24 research outputs found

    The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

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    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

    Morphological aspects of the propagation in Heliconia velloziana L. Emygd. (Zingiberales: Heliconiaceae)

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    A morfologia da propagação por sementes e da propagação vegetativa foi estudada em Heliconia velloziana L. Emygd. (Heliconiaceae). As sementes levaram cerca de quatro meses para germinar, provavelmente pelo embrião indiferenciado na época da maturação do fruto e também devido ao endocarpo pétreo, que envolve a semente. As duas primeiras estruturas foliares nas plântulas são escamiformes e as raízes adventícias são mais conspícuas do que a raiz primária. Na propagação vegetativa as raízes se desenvolveram a partir de quatro semanas e os brotos a partir de quatro a seis semanas; inicialmente foram formados os catafilos, e depois dois protofilos.Morphology of seed and vegetative propagation was studied toHeliconia velloziana L. Emygd. (Heliconiaceae), a rhizomatous herb with a large aerial part. Seeds took about four months to germinate, probably due to the undifferentiated embryo and hard endocarp. Seedlings had two first foliar structures as scale leaves and the primary root developed, but the adventitious roots were more conspicuous. Vegetative propagation by rhizomes was faster than the sexual one. The roots developed after one month, while young shoots started developing after four to six weeks; young aerial shoots presented a variable number of cataphylls and two protophylls.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

    Contrasting patterns in the vertical distribution of decapod crustaceans throughout ontogeny

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    In marine ecosystems, the most significant migration observed in terms of biomass distribution is the one connected with the vertical movements in the water column. In the present study, the vertical profiles of the mesopelagic shrimps Gennadas elegans, Eusergestes arcticus, Sergia robusta, and the epipelagic Parasergestes vigilax in the Balearic Sea (western Mediterranean), during the stratified (summer) and non-stratified (autumn) hydrographic conditions, were investigated through their ontogeny, from the larval to adult stages. The mesopelagic adults were observed to move down to the deeper layers during the night more than during the daylight hours. Most larvae aggregated within the limits of the upper water column. The P. vigilax larvae were collected only during the stratified period. The first two larval stages vertical distribution indicates that the mesopelagic crustacean spawning could occur at greater depths. During the non-stratified period, the larvae of the mesopelagic species tended to remain at about 500 m depth at night, rising towards the upper layers at sunrise. Vertical patterns are discussed, as strategies associated with predator–prey trade-offs. To our knowledge, the present study is the first such attempt to jointly analyze the vertical migrations of the developmental stages of the pelagic shrimps in the Mediterranean SeaVersión del editor1,78

    Gestão compartilhada ecomunitária da pesca no Brasil: avanços e desafios Shared and community management of fisheries in Brazil: progress and challenges

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    Neste trabalho buscamos revisar as oportunidades e os desafios na implementação de sistemas de co-gerenciamento da pesca no Brasil. A metodologia de estudo foi baseada na análise e revisão de 116 referências bibliográficas a respeito desse tipo de experiências. O trabalho mostra fatores que têm sido chaves na criação e na manutenção de arranjos de gestão compartilhada bem como aqueles que representam os maiores desafios encontrados para o avanço na gestão compartilhada da pesca no Brasil.<br>This work focuses on the opportunities and challenges in the implementation of fisheries co-management arrangements in Brazil. The methodology of this study was based on the analysis and revision of 116 bibliographical references regarding this type of arrangements. The paper shows the key factors that have been influencing the creation and maintenance of fisheries co-management as well as the ones that represent the biggest challenges to the advancement of fisheries co-management in Brazil
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