Longitudinal cohort study of SARS-CoV2 sero-conversion in a malaria-endemic community in Western Kenya

在许多发展中国家，新冠肺炎疫情的直接影响有限，包括肯尼亚，该国作为 截至2021年3月5日，仅记录了107，329例新冠肺炎病例和1，870例死亡。虽然这有限 临床影响的部分原因是严格的旅行和行动限制以及报告不足，这些低 这一数字与肯尼亚献血者中4-8%的血清阳性率形成鲜明对比，表明大量的 肯尼亚的Covid 19病例为亚临床病例。在这种情况下，进一步考虑的是相互作用的可能性 SARS-CoV 2和地方性病原体之间的关系，如恶性疟原虫，在肯尼亚西部， 常年强烈地传播这些无症状感染会形成随后发生疟疾的风险， 对宿主有不同的影响。在这项血清流行病学研究中，我们的具体目标是调查 SARS-CoV 2在肯尼亚农村一个大型、密集抽样社区队列中的传播。我们的纵向队列 包括自2020年1月以来参加一项观察性研究的所有年龄段的肯尼亚家庭成员， Webuye农村地区的疟疾传播（母研究R 01 AI 146849，MPI：O 'Meara/Taylor）。从 550人，我们在i）每月监测访视以及ii） 在发热性疾病访视时，收集将持续到2023年。SARS-CoV 2抗体流行率和 肯尼亚农村收购（SPARK）研究将是该母队列的子研究，我们将在其中测试 在Covid 19大流行之前和期间，使用ELISA检测中和 SARS-CoV 2刺突蛋白的抗体。将在2020年1月的标本中测量基线血清阳性， 以及血清转化，即在先前阴性的人中出现中和抗体。每月 调查问卷将收集以前没有向研究小组报告的最近旅行和疾病。我们会的， 使用来自亲本研究的恶性疟原虫检测和基因型数据，估计恶性疟原虫的影响 使用纵向统计模型对SARS-CoV 2感染风险的影响 累积疟疾感染和特定寄生虫基因型对血清转化风险和 血清转换期间的急性疾病。我们的多学科团队将使用来自大型， 单独资助，密集抽样的纵向社区队列，以描述社区传播， SARS-CoV 2在肯尼亚农村地区的血清流行病学研究及其与恶性疟原虫的相关性 疟疾

In many developing countries, the Covid-19 pandemic has had limited direct impact, including Kenya, which as of 5 March 2021, has recorded only 107,329 cases and 1,870 deaths owing to Covid19. Although this limited clinical impact is in part the result of strict travel and movement restrictions and under-reporting, these low numbers contrast with seroprevalences of 4-8% in Kenyan blood donors, suggesting that a large number of Covid19 cases in Kenya are subclinical. A further consideration in such settings is the potential for interactions between SARS-CoV2 and endemic pathogens such as Plasmodium falciparum, which in Western Kenya is transmitted perennially and intensely. These asymptomatic infections shape the risk of subsequent malaria and have differential impact on hosts. In this sero-epidemiologic study, our specific objective is to investigate the spread of SARS-CoV2 in a large, densely-sampled community cohort in rural Kenya. Our longitudinal cohort consists of Kenyan household members of all ages enrolled since January 2020 in an observational study of malaria transmission in the rural district of Webuye (parent study R01 AI146849, MPI: O’Meara/Taylor). From 550 people, we have collected blood from all participants during both i) monthly surveillance visits as well as ii) at febrile sick visits, and collection will be ongoing through 2023. The SARS-CoV2 antibody Prevalence and Acquisition in Rural Kenya (SPARK) study will be a sub-study of this parent cohort, in which we will test monthly specimens collected prior to and during the Covid19 pandemic using an ELISA detecting neutralizing antibodies to the SARS-CoV2 spike protein. Baseline sero-positivity will be measured in Jan 2020 specimens, and sero-conversion as the appearance of neutralizing antibodies in a previously-negative person. Monthly questionnaires will capture recent travel and illness not previously reported to the study team. We will then, using P. falciparum detection and genotype data from the parent study, estimate the impact of P. falciparum infection on the risk of SARS-CoV2 acquisition using longitudinal statistical modelling of the effect of cumulative malaria infections and of specific parasite genotypes on the risk of sero-conversion and the risk of acute illness during sero-conversion. Our multidisciplinary team will use samples and data from a large, separately-funded, densely-sampled longitudinal community cohort to describe the community spread and sero-epidemiology of SARS-CoV2 in a rural Kenyan setting and investigate its associated with P. falciparum malaria.