Recurrent MRSA Infections: A Study of Risk Factors and Molecular Epidemiology

复发性 MRSA 感染：危险因素和分子流行病学研究

• 批准号: 8471638
• 负责人: Michael Zdenek David
• 金额: $ 12.66万
• 依托单位: UNIVERSITY OF CHICAGO
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-06-01 至 2016-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8471638
• 关键词: Aftercare; Anatomic Sites; Antibiotic Therapy; Antibiotics; Biology; Blood; Caring; Case-Control Studies; Characteristics; Chicago; Chronic; Clinical; Cohort Studies; Collection; Communicable Diseases; Communities; Comorbidity; Complement; Databases; Diagnosis; Disease; Ecology; Enrollment; Environment; Epidemic; Epidemiology; Exposure to; Future; Gastrointestinal tract structure; Genetic; Genetic Predisposition to Disease; Genotype; Goals; HIV; Healthcare; Healthcare Systems; Household; Human; Incidence; Individual; Infection; Intervention; Jail; Life; Literature; Medical; Medical Records; Medical center; Modality; Molecular Epidemiology; Monitor; Monobactams; Nose; Organism; Patients; Pneumonia; Population; Predisposition; Prospective Studies; Protocols documentation; Recurrence; Recurrent disease; Reporting; Research; Research Personnel; Risk; Risk Factors; Role; Safety; Sepsis; Site; Skin; Skin Tissue; Soft Tissue Infections; Specialist; Staphylococcus aureus; Surveillance Program; Techniques; Time; United States; Universities; Vaccines; burden of illness; clinical epidemiology; cohort; demographics; high risk; medical attention; men who have sex with men; methicillin resistant Staphylococcus aureus; microbial; pathogen; patient oriented; prevent; prospective; public health relevance; resistant strain; skills; stem; surveillance data

DESCRIPTION (provided by applicant): Staphylococcus aureus is among the most common bacterial pathogens in human beings. The epidemiology of methicillin-resistant S. aureus (MRSA), which are strains resistant to all ¿-lactam antibiotics, has changed dramatically in the past fifteen years. While MRSA infections before that time occurred almost exclusively within the health care environment and in patients with health care exposure, since the mid-1990s, new strains of MRSA have arisen that are causing an epidemic of infections in the community, particularly skin and soft tissue infections but also less common severe, invasive infections. These community-associated (CA-) MRSA strains differ from the older healthcare-associated (HA-) MRSA strains in the population that they infect, in the type of infections that they cause, and in the genetic characteristics of the strains themselves. MRSA is often a commensal organism, living on the skin, in the gastrointestinal tract, and in the nose of individuals, and asymptomatic carriage is thought to be common before an infection occurs. MRSA infections often recur in patients, but it is not known which patients are at highest risk for recurrence nor whether CA- or HA-strains are more likely to cause recurrence. In the era of CA-MRSA, it is not known if patients with persistent carriage of MRSA are at elevated risk of recurrent MRSA infections. There are interventions that may decrease the likelihood of recurrent MRSA infections in an individual: decolonization protocols, cleaning of fomites, antibiotic therapies, and vaccines are all potentially relevant avenues for the future control of MRSA in the community. Each of these modalities will require further study to assess its efficacy and safety. Patients with recurrent MRSA disease are likely to benefit from such interventions, and the control of MRSA infections in this population may be critical to stemming the dissemination of CA-MRSA in the U.S. In this a two-part study, using a collection of >13,800 stored clinical S. aureus strains, obtained through surveillance at the University of Chicago Medical Center (UCMC), I will attempt to define risk factors for recurrent MRSA infections. First, using existing surveillance data from UCMC in 2003-9, in a case-control study treating those with multiple infections as the cases and those with a single infection as controls, I will examine the following as risk factors for re- infection: anatomic site of first infection, genotype of first and subsequent infecting MRSA strains including CA- and HA-MRSA strain characteristics, patient demographic characteristics, previous exposures to the health care system, and patient comorbidities. Second, nesting a prospective cohort study of recurrent MRSA infections in surveillance at UCMC, I will enroll 400 patients with incident MRSA infections and monitor them for two years. I will determine how frequently these patients have recurrent MRSA infections, how commonly they seek medical attention for the infections, the presence of the risk factors for re-infection listed above, and the genotypes of MRSA strains associated with infections and any identified asymptomatic colonization to assess the role of chronic colonization in the recurrence of MRSA infections.

描述(申请人提供)：金黄色葡萄球菌是人类最常见的细菌病原体之一。耐甲氧西林金黄色葡萄球菌(MRSA)是对所有内酰胺类抗生素耐药的菌株，其流行病学在过去15年中发生了巨大变化。虽然在此之前，MRSA感染几乎完全发生在卫生保健环境中和有卫生保健接触的患者中，但自20世纪90年代中期以来，出现了新的MRSA菌株，它们正在导致社区感染的流行，特别是皮肤和软组织感染，但也不太常见的严重侵袭性感染。这些社区相关(CA-)MRSA菌株与它们感染的人群中较老的与医疗保健相关(HA-)MRSA菌株不同，它们引起的感染类型以及菌株本身的遗传特征都不同。MRSA通常是一种共生生物，生活在皮肤、胃肠道和个人鼻子中，在感染发生之前，无症状携带被认为是常见的。MRSA感染经常在患者中复发，但尚不清楚哪些患者复发的风险最高，也不知道CA或HA菌株更有可能导致复发。在CA-MRSA时代，不知道持续携带MRSA的患者是否有较高的复发MRSA感染风险。有一些干预措施可能会降低个人再次感染MRSA的可能性：非殖民化协议、清除混合物、抗生素治疗和疫苗都是未来社区控制MRSA的潜在相关途径。这些方法中的每一种都需要进一步研究，以评估其有效性和安全性。复发的MRSA病患者很可能从这种干预措施中受益，而在这一人群中控制MRSA感染可能是阻止CA-MRSA在美国传播的关键。在这项由两部分组成的研究中，使用芝加哥大学医学中心(UCMC)监测获得的13,800株储存的临床金黄色葡萄球菌菌株，我将尝试定义复发MRSA感染的风险因素。首先，利用UCMC 2003-2009年的现有监测数据，在一项病例对照研究中，以多重感染者为病例，以单一感染者为对照，研究以下因素作为再感染的危险因素：首次感染的解剖部位、首次和后续感染的MRSA菌株的基因类型(包括CA-和HA-MRSA菌株特征)、患者的人口学特征、既往医疗保健系统的暴露以及患者的合并症。第二，在UCMC的监测中嵌套一项关于复发MRSA感染的前瞻性队列研究，我将招募400名发生MRSA感染的患者，并对他们进行为期两年的监测。我将确定这些患者复发MRSA感染的频率，他们为感染寻求医疗护理的频率，上面列出的再次感染的危险因素的存在，以及与感染相关的MRSA菌株的基因类型和任何已确定的无症状定植，以评估慢性定植在MRSA感染复发中的作用。