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

Performances optimales d'une allocation globale de ressources radio dans des réseaux hétérogènes

L'évolution des réseaux sans fil et mobiles devient de plus en plus rapide, ainsi l'allocation optimale de ressources radio est un problème qui s'impose. Ce développement de réseaux de télécommunications est accompagné d'un déploiement efficient de réseaux sans fil tels que le Wireless Fidelity et des réseaux mobiles comme le LongTerm Evolution(LTE). Dans cet article, nous proposons un algorithme améliorant l'allocation globale de ressources radio dans le cadre d'un système hétérogène de réseaux sans fil et mobile à l'aide de la programmation dynamique notamment le principe d'optimalité de Bellman. Nous avons pris en compte la mobilité des utilisateurs en utilisant le modèle 2D Fluid Flow pour obtenir de meilleures performances testées numériquement par le Network Simulator 3(NS3)

Performances optimales d'une allocation globale de ressources radio dans des réseaux hétérogènes

L'évolution des réseaux sans fil et mobiles devient de plus en plus rapide, ainsi l'allocation optimale de ressources radio est un problème qui s'impose. Ce développement de réseaux de télécommunications est accompagné d'un déploiement efficient de réseaux sans fil tels que le Wireless Fidelity et des réseaux mobiles comme le LongTerm Evolution(LTE). Dans cet article, nous proposons un algorithme améliorant l'allocation globale de ressources radio dans le cadre d'un système hétérogène de réseaux sans fil et mobile à l'aide de la programmation dynamique notamment le principe d'optimalité de Bellman. Nous avons pris en compte la mobilité des utilisateurs en utilisant le modèle 2D Fluid Flow pour obtenir de meilleures performances testées numériquement par le Network Simulator 3(NS3)

A spectrofluorimetric method for the determination of pindolol in natural waters using various organic and cyclodextrin media

International audienc

Systemic structural gender discrimination and inequality in the health workforce: theoretical lenses for gender analysis, multi-country evidence and implications for implementation and HRH policy

Abstract This commentary brings together theory, evidence and lessons from 15 years of gender and HRH analyses conducted in health systems in six WHO regions to address selected data-related aspects of WHO’s 2016 Global HRH Strategy and 2022 Working for Health Action Plan. It considers useful theoretical lenses, multi-country evidence and implications for implementation and HRH policy. Systemic, structural gender discrimination and inequality encompass widespread but often masked or invisible patterns of gendered practices, interactions, relations and the social, economic or cultural background conditions that are entrenched in the processes and structures of health systems (such as health education and employment institutions) that can create or perpetuate disadvantage for some members of a marginalized group relative to other groups in society or organizations. Context-specific sex- and age-disaggregated and gender-descriptive data on HRH systems’ dysfunctions are needed to enable HRH policy planners and managers to anticipate bottlenecks to health workforce entry, flows and exit or retention. Multi-method approaches using ethnographic techniques reveal rich contextual detail. Accountability requires that gender and HRH analyses measure SDGs 3, 4, 5 and 8 targets and indicators. To achieve gender equality in paid work, women also need to achieve equality in unpaid work, underscoring the importance of SDG target 5.4. HRH policies based on principles of substantive equality and nondiscrimination are effective in countering gender discrimination and inequality. HRH leaders and managers can make the use of gender and HRH evidence a priority in developing transformational policy that changes the actual conditions and terms of health workers’ lives and work for the better. Knowledge translation and intersectoral coalition-building are also critical to effectiveness and accountability. These will contribute to social progress, equity and the realization of human rights, and expand the health care workforce. Global HRH strategy objectives and UHC and SDG goals will more likely be realized

Case report of a lithopedion of tubal location, in a young woman

Lithopedion is a rare situation, corresponding to an ectopic pregnancy which evolves beyond the first trimester toward death and fetal calcification. This ectopic pregnancy is most often abdominal in location. Through this case report, we report the case of a lithopedion of left tubal localization in a young woman, diagnosed on CT scan following abdominal pain and confirmed by laparotomy with excision

Spectrofluorimetric determination of beta-blockers atenolol and bisoprolol fumarate residues in Senegal natural waters

A spectrofluorimetric method was developed to determine residues of two β-blockers, atenolol (AT) and bisoprolol fumarate (BF), in Senegal's natural waters. The electronic absorption and fluorescence spectral properties of both β-blockers were investigated in several organic solvent mixtures [e.g., MeOH/H2O (60/40 v/v), cyclodextrins (β-cyclodextrin, HP-β-CD], and in the presence of surfactants (SDS, Triton X, Tween 80). After optimization, satisfactory analytical figures of merit were obtained for the determination of both β-blockers: concentration linear dynamic range of over one to two orders of magnitude, limits of detection (LODs) from 1.3 to 5.4 ng/ml for BF and from 1.2 to 3.7 ng/ml for AT, limits of quantification (LOQs) from 4.5 to 18.1 ng/ml for BF and from 4.0 to 12.5 ng/ml for AT. Relative standard deviations (RSDs) were between 2.1 and 5.3 %, according to the β-blockers. The spectrofluorimetric method was applied to the analysis of fortified river water and wastewater (effluent) collected in Senegal and France and spiked with both β-blockers. It yielded good recovery values, from 93.3 to 107.8 % for AT and from 97.4 to 108.9 % for BF. Our results demonstrated the simplicity, rapidity, and sensitivity of the spectrofluorimetric method to quantify residues of β-blockers in environmental waters