Epidemiology of rural MRSA: is livestock contact a risk factor?

项目摘要 最近的一份报告记录了耐甲氧西林金黄色葡萄球菌（MRSA）的临床影响， 这表明MRSA在美国造成了超过94，000例严重感染和超过18，000例死亡。 2005.在过去的十年中，出现了新的有感染MRSA风险的群体，来自欧洲和 加拿大已经确定了另一个紧急风险群体：与生猪接触的个人。 我们小组在美国进行的试点研究表明，几乎一半的养猪工人 被检查的人被MRSA定殖。虽然在一个国家发现了与牲畜相关的MRSA（LA-MRSA）， 越来越多的国家，大多数研究都检查了少数工人使用交叉- 在农场现场进行分区设计。一项针对接触畜牧业工人的大型队列研究尚未得到 在美国进行，但由于MRSA的流行病学正在迅速变化，因此迫切需要更好地 了解新型S.与农业暴露相关的金黄色葡萄球菌菌株。这种知识 在评估传染病风险和确定预防措施方面将非常宝贵。 我们的长期目标是更好地了解S。农村社区的金黄色葡萄球菌， S.金黄色葡萄球菌在医疗机构内部和外部收集。我们在此应用程序中的目标是 描述了S.一个农村州的金黄色葡萄球菌我们将通过实施两项 平行前瞻性队列研究，检查1）参加农业健康研究的个人，重点是 对那些养猪的人; 2）一个以人口为基础的群体，代表了爱荷华州的一个横截面。虽然这些 队列研究的重点是定植，我们将进行第三组检查金黄色葡萄球菌分离株， 有症状的感染者我们的中心假设是，与牲畜打交道的人将在 职业暴露于MRSA的风险，以及牲畜相关菌株也会引起症状性 感染.我们对这个项目的理由是，成功完成将允许发展 针对新兴S.金黄色葡萄球菌菌株在人类中广泛传播之前 人口 这项拟议的研究是创新的，因为它旨在前瞻性地检查 S.金黄色葡萄球菌在农业/农村环境，这代表了40%的社区医院在美国。 完成这项研究，这是我们的期望，我们将建立流行和主导 S.爱荷华州农村地区的金黄色葡萄球菌;描述了抗生素耐药金黄色葡萄球菌定植的风险因素。 金黄色葡萄球菌菌株，以及这些菌株在我们的队列中引起症状性感染的频率;以及 确定了在爱荷华州引起有症状感染的MRSA菌株的分子流行病学。这些结果 将提供深入了解的维护和传播的S。农村环境中的金黄色葡萄球菌，以及潜在的 可以实施的机制，以防止这种情况的出现和蔓延。

Project Summary A recent report has documented the clinical impact of methicillin-resistant Staphylococcus aureus (MRSA), suggesting that MRSA caused over 94,000 serious infections and more than 18,000 deaths in the U.S. in 2005. In the past decade, new groups at risk of acquiring MRSA have emerged, and reports from Europe and Canada have identified another emergent risk group: individuals in contact with live swine. Pilot studies in the U.S. carried out by our group have shown that almost half of the swine workers examined were colonized with MRSA. Though livestock-associated MRSA (LA-MRSA) have been found in an increasing number of countries, most studies have examined a small number of workers using a cross- sectional design conducted on the farm site. A large cohort study of livestock-exposed workers has not been conducted in the U.S., but as the epidemiology of MRSA is rapidly changing, there is a critical need to better understand the epidemiology of novel S. aureus isolates associated with farming exposures. Such knowledge would be invaluable in assessing infectious disease risks and determining preventative measures. Our long-term goal is to better understand the epidemiology of S. aureus in the rural community, including S. aureus collected both inside and outside of the healthcare setting. Our objective in this application is to characterize the epidemiology of S. aureus in a rural state. We will achieve this goal by carrying out two parallel prospective cohort studies, examining 1) individuals enrolled in the Agricultural Health Study, focusing on those who raise swine; 2) a population-based group representing a cross-section of Iowans. While these cohort studies will focus on colonization, we will carry out a third arm examining S.aureus isolates from symptomatic infections in the state. Our central hypothesis is that individuals working with livestock will be at risk of occupational exposure to MRSA, and that livestock-associated strains will also be causing symptomatic infections. Our rationale for this project is that successful completion will allow for the development of interventions targeting emerging S. aureus strains prior to their widespread dissemination in the human population. The proposed research is innovative because it is designed to prospectively examine the epidemiology of S. aureus in an agricultural/rural setting, which represents 40% of the community hospitals in the U.S. At the completion of this research, it is our expectation that we will have established the prevalence and dominant molecular types of S. aureus in rural Iowans; delineated risk factors for colonization with antibiotic-resistant S. aureus strains, and the frequency with which these cause symptomatic infection in our cohorts; and determined the molecular epidemiology of MRSA strains causing symptomatic infections in Iowa. These results will provide insight into the maintenance and spread of S. aureus in the rural environment, as well as potential mechanisms that could be implemented to prevent such emergence and spread.