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BackgroundAs of 26 March 2021, the Africa CDC had reported 4,159,055 cases of COVID-19 and 111,357 deaths among the 55 African Union Member States; however, no country has published a nationally representative serosurvey as of May 2021. Such data are vital for understanding the pandemics progression on the continent, evaluating containment measures, and policy planning. MethodsWe conducted a cross-sectional, nationally representative, age-stratified serosurvey in Sierra Leone in March 2021 by randomly selecting 120 Enumeration Areas throughout the country and 10 randomly selected households in each of these. One to two persons per selected household were interviewed to collect information on socio-demographics, symptoms suggestive of COVID-19, exposure history to laboratory-confirmed COVID-19 cases, and history of COVID-19 illness. Capillary blood was collected by fingerstick, and blood samples were tested using the Hangzhou Biotest Biotech RightSign COVID-19 IgG/IgM Rapid Test Cassette. Total seroprevalence was was estimated after applying sampling weights. FindingsThe overall weighted seroprevalence was 2.6% (95% CI 1.9-3.4). This is 43 times higher than the reported number of cases. Rural seropositivity was 1.8% (95% CI 1.0-2.5), and urban seropositivity was 4.2% (95% CI 2.6-5.7). InterpretationAlthough overall seroprevalence was low compared to countries in Europe and the Americas (suggesting relatively successful containment in Sierra Leone), our findings indicate enormous underreporting of active cases. This has ramifications for the countrys third wave (which started in June 2021), where the average number of daily reported cases was 87 by the end of the month--this could potentially be on the order of 3,700 actual infections, calling for stronger containment measures in a country with only 0.2% of people fully vaccinated. It may also reflect significant underreporting of incidence and mortality across the continent. FundingThis study was supported by NIAID K08 AI139361, the Sierra Leone Ministry of Health and Sanitation, and the Africa CDC.
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IntroductionVery little is known about possible clinical sequelae that may persist after resolution of the acute Coronavirus Disease 2019 (COVID-19). A recent longitudinal cohort from Italy including 143 patients recovered after hospitalisation with COVID-19 reported that 87% had at least one ongoing symptom at 60 day follow-up. Early indications suggest that patients with COVID-19 may need even more psychological support than typical ICU patients. The assessment of risk factors for longer term consequences requires a longitudinal study linked to data on pre-existing conditions and care received during the acute phase of illness. Methods and analysisThis is an international open-access prospective, observational multi-site study. It will enrol patients following a diagnosis of COVID-19. Tier 1 is developed for following up patients day 28 post-discharge, additionally at 3 to 6 months intervals. This module can be used to identify sub-sets of patients experiencing specific symptomatology or syndromes for further follow up. A Tier 2 module will be developed for in-clinic, in-depth follow up. The primary aim is to characterise physical consequences in patients post-COVID-19. Secondary aim includes estimating the frequency of and risk factors for post-COVID-19 medical sequalae, psychosocial consequences and post-COVID-19 mortality. A subset of patients will have sampling to characterize longer term antibody, innate and cell-mediated immune responses to SARS-CoV-2. Ethics and disseminationThis collaborative, open-access study aims to characterize the frequency of and risk factors for long-term consequences and characterise the immune response over time in patients following a diagnosis of COVID-19 and facilitate standardized and longitudinal data collection globally. The outcomes of this study will inform strategies to prevent long term consequences; inform clinical management, direct rehabilitation, and inform public health management to reduce overall morbidity and improve outcomes of COVID-19. Article summaryO_ST_ABSStrengths and limitations of this studyC_ST_ABSO_LIAs an international prospective, observational study we provide open-access standardised tools that can be adapted by any site interested in following up patients with COVID-19, for independent or combined analysis, to forward knowledge into short and long term consequences of COVID-19. C_LIO_LIThis study aims to inform strategies to prevent longer term sequalae; inform clinical management, rehabilitation, and public health management strategies to reduce morbidity and improve outcomes. C_LIO_LIThe protocol will be used for a sub-set of patients, already included in the existing cohort of more than 85,973 individuals hospitalized with confirmed COVID-19 infection across 42 countries (as of 20 July 2020), using the ISARIC/WHO standardized Core- or RAPID Case Report Forms (CRFs). C_LIO_LIThe data will be linked with data on pre-existing comorbidities, presentation, clinical care and treatments documented in the existing cohort already documented using the ISARIC/WHO standardized Core- or RAPID CRFs. C_LIO_LIThe data collection tool is developed to facilitate wide dissemination and uptake, by enabling patient self-assessment, however, follow up of patients requires consent and resources, which might limit the uptake and bias the data towards countries /sites with capacity to follow up patients over time. C_LI
