Environmental Surveillance of Coronavirus in Malawi

马拉维冠状病毒环境监测

• 批准号: 2269409
• 金额: --
• 依托单位: Liverpool School of Tropical Medicine
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2019
• 资助国家: 英国
• 起止时间: 2019 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2269409
• 关键词: Environmental; Surveillance; Coronavirus; Malawi

With early and prolonged gastrointestinal shedding of SARS-CoV-2 during and after infectionregardless of presentation of symptoms, environmental surveillance provides a promisingmonitoring tool for estimating circulating COVID-19 in a community, in the absence of clinicaltesting. However, current methods of concentrating virus from wastewater (ultrafiltration, PEGprecipitation, and electronegative membrane adsorption) can readily co-purify contaminants that,both hinder detection of virus RNA by PCR and, and also do not allow for subsequent processing ofvirus in culture to determine viral viability and thus infectiousness. An attractive solution is toconstruct high affinity binding reagents which specifically enrich for intact virus from large volumesof wastewater. We propose the use of the SARS-CoV-2 entry receptor ACE-2 fused to tags (histidineand streptavidin) for the purification of intact PCR detectable SARS-CoV-2 from wastewater usingmagnetic beads.A recent clinical surveillance study in Malawi illustrated a high prevalence (13.3%) of SARS-CoV2present within the population (unpublished). However, currently only having 19 COVID-19 testingsites, Malawi thus has limited capacity to facilitate large scale clinical surveillance. Within theMalawi-Liverpool Welcome Trust previously established environmental surveillance systems inplace for typhoid have been utilized to monitor COVID-19 in wastewater from as early as May 2020.Preliminary data shows that SARS-CoV-2 was detected in 19% of samples using the CDC N1 assay.This limited dataset highlights the potential for large scale environmental surveillance of SARS-CoV-2 to understand transmission hotspots and monitor intervention strategies in Malawi. This project will establish if tagged ACE-2 can be used to purify intact virus from wastewater and scaled up forappropriate use in LMIC's, followed by establishing infectivity of purified virus and genomic analysisfollowing NGS.

无论是否出现症状，在感染期间和感染后都会出现SARS-CoV-2的早期和长期胃肠道脱落，因此在没有临床检测的情况下，环境监测为估计社区中流行的COVID-19提供了一种有希望的监测工具。然而，目前从废水中浓缩病毒的方法（超滤、聚乙二醇沉淀法和电负性膜吸附）可以很容易地共同净化污染物，这些污染物既阻碍了PCR检测病毒RNA，也不允许在培养物中对病毒进行后续处理，以确定病毒的活力和传染性。一个有吸引力的解决方案是构建高亲和力的结合试剂，专门富集大量废水中的完整病毒。我们建议使用融合标签（组氨酸和链亲和素）的SARS-CoV-2进入受体ACE-2，利用磁珠从废水中纯化完整的PCR可检测的SARS-CoV-2。马拉维最近的一项临床监测研究表明，人口中存在高流行率（13.3%）（未发表）。然而，马拉维目前只有19个COVID-19检测点，因此促进大规模临床监测的能力有限。在马拉维-利物浦欢迎信托基金内，早在2020年5月，就利用先前建立的伤寒环境监测系统监测废水中的COVID-19。初步数据显示，使用CDC N1测定法在19%的样本中检测到SARS-CoV-2。这一有限的数据集强调了在马拉维对SARS-CoV-2进行大规模环境监测以了解传播热点和监测干预策略的潜力。该项目将确定标记的ACE-2是否可用于纯化废水中的完整病毒，并扩大在LMIC中的适当使用，随后建立纯化病毒的感染性和NGS后的基因组分析。