Emerging Infectious Diseases Research Center - East and Central Africa

新发传染病研究中心 - 东非和中非

• 批准号: 10427187
• 负责人: M KARIUKI NJENGA
• 金额: $ 151.22万
• 依托单位: WASHINGTON STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-06-01 至 2025-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10427187
• 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; marginalized community; mortality; pathogen; physical conditioning; programs; respiratory; response; social culture; translational study; transmission process; vector; viral detection; viral transmission

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.

项目摘要 自2012年中东呼吸道综合征冠状病毒（MERS-COV）的第一个人类病例以来 确认，世界卫生组织报告了> 2220种人类感染和近800例死亡传播 位于中东，欧洲，亚洲和美国的27个国家。虽然骆驼 是该病毒的已知储层，关于与 骆驼到人类传播，这仍然是人类感染的主要机制。人类爆发 在中东和亚洲，有记录的MERS-COV病例的数量继续增加；然而 迄今为止，在东非国家尚无记录的人类疾病病例 发现了世界上杂乱无章的骆驼。这是骆驼流行的MERS-COV感染的泛岩证据 在该地区。东非没有人类疾病可以通过病毒可塑性来解释 效率低下的传播和/或病毒降低，或疾病监测不良和报告 边缘化的骆驼拥有的游牧牧民种群，继承了该地区的偏远干旱土地。我们将 通过在幼稚的封闭社区内进行综合纵向队列研究来检验这些假设 牧师及其骆驼种群在马萨比县维持MERS-COV圈子， 肯尼亚，为了确定病毒在骆驼之间的维护和传播，人畜共患病 向人类传播以及人类感染的严重程度。确定循环的MERS-COV是否为 在遗传和表型上与中东和亚洲的已知病毒进化枝不同，我们将分离 东非病毒通过从婴儿队列（出生-1岁）的211种骆驼收集样品，然后 病毒与已知进化枝病毒进行基因型和表型比较的培养和分离 调查弱监视和获得医疗保健差的差的组合是否负责 缺乏疾病，我们将跟进一年 电话电话，并访问免费电话号码，以便深入检查和测试MERS-COV 疾病。此外，我们将识别，测试和随访> 4500的呼吸系统疾病和门诊病人 马萨比县转诊医院已有3年。为了评估人类病毒位置的风险，我们将确定 骆驼中的病毒脱落水平，并将其与人畜共形传播事件和骆驼的类型相关联 接触该增加传输风险。这些研究将确定东非循环的病毒类型， 对MERS-COV的可塑性的了解及其对人畜共患疾病的影响。经过 阐明人畜共动传播的频率和机制，并发展为临床人类疾病， 通过 他们的职业和生活方式的优点，为改进的监视和适当的发展铺平了道路 预防和控制策略。