Vulnérabilités et stratégies d’adaptation des paysans face aux changements socio-environnementaux en Haute Casamance (Sud-Sénégal)

La sécurité alimentaire a toujours été le vœu des plus hautes autorités politiques sénégalaises. De l’indépendance à nos jours, différentes politiques agricoles ont été proposées pour satisfaire au moins la demande alimentaire du pays. La Haute Casamance constitue l’une des régions devant permettre l’atteinte de cet objectif. Toutefois, dans cette région, les perspectives de développement de l’agriculture sont très incertaines du fait de la conjonction de nombreux aléas pédoclimatiques, socio-économiques, technologiques, organisationnels et politiques qui empêchent encore de porter la production et la productivité agricoles à des niveaux satisfaisants. L’objectif de cette étude est d’analyser la vulnérabilité et l’adaptabilité des paysans face aux dynamiques socio-environnementales en Haute Casamance. L’ampleur des changements est mesurée grâce à une approche géographique globale et multi-scalaire, qui intègre à la fois des outils de la géomatique et des travaux de terrain (observations directes, enquêtes auprès de 441 ménages répartis dans 12 communes et analyse de perceptions). Cette approche a conduit à l’identification des facteurs de vulnérabilité qui tournent autour des obstacles pédoclimatiques, des contraintes politico-techniques et organisationnelles. Aussi, l’analyse des stratégies développées pour remédier à la baisse des productions agricoles a montré que la rotation et la jachère effectuées respectivement par 91 % et 38 % des producteurs, l’association culturale ainsi que les aménagements hydroagricoles sont les techniques culturales utilisées pour redresser l’agriculture.Food security is an old wish of the highest political authorities in Senegal. From independence to the present day, various agricultural policies have been proposed to satisfy at least the country’s food demand. The Upper Casamance is one of the regions which should enable this objective to be achieved. However, in this region the prospects for agricultural development are very uncertain due to the combination of many soil, socio-economic and technological hazards. The European Union is also committed to the development of the European Agricultural Area. The objective of this study is to analyse the vulnerability and adaptability of farmers in the face of socio-environmental dynamics in Upper Casamance. The magnitude of change is measured through a comprehensive and multi-scaled geographic approach that integrates both geomatics tools (GIS, GPS point surveys) and fieldwork (direct observations, surveys of 441 households in 12 communes and analysis of perceptions). This approach led to the identification of vulnerability factors that revolve around soil-climatic obstacles, political-technical and organisational constraints. Also, analysis of mitigation strategies showed that rotation (91%), fallow land (38%), crop association, hydroagricultural development are the techniques used to increase production

Investigation d’une épidémie de coqueluche à Dialakon, Mali, 2016: Investigation of a pertussis outbreak in Dialakon, Mali, 2016

Introduction: De janvier 2008 à juin 2016, le Mali n'a notifié aucun cas de coqueluche. En juillet 2016, Bafoulabé a signalé 38 cas suspects de coqueluche dans le village de Djombomadji à Dialakon. L’objectif était de décrire cette épidémie en temps, lieu et personne. Méthodes: Nous avons mené une étude transversale descriptive à Dialakon de mars à août 2016. Un cas suspect de coqueluche était toute personne présentant une toux paroxystique avec ou sans vomissements, fièvre, dyspnée ou éternuement. Nous avons effectué une recherche active de cas. Les données ont été collectées à l’aide d’un questionnaire et analysées en temps, lieu et personne.Résultats: Au total, 112 cas suspects de coqueluche enregistrés sur 7238 habitants (taux d'attaque : 16/1000) avec zéro décès. L'âge médian était de 4 ans, étendu de 3 mois-13 ans, 52% étaient de sexe féminin. Parmi les cas, 4% étaient complètement vaccinés contre la coqueluche. Tous les cas provenaient du village de Djombomadji. L'épidémie avait commencé le 10 mars, avec 2 pics le 16 mai et le 16 juin 2016 qui avaient respectivement 20 et 16 cas. Le nombre de cas a ensuite progressivement diminué jusqu'au 26 juillet 2016 quand les 2 derniers cas ont été enregistrés. Conclusion: L'épidémie a duré 5 mois, la majorité des cas ont eu lieu le 16 mai 2016, étaient du sexe féminin, n'étaient pas vaccinés et provenaient du village de Djombomadji. Tous les cas ont été traités, les enfants non malades ont été vaccinés et la population a été sensibilisée. Introduction: From January 2008 to June 2016, Mali reported no cases of pertussis. In July 2016, Bafoulabé reported 38 suspected cases of pertussis in the village of Djombomadji in Dialakon. The objective this investigation was to describe this outbreak in time, place and person. Methods: We conducted a descriptive cross-sectional study in Dialakon from March to August 2016. A suspected case of pertussis was any person presenting paroxysmal cough with or without vomiting, fever, dyspnoea or sneezing. We conducted an active case search. Data were collected using a questionnaire and analysed for time, place and person. Results: A total of 112 suspected cases of pertussis were recorded out of 7238 inhabitants (attack rate: 16/1000) with zero deaths. The median age was 4 years, range 3 months-13 years, 52% were female. Of the cases, 4% were fully vaccinated against pertussis. All cases were from the village of Djombomadji. The epidemic started on 10 March, with two peaks on 16 May and 16 June 2016, with 20 and 16 cases respectively. The number of cases then gradually decreased until 26 July 2016 when the last 2 cases were recorded. Conclusions: The epidemic lasted 5 months, the majority of cases occurred on 16 May 2016, (they)were female, unvaccinated and from Djombomadji village. All cases were treated, unvaccinated children were vaccinated and the population was sensitised

Plano Ambiental Inter-Sectorial Ambiente e Agricultura, Silvicultura e Pecuária

Cabo Verde é um país ecologicamente frágil e de fracos recursos naturais. A satisfação das necessidades básicas do Homem exige que sejam bem definidas orientações estratégicas de aproveitamento e uma aplicação optimizada dos recursos naturais a favor do desenvolvimento de actividades económicas. Desde a independência, os sucessivos Governos Cabo-verdianos têm-se mostrado preocupados com a questão da preservação dos ecossistemas e com o enquadramento dos organismos vocacionados para a gestão ambiental. Na estratégia expressa nas Grandes Opções para do Desenvolvimento (2002), o ambiente é um dos temas mais importantes. Projecta-se uma sociedade dotada de um sentimento profundo para o ambiente e de uma consciência ecológica desenvolvida sendo as medidas de preservação encaradas de forma sistémica e transversal, pretendendo-se que sejam equitativas. O segundo Plano de Acção Nacional para o Ambiente (PANA II) constitui a concretização destas políticas e define as orientações estratégicas de aproveitamento dos recursos naturais bem como os seus efeitos sobre a gestão sustentável das actividades económicas. É um documento orientador de um processo continuo caracterizado por uma dinâmica própria e que nos próximos 10 anos (2004-2014), servirá de base de trabalho, permitindo um desenvolvimento Cabo-verdiano sustentável e harmonioso, garantindo um ambiente sadio. A elaboração do PANA II foi um processo complexo com o objectivo de assegurar o envolvimento dos parceiros e estabelecer as respectivas interligações entre os vários níveis. Incluído neste processo esteve a elaboração dos nove Planos Ambientais Inter-sectoriais (PAIS). Esses PAIS incluem as preocupações e planos de todos os ministérios e agências envolvidas em sub-sectores específicos. Assim resultarão em programas e actividades coerentes, transversais e com uma visão clara sobre o desenvolvimento sustentável. Este documento apresenta os resultados dos trabalhos e planificação dos parceiros no sector Ambiente e Agricultura.Governo dos Países Baixo

Reemergence of Sylvatic Dengue Virus in Southern Senegal, 2021

As part of the syndromic surveillance of fever in Senegal, the virology department at Institut Pasteur de Dakar (IPD) in collaboration with the Epidemiology Unit and the Senegalese Ministry of Health conducted syndromic surveillance of fever in Senegal. Sample are from all suspected arboviral infections patients attending any of the sentinel sites. Collected blood samples were sent on a weekly basis at WHOCC for arboviruses and hemorrhagic fever viruses for screening of seven medically important arboviruses, including dengue virus (DENV). From January to December 2021, 2010 suspected cases were received among them 124 for confirmed to be DENV+ by RT-qPCR attempt of serotyping led to the detection of atypical DENV case from Sare Yoba area (Kolda region) which is unable to be correctly assigned to a serotype by the available tools (TIB Molbiol Modular Dx Dengue typing kit). Performed genome sequencing et phylogenetic analysis leads to the identification of a sylvatic DENV-2 strain closely related to a virus previously detected in Guinee-Bissau in 2009. This finding constitutes proof of the contemporary circulation of DENV-2 strain belonging to the sylvatic cycle in addition to well-known epidemic strains; this adds a piece of complexity to dengue management in Senegal. Alarmingly, it calls for improved genomic surveillance of DENV to know the genetic diversity of circulating strains in order to strengthen future vaccination policies

Subsequent mortality in survivors of Ebola virus disease in Guinea: a nationwide retrospective cohort study.

BACKGROUND: A record number of people survived Ebola virus infection in the 2013-16 outbreak in west Africa, and the number of survivors has increased after subsequent outbreaks. A range of post-Ebola sequelae have been reported in survivors, but little is known about subsequent mortality. We aimed to investigate subsequent mortality among people discharged from Ebola treatment units. METHODS: From Dec 8, 2015, Surveillance Active en ceinture, the Guinean national survivors' monitoring programme, attempted to contact and follow-up all survivors of Ebola virus disease who were discharged from Ebola treatment units. Survivors were followed up until Sept 30, 2016, and deaths up to this timepoint were recorded. Verbal autopsies were done to gain information about survivors of Ebola virus disease who subsequently died from their closest family members. We calculated the age-standardised mortality ratio compared with the general Guinean population, and assessed risk factors for mortality using survival analysis and a Cox proportional hazards regression model. FINDINGS: Of the 1270 survivors of Ebola virus disease who were discharged from Ebola treatment units in Guinea, information was retrieved for 1130 (89%). Compared with the general Guinean population, survivors of Ebola virus disease had a more than five-times increased risk of mortality up to Dec 31, 2015 (age-standardised mortality ratio 5·2 [95% CI 4·0-6·8]), a mean of 1 year of follow-up after discharge. Thereafter (ie, from Jan 1-Sept 30, 2016), mortality did not differ between survivors of Ebola virus disease and the general population. (0·6 [95% CI 0·2-1·4]). Overall, 59 deaths were reported, and the cause of death was tentatively attributed to renal failure in 37 cases, mostly on the basis of reported anuria. Longer stays (ie, equal to or longer than the median stay) in Ebola treatment units were associated with an increased risk of late death compared with shorter stays (adjusted hazard ratio 2·62 [95% CI 1·43-4·79]). INTERPRETATION: Mortality was high in people who recovered from Ebola virus disease and were discharged from Ebola treatment units in Guinea. The finding that survivors who were hospitalised for longer during primary infection had an increased risk of death, could help to guide current and future survivors' programmes and in the prioritisation of funds in resource-constrained settings. The role of renal failure in late deaths after recovery from Ebola virus disease should be investigated. FUNDING: WHO, International Medical Corps, and the Guinean Red Cross

Effect of 4 years of seasonal malaria chemoprevention on the acquisition of antibodies to Plasmodium falciparum antigens in Ouelessebougou, Mali.

BACKGROUND: More than 200 million people live in areas of highly seasonal malaria transmission where Seasonal Malaria Chemoprevention (SMC) with sulfadoxine-pyrimethamine (SP) and amodiaquine (AQ) was recommended in 2012 by WHO. This strategy is now implemented widely and protected more than 19 million children in 2018. It was previously reported that exposure to SMC reduced antibody levels to AMA1, MSP-142 and CSP, but the duration of exposure to SMC up to three 3 years, had no effect on antibody levels to MSP-142 and CSP. METHODS: In 2017, a cross-sectional survey was carried out 1 month after the last dose of SMC had been given to children aged 4-5 years randomly selected from areas where SMC had been given for 2 or 4 years during the malaria transmission season. A total of 461 children were enrolled, 242 children in areas where SMC had been implemented for 4 years and 219 children in areas where SMC had been implemented for 2 years. Antibody extracted from dry blood spots was used to measure IgG levels to the malaria antigens CSP, MSP-142 and AMA1 by ELISA. RESULTS: The prevalence of antibodies to MSP-142 was similar in children who had received SMC for 4 years compared to those who had received SMC for only 2 years (85.1 vs 86.0%, ajusted odd ratio (aOR) = 1.06, 95% confidence intervals (CI 0.62-1.80), p = 0.80). The prevalence of antibodies to AMA-1 and to CSP was not lower in children who received SMC for 4 years compared to those who had received SMC for only 2 years (95.3 vs 88.8%, aOR = 3.16, 95% CI 1.44-6.95, p = 0.004 for AMA-1; and 91.2 vs 81.9%, aOR = 3.14, 95% CI 1.70-5.76, p < 0.001 for CSP). Median antibody levels for anti-MSP-142 IgG were not significatively inferior in children who had received SMC for four rather than 2 years (0.88 (IQR: 0.64-1.15) and 0.95 ((0.68-1.15), respectively), anti-CSP (1.30 (1.00-1.56) and 1.17 (0.87-1.47)), and anti-AMA-1 (1.45 (1.24-1.68) and 1.41 (1.17-1.64)). CONCLUSION: In an area of high seasonal malaria transmission, children who had received SMC for 4 years did not had lower seropositivity or antibody levels to AMA1, MSP-142 and CSP compared to children who had received SMC for only 2 years suggesting that children who have received SMC for 4 years may not be more at risk of malaria after the cessation of SMC than children who have received SMC for a shorter period

Preliminary inventory of fruit fly species (Diptera, Tephritidae) in mango orchards in the Niayes region, Senegal, in 2004

Introduction. Knowledge of tephritid diversity in Senegal was poor before 2004, so PIP-COLEACP and CIRAD, in collaboration with Cérès-DPV, carried out, in 2004, trapping for preliminary detection of fruit flies in six orchards in the Niayes zone. Materials and methods. We selected three mixed mango orchards and three homogeneous mango orchards in this zone. In each orchard, we used three attractants: Terpinyl acetate (Ter), Trimedlure (Tri) and Torula (Tor). Traps were serviced weekly. Results. We captured 77 642 fruit flies in more than 4 months including mango season; they were represented by 18 identified fly species, including ten Ceratitis, six Dacus and two Bactrocera species. Two very serious pests were identified with the confirmation of Bactrocera cucurbitae (Coquillett) for cucurbit crops and the detection of B. invadens Drew Tsuruta & White for fruit crops. The two most abundant species of Ceratitis were C. cosyra and C. silvestrii. Discussion. We captured more fruit fly specie s in mixed mango orchards than in homogeneous mango orchards. Bactrocera invadens was also more abundant in mixed orchards, probably because of its polyphagous status. This new invasive species, B. invadens , can have many hosts in mixed mango orchards , enhancing its breeding potential. Conclusion. Effective management to deal with this alien species requires: (i) improvement of basic and applied research; (ii) an effective IPM package; (iii) an area-wide management approach; (iv) a sub-regional effort on the part of researchers, extension services, growers, exporters, farming associations and the different actors in fruit value chains (mainly mango). (Résumé d'auteur

Quantifying the value of viral genomics when inferring who infected whom in the 2014–16 Ebola virus outbreak in Guinea

Transmission trees can be established through detailed contact histories, statistical or phylogenetic inference, or a combination of methods. Each approach has its limitations, and the extent to which they succeed in revealing a 'true' transmission history remains unclear. In this study, we compared the transmission trees obtained through contact tracing investigations and various inference methods to identify the contribution and value of each approach. We studied eighty-six sequenced cases reported in Guinea between March and November 2015. Contact tracing investigations classified these cases into eight independent transmission chains. We inferred the transmission history from the genetic sequences of the cases (phylogenetic approach), their onset date (epidemiological approach), and a combination of both (combined approach). The inferred transmission trees were then compared to those from the contact tracing investigations. Inference methods using individual data sources (i.e. the phylogenetic analysis and the epidemiological approach) were insufficiently informative to accurately reconstruct the transmission trees and the direction of transmission. The combined approach was able to identify a reduced pool of infectors for each case and highlight likely connections among chains classified as independent by the contact tracing investigations. Overall, the transmissions identified by the contact tracing investigations agreed with the evolutionary history of the viral genomes, even though some cases appeared to be misclassified. Therefore, collecting genetic sequences during outbreak is key to supplement the information contained in contact tracing investigations. Although none of the methods we used could identify one unique infector per case, the combined approach highlighted the added value of mixing epidemiological and genetic information to reconstruct who infected whom