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Background: The WHO Emergency Medical Teams (EMT) Initiative coordinates the deployment of qualified medical teams who promptly respond to public health emergencies (PHEs) and provide quality service during emergencies whilst strengthening capacity. Globally, 40 EMTs have been classified between 2016 and the present (as of the writing of this article in December 2023) and are from across all the WHO regions except the WHO Africa Region (AFRO). However, WHO Africa has prioritised the implementation of EMTs in 10 priority countries to address the public health emergencies (PHEs) affecting the region. Objective: This article describes the development and progress of national EMTs in the WHO African Region over the past 7 years and elucidates the main lessons learned and the complexity and challenges in the process. Methods: This study employed a case study approach because of its appropriateness in examining a complex social phenomenon in a socio-political context in depth, using multiple lenses simultaneously. Data and information were obtained through document reviews and key informant interviews (KIIs) (n = 5) with the members of the EMT Initiative on shared field experiences. Data were systematically analysed using the Stages of Implementation Completion (SIC) framework, and the lessons learnt were presented using components of a framework from Adini et al. Results: The Initiative commenced in the WHO African Region following its launch in December 2017 in Senegal. The assessments of the concept's engagement (involved learning and deciding), feasibility (reviewing expectation and capacity), and readiness planning (collaborating and preparing) showed that the context-specific (African context) challenges, lessons from different emergency response actions mainly guided the Initiative's pre-implementation phase in the region and prompted the WHO emergency leadership on the urgency and need for the EMT concept in the region. The assessment of the implementation processes showed progress in key areas, with staff demonstrating improved competency, EMT services maintaining high fidelity, effective consultation launching critical components, and ongoing services providing successful support and monitoring. Creating the N-EMTs and revitalising the EMT concept required an aligned strategy with other regional emergency programmes and a futuristic vision. Proposed sustainability and governance components include creating N-EMT, developing a coordination structure, collaborating with partners, and finalising the N-EMT. Conclusion: The Initiative is an imperative component that would allow better-targeted management of health emergencies in the region. The continuous refinement of the EMT initiative is crucial. There is a need to work on additional components, such as a context-specific framework for collaborations and partnerships that would enhance deployment and procurement modalities and the complementarity between other regional initiatives to improve the work. Emphasis should be placed on strengthening local health systems, enhancing training and capacity-building programmes, and fostering regional and international collaborations. Additionally, sustainable funding and resource allocation are essential to ensure the resilience of EMTs in the African region and their long-term success.
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Servicios Médicos de Urgencia , Organización Mundial de la Salud , Humanos , África , Creación de Capacidad , Salud PúblicaRESUMEN
High-grade osteosarcoma is the most common paediatric bone cancer. More than one third of patients relapse and die of osteosarcoma using current chemotherapeutic and surgical strategies. To improve outcomes in osteosarcoma, two crucial challenges need to be tackled: 1-the identification of hard-to-treat disease, ideally from diagnosis; 2- choosing the best combined or novel therapies to eradicate tumor cells which are resistant to current therapies leading to disease dissemination and metastasize as well as their favorable microenvironment. Genetic chaos, tumor complexity and heterogeneity render this task difficult. The development of new technologies like next generation sequencing has led to an improvement in osteosarcoma oncogenesis knownledge. This review summarizes recent biological and therapeutical advances in osteosarcoma, as well as the challenges that must be overcome in order to develop personalized medicine and new therapeutic strategies and ultimately improve patient survival.
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Neoplasias Óseas , Osteosarcoma , Medicina de Precisión , Osteosarcoma/genética , Osteosarcoma/patología , Humanos , Medicina de Precisión/métodos , Neoplasias Óseas/genética , Neoplasias Óseas/patología , Neoplasias Óseas/terapiaRESUMEN
BACKGROUND: The declaration of SARS-CoV-2 as a public health emergency of international concern in January 2020 prompted the need to strengthen infection prevention and control (IPC) capacities within health care facilities (HCF). IPC guidelines, with standard and transmission-based precautions to be put in place to prevent the spread of SARS-CoV-2 at these HCFs were developed. Based on these IPC guidelines, a rapid assessment scorecard tool, with 14 components, to enhance assessment and improvement of IPC measures at HCFs was developed. This study assessed the level of implementation of the IPC measures in HCFs across the African Region during the COVID-19 pandemic. METHOD: An observational study was conducted from April 2020 to November 2022 in 17 countries in the African Region to monitor the progress made in implementing IPC standard and transmission-based precautions in primary-, secondary- and tertiary-level HCFs. A total of 5168 primary, secondary and tertiary HCFs were assessed. The HCFs were assessed and scored each component of the tool. Statistical analyses were done using R (version 4.2.0). RESULTS: A total of 11 564 assessments were conducted in 5153 HCFs, giving an average of 2.2 assessments per HCF. The baseline median score for the facility assessments was 60.2%. Tertiary HCFs and those dedicated to COVID-19 patients had the highest IPC scores. Tertiary-level HCFs had a median score of 70%, secondary-level HCFs 62.3% and primary-level HCFs 56.8%. HCFs dedicated to COVID-19 patients had the highest scores, with a median of 68.2%, followed by the mixed facilities that attended to both COVID-19 and non-COVID-19 patients, with 64.84%. On the components, there was a strong correlation between high IPC assessment scores and the presence of IPC focal points in HCFs, the availability of IPC guidelines in HCFs and HCFs that had all their health workers trained in basic IPC. CONCLUSION: In conclusion, a functional IPC programme with a dedicated focal person is a prerequisite for implementing improved IPC measures at the HCF level. In the absence of an epidemic, the general IPC standards in HCFs are low, as evidenced by the low scores in the non-COVID-19 treatment centres.
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COVID-19 , Humanos , COVID-19/prevención & control , Pandemias/prevención & control , SARS-CoV-2 , Instituciones de Salud , Control de Infecciones , Atención a la SaludRESUMEN
INTRODUCTION: In sub-Saharan Africa (SSA), the clinical and progressive diagnostic certainty of AIDS dementia is difficult to establish due to under-medicalization and delays in consultation and especially the diversity of etiologies of demented states. MATERIAL AND METHODS: We carried out a retrospective study of 196 patients hospitalized for dementia syndrome between 2016 and 2021 in the neurology department of the University Hospital of Conakry. The criteria labeled in this study are those retained by the DSM-IV and the classification of the American Academy of Neurology (AAN) developed in accordance with the WHO. RESULTS: HIV etiology was identified in patients aged 44-67 years (17 women and 19 men). The clinical picture was dominated by severe cognitive disorders, slowed ideation, memory disorders and reduced motor skills associated with personality changes. Neurological examination revealed dysphoric disorders in most patients, sphincter abnormalities in 13 cases and labio-lingual tremor in 11 cases. Diagnosis was based on positive serological tests for HIV1 antibodies (25 cases) and HIV2 antibodies (1 case) using the Elisa and Western blot techniques, and the presence of discretely hypercellular CSF. Magnetic resonance imaging contributed to the diagnosis, showing diffuse white matter abnormalities with hyper signals on T2-weighted or FLAIR sequences. CONCLUSION: This study shows a non-stereotype clinical picture of AIDS dementia requiring a differential diagnosis with other infectious dementias. These results are important for the therapeutic and prognostic discussion.
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Síndrome de Inmunodeficiencia Adquirida , Demencia , Masculino , Humanos , Femenino , Estudios Retrospectivos , Guinea , Demencia/diagnóstico , HospitalesRESUMEN
OBJECTIVE: This study describes the progress that the World Health Organization (WHO) African (AFRO) region has made in establishing National Emergency Medical Teams (N-EMTs), the coordination mechanisms of the EMTs, and the regional training centers. METHODS: It used a retrospective descriptive analysis of the formulation and implementation of the EMTs Initiative from an insider perspective. The analysis is based on the review of available documents such as EMTs mission reports, assessments, surveys, EMT monthly bulletins, and meeting minutes in addition to key informant interviews (n = 5) with the EMT teams' members to validate the findings and share field experiences. RESULTS: The emergence of coronavirus disease 2019 (COVID-19) acted as an accelerator for the implementation of the EMT initiative in the AFRO region. A total of 18 EMT deployments were carried out in 16 countries in the AFRO region through the WHO EMT-network during COVID-19, providing support to countries in managing severe and critical COVID-19 cases. CONCLUSIONS: A Regional Training Center for N-EMTs is being set up in Addis Ababa to train the N-EMTs and strengthen local capacity of health personnel in the region. Challenges include unavailability of mentors to support countries in implementing N-EMTs and the Regional Simulation Training Center, poor funding, and coordination in the rolling out of the N-EMTs.
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COVID-19 , Entrenamiento Simulado , Humanos , Estudios Retrospectivos , COVID-19/epidemiología , Etiopía , Personal de SaludRESUMEN
The WHO Unity Studies initiative engaged low- and middle-income countries in the implementation of standardised SARS-CoV-2 sero-epidemiological investigation protocols and timely sharing of comparable results for evidence-based action. To gain a deeper understanding of the methodological challenges faced when conducting seroprevalence studies in the African region, we conducted unstructured interviews with key study teams in five countries. We discuss the challenges identified: participant recruitment and retention, sampling, sample and data management, data analysis and presentation. Potential solutions to aid future implementation include preparedness actions such as the development of new tools, robust planning and practice.
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COVID-19 , Humanos , COVID-19/epidemiología , COVID-19/prevención & control , SARS-CoV-2 , Estudios Seroepidemiológicos , África/epidemiologíaRESUMEN
Engaging communities is a key factor in efficient response to public health emergencies (PHE). Previous and recent outbreaks have shown that civil society organizations (CSOs) can mobilize the communities to better prepare and respond to a PHE. Consequently, the World Health Organization (WHO) Regional Office for Africa (AFRO) implemented an initiative to partner with community leaders by engaging CSOs. The Civil Society Organization Initiative (CSO Initiative) aims to work directly with well-established community-based organizations to accelerate whole-of-society preparation and response. Twenty-three CSOs from 12 WHO African Region Member States have been supported financially and technically to implement effective community-based interventions to respond to the coronavirus disease (COVID-19) pandemic. After 1 year of implementation (2021), the successes, challenges, and recommendations for maximizing future engagements with CSOs are outlined. As the COVID-19 outbreak is again underlining, partnering with established CSOs to engage diverse social groups from various communities can help provide a timely and efficient response to a PHE.
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COVID-19 , Salud Pública , Humanos , Pandemias/prevención & control , Urgencias Médicas , COVID-19/epidemiología , COVID-19/prevención & control , Organización Mundial de la SaludRESUMEN
BACKGROUND: Cameroon has been struggling with low Covid-19 vaccination coverage, with only 4.5 % of the population receiving the primary series as of November 2022. The COVID-19 Vaccine Delivery Partnership (CoVDP) conducted a high-level mission to Cameroon to assess progress and advocate for actions to address bottlenecks. The objective of the mission was to administer at least 3,000,000 doses of vaccines during the 5th Mass vaccination campaign. This study examines the factors contributing to the success of the campaign and uses a geographical and gender lens to assess the results. METHODS: The study is a secondary analysis of data from the DHIS2 collected during the 5th mass vaccination campaign for Covid-19. Descriptive statistics were used to assess coverages per location and gender expressed in OR. sccess factors, and chi-squared tests were used to assess differences in vaccine distribution across regions and by gender. RESULTS: This 5th vaccination campaign benefitted from a strong political commitment facilitated by CoVDP's mission, international support, collaboration, planning, supervision, and demand generation. The campaign recorded 2 019 118 administered vaccine doses, a staggering 46-fold increase in vaccinated individuals relative to the first round, with vaccination coverage reaching 10.1 % of the general population. However, the study reveals regional and gender disparities in vaccination coverage. Men had higher odds of being vaccinated than women in the three Sahel regions. Among individuals with comorbidities, the national coverage rate was only 14 %, and the Far North and East regions exhibited the lowest coverage rates. Janssen was the most used vaccine, and the total AEFI cases reported were 2 per 1000 vaccine doses. CONCLUSION: The 5th COVID-19 vaccination campaign in Cameroon saw a strong political commitment and was the most successful so far. Despite the gains, there was gender disparity in coverage in some regions. It is important to continue the established momentum, ensure equitable access in the Sahel regions, and reach high-priority groups with primary series and booster doses.
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Vacunas contra la COVID-19 , COVID-19 , Masculino , Humanos , Femenino , Camerún/epidemiología , COVID-19/epidemiología , COVID-19/prevención & control , Vacunación , Programas de InmunizaciónRESUMEN
BACKGROUND: Globally, since 1 January 2020 and as of 24 January 2023, there have been over 664 million cases of COVID-19 and over 6.7 million deaths reported to WHO. WHO developed an evidence-based alert system, assessing public health risk on a weekly basis in 237 countries, territories and areas from May 2021 to June 2022. This aimed to facilitate the early identification of situations where healthcare capacity may become overstretched. METHODS: The process involved a three-stage mixed methods approach. In the first stage, future deaths were predicted from the time series of reported cases and deaths to produce an initial alert level. In the second stage, this alert level was adjusted by incorporating a range of contextual indicators and accounting for the quality of information available using a Bayes classifier. In the third stage, countries with an alert level of 'High' or above were added to an operational watchlist and assistance was deployed as needed. RESULTS: Since June 2021, the system has supported the release of more than US$27 million from WHO emergency funding, over 450 000 rapid antigen diagnostic testing kits and over 6000 oxygen concentrators. Retrospective evaluation indicated that the first two stages were needed to maximise sensitivity, where 44% (IQR 29%-67%) of weekly watchlist alerts would not have been identified using only reported cases and deaths. The alerts were timely and valid in most cases; however, this could only be assessed on a non-representative sample of countries with hospitalisation data available. CONCLUSIONS: The system provided a standardised approach to monitor the pandemic at the country level by incorporating all available data on epidemiological analytics and contextual assessments. While this system was developed for COVID-19, a similar system could be used for future outbreaks and emergencies, with necessary adjustments to parameters and indicators.
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COVID-19 , Salud Pública , Humanos , Teorema de Bayes , Brotes de Enfermedades , Estudios Retrospectivos , Organización Mundial de la SaludRESUMEN
The WHO Regional Office for Africa (AFRO) COVID-19 Incident Management Support Team (IMST) was first established on 21 January 2020 to coordinate the response to the pandemic in line with the Emergency Response Framework and has undergone three modifications based on intra-action reviews (IAR). An IAR of the WHO AFRO COVID-19 IMST was conducted to document best practices, challenges, lessons learnt and areas for improvement from the start of 2021 to the end of the third wave in November 2021. In addition, it was designed to contribute to improving the response to COVID-19 in the Region. An IAR design as proposed by WHO, encompassing qualitative approaches to collecting critical data and information, was used. It employed mixed methods of data collection: document reviews, online surveys, focus group discussions and key informant interviews. A thematic analysis of the data focused on four thematic areas, namely operations of IMST, data and information management, human resource management and institutional framework/governance. Areas of good practice identified, included the provision of guidelines, protocols and technical expertise, resource mobilisation, logistics management, provision of regular updates, timely situation reporting, timely deployment and good coordination. Some challenges identified included a communication gap; inadequate emergency personnel; lack of scientific updates; and inadequate coordination with partners. The identified strong points/components are the pivot for informed decisions and actions for reinvigorating the future response coordination mechanism.
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COVID-19 , Humanos , África , Comunicación , Grupos Focales , Organización Mundial de la SaludRESUMEN
Healthcare workers are much more likely to be infected with HIV and hepatitis viruses compared to the general population. Although healthcare workers are more aware of HIV and hepatitis viruses, several countries in Africa lack a comprehensive grasp of disease routes and transmission risks. The aim of this study was to assess the prevalence of the serological and molecular biological markers of HIV and viral hepatitis among healthcare workers in the Republic of Guinea. The study material was 74 blood serum samples collected from healthcare workers who received additional training at the Institute of Applied Biological Research of Guinea (IRBAG, Kindia, Republic of Guinea). The markers examined included HBsAg, HBeAg, anti-HBs IgG, anti-HBcore IgG, anti-HCV qualitative determination, anti-HEV IgM and IgG, anti-HAV IgM and IgG, and anti-HIV. For viral DNA and RNA detection, nucleic acids were extracted from blood serum, and viral presence was inferred using real-time PCR with hybridization fluorescence detection. A high prevalence of viral hepatitis B markers was shown, and significantly fewer cases of viral hepatitis C and HIV were detected. Almost all examined medical workers had anti-HAV IgG antibodies, but no antibodies to hepatitis E virus. Apparently, the identified markers depend on the general prevalence of certain pathogens in the region and are associated with the traditions and characteristics of the country's residents.
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The COVID-19 pandemic has exposed faults in the way we assess preparedness and response capacities for public health emergencies. Existing frameworks are limited in scope, and do not sufficiently consider complex social, economic, political, regulatory, and ecological factors. One Health, through its focus on the links among humans, animals, and ecosystems, is a valuable approach through which existing assessment frameworks can be analysed and new ways forward proposed. Although in the past few years advances have been made in assessment tools such as the International Health Regulations Joint External Evaluation, a rapid and radical increase in ambition is required. To sufficiently account for the range of complex systems in which health emergencies occur, assessments should consider how problems are defined across stakeholders and the wider sociopolitical environments in which structures and institutions operate. Current frameworks do little to consider anthropogenic factors in disease emergence or address the full array of health security hazards across the social-ecological system. A complex and interdependent set of challenges threaten human, animal, and ecosystem health, and we cannot afford to overlook important contextual factors, or the determinants of these shared threats. Health security assessment frameworks should therefore ensure that the process undertaken to prioritise and build capacity adheres to core One Health principles and that interventions and outcomes are assessed in terms of added value, trade-offs, and cobenefits across human, animal, and environmental health systems.
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COVID-19 , Salud Única , Animales , Humanos , Salud Global , Ecosistema , Urgencias Médicas , PandemiasRESUMEN
The onset of the pandemic revealed the health system inequities and inadequate preparedness, especially in the African continent. Over the past months, African countries have ensured optimum pandemic response. However, there is still a need to build further resilient health systems that enhance response and transition from the acute phase of the pandemic to the recovery interpandemic/preparedness phase. Guided by the lessons learnt in the response and plausible pandemic scenarios, the WHO Regional Office for Africa has envisioned a transition framework that will optimise the response and enhance preparedness for future public health emergencies. The framework encompasses maintaining and consolidating the current response capacity but with a view to learning and reshaping them by harnessing the power of science, data and digital technologies, and research innovations. In addition, the framework reorients the health system towards primary healthcare and integrates response into routine care based on best practices/health system interventions. These elements are significant in building a resilient health system capable of addressing more effectively and more effectively future public health crises, all while maintaining an optimal level of essential public health functions. The key elements of the framework are possible with countries following three principles: equity (the protection of all vulnerable populations with no one left behind), inclusiveness (full engagement, equal participation, leadership, decision-making and ownership of all stakeholders using a multisectoral and transdisciplinary, One Health approach), and coherence (to reduce the fragmentation, competition and duplication and promote logical, consistent programmes aligned with international instruments).
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COVID-19 , Planes de Sistemas de Salud , Pandemias , Humanos , África/epidemiología , COVID-19/epidemiología , COVID-19/prevención & control , Pandemias/prevención & control , Organización Mundial de la Salud , Planes de Sistemas de Salud/organización & administraciónRESUMEN
BACKGROUND: With the evolving epidemiological parameters of COVID-19 in Africa, the response actions and lessons learnt during the pandemic's past two years, SARS-COV 2 will certainly continue to circulate in African countries in 2022 and beyond. As countries in the African continent need to be more prepared and plan to 'live with the virus' for the upcoming two years and after and at the same time mitigate risks by protecting the future most vulnerable and those responsible for maintaining essential services, WHO AFRO is anticipating four interim scenarios of the evolution of the pandemic in 2022 and beyond in the region. OBJECTIVE: In preparation for the rollout of response actions given the predicted scenarios, WHO AFRO has identified ten strategic orientations and areas of focus for supporting member states and partners in responding to the COVID-19 pandemic in Africa in 2022 and beyond. METHODS: WHO analysed trends of the transmissions since the first case in the African continent and reviewed lessons learnt over the past months. RESULTS: Establishing a core and agile team solely dedicated to the COVID-19 response at the WHO AFRO, the emergency hubs, and WCOs will improve the effectiveness of the response and address identified challenges. The team will collaborate with the various clusters of the regional office, and other units and subunits in the WCOs supported with good epidemics intelligence. COVID-19 pandemic has afflicted global humanity at unprecedented levels. CONCLUSION: Two years later and while starting the third year of the COVID-19 response, we now need to change and adapt our strategies, tools and approaches in responding timely and effectively to the pandemic in Africa and save more lives.
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COVID-19 , Humanos , COVID-19/epidemiología , Pandemias/prevención & control , SARS-CoV-2 , Organización Mundial de la Salud , África/epidemiologíaRESUMEN
INTRODUCTION: Estimating COVID-19 cumulative incidence in Africa remains problematic due to challenges in contact tracing, routine surveillance systems and laboratory testing capacities and strategies. We undertook a meta-analysis of population-based seroprevalence studies to estimate SARS-CoV-2 seroprevalence in Africa to inform evidence-based decision making on public health and social measures (PHSM) and vaccine strategy. METHODS: We searched for seroprevalence studies conducted in Africa published 1 January 2020-30 December 2021 in Medline, Embase, Web of Science and Europe PMC (preprints), grey literature, media releases and early results from WHO Unity studies. All studies were screened, extracted, assessed for risk of bias and evaluated for alignment with the WHO Unity seroprevalence protocol. We conducted descriptive analyses of seroprevalence and meta-analysed seroprevalence differences by demographic groups, place and time. We estimated the extent of undetected infections by comparing seroprevalence and cumulative incidence of confirmed cases reported to WHO. PROSPERO: CRD42020183634. RESULTS: We identified 56 full texts or early results, reporting 153 distinct seroprevalence studies in Africa. Of these, 97 (63%) were low/moderate risk of bias studies. SARS-CoV-2 seroprevalence rose from 3.0% (95% CI 1.0% to 9.2%) in April-June 2020 to 65.1% (95% CI 56.3% to 73.0%) in July-September 2021. The ratios of seroprevalence from infection to cumulative incidence of confirmed cases was large (overall: 100:1, ranging from 18:1 to 954:1) and steady over time. Seroprevalence was highly heterogeneous both within countries-urban versus rural (lower seroprevalence for rural geographic areas), children versus adults (children aged 0-9 years had the lowest seroprevalence)-and between countries and African subregions. CONCLUSION: We report high seroprevalence in Africa suggesting greater population exposure to SARS-CoV-2 and potential protection against COVID-19 severe disease than indicated by surveillance data. As seroprevalence was heterogeneous, targeted PHSM and vaccination strategies need to be tailored to local epidemiological situations.
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COVID-19 , Adulto , África/epidemiología , COVID-19/epidemiología , Niño , Europa (Continente) , Humanos , SARS-CoV-2 , Estudios SeroepidemiológicosRESUMEN
In October 2021, the WHO published an ambitious strategy to ensure that all countries had vaccinated 40% of their population by the end of 2021 and 70% by mid-2022. The end of June 2022 marks 18 months of implementation of coronavirus disease 2019 (COVID-19) vaccination in the African region and provides an opportunity to look back and think ahead about COVID-19 vaccine set targets, demand and delivery strategies. As of 26 June 2022 two countries in the WHO African region have achieved this target (Mauritius and Seychelles) and seven are on track, having vaccinated between 40% and 69% of their population. By the 26 June 2022, seven among the 20 countries that had less than 10% of people fully vaccinated at the end of January 2022, have surpassed 15% of people fully vaccinated at the end of June 2022. This includes five targeted countries, which are being supported by the WHO Regional Office for Africa through the Multi-Partners' Country Support Team Initiative. As we enter the second semester of 2022, a window of opportunity has opened to provide new impetus to COVID-19 vaccination rollout in the African region guided by the four principles: Scale-up, Transition, Consolidation and Communication. Member States need to build on progress made to ensure that this impetus is not lost and that the African region does not remain the least vaccinated global region, as economies open up and world priorities change.
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COVID-19 , África/epidemiología , COVID-19/epidemiología , COVID-19/prevención & control , Vacunas contra la COVID-19 , Humanos , Vacunación , Organización Mundial de la SaludRESUMEN
BACKGROUND: COVID-19 has affected the African region in many ways. We aimed to generate robust information on the transmission dynamics of COVID-19 in this region since the beginning of the pandemic and throughout 2022. METHODS: For each of the 47 countries of the WHO African region, we consolidated COVID-19 data from reported infections and deaths (from WHO statistics); published literature on socioecological, biophysical, and public health interventions; and immunity status and variants of concern, to build a dynamic and comprehensive picture of COVID-19 burden. The model is consolidated through a partially observed Markov decision process, with a Fourier series to produce observed patterns over time based on the SEIRD (denoting susceptible, exposed, infected, recovered, and dead) modelling framework. The model was set up to run weekly, by country, from the date the first infection was reported in each country until Dec 31, 2021. New variants were introduced into the model based on sequenced data reported by countries. The models were then extrapolated until the end of 2022 and included three scenarios based on possible new variants with varying transmissibility, severity, or immunogenicity. FINDINGS: Between Jan 1, 2020, and Dec 31, 2021, our model estimates the number of SARS-CoV-2 infections in the African region to be 505·6 million (95% CI 476·0-536·2), inferring that only 1·4% (one in 71) of SARS-CoV-2 infections in the region were reported. Deaths are estimated at 439 500 (95% CI 344 374-574 785), with 35·3% (one in three) of these reported as COVID-19-related deaths. Although the number of infections were similar between 2020 and 2021, 81% of the deaths were in 2021. 52·3% (95% CI 43·5-95·2) of the region's population is estimated to have some SARS-CoV-2 immunity, given vaccination coverage of 14·7% as of Dec 31, 2021. By the end of 2022, we estimate that infections will remain high, at around 166·2 million (95% CI 157·5-174·9) infections, but deaths will substantially reduce to 22 563 (14 970-38 831). INTERPRETATION: The African region is estimated to have had a similar number of COVID-19 infections to that of the rest of the world, but with fewer deaths. Our model suggests that the current approach to SARS-CoV-2 testing is missing most infections. These results are consistent with findings from representative seroprevalence studies. There is, therefore, a need for surveillance of hospitalisations, comorbidities, and the emergence of new variants of concern, and scale-up of representative seroprevalence studies, as core response strategies. FUNDING: None.
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COVID-19 , COVID-19/epidemiología , Prueba de COVID-19 , Humanos , Crecimiento Demográfico , SARS-CoV-2 , Estudios Seroepidemiológicos , Organización Mundial de la SaludRESUMEN
Seychelles, an archipelago of 155 islands in the Indian Ocean, had confirmed 24,788 cases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by the 31st of December 2021. The first SARS-CoV-2 cases in Seychelles were reported on the 14th of March 2020, but cases remained low until January 2021, when a surge was observed. Here, we investigated the potential drivers of the surge by genomic analysis of 1056 SARS-CoV-2 positive samples collected in Seychelles between 14 March 2020 and 31 December 2021. The Seychelles genomes were classified into 32 Pango lineages, 1042 of which fell within four variants of concern, i.e., Alpha, Beta, Delta and Omicron. Sporadic cases of SARS-CoV-2 detected in Seychelles in 2020 were mainly of lineage B.1 (lineage predominantly observed in Europe) but this lineage was rapidly replaced by Beta variant starting January 2021, and which was also subsequently replaced by the Delta variant in May 2021 that dominated till November 2021 when Omicron cases were identified. Using the ancestral state reconstruction approach, we estimated that at least 78 independent SARS-CoV-2 introduction events occurred in Seychelles during the study period. The majority of viral introductions into Seychelles occurred in 2021, despite substantial COVID-19 restrictions in place during this period. We conclude that the surge of SARS-CoV-2 cases in Seychelles in January 2021 was primarily due to the introduction of more transmissible SARS-CoV-2 variants into the islands.