contains all subtype C strains that circulate among MSM in Senegal. The MSM cluster and other strains from Senegal are widely dispersed among the different subclusters of African HIV-1 C strains, suggesting multiple introductions of subtype C in Senegal from many different southern and east African countries. More detailed analyses show that HIV-1 C strains from MSM are more closely related to those from southern Africa. The estimated date of the MRCA of subtype C in the MSM population in Senegal is estimated to be in the early 80's. Conclusions/Significance: Our evolutionary reconstructions suggest that multiple subtype C viruses with a common ancestor originating in the early 1970s entered Senegal. There was only one efficient spread in the MSM population, which most likely resulted from a single introduction, underlining the importance of high-risk behavior in spread of viruses

Low and seasonal malaria transmission in the middle Senegal River basin: identification and characteristics of Anopheles vectors

<p>Abstract</p> <p>Background</p> <p>During the last decades two dams were constructed along the Senegal River. These intensified the practice of agriculture along the river valley basin. We conducted a study to assess malaria vector diversity, dynamics and malaria transmission in the area.</p> <p>Methods</p> <p>A cross-sectional entomological study was performed in September 2008 in 20 villages of the middle Senegal River valley to evaluate the variations of <it>Anopheles </it>density according to local environment. A longitudinal study was performed, from October 2008 to January 2010, in 5 selected villages, to study seasonal variations of malaria transmission.</p> <p>Results</p> <p>Among malaria vectors, 72.34% of specimens collected were <it>An. arabiensis</it>, 5.28% <it>An. gambiae </it>of the S molecular form, 3.26% M form, 12.90% <it>An. pharoensis</it>, 4.70% <it>An. ziemanni</it>, 1.48% <it>An. funestus </it>and 0.04% <it>An. wellcomei</it>. <it>Anopheles </it>density varied according to village location. It ranged from 0 to 21.4 <it>Anopheles</it>/room/day and was significantly correlated with the distance to the nearest ditch water but not to the river.</p> <p>Seasonal variations of <it>Anopheles </it>density and variety were observed with higher human biting rates during the rainy season (8.28 and 7.55 <it>Anopheles </it>bite/man/night in October 2008 and 2009 respectively). Transmission was low and limited to the rainy season (0.05 and 0.06 infected bite/man/night in October 2008 and 2009 respectively). During the rainy season, the endophagous rate was lower, the anthropophagic rate higher and L1014F kdr frequency higher.</p> <p>Conclusions</p> <p>Malaria vectors are present at low-moderate density in the middle Senegal River basin with <it>An. arabiensis </it>as the predominant species. Other potential vectors are <it>An. gambiae </it>M and S form and <it>An. funestus</it>. Nonetheless, malaria transmission was extremely low and seasonal.</p

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

Socializing One Health: an innovative strategy to investigate social and behavioral risks of emerging viral threats

In an effort to strengthen global capacity to prevent, detect, and control infectious diseases in animals and people, the United States Agency for International Development’s (USAID) Emerging Pandemic Threats (EPT) PREDICT project funded development of regional, national, and local One Health capacities for early disease detection, rapid response, disease control, and risk reduction. From the outset, the EPT approach was inclusive of social science research methods designed to understand the contexts and behaviors of communities living and working at human-animal-environment interfaces considered high-risk for virus emergence. Using qualitative and quantitative approaches, PREDICT behavioral research aimed to identify and assess a range of socio-cultural behaviors that could be influential in zoonotic disease emergence, amplification, and transmission. This broad approach to behavioral risk characterization enabled us to identify and characterize human activities that could be linked to the transmission dynamics of new and emerging viruses. This paper provides a discussion of implementation of a social science approach within a zoonotic surveillance framework. We conducted in-depth ethnographic interviews and focus groups to better understand the individual- and community-level knowledge, attitudes, and practices that potentially put participants at risk for zoonotic disease transmission from the animals they live and work with, across 6 interface domains. When we asked highly-exposed individuals (ie. bushmeat hunters, wildlife or guano farmers) about the risk they perceived in their occupational activities, most did not perceive it to be risky, whether because it was normalized by years (or generations) of doing such an activity, or due to lack of information about potential risks. Integrating the social sciences allows investigations of the specific human activities that are hypothesized to drive disease emergence, amplification, and transmission, in order to better substantiate behavioral disease drivers, along with the social dimensions of infection and transmission dynamics. Understanding these dynamics is critical to achieving health security--the protection from threats to health-- which requires investments in both collective and individual health security. Involving behavioral sciences into zoonotic disease surveillance allowed us to push toward fuller community integration and engagement and toward dialogue and implementation of recommendations for disease prevention and improved health security