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

Aging, physical conditioning and exercice induced changes in hemostatic factors and reaction products

Une étude de l'influence de l'âge sur les changements de l'activité hémostatique, de sujets masculins de 3 catégories d'âge (20-30; 35-45 et 50-60 ans), avant et après 12 semaines d'entraînement. Etude de l'activité fibrinolytique, de la coagulation et des marqueurs d'activité des sujet

Physico-Chemical Characterization of Medical Solid Waste Leachate: Case of the Hospital de l'Amitié of Nouakchott, Mauritania

At the Hospital de l'Amitié, hospital waste corresponds to a mixture of waste assimilated to household waste and the waste from healthcare activities with infectious risks. In the context of hospital hygiene, the conducted study focuses on the impact of this hospital waste on the people of the Hospital de l'Amitié and the environment, and their handling of hospital waste (collection and transport). From an environmental point of view, the physico-chemical characterization of the leachate leaving submerged waste in three media (drinking water, distilled water and alcoholic distilled water) show high concentrations for most of the parameters studied. Physico-chemical characterization of solid waste from Hospital de l'Amitié in Nouakchott (Mauritania) was carried out from September to December 2020. The objective was to determine the value of 14 parameters (pH, temperature, turbidity, electrical conductivity, COD, BOD5, COD/BOD5, BOD5/COD, SS/BOD5, SS, nitrite, nitrate, sulfate and phosphorus), and improve the treatment method for this solid waste by immersing it in three different mediums (drinking water, distilled water and alcoholic distilled water). Among the 14 parameters, seven exceeded the Moroccan and WHO standards for medium 1, 2 and 3 respectively, conductivity (5340.00 μs/cm, 5820.00 μs/cm and 3550.00 μs/cm), BOD5 (122.00 mg/L, 106.00 mg/L and 142.00 mg/L), BOD5/COD (2.30, 1.93 and 2.88), SS (1000.00 mg/L, 600.00 mg/L and 600.00 mg/L), nitrite (0.91 mg/L, 25.00 mg/L and 45.00 mg/L), nitrate (210.00 mg/L, 200.00 mg/L and 110.00 mg/L) and sulfate (1000.00 mg/L, 2000.00 mg/L and 1000.00 mg/L). These results indicate the existence of toxic substances in these leachates that may impact the environment. In addition, the study proposes solid waste treatment from the Hospital de l'Amitié in Nouakchott (Mauritania) before its discharge into the natural environment. This observation is consolidated by the analyses carried out on the leachate of the waste immersed in three aqueous media (drinking water, distilled water and alcoholic distilled water)