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

在许多发展中国家，新冠肺炎大流行的直接影响有限，包括肯尼亚 截至2021年3月5日，仅记录到107,329例和1,870例因Covid19死亡。尽管这限制了 临床影响在一定程度上是严格的旅行和行动限制以及漏报的结果，这些低 与肯尼亚献血者4%-8%的血清感染率形成鲜明对比的是，这表明大量的 肯尼亚有19例为亚临床病例。在这样的环境中，进一步考虑的是相互作用的可能性 SARS-CoV2与恶性疟原虫等地方性病原体之间的关系，恶性疟原虫在肯尼亚西部是 常年而强烈地传播。这些无症状感染形成了随后疟疾和 对主机有不同的影响。在这项血清流行病学研究中，我们的具体目标是调查 在肯尼亚农村，SARS-CoV2病毒在一个大的、密集抽样的社区队列中传播。我们的纵向队列 由肯尼亚所有年龄段的家庭成员组成，自2020年1月以来在一项观察研究中登记 Webuye农村地区的疟疾传播(家长研究R01 AI146849，MPI：O‘Meara/Taylor)。从… 550人，我们在I)每月的监测访问以及II)期间收集了所有参与者的血液 在发烧的病人探视中，收集将持续到2023年。SARS-CoV2抗体流行率和 肯尼亚农村收购(SPARK)研究将是这一父母队列的子研究，我们将在其中测试 在Covid19大流行之前和期间使用检测中和作用的ELISA法收集的每月样本 SARS-CoV2刺突蛋白的抗体。基线血清阳性将在2020年1月的样本中进行测量， 而血清转换是在以前阴性的人身上出现中和抗体。每月 问卷将包括最近的旅行和以前没有报告给研究团队的疾病。到时候我们会， 利用恶性疟原虫检测和来自亲代研究的基因数据，估计恶性疟原虫的影响。 感染对SARS-CoV2感染风险影响的纵向统计模拟 累计疟疾感染和特定寄生虫基因型别对血清转换和疟疾风险的影响 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，以描述社区传播和 肯尼亚农村地区SARS-CoV2的血清流行病学调查及其与恶性疟原虫的关系 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.