Child health risks attributable to swimming in contaminated water at beaches in t

背景：每年，人们在美国的海洋和淡水海滩上花费大约9.7亿人/天。许多研究已经测量了一般人群（所有年龄段）与粪便指示细菌暴露相关的游泳相关健康风险，但个别研究通常没有招募足够的游泳者来单独估计幼儿的健康风险。据推测，儿童比成年游泳者患游泳相关疾病的风险更高，因为他们在水中花费的时间更长，更容易吞咽水（病原体暴露的主要机制），并且免疫系统发育不全。然而，幼儿游泳相关的风险和健康负担代表了该领域的一个关键知识缺口：个别研究太小，无法研究这个年龄组。 在2003年至2009年期间，我们的团队在美国的13个海洋和淡水海滩完成了纵向队列研究。我们现在有一个独特的机会来联合收割机这些数据来填补这一知识空白。 目的：我们有两个具体的目的，我们将实现与二次分析使用的组合，13-海滩数据集。目标1中的分析将描述儿童暴露的特征，并将使用来自13个海滩的水暴露和游泳者结果数据来估计10岁以下儿童的肠球菌水平与胃肠道疾病之间的关联。目标2中的分析将估计10岁以下儿童的健康负担，这是由于在肠球菌水平超过国家海滩监管指南的水中游泳。这将是第一个大规模的研究，以描述暴露，健康风险和健康负担，从游泳在受污染的水在美国的幼儿。 研究方法：本研究将结合来自本提案团队进行的13项前瞻性海滩队列研究的联合收割机数据，这些研究使用了高度可比的研究设计、水采样程序、实验室分析方法和健康结果测量。合并后的数据集将包括74，531名各年龄段的个人（49，267名游泳运动员）和16，022名10岁以下的儿童（13，499名游泳运动员）。所有研究均使用qPCR和基于培养的方法测量肠球菌（粪便污染的指示细菌），并在海滩访问后10-14天测量游泳者的胃肠道（GI）疾病。在目标1中，我们将描述儿童暴露的特征，并使用肠球菌的连续测量和根据水条件是否超过国家指南对天数进行分类的二分测量来估计10岁以下游泳者中肠球菌水平与随后的GI疾病之间的关联。在目标2中，我们将估计10岁以下儿童因在超过肠球菌国家监管指南（> 35个菌落形成单位/ 100 ml，由EPA 1600测量）的水中游泳而导致的GI疾病的健康负担。 我们将使用人口干预模型参数来估计归因风险，这是该领域先前工作的一个重大进展。 项目 公共卫生相关性：在美国，每年有数千万人在受粪便污染影响的淡水和海水海滩游泳。流行病学研究一致表明，水中的细菌水平与胃肠道疾病的风险之间存在很强的关联（例如，腹泻），但个别研究通常不够大， 尽管有证据表明幼儿面临更高的风险，但应单独估计幼儿的风险。这项分析将通过结合最近13项海滩研究（13，499名10岁以下游泳者）的数据，首次全面估计美国儿童在污染水中游泳的暴露、健康风险和健康负担。

DESCRIPTION (provided by applicant): Background: Each year, people spend an estimated 970 million person-days at marine and freshwater beaches in the United States. Numerous studies have measured swimming-related health risks associated with fecal indicator bacteria exposure in the general population (all ages), but individual studies usually do not enroll enough swimmers to estimate health risks separately among young children. Children are hypothesized to have a higher risk of swimming-related illness than adult swimmers because they spend more time in the water, are more likely to swallow water (the primary mechanism of pathogen exposure), and have less developed immune systems. However, swimming-associated risks and health burdens among young children represent a key knowledge gap in the field: individual studies have been too small to look at this age group. Between 2003 and 2009 our teams completed longitudinal cohort studies at 13 marine and freshwater beaches in the United States. We now have a unique opportunity to combine these data to fill this knowledge gap. Aims: We have two Specific Aims that we will achieve with secondary analyses using the combined, 13-beach dataset. The analysis in Aim 1 will characterize child exposure and will use water exposure and swimmer outcome data from the 13 beaches to estimate the association between Enterococcus levels and gastrointestinal illness among children ¿ 10 years old. The analysis in Aim 2 will estimate the health burden among children ¿ 10 years old that is attributable to swimming in water with Enterococcus levels that exceed national beach regulatory guidelines. This will be the first large-scale study to characterize exposure, health risk, and health burden from swimming in contaminated water among young children in the United States. Methods: This study will combine data from 13 prospective beach cohort studies conducted by this proposal team that used highly comparable study designs, water sampling procedures, laboratory analysis methodology, and health outcome measurement. The combined dataset will include 74,531 individuals (49,267 swimmers) of all ages and 16,022 children (13,499 swimmers) ¿ 10 years old. All studies measured Enterococcus (an indicator bacteria of fecal contamination) using both qPCR and culture-based methods, and gastrointestinal (GI) illness in swimmers 10-14 days following the beach visit. In Aim 1, we will characterize child exposure and estimate the association between Enterococcus levels and subsequent GI illness among swimmers ¿ 10 years old using continuous measures of Enterococcus and dichotomous measures which classify days by whether or not water conditions exceeded national guidelines. In Aim 2, we will estimate the health burden of GI illness among children ¿ 10 years old that is attributable to swimming in water exceeding national regulatory guidelines for Enterococcus (> 35 colony forming units / 100 ml, measured by EPA 1600). We will estimate attributable risk using a population intervention model parameter, which is a significant advance over prior work in this field. Project Public Health Relevance: Each year in the United States, tens of millions of people swim at fresh- and marine water beaches impacted by fecal contamination. Epidemiologic studies consistently show a strong association between bacteria levels in the water and the risk of gastrointestinal illness (e.g., diarrhea), but individual studies are not typically large enough to estimate the risk separately for young children despite some evidence of higher risk for these children. This analysis will generate the first comprehensive estimates of the exposure, health risk, and health burden associated with swimming in contaminated water for children in the United States by combining data from 13 recent beach studies (13,499 swimmers ¿ 10 years old).