4 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

    CRADLE-5: a stepped-wedge type 2 hybrid implementation-effectiveness cluster randomised controlled trial to evaluate the real-world scale-up of the CRADLE Vital Signs Alert intervention into routine maternity care in Sierra Leone—study protocol

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    Abstract Background The CRADLE Vital Signs Alert intervention (an accurate easy-to-use device that measures blood pressure and pulse with inbuilt traffic-light early warning system, and focused training package) was associated with reduced rates of eclampsia and maternal death when trialled in urban areas in Sierra Leone. Subsequently, implementation was successfully piloted as evidenced by measures of fidelity, feasibility and adoption. The CRADLE-5 trial will examine whether national scale-up, including in the most rural areas, will reduce a composite outcome of maternal and fetal mortality and maternal morbidity and will evaluate how the CRADLE package can be embedded sustainably into routine clinical pathways. Methods CRADLE-5 is a stepped-wedge cluster-randomised controlled trial of the CRADLE intervention compared to routine maternity care across eight rural districts in Sierra Leone (Bonthe, Falaba, Karene, Kailahun, Koinadugu, Kono, Moyamba, Tonkolili). Each district will cross from control to intervention at six-weekly intervals over the course of 1 year (May 2022 to June 2023). All women identified as pregnant or within six-weeks postpartum presenting for maternity care in the district are included. Primary outcome data (composite rate of maternal death, stillbirth, eclampsia and emergency hysterectomy) will be collected. A mixed-methods process and scale-up evaluation (informed by Medical Research Council guidance for complex interventions and the World Health Organization ExpandNet tools) will explore implementation outcomes of fidelity, adoption, adaptation and scale-up outcomes of reach, maintenance, sustainability and integration. Mechanisms of change and contextual factors (barriers and facilitators) will be assessed. A concurrent cost-effectiveness analysis will be undertaken. Discussion International guidance recommends that all pregnant and postpartum women have regular blood pressure assessment, and healthcare staff are adequately trained to respond to abnormalities. Clinical effectiveness to improve maternal and perinatal health in more rural areas, and ease of integration and sustainability of the CRADLE intervention at scale has yet to be investigated. This trial will explore whether national scale-up of the CRADLE intervention reduces maternal and fetal mortality and severe maternal adverse outcomes and understand the strategies for adoption, integration and sustainability in low-resource settings. If successful, the aim is to develop an adaptable, evidence-based scale-up roadmap to improve maternal and infant outcomes. Trial registration ISRCTN 94429427. Registered on 20 April 2022
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