Streptococcal pharyngitis in slum versus non-slum communities in Salvador Brazil

描述（由申请人提供）：链球菌性咽炎是先于风湿性心脏病（RHD）慢性疾病过程的急性疾病。最近的研究表明，热带环境中RHD的微生物学和流行病学特征与文献中描述的不同，这些文献大多基于温带群落的研究。这些差异是否由于温带和热带环境，或社区结构的性质，在所谓的热带地区贫民窟与非贫民窟仍然未知。在巴西，RHD似乎主要发生在城市贫民窟（favelas）的人口中。贫民窟的RHD流行病学可能与文献中描述的非常不同。这可能是由于贫民窟的结构、社会或其他方面造成的。有效的预防策略取决于对人群中疾病动态的了解。因此，本项目旨在研究这些社区中已知与RHD最终结果相关的早期事件。具体而言，该项目将比较同一城市中心不同人群（贫民窟与非贫民窟）链球菌性咽炎的流行病学和微生物学。具体目标：美国疾病控制与预防中心《健康世界中的健康人健康保护目标》的一个目标是预防传染病及其后果。本研究将通过以下研究帮助实现这一目标：评估来自发展中国家（巴西萨尔瓦多）同一城市环境中贫民窟和非贫民窟人群的咽炎（有症状）病例的A群链球菌分离株的多样性和克隆组成，并将这些分离株与来自发达国家（美国加利福尼亚州奥克兰）不相关地理环境的GAS分离株的种群结构进行比较；和2)。对3个人群（巴西萨尔瓦多贫民窟和非贫民窟）咽炎（症状）病例中G群链球菌（GGS）和C群链球菌（GCS）的相对患病率、比例和克隆组成进行评估；以及美国加州奥克兰的儿科人群。研究设计和方法：将在巴西萨尔瓦多的两个诊所从患有咽炎的5-14岁儿童中收集链球菌分离株。一家诊所为高社会经济地位的人群服务，另一家诊所为贫民窟人口服务。分离株将进行基因分型，并使用emm分型和多位点序列分型（MLST）分析克隆多样性和血清群。结论：通过解决这些目标，本研究将确定贫民窟人口中的链球菌性咽炎是否具有与医学文献中描述的不同的模式；还有来自同一城市的社区，但不被认为是贫民窟。既往文献表明菌株类型（以M表面蛋白为基础）对RHD的发展具有重要意义。重要的是，我们在一个RHD高风险的贫民窟社区评估这一已知的风险因素。

DESCRIPTION (provided by applicant): Streptococcal pharyngitis is the acute disease that precedes the chronic disease process of rheumatic heart disease (RHD). Recent studies have revealed that the microbiologic and epidemiologic features of RHD in tropical environments are distinct from those described in the literature, which are based mostly on studies from temperate zone communities. Whether these differences are due to temperate versus tropical environment, or the nature of community structures in the so-called tropical areas slum versus non- slum remains unknown. In Brazil, RHD appears to occur predominantly in populations that reside in urban slums (favelas). RHD epidemiology in slums may be very distinct from what is described in the literature. This may be due to structural, social or other aspects of slums. Effective prevention strategies depend on understanding the disease dynamics in a population. Therefore, this project seeks to study the early events that are known to be associated with the eventual outcome of RHD in these communities. Specifically, this project will compare the epidemiology and microbiology of streptococcal pharyngitis in contrasting populations- -slum versus non-slum--in the same urban center. Specific Aims: One aim of the CDC Health Protection Goal of Healthy People in a Healthy World is to prevent infectious diseases and their consequences. This study will help achieve this objective with the following studies: 1.) An assessment of the diversity and clonal composition of Group A Streptococcus isolates from pharyngitis (symptomatic) cases from favela and non-favela populations in the same urban setting in a developing country (Salvador, Brazil), and a comparison of these isolates with the population structure of GAS from an unrelated geographic setting in a developed country (Oakland, CA, USA); and 2.) An evaluation of the relative prevalence, proportion, and clonal composition of Group G Streptococcus (GGS) and Group C Streptococcus (GCS) from pharyngitis (symptomatic) cases in three populations: favela and non-favela populations in Salvador, Brazil; and a pediatric population in Oakland, CA, USA. Research Design and Methods: Streptococcal isolates will be collected from children aged 5-14 who present with pharyngitis to two clinics in Salvador, Brazil. One clinic serves a population with high socioeconomic status, and the other clinic serves a favela population. Isolates will be genotyped and analyzed for clonal diversity and serogroup with emm-typing, as well as multilocus sequence typing (MLST). Conclusion: By addressing these aims, this study will determine whether streptococcal pharyngitis in a slum population has patterns distinct from that described in the medical literature; and also from communities in the same city but which are not considered slums. Past literature has demonstrated that strain type (based on M surface protein) has important implications for development of RHD. It is important that we assess this known risk factor in a slum community at high risk for RHD.