COVID-19 concerns among caregivers and vitamin A supplementation coverage among children aged 6–59 months in four countries in Western sub-Saharan Africa

Abstract Objective: To assess child vitamin A supplementation (VAS) coverage in 2019 and 2020 and explore key factors, including COVID-19 concerns, that influenced VAS status in four sub-Saharan African countries. Design: Data from eight representative household surveys were used to assess VAS coverage. Multivariable logistic regression models examined the effect of rural/urban residence, child sex and age, caregiver education, COVID-19 concern and household wealth on VAS status. Setting: Nine (2019) and 12 (2020) districts in Burkina Faso, Côte d’Ivoire, Guinea and Mali. Participants: 28 283 caregivers of children aged 6–59 months. Results: Between 2019 and 2020, VAS coverage increased in Burkina Faso (82·2–93·1 %), Côte d’Ivoire (90·3–93·3 %) and Mali (76·1–79·3 %) and decreased in Guinea (86·0 % to 81·7 %). Rural children had a higher likelihood of VAS uptake compared with urban children in Burkina Faso (adjusted OR (aOR) = 4·22; 95 % CI: 3·11, 5·72), Côte d’Ivoire (aOR = 5·19; 95 % CI: 3·10, 8·70) and Mali (aOR = 1·41; 95 % CI: 1·15, 1·74). Children aged 12–59 months had a higher likelihood of VAS uptake compared with children aged 6–11 months in Côte d’Ivoire (aOR = 1·67; 95 % CI: 1·12, 2·48) and Mali (aOR = 1·74; 95 % CI: 1·34, 2·26). Moderate-to-high COVID-19 concern was associated with a lower likelihood of VAS uptake in Côte d’Ivoire (aOR = 0·55; 95 % CI: 0·37, 0·80). Conclusion: The increase in VAS coverage from 2019 to 2020 suggests that COVID-19 concerns may not have limited VAS uptake in some African countries, though geographic inequities should be considered

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

Determinants of Transmission Risk During the Late Stage of the West African Ebola Epidemic.

Understanding risk factors for Ebola transmission is key for effective prediction and design of interventions. We used data on 860 cases in 129 chains of transmission from the latter half of the 2013-2016 Ebola epidemic in Guinea. Using negative binomial regression, we determined characteristics associated with the number of secondary cases resulting from each infected individual. We found that attending an Ebola treatment unit was associated with a 38% decrease in secondary cases (incidence rate ratio (IRR) = 0.62, 95% confidence interval (CI): 0.38, 0.99) among individuals that did not survive. Unsafe burial was associated with a higher number of secondary cases (IRR = 1.82, 95% CI: 1.10, 3.02). The average number of secondary cases was higher for the first generation of a transmission chain (mean = 1.77) compared with subsequent generations (mean = 0.70). Children were least likely to transmit (IRR = 0.35, 95% CI: 0.21, 0.57) compared with adults, whereas older adults were associated with higher numbers of secondary cases. Men were less likely to transmit than women (IRR = 0.71, 95% CI: 0.55, 0.93). This detailed surveillance data set provided an invaluable insight into transmission routes and risks. Our analysis highlights the key role that age, receiving treatment, and safe burial played in the spread of EVD

Case Report: COVID-19 and Lassa Fever Coinfection in an Ebola Suspected Patient in Guinea

ABSTRACT. In this case report, we describe a clinical presentation and therapeutic history of a unique case diagnosed with Lassa fever and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in a 23-year-old man from Yomou prefecture in southeast Guinea identified with suspected Ebola Virus Disease (EVD) in the midst of an ongoing outbreak of that disease in the same region. On May 3, 2021, he was admitted to the Nzérékoré Epidemic disease treatment center where his clinical condition deteriorated significantly. Laboratory testing performed on the same day reveals a negative EVD polymerase chain reaction (PCR). Three days later, the patient was tested positive for SARS-CoV-2 and Lassa fever by reverse transcriptase PCR (RT-PCR) assays. Laboratory examination also indicated severe hematological and biochemical deteriorations in the patient. This case substantiates the need for systematic differential diagnosis during epidemic-prone disease outbreaks to better manage severely unwell patients.</jats:p

Chapitre 4. Prévention des risques

Introduction Méthodologie La prévention des catastrophes naturelles a d’autant plus d’importance que la confrontation des « systèmes naturels » et des « systèmes humains » génère, et générera de plus en plus compte tenu de l’importance croissante des « systèmes anthropiques » – en particulier urbains -, des enjeux tellement considérables que le développement global des sociétés peut être durablement gêné, voire arrêté pendant de nombreuses années. Les économistes considèrent en effet que, si ..

Modelling surface electric discharge propagation on polluted insulators under AC voltage

In this contribution, a mathematical model allowing for the prediction of the AC surface arc propagation on polluted insulators under non-uniform electric field is proposed. The approach is based on the experimental concept of Claverie and Porcheron. The proposed model, which makes it possible to reproduce the surface electric discharge, includes a condition for arrest of the propagating discharge. The electric field at the tip of the discharge is the key parameter governing its random propagation. A finite element approach allows for mapping of the electric field distribution while the discharge propagation process is simulated in two dimensions. The voltage drop along the arc discharge path at each propagation step is also taken into account. The simulation results are validated against experimental data, taking into account several electro-geometric parameters (distance between electrodes, pollution conductivity, radius of high-voltage electrode, length of the plane electrode). Good agreement between computed and experimental results were obtained for various test configurations

Dynamique hydrologique du delta intérieur du Niger (Mali)

Le delta intérieur du fleuve Niger au Mali constitue une singularité hydrologique de par sa situation géographique au milieu de la zone sahélienne. L’étude de la variabilité tant spatiale que temporelle des paramètres hydroclimatiques (pluviométrie, température de l’air, évapotranspiration potentielle et nébulosité) devrait permettre une utilisation plus rationnelle de la ressource en eau. Le but de cet article a été non seulement de cartographier les variations spatiotemporelles des paramètr..

Avenir du fleuve Niger

Le fleuve Niger constitue un véritable poumon humide pour l’Afrique de l’Ouest et plus spécialement pour la république du Mali. Dans ce pays, la gestion du fleuve constitue un enjeu majeur car on y trouve à la fois de remarquables systèmes de production traditionnels associés au phénomène naturel de crue – sources de moyens d’existence pour des centaines de milliers de personnes – mais aussi de grandes réalisations et promesses en matière d’aménagements modernes, hydroélectriques et hydroagricoles. À l’heure où de nouveaux projets d’équipement arrivent à concrétisation et où d’autres sont annoncés, il est important de faire le point sur l’état de santé de ce fleuve et de peser ce qu’il représente pour ses multiples usagers. Cette expertise collégiale, conduite par l’IRD et l’IER et réalisée avec le soutien de plusieurs institutions d’aide au développement et de défense de l’environnement, traite de ces différents aspects avec pour objectif, d’une part, la clarification des cadres institutionnels et des options de politiques publiques et, d’autre part, le renforcement des outils de suivi et d’aide à la décision.The Niger river is truly the main source of life for Western Africa, more specifically for the Republic of Mali. In the country, management of the river is a key topic, as one can find at the same time remarkable traditional production systems associated with the floods which supply hundreds thousands of people – but also great projects which promise modern installations, hydroelectrical and hydroagricultural systems. As new projects come to their end and others begin, it seems important to make a point regarding the health of the river and to evaluate what it represents for its diverse users, civil society or for the economy of Mali. This is the aim of this expert group review, led by the IRD and the IER, with the support of different development and nature protection institutes. Complementarities as well as oppositions that appear from the interactions between the river’s users are described. For the decision-makers in charge of those problems, different recommendations are made, aiming on one hand to clarify institutional frameworks and policy options, and on the other hand to reinforce management and decision-making tools