Emerging Infectious Diseases Research Center - East and Central Africa

新发传染病研究中心 - 东非和中非

基本信息

批准号：
10464357
负责人：
M KARIUKI NJENGA
金额：
$ 66.45万
依托单位：
WASHINGTON STATE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-09-13 至 2022-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10464357
关键词：
Africa Africa South of the Sahara African Agriculture Air Animals Asia Berlin Birth Blood Circulation Camels Centers for Disease Control and Prevention (U.S.)Central Africa Cessation of life China Clinical Clinical Research Collaborations Communicable Diseases Communities Congo Coronavirus Infections Country County Democratic Republic of the Congo Development Diagnostics Research Disease Disease Outbreaks Disease Surveillance Dromedaries Eastern Africa Ebola Emerging Communicable Diseases Environment Epidemic Europe Far East Food Frequencies Genotype Health High Prevalence Hospital Referrals Human Incidence Infant Infection Infectious Diseases Research Influenza Influenza A Virus, H1N1 Subtype Influenza A Virus, H5N1 Subtype Infrastructure Institutes International Kenya Knowledge Laboratories Life Style Livestock Longitudinal cohort study Maintenance Marburgvirus Measures Middle East Middle East Respiratory Syndrome Middle East Respiratory Syndrome Coronavirus Morbidity - disease rate Nomads Occupations Outpatients Pathogenicity Phenotype Physicians Pilot Projects Population Prevention Public Health Reagent Recurrence Reporting Research Rift Valley Fever Rift Valley fever virus Risk Role Sampling Scientist Seroprevalences Services Severe Acute Respiratory Syndrome Severities Severity of illness Site Tanzania Telephone Testing Time Travel Tropical Medicine Uganda United States Universities Veterinarians Viral Viral Hemorrhagic Fevers Viral reservoir Virulence Virulent Virus Virus Diseases Virus Shedding Visit Washington World Health Organization ZIKA Zoonoses base cohort community living density emerging pathogen experience field study follow-up forest global health health care availability health seeking behavior human disease improved influenza epidemic mortality pathogen physical conditioning programs respiratory response social culture translational study transmission process vector viral detection viral transmission

项目摘要

PROJECT SUMMARY Since 2012 when the first human case of Middle East respiratory syndrome coronavirus (MERS-CoV) was confirmed, the World Health Organization has reported >2220 human infections and almost 800 deaths spread across 27 countries located in the Middle East, Europe, Asia, and the United States. Although dromedary camels are the known reservoir of the virus, there is limited knowledge on the mechanisms and factors associated with camel-to-human transmission, which remains the primary mechanism of human infections. Human outbreaks and the number of documented cases of MERS-CoV continue to grow in the Middle East and Asia; however there have, to date, been no documented cases of human disease in the eastern Africa countries where >65% of the world’s dromedary camels are found. This is despite evidence of prevalent MERS-CoV infection of camels in the region. The absence of human disease in East Africa may be explained by viral plasticity resulting in inefficient transmission and/or weakened virulence, or poor disease surveillance and reporting among the marginalized camel-owning nomadic pastoralist populations that inhabit remote arid lands of the regions. We will test these hypotheses by conducting integrated longitudinal cohort studies within a closed community of naïve pastoralists and their camel population that is known to sustain MERS-CoV circulation in Marsabit County, Kenya, in order to determine the maintenance and transmission of the virus among camels, zoonotic transmission to humans, and severity of human infections. To determine if the circulating MERS-CoV is genetically and phenotypically distinct from known virus clades in the Middle East and Asia, we will isolate the East African virus by collecting samples biweekly from an infant cohort (birth -1 year) of 211 camels, followed by culture and isolation of the virus to performed genotypic and phenotypic comparison with the known clade viruses To investigate whether a combination of weak surveillance and poor access to health care are responsible for absence of disease, we will follow-up for a year, a cohort of 573 camel handlers through biweekly visits, weekly telephone calls, and access to a toll-free number in order to intensively examine and test them for MERS-CoV disease. In addition, we will identify, test, and follow-up >4500 in- and out-patients with respiratory illness at Marsabit County Referral Hospital for 3 years. To assess the risk the virus poses to humans, we will determine the level of viral shedding in camels, and relate this to the incidence of zoonotic transmission, and types of camel contact that increase transmission risk. These studies will identify the type of virus circulating in East Africa, increasing knowledge about plasticity of MERS-CoV and its impact on zoonotic transmission and disease. By elucidating the frequency and mechanisms of zoonotic transmission, and progression to clinical human disease, we will define the risk the virus poses to this community at the frontline of a newly emergent virulent virus by virtue of their occupation and lifestyle, paving the way for development of improved surveillance and appropriate prevention and control strategies.

项目概要自 2012 年发现首例中东呼吸综合征冠状病毒 (MERS-CoV) 人类病例以来经证实，世界卫生组织已报告超过 2220 例人类感染病例和近 800 例死亡病例分布于中东、欧洲、亚洲和美国的 27 个国家。是已知的病毒储存库，但对其相关机制和因素的了解有限骆驼向人类传播，这仍然是人类感染的主要机制。然而，中东和亚洲记录的中东呼吸综合征冠状病毒病例数量继续增加；迄今为止，东非国家还没有记录到人类疾病病例，这些国家的人口比例超过 65% 尽管有证据表明骆驼普遍感染中东呼吸综合征冠状病毒，但还是发现了世界上的单峰骆驼。该地区没有人类疾病可能是由于病毒的可塑性导致的。传播效率低下和/或毒力减弱，或疾病监测和报告不力居住在偏远干旱地区的拥有骆驼的游牧民族。通过在一个封闭的幼稚社区内进行综合纵向队列研究来检验这些假设已知在马萨比特县维持中东呼吸综合征冠状病毒循环的牧民及其骆驼种群，肯尼亚，为了确定病毒在骆驼中的维持和传播，人畜共患传播给人类，以及人类感染的严重程度，以确定循环中的中东呼吸综合征冠状病毒是否是冠状病毒。在遗传和表型上与中东和亚洲已知的病毒分支不同，我们将分离出东非病毒，每两周从 211 头骆驼的婴儿组（出生 -1 岁）收集样本，然后病毒的培养和分离，与已知的进化枝病毒进行基因型和表型比较调查薄弱的监测和难以获得医疗保健是否是造成这种情况的原因如果没有疾病，我们将对 573 名骆驼饲养员进行为期一年的跟踪，每两周一次、每周一次拨打电话并拨打免费电话，以便对他们进行中东呼吸综合征冠状病毒检查和测试此外，我们还将识别、检测和随访超过 4500 名患有呼吸道疾病的住院和门诊患者。马萨比特县转诊医院为期 3 年。为了评估该病毒对人类造成的风险，我们将确定骆驼的病毒排出水平，并将其与人畜共患传播的发生率以及骆驼的类型联系起来这些研究将确定在东非传播的病毒类型，增加对中东呼吸综合征冠状病毒的可塑性及其对人畜共患传播和疾病的影响的了解。阐明人畜共患病传播的频率和机制以及临床人类疾病的进展，我们将通过以下方式定义该病毒对处于新出现的剧毒病毒前线的社区构成的风险：凭借他们的职业和生活方式，为改进监测和适当的发展铺平道路预防和控制策略。